new undo system

Also enables undoing when working with node input arrays

app/common/xmlutils.cpp

@@ -26,14 +26,14 @@
 
 namespace olive {
 
-void XMLConnectNodes(const XMLNodeData &xml_node_data, QUndoCommand *command)
+void XMLConnectNodes(const XMLNodeData &xml_node_data, MultiUndoCommand *command)
 {
   foreach (const XMLNodeData::SerializedConnection& con, xml_node_data.desired_connections) {
     Node* out = xml_node_data.node_ptrs.value(con.output);
 
     if (out) {
       if (command) {
-        new NodeEdgeAddCommand(out, con.input, con.element, command);
+        command->add_child(new NodeEdgeAddCommand(out, con.input, con.element));
       } else {
         Node::ConnectEdge(out, con.input, con.element);
       }

app/common/xmlutils.h

@@ -21,10 +21,10 @@
 #ifndef XMLREADLOOP_H
 #define XMLREADLOOP_H
 
-#include <QUndoCommand>
 #include <QXmlStreamReader>
 
 #include "project/item/footage/stream.h"
+#include "undo/undocommand.h"
 
 namespace olive {
 
@@ -63,7 +63,7 @@ struct XMLNodeData {
 
 };
 
-void XMLConnectNodes(const XMLNodeData& xml_node_data, QUndoCommand* command = nullptr);
+void XMLConnectNodes(const XMLNodeData& xml_node_data, MultiUndoCommand *command = nullptr);
 
 bool XMLReadNextStartElement(QXmlStreamReader* reader);
 

app/core.cpp

@@ -479,7 +479,7 @@ void Core::ImportTaskComplete(Task* task)
 {
   ProjectImportTask* import_task = static_cast<ProjectImportTask*>(task);
 
-  QUndoCommand *command = import_task->GetCommand();
+  MultiUndoCommand *command = import_task->GetCommand();
 
   if (import_task->HasInvalidFiles()) {
     ProjectImportErrorDialog d(import_task->GetInvalidFiles(), main_window_);

app/dialog/footageproperties/footageproperties.cpp

@@ -124,21 +124,19 @@ void FootagePropertiesDialog::accept() {
     }
   }
 
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   if (footage_->name() != footage_name_field_->text()) {
-    new FootageChangeCommand(footage_,
-                             footage_name_field_->text(),
-                             command);
+    command->add_child(new FootageChangeCommand(footage_,
+                                                footage_name_field_->text()));
   }
 
   for (int i=0;i<footage_->streams().size();i++) {
     bool stream_enabled = (track_list->item(i)->checkState() == Qt::Checked);
 
     if (footage_->stream(i)->enabled() != stream_enabled) {
-      new StreamEnableChangeCommand(footage_->stream(i),
-                                    stream_enabled,
-                                    command);
+      command->add_child(new StreamEnableChangeCommand(footage_->stream(i),
+                                                       stream_enabled));
     }
   }
 
@@ -151,8 +149,7 @@ void FootagePropertiesDialog::accept() {
   QDialog::accept();
 }
 
-FootagePropertiesDialog::FootageChangeCommand::FootageChangeCommand(Footage *footage, const QString &name, QUndoCommand* command) :
-  UndoCommand(command),
+FootagePropertiesDialog::FootageChangeCommand::FootageChangeCommand(Footage *footage, const QString &name) :
   footage_(footage),
   new_name_(name)
 {
@@ -163,20 +160,19 @@ Project *FootagePropertiesDialog::FootageChangeCommand::GetRelevantProject() con
   return footage_->project();
 }
 
-void FootagePropertiesDialog::FootageChangeCommand::redo_internal()
+void FootagePropertiesDialog::FootageChangeCommand::redo()
 {
   old_name_ = footage_->name();
 
   footage_->set_name(new_name_);
 }
 
-void FootagePropertiesDialog::FootageChangeCommand::undo_internal()
+void FootagePropertiesDialog::FootageChangeCommand::undo()
 {
   footage_->set_name(old_name_);
 }
 
-FootagePropertiesDialog::StreamEnableChangeCommand::StreamEnableChangeCommand(Stream *stream, bool enabled, QUndoCommand *command) :
-  UndoCommand(command),
+FootagePropertiesDialog::StreamEnableChangeCommand::StreamEnableChangeCommand(Stream *stream, bool enabled) :
   stream_(stream),
   old_enabled_(stream->enabled()),
   new_enabled_(enabled)
@@ -188,12 +184,12 @@ Project *FootagePropertiesDialog::StreamEnableChangeCommand::GetRelevantProject(
   return stream_->footage()->project();
 }
 
-void FootagePropertiesDialog::StreamEnableChangeCommand::redo_internal()
+void FootagePropertiesDialog::StreamEnableChangeCommand::redo()
 {
   stream_->set_enabled(new_enabled_);
 }
 
-void FootagePropertiesDialog::StreamEnableChangeCommand::undo_internal()
+void FootagePropertiesDialog::StreamEnableChangeCommand::undo()
 {
   stream_->set_enabled(old_enabled_);
 }

app/dialog/footageproperties/footageproperties.h

@@ -59,14 +59,12 @@ private:
   class FootageChangeCommand : public UndoCommand {
   public:
     FootageChangeCommand(Footage* footage,
-                         const QString& name,
-                         QUndoCommand *command = nullptr);
+                         const QString& name);
 
     virtual Project* GetRelevantProject() const override;
 
-  protected:
-    virtual void redo_internal() override;
-    virtual void undo_internal() override;
+    virtual void redo() override;
+    virtual void undo() override;
 
   private:
     Footage* footage_;
@@ -78,14 +76,12 @@ private:
   class StreamEnableChangeCommand : public UndoCommand {
   public:
     StreamEnableChangeCommand(Stream* stream,
-                              bool enabled,
-                              QUndoCommand* command = nullptr);
+                              bool enabled);
 
     virtual Project* GetRelevantProject() const override;
 
-  protected:
-    virtual void redo_internal() override;
-    virtual void undo_internal() override;
+    virtual void redo() override;
+    virtual void undo() override;
 
   private:
     Stream* stream_;

app/dialog/footageproperties/streamproperties/audiostreamproperties.cpp

@@ -27,7 +27,7 @@ AudioStreamProperties::AudioStreamProperties(AudioStream *stream) :
 {
 }
 
-void AudioStreamProperties::Accept(QUndoCommand*)
+void AudioStreamProperties::Accept(MultiUndoCommand*)
 {
   Q_UNUSED(stream_)
 }

app/dialog/footageproperties/streamproperties/audiostreamproperties.h

@@ -31,7 +31,7 @@ class AudioStreamProperties : public StreamProperties
 public:
   AudioStreamProperties(AudioStream* stream);
 
-  virtual void Accept(QUndoCommand* parent) override;
+  virtual void Accept(MultiUndoCommand* parent) override;
 
 private:
   AudioStream* stream_;

app/dialog/footageproperties/streamproperties/streamproperties.h

@@ -21,10 +21,10 @@
 #ifndef STREAMPROPERTIES_H
 #define STREAMPROPERTIES_H
 
-#include <QUndoCommand>
 #include <QWidget>
 
 #include "common/define.h"
+#include "undo/undocommand.h"
 
 namespace olive {
 
@@ -33,7 +33,7 @@ class StreamProperties : public QWidget
 public:
   StreamProperties(QWidget* parent = nullptr);
 
-  virtual void Accept(QUndoCommand*){}
+  virtual void Accept(MultiUndoCommand*){}
 
   virtual bool SanityCheck(){return true;}
 

app/dialog/footageproperties/streamproperties/videostreamproperties.cpp

@@ -124,7 +124,7 @@ VideoStreamProperties::VideoStreamProperties(VideoStream *stream) :
   }
 }
 
-void VideoStreamProperties::Accept(QUndoCommand *parent)
+void VideoStreamProperties::Accept(MultiUndoCommand *parent)
 {
   QString set_colorspace;
 
@@ -137,12 +137,11 @@ void VideoStreamProperties::Accept(QUndoCommand *parent)
       || static_cast<VideoParams::Interlacing>(video_interlace_combo_->currentIndex()) != stream_->interlacing()
       || pixel_aspect_combo_->GetPixelAspectRatio() != stream_->pixel_aspect_ratio()) {
 
-    new VideoStreamChangeCommand(stream_,
+    parent->add_child(new VideoStreamChangeCommand(stream_,
                                                    video_premultiply_alpha_ ? video_premultiply_alpha_->isChecked() : stream_->premultiplied_alpha(),
                                                    set_colorspace,
                                                    static_cast<VideoParams::Interlacing>(video_interlace_combo_->currentIndex()),
-                                 pixel_aspect_combo_->GetPixelAspectRatio(),
-                                 parent);
+                                                   pixel_aspect_combo_->GetPixelAspectRatio()));
   }
 
   if (stream_->video_type() == VideoStream::kVideoTypeImageSequence) {
@@ -153,11 +152,10 @@ void VideoStreamProperties::Accept(QUndoCommand *parent)
     if (video_stream->start_time() != imgseq_start_time_->GetValue()
         || video_stream->duration() != new_dur
         || video_stream->frame_rate() != imgseq_frame_rate_->GetFrameRate()) {
-      new ImageSequenceChangeCommand(video_stream,
+      parent->add_child(new ImageSequenceChangeCommand(video_stream,
                                                        imgseq_start_time_->GetValue(),
                                                        new_dur,
-                                     imgseq_frame_rate_->GetFrameRate(),
-                                     parent);
+                                                       imgseq_frame_rate_->GetFrameRate()));
     }
   }
 }
@@ -181,9 +179,7 @@ VideoStreamProperties::VideoStreamChangeCommand::VideoStreamChangeCommand(VideoS
                                                                           bool premultiplied,
                                                                           QString colorspace,
                                                                           VideoParams::Interlacing interlacing,
-                                                                          const rational &pixel_ar,
-                                                                          QUndoCommand *parent) :
-  UndoCommand(parent),
+                                                                          const rational &pixel_ar) :
   stream_(stream),
   new_premultiplied_(premultiplied),
   new_colorspace_(colorspace),
@@ -197,7 +193,7 @@ Project *VideoStreamProperties::VideoStreamChangeCommand::GetRelevantProject() c
   return stream_->footage()->project();
 }
 
-void VideoStreamProperties::VideoStreamChangeCommand::redo_internal()
+void VideoStreamProperties::VideoStreamChangeCommand::redo()
 {
   old_premultiplied_ = stream_->premultiplied_alpha();
   old_colorspace_ = stream_->colorspace(false);
@@ -210,7 +206,7 @@ void VideoStreamProperties::VideoStreamChangeCommand::redo_internal()
   stream_->set_pixel_aspect_ratio(new_pixel_ar_);
 }
 
-void VideoStreamProperties::VideoStreamChangeCommand::undo_internal()
+void VideoStreamProperties::VideoStreamChangeCommand::undo()
 {
   stream_->set_premultiplied_alpha(old_premultiplied_);
   stream_->set_colorspace(old_colorspace_);
@@ -218,8 +214,7 @@ void VideoStreamProperties::VideoStreamChangeCommand::undo_internal()
   stream_->set_pixel_aspect_ratio(old_pixel_ar_);
 }
 
-VideoStreamProperties::ImageSequenceChangeCommand::ImageSequenceChangeCommand(VideoStream *video_stream, int64_t start_index, int64_t duration, const rational &frame_rate, QUndoCommand *parent) :
-  UndoCommand(parent),
+VideoStreamProperties::ImageSequenceChangeCommand::ImageSequenceChangeCommand(VideoStream *video_stream, int64_t start_index, int64_t duration, const rational &frame_rate) :
   video_stream_(video_stream),
   new_start_index_(start_index),
   new_duration_(duration),
@@ -232,7 +227,7 @@ Project *VideoStreamProperties::ImageSequenceChangeCommand::GetRelevantProject()
   return video_stream_->footage()->project();
 }
 
-void VideoStreamProperties::ImageSequenceChangeCommand::redo_internal()
+void VideoStreamProperties::ImageSequenceChangeCommand::redo()
 {
   old_start_index_ = video_stream_->start_time();
   video_stream_->set_start_time(new_start_index_);
@@ -245,7 +240,7 @@ void VideoStreamProperties::ImageSequenceChangeCommand::redo_internal()
   video_stream_->set_timebase(new_frame_rate_.flipped());
 }
 
-void VideoStreamProperties::ImageSequenceChangeCommand::undo_internal()
+void VideoStreamProperties::ImageSequenceChangeCommand::undo()
 {
   video_stream_->set_start_time(old_start_index_);
   video_stream_->set_duration(old_duration_);

app/dialog/footageproperties/streamproperties/videostreamproperties.h

@@ -26,7 +26,6 @@
 
 #include "project/item/footage/videostream.h"
 #include "streamproperties.h"
-#include "undo/undocommand.h"
 #include "widget/slider/integerslider.h"
 #include "widget/standardcombos/standardcombos.h"
 
@@ -38,7 +37,7 @@ class VideoStreamProperties : public StreamProperties
 public:
   VideoStreamProperties(VideoStream* stream);
 
-  virtual void Accept(QUndoCommand* parent) override;
+  virtual void Accept(MultiUndoCommand *parent) override;
 
   virtual bool SanityCheck() override;
 
@@ -89,14 +88,12 @@ private:
                              bool premultiplied,
                              QString colorspace,
                              VideoParams::Interlacing interlacing,
-                             const rational& pixel_ar,
-                             QUndoCommand* parent = nullptr);
+                             const rational& pixel_ar);
 
     virtual Project* GetRelevantProject() const override;
 
-  protected:
-    virtual void redo_internal() override;
-    virtual void undo_internal() override;
+    virtual void redo() override;
+    virtual void undo() override;
 
   private:
     VideoStream* stream_;
@@ -118,14 +115,12 @@ private:
     ImageSequenceChangeCommand(VideoStream* video_stream,
                                int64_t start_index,
                                int64_t duration,
-                               const rational& frame_rate,
-                               QUndoCommand* parent = nullptr);
+                               const rational& frame_rate);
 
     virtual Project* GetRelevantProject() const override;
 
-  protected:
-    virtual void redo_internal() override;
-    virtual void undo_internal() override;
+    virtual void redo() override;
+    virtual void undo() override;
 
   private:
     VideoStream* video_stream_;

app/dialog/keyframeproperties/keyframeproperties.cpp

@@ -194,30 +194,28 @@ KeyframePropertiesDialog::KeyframePropertiesDialog(const QVector<NodeKeyframe*>
 
 void KeyframePropertiesDialog::accept()
 {
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   rational new_time = Timecode::timestamp_to_time(time_slider_->GetValue(), timebase_);
   int new_type = type_select_->currentData().toInt();
 
   foreach (NodeKeyframe* key, keys_) {
     if (time_slider_->isEnabled() && !time_slider_->IsTristate()) {
-      new NodeParamSetKeyframeTimeCommand(key, new_time, command);
+      command->add_child(new NodeParamSetKeyframeTimeCommand(key, new_time));
     }
 
     if (new_type > -1) {
-      new KeyframeSetTypeCommand(key, static_cast<NodeKeyframe::Type>(new_type), command);
+      command->add_child(new KeyframeSetTypeCommand(key, static_cast<NodeKeyframe::Type>(new_type)));
     }
 
     if (bezier_group_->isEnabled()) {
-      new KeyframeSetBezierControlPoint(key,
+      command->add_child(new KeyframeSetBezierControlPoint(key,
                                                            NodeKeyframe::kInHandle,
-                                        QPointF(bezier_in_x_slider_->GetValue(), bezier_in_y_slider_->GetValue()),
-                                        command);
+                                                           QPointF(bezier_in_x_slider_->GetValue(), bezier_in_y_slider_->GetValue())));
 
-      new KeyframeSetBezierControlPoint(key,
+      command->add_child(new KeyframeSetBezierControlPoint(key,
                                                            NodeKeyframe::kOutHandle,
-                                        QPointF(bezier_out_x_slider_->GetValue(), bezier_out_y_slider_->GetValue()),
-                                        command);
+                                                           QPointF(bezier_out_x_slider_->GetValue(), bezier_out_y_slider_->GetValue())));
     }
   }
 

app/dialog/sequence/sequence.cpp

@@ -139,9 +139,7 @@ void SequenceDialog::accept()
 SequenceDialog::SequenceParamCommand::SequenceParamCommand(Sequence* s,
                                                            const VideoParams& video_params,
                                                            const AudioParams &audio_params,
-                                                           const QString& name,
-                                                           QUndoCommand* parent) :
-  UndoCommand(parent),
+                                                           const QString& name) :
   sequence_(s),
   new_video_params_(video_params),
   new_audio_params_(audio_params),
@@ -157,14 +155,14 @@ Project *SequenceDialog::SequenceParamCommand::GetRelevantProject() const
   return sequence_->project();
 }
 
-void SequenceDialog::SequenceParamCommand::redo_internal()
+void SequenceDialog::SequenceParamCommand::redo()
 {
   sequence_->set_video_params(new_video_params_);
   sequence_->set_audio_params(new_audio_params_);
   sequence_->set_name(new_name_);
 }
 
-void SequenceDialog::SequenceParamCommand::undo_internal()
+void SequenceDialog::SequenceParamCommand::undo()
 {
   sequence_->set_video_params(old_video_params_);
   sequence_->set_audio_params(old_audio_params_);

app/dialog/sequence/sequence.h

@@ -38,7 +38,7 @@ namespace olive {
  * This dialog exposes all the parameters of a Sequence to users allowing them to set up a Sequence however they wish.
  * A Sequence can be sent to this dialog through the constructor. All fields will be filled using that Sequence's
  * parameters, allowing the user to view and edit them. Accepting the dialog will apply them back to that Sequence,
- * either directly or using a QUndoCommand (see SetUndoable()).
+ * either directly or using an UndoCommand (see SetUndoable()).
  *
  * If creating a new Sequence, the Sequence must still be constructed first before sending it to SequenceDialog.
  * SequenceDialog does not create any new objects. In most cases when creating a new Sequence, editing its parameters
@@ -104,21 +104,19 @@ private:
   QLineEdit* name_field_;
 
   /**
-   * @brief A QUndoCommand for setting the parameters on a sequence
+   * @brief An UndoCommand for setting the parameters on a sequence
    */
   class SequenceParamCommand : public UndoCommand {
   public:
     SequenceParamCommand(Sequence* s,
                          const VideoParams& video_params,
                          const AudioParams& audio_params,
-                         const QString& name,
-                         QUndoCommand* parent = nullptr);
+                         const QString& name);
 
     virtual Project* GetRelevantProject() const override;
 
-  protected:
-    virtual void redo_internal() override;
-    virtual void undo_internal() override;
+    virtual void redo() override;
+    virtual void undo() override;
 
   private:
     Sequence* sequence_;

app/node/CMakeLists.txt

@@ -43,6 +43,7 @@ set(OLIVE_SOURCES
   node/node.cpp
   node/nodecopypaste.h
   node/nodecopypaste.cpp
+  node/splitvalue.h
   node/traverser.h
   node/traverser.cpp
   node/value.h

app/node/generator/polygon/polygon.cpp

@@ -27,7 +27,7 @@ namespace olive {
 
 PolygonGenerator::PolygonGenerator()
 {
-  points_input_ = new NodeInput(this, QStringLiteral("points_in"), NodeValue::kVec2);
+  points_input_ = new NodeInput(this, QStringLiteral("points_in"), NodeValue::kVec2, QVector2D(0, 0));
   points_input_->SetIsArray(true);
 
   color_input_ = new NodeInput(this, QStringLiteral("color_in"), NodeValue::kColor, QVariant::fromValue(Color(1.0, 1.0, 1.0)));

app/node/input.cpp

@@ -23,14 +23,16 @@
 #include "common/bezier.h"
 #include "common/lerp.h"
 #include "common/xmlutils.h"
+#include "core.h"
 #include "node.h"
 #include "project/item/footage/stream.h"
+#include "widget/nodeview/nodeviewundo.h"
 
 #define super NodeConnectable
 
 namespace olive {
 
-NodeInput::NodeInput(Node* parent, const QString& id, NodeValue::Type type, const QVector<QVariant> &default_value)
+NodeInput::NodeInput(Node* parent, const QString& id, NodeValue::Type type, const SplitValue &default_value)
 {
   Init(parent, id, type, default_value);
 }
@@ -42,7 +44,7 @@ NodeInput::NodeInput(Node *parent, const QString &id, NodeValue::Type type, cons
 
 NodeInput::NodeInput(Node* parent, const QString &id, NodeValue::Type type)
 {
-  Init(parent, id, type, QVector<QVariant>());
+  Init(parent, id, type, SplitValue());
 }
 
 NodeInput::~NodeInput()
@@ -217,7 +219,16 @@ void NodeInput::childEvent(QChildEvent *event)
   }
 }
 
-void NodeInput::Init(Node* parent, const QString &id, NodeValue::Type type, const QVector<QVariant>& default_val)
+void NodeInput::ClearElement(int index)
+{
+  GetImmediate(index)->delete_all_keyframes();
+
+  SetIsKeyframing(false, index);
+
+  SetSplitStandardValue(default_value_, index);
+}
+
+void NodeInput::Init(Node* parent, const QString &id, NodeValue::Type type, const SplitValue& default_val)
 {
   setParent(parent);
 
@@ -381,12 +392,26 @@ void NodeInput::SaveImmediate(QXmlStreamWriter* writer, int element) const
   }
 }
 
-void NodeInput::ChangeArraySizeInternal(int size)
+void NodeInput::ArrayResizeInternal(int size)
 {
+  if (array_size_ != size) {
+    // Update array size
+    if (array_size_ < size) {
+      // Size is larger, create any immediates that don't exist
+      for (int i=subinputs_.size(); i<size; i++) {
+        subinputs_.append(CreateImmediate());
+      }
+
+      // Note that we do not delete any immediates when decreasing size since the user might still
+      // want that data. Therefore it's important to note that array_size_ does NOT necessarily
+      // equal subinputs_.size()
+    }
+
     array_size_ = size;
     emit ArraySizeChanged(array_size_);
     emit ValueChanged(TimeRange(RATIONAL_MIN, RATIONAL_MAX), -1);
   }
+}
 
 NodeInputImmediate *NodeInput::CreateImmediate()
 {
@@ -440,12 +465,18 @@ QVector<Node *> NodeInput::GetImmediateDependencies() const
   return GetDependencies(false, false);
 }
 
-void NodeInput::ArrayInsert(int index)
+void NodeInput::ArrayAppend(bool undoable)
 {
-  // Add new input
-  subinputs_.insert(index, CreateImmediate());
+  ArrayResize(ArraySize() + 1, undoable);
+}
 
-  ChangeArraySizeInternal(array_size_ + 1);
+void NodeInput::ArrayInsert(int index, bool undoable)
+{
+  if (undoable) {
+    Core::instance()->undo_stack()->push(new ArrayInsertCommand(this, index));
+  } else {
+    // Add new input
+    ArrayResizeInternal(ArraySize() + 1);
 
     // Move connections down
     std::map<int, Node*> copied_edges = edges();
@@ -456,13 +487,24 @@ void NodeInput::ArrayInsert(int index)
         ConnectEdge(it->second, this, it->first + 1);
       }
     }
+
+    // Shift values and keyframes up one element
+    for (int i=ArraySize()-1; i>index; i--) {
+      CopyValuesOfElement(this, this, i-1, i);
     }
 
-void NodeInput::ArrayRemove(int index)
+    // Reset value of element we just "inserted"
+    ClearElement(index);
+  }
+}
+
+void NodeInput::ArrayRemove(int index, bool undoable)
 {
+  if (undoable) {
+    Core::instance()->undo_stack()->push(new ArrayRemoveCommand(this, index));
+  } else {
     // Remove input
-  delete subinputs_.takeAt(index);
-  ChangeArraySizeInternal(array_size_ - 1);
+    ArrayResizeInternal(ArraySize() - 1);
 
     // Move connections up
     std::map<int, Node*> copied_edges = edges();
@@ -476,43 +518,42 @@ void NodeInput::ArrayRemove(int index)
         }
       }
     }
+
+    // Shift values and keyframes down one element
+    for (int i=index; i<ArraySize(); i++) {
+      // Copying ArraySize()+1 is actually legal because immediates are never deleted
+      CopyValuesOfElement(this, this, i+1, i);
     }
 
-void NodeInput::ArrayPrepend()
+    // Reset value of last element
+    ClearElement(ArraySize());
+  }
+}
+
+void NodeInput::ArrayPrepend(bool undoable)
 {
-  ArrayInsert(0);
+  ArrayInsert(0, undoable);
 }
 
-void NodeInput::ArrayResize(int size)
+void NodeInput::ArrayResize(int size, bool undoable)
 {
-  if (array_size_ != size) {
-    // Update array size
-    if (array_size_ < size) {
-      // Size is larger, create any immediates that don't exist
-      for (int i=subinputs_.size(); i<size; i++) {
-        subinputs_.append(CreateImmediate());
+  if (array_size_ == size) {
+    return;
+  }
+
+  ArrayResizeCommand* c = new ArrayResizeCommand(this, size);
+
+  if (undoable) {
+    Core::instance()->undo_stack()->push(c);
+  } else {
+    c->redo();
+    delete c;
   }
 }
 
-    ChangeArraySizeInternal(size);
-
-    if (array_size_ > size) {
-      // Decreasing in size, disconnect any extraneous edges
-      for (int i=size; i<array_size_; i++) {
-        try {
-          DisconnectEdge(edges().at(i), this, i);
-        } catch (std::out_of_range&) {}
-      }
-
-      // Note that we do not delete any immediates since the user might still want that data.
-      // Therefore it's important to note that array_size_ does NOT necessarily equal subinputs_.size()
-    }
-  }
-}
-
-void NodeInput::ArrayRemoveLast()
+void NodeInput::ArrayRemoveLast(bool undoable)
 {
-  ArrayResize(ArraySize() - 1);
+  ArrayResize(ArraySize() - 1, undoable);
 }
 
 QVariant NodeInput::GetValueAtTime(const rational &time, int element) const
@@ -520,9 +561,9 @@ QVariant NodeInput::GetValueAtTime(const rational &time, int element) const
   return NodeValue::combine_track_values_into_normal_value(data_type_, GetSplitValuesAtTime(time, element));
 }
 
-QVector<QVariant> NodeInput::GetSplitValuesAtTime(const rational &time, int element) const
+SplitValue NodeInput::GetSplitValuesAtTime(const rational &time, int element) const
 {
-  QVector<QVariant> vals;
+  SplitValue vals;
 
   int nb_tracks = GetNumberOfKeyframeTracks();
 
@@ -669,26 +710,31 @@ void NodeInput::CopyValues(NodeInput *source, NodeInput *dest, bool include_conn
   }
 }
 
-void NodeInput::CopyValuesOfElement(NodeInput *src, NodeInput *dst, int element)
+void NodeInput::CopyValuesOfElement(NodeInput *src, NodeInput *dst, int src_element, int dst_element)
 {
+  if (dst_element >= dst->subinputs_.size()) {
+    qDebug() << "Ignored destination element that was out of array bounds";
+    return;
+  }
+
   // Copy standard value
-  dst->SetSplitStandardValue(src->GetSplitStandardValue(element), element);
+  dst->SetSplitStandardValue(src->GetSplitStandardValue(src_element), dst_element);
 
   // Copy keyframes
-  dst->GetImmediate(element)->delete_all_keyframes();
-  foreach (const NodeKeyframeTrack& track, src->GetImmediate(element)->keyframe_tracks()) {
+  dst->GetImmediate(dst_element)->delete_all_keyframes();
+  foreach (const NodeKeyframeTrack& track, src->GetImmediate(src_element)->keyframe_tracks()) {
     foreach (NodeKeyframe* key, track) {
-      key->copy(dst);
+      key->copy(dst_element, dst);
     }
   }
 
   // Copy keyframing state
   if (src->IsKeyframable()) {
-    dst->SetIsKeyframing(src->IsKeyframing(element), element);
+    dst->SetIsKeyframing(src->IsKeyframing(src_element), dst_element);
   }
 
   // If this is the root of an array, copy the array size
-  if (element == -1) {
+  if (src_element == -1 && dst_element == -1) {
     dst->ArrayResize(src->ArraySize());
   }
 }
@@ -839,4 +885,19 @@ uint qHash(const NodeInput::KeyframeTrackReference &ref, uint seed)
   return qHash(ref.input, seed) ^ qHash(ref.element, seed) ^ qHash(ref.track, seed);
 }
 
+Project *NodeInput::ArrayRemoveCommand::GetRelevantProject() const
+{
+  return input_->parent()->parent()->project();
+}
+
+Project *NodeInput::ArrayResizeCommand::GetRelevantProject() const
+{
+  return input_->parent()->parent()->project();
+}
+
+Project *NodeInput::ArrayInsertCommand::GetRelevantProject() const
+{
+  return input_->parent()->parent()->project();
+}
+
 }

app/node/input.h

@@ -26,6 +26,8 @@
 #include "node/connectable.h"
 #include "node/inputimmediate.h"
 #include "node/value.h"
+#include "splitvalue.h"
+#include "undo/undocommand.h"
 
 namespace olive {
 
@@ -47,7 +49,7 @@ public:
    * saving/loading data from this Node so that parameter order can be changed without issues loading data saved by an
    * older version. This of course assumes that parameters don't change their ID.
    */
-  NodeInput(Node* parent, const QString &id, NodeValue::Type type, const QVector<QVariant>& default_value);
+  NodeInput(Node* parent, const QString &id, NodeValue::Type type, const SplitValue& default_value);
   NodeInput(Node* parent, const QString &id, NodeValue::Type type, const QVariant& default_value);
   NodeInput(Node* parent, const QString &id, NodeValue::Type type);
 
@@ -176,7 +178,7 @@ public:
   /**
    * @brief Get non-keyframed value split into components (the way it's stored)
    */
-  const QVector<QVariant>& GetSplitStandardValue(int element = -1) const
+  const SplitValue& GetSplitStandardValue(int element = -1) const
   {
     return GetImmediate(element)->get_split_standard_value();
   }
@@ -197,7 +199,7 @@ public:
     SetSplitStandardValue(NodeValue::split_normal_value_into_track_values(data_type_, value), element);
   }
 
-  void SetSplitStandardValue(const QVector<QVariant>& value, int element = -1)
+  void SetSplitStandardValue(const SplitValue& value, int element = -1)
   {
     GetImmediate(element)->set_split_standard_value(value);
 
@@ -231,7 +233,11 @@ public:
    */
   static void CopyValues(NodeInput* source, NodeInput* dest, bool include_connections = true, bool traverse_arrays = true);
 
-  static void CopyValuesOfElement(NodeInput* source, NodeInput* dst, int element);
+  static void CopyValuesOfElement(NodeInput* source, NodeInput* dst, int src_element, int dst_element);
+  static void CopyValuesOfElement(NodeInput* source, NodeInput* dst, int element)
+  {
+    CopyValuesOfElement(source, dst, element, element);
+  }
 
   QStringList get_combobox_strings() const;
 
@@ -244,7 +250,7 @@ public:
     return NodeValue::combine_track_values_into_normal_value(data_type_, default_value_);
   }
 
-  const QVector<QVariant>& GetSplitDefaultValue() const
+  const SplitValue& GetSplitDefaultValue() const
   {
     return default_value_;
   }
@@ -279,33 +285,36 @@ public:
 
   void SetIsKeyframing(bool keyframing, int element)
   {
-    Q_ASSERT(IsKeyframable());
+    if (IsKeyframable()) {
+      qDebug() << "Ignored set keyframing because this input is not keyframable";
+      return;
+    }
 
     GetImmediate(element)->set_is_keyframing(keyframing);
 
     emit KeyframeEnableChanged(keyframing, element);
   }
 
-  void ArrayAppend()
-  {
-    ArrayResize(ArraySize() + 1);
-  }
+  /// Alias for ArrayResize(ArraySize() + 1)
+  void ArrayAppend(bool undoable = false);
 
-  void ArrayInsert(int index);
+  void ArrayInsert(int index, bool undoable = false);
 
-  void ArrayRemove(int index);
+  void ArrayRemove(int index, bool undoable = false);
 
-  void ArrayPrepend();
+  /// Alias for ArrayInsert(0)
+  void ArrayPrepend(bool undoable = false);
 
-  void ArrayResize(int size);
+  void ArrayResize(int size, bool undoable = false);
+
+  /// Alias for ArrayResize(ArraySize() - 1)
+  void ArrayRemoveLast(bool undoable = false);
 
   int ArraySize() const
   {
     return array_size_;
   }
 
-  void ArrayRemoveLast();
-
   int GetNumberOfKeyframeTracks() const
   {
     return NodeValue::get_number_of_keyframe_tracks(data_type_);
@@ -318,7 +327,7 @@ public:
    */
   QVariant GetValueAtTime(const rational& time, int element = -1) const;
 
-  QVector<QVariant> GetSplitValuesAtTime(const rational& time, int element = -1) const;
+  SplitValue GetSplitValuesAtTime(const rational& time, int element = -1) const;
 
   /**
    * @brief Calculate the stored value for a specific track
@@ -378,13 +387,139 @@ protected:
   virtual void childEvent(QChildEvent* e) override;
 
 private:
-  void Init(Node *parent, const QString& id, NodeValue::Type type, const QVector<QVariant> &default_val);
+  class ArrayInsertCommand : public UndoCommand
+  {
+  public:
+    ArrayInsertCommand(NodeInput* input, int index) :
+      input_(input),
+      index_(index)
+    {
+    }
+
+    virtual Project* GetRelevantProject() const override;
+
+    virtual void redo() override
+    {
+      input_->ArrayInsert(index_, false);
+    }
+
+    virtual void undo() override
+    {
+      input_->ArrayRemove(index_, false);
+    }
+
+  private:
+    NodeInput* input_;
+    int index_;
+
+  };
+
+  class ArrayRemoveCommand : public UndoCommand
+  {
+  public:
+    ArrayRemoveCommand(NodeInput* input, int index) :
+      input_(input),
+      index_(index)
+    {
+    }
+
+    virtual Project* GetRelevantProject() const override;
+
+  protected:
+    virtual void redo() override
+    {
+      // Save immediate data
+      is_keyframing_ = input_->IsKeyframing(index_);
+      standard_value_ = input_->GetSplitStandardValue(index_);
+      keyframes_ = input_->GetImmediate(index_)->keyframe_tracks();
+      input_->GetImmediate(index_)->delete_all_keyframes(&memory_manager_);
+
+      input_->ArrayRemove(index_, false);
+    }
+
+    virtual void undo() override
+    {
+      input_->ArrayInsert(index_, false);
+
+      // Restore keyframes
+      foreach (const NodeKeyframeTrack& track, keyframes_) {
+        foreach (NodeKeyframe* key, track) {
+          key->setParent(input_);
+        }
+      }
+      input_->SetSplitStandardValue(standard_value_, index_);
+      input_->SetIsKeyframing(is_keyframing_, index_);
+    }
+
+  private:
+    NodeInput* input_;
+    int index_;
+
+    SplitValue standard_value_;
+    bool is_keyframing_;
+    QVector<NodeKeyframeTrack> keyframes_;
+    QObject memory_manager_;
+
+  };
+
+  class ArrayResizeCommand : public UndoCommand
+  {
+  public:
+    ArrayResizeCommand(NodeInput* input, int size) :
+      input_(input),
+      size_(size)
+    {}
+
+    virtual void redo() override
+    {
+      old_size_ = input_->array_size_;
+
+      if (old_size_ > size_) {
+        // Decreasing in size, disconnect any extraneous edges
+        for (int i=size_; i<old_size_; i++) {
+          try {
+            Node* output = input_->edges().at(i);
+
+            removed_connections_.insert(i, output);
+
+            DisconnectEdge(output, input_, i);
+          } catch (std::out_of_range&) {}
+        }
+      }
+
+      input_->ArrayResizeInternal(size_);
+    }
+
+    virtual void undo() override
+    {
+      for (auto it=removed_connections_.cbegin(); it!=removed_connections_.cend(); it++) {
+        ConnectEdge(it.value(), input_, it.key());
+      }
+      removed_connections_.clear();
+
+      input_->ArrayResizeInternal(old_size_);
+    }
+
+    virtual Project* GetRelevantProject() const override;
+
+  private:
+    NodeInput* input_;
+    int size_;
+    int old_size_;
+
+    QHash<int, Node*> removed_connections_;
+
+  };
+
+  void ClearElement(int index);
+
+  void Init(Node *parent, const QString& id, NodeValue::Type type, const SplitValue &default_val);
 
   void LoadImmediate(QXmlStreamReader *reader, int element, XMLNodeData& xml_node_data, const QAtomicInt* cancelled);
 
   void SaveImmediate(QXmlStreamWriter *writer, int element) const;
 
-  void ChangeArraySizeInternal(int size);
+  void ArrayResizeInternal(int size);
 
   NodeInputImmediate* CreateImmediate();
 
@@ -426,7 +561,7 @@ private:
 
   QVector<NodeInputImmediate*> subinputs_;
 
-  QVector<QVariant> default_value_;
+  SplitValue default_value_;
 
   /**
    * @brief Unique identifier of this input within this node

app/node/inputdragger.cpp

@@ -106,21 +106,21 @@ void NodeInputDragger::End()
     return;
   }
 
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   if (input_->IsKeyframing(element_)) {
     if (drag_created_key_) {
       // We created a keyframe in this process
-      new NodeParamInsertKeyframeCommand(input_, dragging_key_, command);
+      command->add_child(new NodeParamInsertKeyframeCommand(input_, dragging_key_));
     }
 
     // We just set a keyframe's value
     // We do this even when inserting a keyframe because we don't actually perform an insert in this undo command
     // so this will ensure the ValueChanged() signal is sent correctly
-    new NodeParamSetKeyframeValueCommand(dragging_key_, end_value_, start_value_, command);
+    command->add_child(new NodeParamSetKeyframeValueCommand(dragging_key_, end_value_, start_value_));
   } else {
     // We just set the standard value
-    new NodeParamSetStandardValueCommand(input_, track_, element_, end_value_, start_value_, command);
+    command->add_child(new NodeParamSetStandardValueCommand(input_, track_, element_, end_value_, start_value_));
   }
 
   Core::instance()->undo_stack()->push(command);

app/node/inputimmediate.cpp

@@ -27,7 +27,7 @@
 
 namespace olive {
 
-NodeInputImmediate::NodeInputImmediate(NodeValue::Type type, const QVector<QVariant> &default_val) :
+NodeInputImmediate::NodeInputImmediate(NodeValue::Type type, const SplitValue &default_val) :
   keyframing_(false)
 {
   int track_size = NodeValue::get_number_of_keyframe_tracks(type);
@@ -43,7 +43,7 @@ void NodeInputImmediate::set_standard_value_on_track(const QVariant &value, int
   standard_value_.replace(track, value);
 }
 
-void NodeInputImmediate::set_split_standard_value(const QVector<QVariant> &value)
+void NodeInputImmediate::set_split_standard_value(const SplitValue &value)
 {
   for (int i=0; i<value.size() && i<standard_value_.size(); i++) {
     standard_value_[i] = value[i];
@@ -267,13 +267,17 @@ void NodeInputImmediate::remove_keyframe(NodeKeyframe *key)
   keyframe_tracks_[key->track()].removeOne(key);
 }
 
-void NodeInputImmediate::delete_all_keyframes()
+void NodeInputImmediate::delete_all_keyframes(QObject* parent)
 {
   for (NodeKeyframeTrack& track : keyframe_tracks_) {
     while (!track.isEmpty()) {
+      if (parent) {
+        track.first()->setParent(parent);
+      } else {
         delete track.first();
       }
     }
   }
+}
 
 }

app/node/inputimmediate.h

@@ -25,6 +25,7 @@
 #include "common/xmlutils.h"
 #include "node/keyframe.h"
 #include "node/value.h"
+#include "splitvalue.h"
 
 namespace olive {
 
@@ -33,7 +34,7 @@ class NodeInput;
 class NodeInputImmediate
 {
 public:
-  NodeInputImmediate(NodeValue::Type type, const QVector<QVariant>& default_val);
+  NodeInputImmediate(NodeValue::Type type, const SplitValue& default_val);
 
   /**
    * @brief Internal insert function, automatically does an insertion sort based on the keyframe's time
@@ -42,19 +43,19 @@ public:
 
   void remove_keyframe(NodeKeyframe* key);
 
-  void delete_all_keyframes();
+  void delete_all_keyframes(QObject *parent = nullptr);
 
   /**
    * @brief Get non-keyframed value split into components (the way it's stored)
    */
-  const QVector<QVariant>& get_split_standard_value() const
+  const SplitValue& get_split_standard_value() const
   {
     return standard_value_;
   }
 
   void set_standard_value_on_track(const QVariant &value, int track = 0);
 
-  void set_split_standard_value(const QVector<QVariant>& value);
+  void set_split_standard_value(const SplitValue& value);
 
   /**
    * @brief Retrieve a list of keyframe objects for all tracks at a given time
@@ -149,7 +150,7 @@ private:
   /**
    * @brief Non-keyframed value
    */
-  QVector<QVariant> standard_value_;
+  SplitValue standard_value_;
 
   /**
    * @brief Internal keyframe array

app/node/keyframe.cpp

@@ -45,14 +45,19 @@ NodeKeyframe::~NodeKeyframe()
   setParent(nullptr);
 }
 
-NodeKeyframe *NodeKeyframe::copy(QObject* parent) const
+NodeKeyframe *NodeKeyframe::copy(int element, QObject *parent) const
 {
-  NodeKeyframe* copy = new NodeKeyframe(time_, value_, type_, track_, element_, parent);
+  NodeKeyframe* copy = new NodeKeyframe(time_, value_, type_, track_, element, parent);
   copy->bezier_control_in_ = bezier_control_in_;
   copy->bezier_control_out_ = bezier_control_out_;
   return copy;
 }
 
+NodeKeyframe *NodeKeyframe::copy(QObject* parent) const
+{
+  return copy(element_, parent);
+}
+
 NodeInput *NodeKeyframe::parent() const
 {
   return static_cast<NodeInput*>(QObject::parent());

app/node/keyframe.h

@@ -65,6 +65,7 @@ public:
 
   virtual ~NodeKeyframe() override;
 
+  NodeKeyframe* copy(int element, QObject* parent = nullptr) const;
   NodeKeyframe* copy(QObject* parent = nullptr) const;
 
   NodeInput* parent() const;

app/node/node.cpp

@@ -247,7 +247,7 @@ TimeRange Node::OutputTimeAdjustment(NodeInput *, int, const TimeRange &input_ti
   return input_time;
 }
 
-QVector<Node *> Node::CopyDependencyGraph(const QVector<Node *> &nodes, QUndoCommand* command)
+QVector<Node *> Node::CopyDependencyGraph(const QVector<Node *> &nodes, MultiUndoCommand *command)
 {
   int nb_nodes = nodes.size();
 
@@ -263,7 +263,7 @@ QVector<Node *> Node::CopyDependencyGraph(const QVector<Node *> &nodes, QUndoCom
     // Add to graph
     NodeGraph* graph = static_cast<NodeGraph*>(nodes.at(i)->parent());
     if (command) {
-      new NodeAddCommand(graph, c, command);
+      command->add_child(new NodeAddCommand(graph, c));
     } else {
       c->setParent(graph);
     }
@@ -277,7 +277,7 @@ QVector<Node *> Node::CopyDependencyGraph(const QVector<Node *> &nodes, QUndoCom
   return copies;
 }
 
-void Node::CopyDependencyGraph(const QVector<Node *> &src, const QVector<Node *> &dst, QUndoCommand *command)
+void Node::CopyDependencyGraph(const QVector<Node *> &src, const QVector<Node *> &dst, MultiUndoCommand *command)
 {
   for (int i=0; i<src.size(); i++) {
     foreach (NodeInput* input, src.at(i)->inputs()) {
@@ -290,7 +290,7 @@ void Node::CopyDependencyGraph(const QVector<Node *> &src, const QVector<Node *>
           NodeInput* dst_input = dst.at(i)->GetInputWithID(input->id());
 
           if (command) {
-            new NodeEdgeAddCommand(dst_output, dst_input, it->first, command);
+            command->add_child(new NodeEdgeAddCommand(dst_output, dst_input, it->first));
           } else {
             ConnectEdge(dst_output, dst_input, it->first);
           }

app/node/node.h

@@ -368,8 +368,8 @@ public:
   /**
    * @brief Clones a set of nodes and connects the new ones the way the old ones were
    */
-  static QVector<Node*> CopyDependencyGraph(const QVector<Node*>& nodes, QUndoCommand *command);
-  static void CopyDependencyGraph(const QVector<Node*>& src, const QVector<Node*>& dst, QUndoCommand *command);
+  static QVector<Node*> CopyDependencyGraph(const QVector<Node*>& nodes, MultiUndoCommand *command);
+  static void CopyDependencyGraph(const QVector<Node*>& src, const QVector<Node*>& dst, MultiUndoCommand *command);
 
   /**
    * @brief Return whether this Node can be deleted or not

app/node/nodecopypaste.cpp

@@ -56,7 +56,7 @@ void NodeCopyPasteService::CopyNodesToClipboard(const QVector<Node *> &nodes, vo
   Core::CopyStringToClipboard(copy_str);
 }
 
-QVector<Node *> NodeCopyPasteService::PasteNodesFromClipboard(NodeGraph *graph, QUndoCommand* command, void *userdata)
+QVector<Node *> NodeCopyPasteService::PasteNodesFromClipboard(NodeGraph *graph, MultiUndoCommand* command, void *userdata)
 {
   QString clipboard = Core::PasteStringFromClipboard();
 
@@ -121,7 +121,7 @@ QVector<Node *> NodeCopyPasteService::PasteNodesFromClipboard(NodeGraph *graph,
 
   // Add all nodes to graph
   foreach (Node* n, pasted_nodes) {
-    new NodeAddCommand(graph, n, command);
+    command->add_child(new NodeAddCommand(graph, n));
   }
 
   // Make connections

app/node/nodecopypaste.h

@@ -37,7 +37,7 @@ public:
 protected:
   void CopyNodesToClipboard(const QVector<Node *> &nodes, void* userdata = nullptr);
 
-  QVector<Node*> PasteNodesFromClipboard(NodeGraph *graph, QUndoCommand *command, void* userdata = nullptr);
+  QVector<Node*> PasteNodesFromClipboard(NodeGraph *graph, MultiUndoCommand *command, void* userdata = nullptr);
 
   virtual void CopyNodesToClipboardInternal(QXmlStreamWriter *writer, void* userdata);
 

app/node/splitvalue.h

@@ -0,0 +1,33 @@
+/***
+
+  Olive - Non-Linear Video Editor
+  Copyright (C) 2020 Olive Team
+
+  This program is free software: you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation, either version 3 of the License, or
+  (at your option) any later version.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+***/
+
+#ifndef SPLITVALUE_H
+#define SPLITVALUE_H
+
+#include <QVariant>
+#include <QVector>
+
+namespace olive {
+
+using SplitValue = QVector<QVariant>;
+
+}
+
+#endif // SPLITVALUE_H

app/project/projectviewmodel.cpp

@@ -330,9 +330,9 @@ bool ProjectViewModel::dropMimeData(const QMimeData *data, Qt::DropAction action
     quint64 enabled_streams;
 
     // Loop through all data
-    QUndoCommand* move_command = new QUndoCommand();
+    MultiUndoCommand* move_command = new MultiUndoCommand();
 
-    move_command->setText(tr("Move Items"));
+    move_command->set_name(tr("Move Items"));
 
     while (!stream.atEnd()) {
       stream >> enabled_streams >> r >> item_ptr;
@@ -343,9 +343,7 @@ bool ProjectViewModel::dropMimeData(const QMimeData *data, Qt::DropAction action
       // no-op
 
       if (item != drop_location && item->parent() != drop_location && !ItemIsParentOfChild(item, drop_location)) {
-        MoveItemCommand* mic = new MoveItemCommand(this, item, static_cast<Folder*>(drop_location), move_command);
-
-        Q_UNUSED(mic)
+        move_command->add_child(new MoveItemCommand(this, item, static_cast<Folder*>(drop_location)));
       }
     }
 
@@ -499,16 +497,14 @@ QModelIndex ProjectViewModel::CreateIndexFromItem(Item *item, int column)
 
 ProjectViewModel::MoveItemCommand::MoveItemCommand(ProjectViewModel *model,
                                                    Item *item,
-                                                   Folder *destination,
-                                                   QUndoCommand *parent) :
-  UndoCommand(parent),
+                                                   Folder *destination) :
   model_(model),
   item_(item),
   destination_(destination)
 {
   source_ = static_cast<Folder*>(item->parent());
 
-  setText(QCoreApplication::translate("MoveItemCommand", "Move Item"));
+  set_name(QCoreApplication::translate("MoveItemCommand", "Move Item"));
 }
 
 Project *ProjectViewModel::MoveItemCommand::GetRelevantProject() const
@@ -516,25 +512,24 @@ Project *ProjectViewModel::MoveItemCommand::GetRelevantProject() const
   return model_->project();
 }
 
-void ProjectViewModel::MoveItemCommand::redo_internal()
+void ProjectViewModel::MoveItemCommand::redo()
 {
   model_->MoveItemInternal(item_, destination_);
 }
 
-void ProjectViewModel::MoveItemCommand::undo_internal()
+void ProjectViewModel::MoveItemCommand::undo()
 {
   model_->MoveItemInternal(item_, source_);
 }
 
-ProjectViewModel::RenameItemCommand::RenameItemCommand(ProjectViewModel* model, Item *item, const QString &name, QUndoCommand *parent) :
-  UndoCommand(parent),
+ProjectViewModel::RenameItemCommand::RenameItemCommand(ProjectViewModel* model, Item *item, const QString &name) :
   model_(model),
   item_(item),
   new_name_(name)
 {
   old_name_ = item->name();
 
-  setText(QCoreApplication::translate("RenameItemCommand", "Rename Item"));
+  set_name(QCoreApplication::translate("RenameItemCommand", "Rename Item"));
 }
 
 Project *ProjectViewModel::RenameItemCommand::GetRelevantProject() const
@@ -542,18 +537,17 @@ Project *ProjectViewModel::RenameItemCommand::GetRelevantProject() const
   return model_->project();
 }
 
-void ProjectViewModel::RenameItemCommand::redo_internal()
+void ProjectViewModel::RenameItemCommand::redo()
 {
   model_->RenameChild(item_, new_name_);
 }
 
-void ProjectViewModel::RenameItemCommand::undo_internal()
+void ProjectViewModel::RenameItemCommand::undo()
 {
   model_->RenameChild(item_, old_name_);
 }
 
-ProjectViewModel::AddItemCommand::AddItemCommand(ProjectViewModel* model, Item* folder, Item* child, QUndoCommand* parent) :
-  UndoCommand(parent),
+ProjectViewModel::AddItemCommand::AddItemCommand(ProjectViewModel* model, Item* folder, Item* child) :
   model_(model),
   parent_(folder),
   child_(child)
@@ -571,18 +565,17 @@ Project *ProjectViewModel::AddItemCommand::GetRelevantProject() const
   return model_->project();
 }
 
-void ProjectViewModel::AddItemCommand::redo_internal()
+void ProjectViewModel::AddItemCommand::redo()
 {
   model_->AddChild(parent_, child_);
 }
 
-void ProjectViewModel::AddItemCommand::undo_internal()
+void ProjectViewModel::AddItemCommand::undo()
 {
   model_->RemoveChild(parent_, child_, &memory_manager_);
 }
 
-ProjectViewModel::RemoveItemCommand::RemoveItemCommand(ProjectViewModel *model, Item *item, QUndoCommand *parent) :
-  UndoCommand(parent),
+ProjectViewModel::RemoveItemCommand::RemoveItemCommand(ProjectViewModel *model, Item *item) :
   model_(model),
   item_(item)
 {
@@ -599,12 +592,12 @@ Project *ProjectViewModel::RemoveItemCommand::GetRelevantProject() const
   return model_->project();
 }
 
-void ProjectViewModel::RemoveItemCommand::redo_internal()
+void ProjectViewModel::RemoveItemCommand::redo()
 {
   model_->RemoveChild(parent_, item_, &memory_manager_);
 }
 
-void ProjectViewModel::RemoveItemCommand::undo_internal()
+void ProjectViewModel::RemoveItemCommand::undo()
 {
   model_->AddChild(parent_, item_);
 }

app/project/projectviewmodel.h

@@ -110,18 +110,17 @@ public:
   QModelIndex CreateIndexFromItem(Item* item, int column = 0);
 
   /**
-   * @brief A QUndoCommand for moving an item from one folder to another folder
+   * @brief An UndoCommand for moving an item from one folder to another folder
    */
   class MoveItemCommand : public UndoCommand {
   public:
-    MoveItemCommand(ProjectViewModel* model, Item* item, Folder* destination, QUndoCommand* parent = nullptr);
+    MoveItemCommand(ProjectViewModel* model, Item* item, Folder* destination);
 
     virtual Project* GetRelevantProject() const override;
 
-  protected:
-    virtual void redo_internal() override;
+    virtual void redo() override;
 
-    virtual void undo_internal() override;
+    virtual void undo() override;
 
   private:
     ProjectViewModel* model_;
@@ -132,18 +131,17 @@ public:
   };
 
   /**
-   * @brief A QUndoCommand for renaming an item
+   * @brief An UndoCommand for renaming an item
    */
   class RenameItemCommand : public UndoCommand {
   public:
-    RenameItemCommand(ProjectViewModel* model, Item* item, const QString& name, QUndoCommand* parent = nullptr);
+    RenameItemCommand(ProjectViewModel* model, Item* item, const QString& name);
 
     virtual Project* GetRelevantProject() const override;
 
-  protected:
-    virtual void redo_internal() override;
+    virtual void redo() override;
 
-    virtual void undo_internal() override;
+    virtual void undo() override;
 
   private:
     ProjectViewModel* model_;
@@ -153,18 +151,17 @@ public:
   };
 
   /**
-   * @brief A QUndoCommand for adding an item
+   * @brief An UndoCommand for adding an item
    */
   class AddItemCommand : public UndoCommand {
   public:
-    AddItemCommand(ProjectViewModel* model, Item* folder, Item *child, QUndoCommand* parent = nullptr);
+    AddItemCommand(ProjectViewModel* model, Item* folder, Item *child);
 
     virtual Project* GetRelevantProject() const override;
 
-  protected:
-    virtual void redo_internal() override;
+    virtual void redo() override;
 
-    virtual void undo_internal() override;
+    virtual void undo() override;
 
   private:
     ProjectViewModel* model_;
@@ -179,14 +176,13 @@ public:
    */
   class RemoveItemCommand : public UndoCommand {
   public:
-    RemoveItemCommand(ProjectViewModel* model, Item* item, QUndoCommand* parent = nullptr);
+    RemoveItemCommand(ProjectViewModel* model, Item* item);
 
     virtual Project* GetRelevantProject() const override;
 
-  protected:
-    virtual void redo_internal() override;
+    virtual void redo() override;
 
-    virtual void undo_internal() override;
+    virtual void undo() override;
 
   private:
     ProjectViewModel* model_;
@@ -240,8 +236,8 @@ private:
    * This function will emit a signal indicating that rows are moving, set `destination` as the new parent of `item`,
    * and then emit a signal that the row has finished moving.
    *
-   * It's not recommended to use this function directly in most cases since it does not create a QUndoCommand allowing
-   * the user to undo the move. Instead this function should primarily be called from QUndoCommands belonging to this
+   * It's not recommended to use this function directly in most cases since it does not create an UndoCommand allowing
+   * the user to undo the move. Instead this function should primarily be called from UndoCommands belonging to this
    * class (e.g. MoveItemCommand).
    */
   void MoveItemInternal(Item* item, Item* destination);

app/task/project/import/import.cpp

@@ -50,7 +50,7 @@ const int &ProjectImportTask::GetFileCount() const
 
 bool ProjectImportTask::Run()
 {
-  command_ = new QUndoCommand();
+  command_ = new MultiUndoCommand();
 
   int imported = 0;
 
@@ -65,7 +65,7 @@ bool ProjectImportTask::Run()
   }
 }
 
-void ProjectImportTask::Import(Folder *folder, QFileInfoList import, int &counter, QUndoCommand* parent_command)
+void ProjectImportTask::Import(Folder *folder, QFileInfoList import, int &counter, MultiUndoCommand* parent_command)
 {
   for (int i=0; i<import.size(); i++) {
     if (IsCancelled()) {
@@ -100,10 +100,9 @@ void ProjectImportTask::Import(Folder *folder, QFileInfoList import, int &counte
         f->set_name(file_info.fileName());
 
         // Create undoable command that adds the items to the model
-        new ProjectViewModel::AddItemCommand(model_,
+        parent_command->add_child(new ProjectViewModel::AddItemCommand(model_,
                                                                        folder,
-                                             f,
-                                             parent_command);
+                                                                       f));
 
         // Recursively follow this path
         Import(f, entry_list, counter, parent_command);
@@ -122,10 +121,9 @@ void ProjectImportTask::Import(Folder *folder, QFileInfoList import, int &counte
         ValidateImageSequence(footage, import, i);
 
         // Create undoable command that adds the items to the model
-        new ProjectViewModel::AddItemCommand(model_,
+        parent_command->add_child(new ProjectViewModel::AddItemCommand(model_,
                                                                        folder,
-                                             footage,
-                                             parent_command);
+                                                                       footage));
       } else {
         // Add to list so we can tell the user about it later
         invalid_files_.append(file_info.absoluteFilePath());

app/task/project/import/import.h

@@ -38,7 +38,7 @@ public:
 
   const int& GetFileCount() const;
 
-  QUndoCommand* GetCommand() const
+  MultiUndoCommand* GetCommand() const
   {
     return command_;
   }
@@ -57,7 +57,7 @@ protected:
   virtual bool Run() override;
 
 private:
-  void Import(Folder* folder, QFileInfoList import, int& counter, QUndoCommand *parent_command);
+  void Import(Folder* folder, QFileInfoList import, int& counter, MultiUndoCommand *parent_command);
 
   void ValidateImageSequence(Footage *footage, QFileInfoList &info_list, int index);
 
@@ -67,7 +67,7 @@ private:
 
   static int64_t GetImageSequenceLimit(const QString &start_fn, int64_t start, bool up);
 
-  QUndoCommand* command_;
+  MultiUndoCommand* command_;
 
   ProjectViewModel* model_;
 

app/undo/undocommand.cpp

@@ -24,34 +24,38 @@
 
 namespace olive {
 
-UndoCommand::UndoCommand(QUndoCommand *parent) :
-  QUndoCommand(parent)
+void MultiUndoCommand::redo()
 {
+  for (auto it=children_.cbegin(); it!=children_.cend(); it++) {
+    (*it)->redo_and_set_modified();
+  }
 }
 
-void UndoCommand::redo()
+void MultiUndoCommand::undo()
 {
-  redo_internal();
-
-  modified_ = GetRelevantProject()->is_modified();
-  GetRelevantProject()->set_modified(true);
+  for (auto it=children_.crbegin(); it!=children_.crend(); it++) {
+    (*it)->undo_and_set_modified();
+  }
 }
 
-void UndoCommand::undo()
+void UndoCommand::redo_and_set_modified()
 {
-  undo_internal();
+  redo();
 
-  GetRelevantProject()->set_modified(modified_);
+  project_ = GetRelevantProject();
+  if (project_) {
+    modified_ = project_->is_modified();
+    project_->set_modified(true);
+  }
 }
 
-void UndoCommand::redo_internal()
+void UndoCommand::undo_and_set_modified()
 {
-  QUndoCommand::redo();
-}
+  undo();
 
-void UndoCommand::undo_internal()
-{
-  QUndoCommand::undo();
+  if (project_) {
+    project_->set_modified(modified_);
+  }
 }
 
 }

app/undo/undocommand.h

@@ -21,31 +21,83 @@
 #ifndef UNDOCOMMAND_H
 #define UNDOCOMMAND_H
 
-#include <QUndoCommand>
+#include <list>
+#include <QString>
+#include <vector>
 
 #include "common/define.h"
-#include "node/graph.h"
 
 namespace olive {
 
 class Project;
 
-class UndoCommand : public QUndoCommand
+class UndoCommand
 {
 public:
-  UndoCommand(QUndoCommand* parent = nullptr);
+  UndoCommand() = default;
+
+  virtual ~UndoCommand(){}
+
+  DISABLE_COPY_MOVE(UndoCommand)
+
+  virtual void redo() = 0;
+  virtual void undo() = 0;
+
+  void redo_and_set_modified();
+
+  void undo_and_set_modified();
+
+  virtual Project* GetRelevantProject() const = 0;
+
+  const QString& name() const
+  {
+    return name_;
+  }
+
+  void set_name(const QString& name)
+  {
+    name_ = name;
+  }
+
+private:
+  bool modified_;
+
+  QString name_;
+
+  Project* project_;
+
+};
+
+class MultiUndoCommand : public UndoCommand
+{
+public:
+  MultiUndoCommand() = default;
 
   virtual void redo() override;
   virtual void undo() override;
 
-  virtual Project* GetRelevantProject() const = 0;
+  virtual Project* GetRelevantProject() const override
+  {
+    return nullptr;
+  }
 
-protected:
-  virtual void redo_internal();
-  virtual void undo_internal();
+  void add_child(UndoCommand* command)
+  {
+    children_.push_back(command);
+  }
+
+  int child_count() const
+  {
+    return children_.size();
+  }
+
+  UndoCommand* child(int i) const
+  {
+    return children_[i];
+  }
 
 private:
-  bool modified_;
+  std::vector<UndoCommand*> children_;
 
 };
 

app/undo/undostack.cpp

@@ -20,15 +20,109 @@
 
 #include "undostack.h"
 
+#include <QCoreApplication>
+
 namespace olive {
 
-void UndoStack::pushIfHasChildren(QUndoCommand *command)
+const int UndoStack::kMaxUndoCommands = 200;
+
+UndoStack::UndoStack()
 {
-  if (command->childCount() > 0) {
+  undo_action_ = new QAction();
+  connect(undo_action_, &QAction::triggered, this, &UndoStack::undo);
+
+  redo_action_ = new QAction();
+  connect(redo_action_, &QAction::triggered, this, &UndoStack::redo);
+
+  UpdateActions();
+}
+
+UndoStack::~UndoStack()
+{
+  clear();
+
+  delete undo_action_;
+  delete redo_action_;
+}
+
+void UndoStack::pushIfHasChildren(MultiUndoCommand *command)
+{
+  if (command->child_count() > 0) {
     push(command);
   } else {
     delete command;
   }
 }
 
+void UndoStack::push(UndoCommand *command)
+{
+  command->redo_and_set_modified();
+  commands_.push_back(command);
+
+  if (commands_.size() > kMaxUndoCommands) {
+    delete commands_.front();
+    commands_.pop_front();
+  }
+
+  if (CanRedo()) {
+    for (auto it=undone_commands_.cbegin(); it!=undone_commands_.cend(); it++) {
+      delete (*it);
+    }
+    undone_commands_.clear();
+  }
+
+  UpdateActions();
+}
+
+void UndoStack::undo()
+{
+  if (CanUndo()) {
+    // Undo most recently done command
+    commands_.back()->undo_and_set_modified();
+
+    // Place at the front of the "undone commands" list
+    undone_commands_.push_front(commands_.back());
+
+    // Remove undone command from the commands list
+    commands_.pop_back();
+
+    // Update actions
+    UpdateActions();
+  }
+}
+
+void UndoStack::redo()
+{
+  if (CanRedo()) {
+    // Redo most recently undone command
+    undone_commands_.front()->redo_and_set_modified();
+
+    // Place at the back of the done commands list
+    commands_.push_back(undone_commands_.front());
+
+    // Remove done command from undone list
+    undone_commands_.pop_front();
+
+    // Update actions
+    UpdateActions();
+  }
+}
+
+void UndoStack::clear()
+{
+  for (auto it=commands_.cbegin(); it!=commands_.cend(); it++) {
+    delete (*it);
+  }
+  commands_.clear();
+}
+
+void UndoStack::UpdateActions()
+{
+  undo_action_->setEnabled(CanUndo());
+  redo_action_->setEnabled(CanRedo());
+
+  undo_action_->setText(QCoreApplication::translate("UndoStack", "Undo %1").arg(CanUndo() ? commands_.back()->name() : QString()));
+  redo_action_->setText(QCoreApplication::translate("UndoStack", "Redo %1").arg(CanRedo() ? undone_commands_.front()->name() : QString()));
+}
+
 }

app/undo/undostack.h

@@ -21,20 +21,70 @@
 #ifndef UNDOSTACK_H
 #define UNDOSTACK_H
 
-#include <QUndoStack>
+#include <QAction>
 
 #include "common/define.h"
+#include "undo/undocommand.h"
 
 namespace olive {
 
-class UndoStack : public QUndoStack {
+class UndoStack : public QObject
+{
+  Q_OBJECT
 public:
+  UndoStack();
+
+  virtual ~UndoStack() override;
+
   /**
    * @brief A wrapper for push() that either pushes if the command has children or deletes if not
    *
    * This function takes ownership of `command`, and may delete it so it should never be accessed after this call.
    */
-  void pushIfHasChildren(QUndoCommand* command);
+  void pushIfHasChildren(MultiUndoCommand* command);
+
+  void push(UndoCommand* command);
+
+  void clear();
+
+  bool CanUndo() const
+  {
+    return !commands_.empty();
+  }
+
+  bool CanRedo() const
+  {
+    return !undone_commands_.empty();
+  }
+
+  void UpdateActions();
+
+  QAction* GetUndoAction()
+  {
+    return undo_action_;
+  }
+
+  QAction* GetRedoAction()
+  {
+    return redo_action_;
+  }
+
+public slots:
+  void undo();
+
+  void redo();
+
+private:
+  static const int kMaxUndoCommands;
+
+  std::list<UndoCommand*> commands_;
+
+  std::list<UndoCommand*> undone_commands_;
+
+  QAction* undo_action_;
+
+  QAction* redo_action_;
+
 };
 
 }

app/widget/curvewidget/curvewidget.cpp

@@ -336,12 +336,12 @@ void CurveWidget::KeyframeTypeButtonTriggered(bool checked)
   // Ensure only the appropriate button is checked
   SetKeyframeButtonCheckedFromType(new_type);
 
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   foreach (QGraphicsItem* item, selected) {
     KeyframeViewItem* key_item = static_cast<KeyframeViewItem*>(item);
 
-    new KeyframeSetTypeCommand(key_item->key(), new_type, command);
+    command->add_child(new KeyframeSetTypeCommand(key_item->key(), new_type));
   }
 
   Core::instance()->undo_stack()->push(command);

app/widget/keyframeview/keyframeviewbase.cpp

@@ -59,13 +59,13 @@ void KeyframeViewBase::Clear()
 
 void KeyframeViewBase::DeleteSelected()
 {
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   QMap<NodeKeyframe*, KeyframeViewItem*>::const_iterator i;
 
   for (i=item_map_.constBegin(); i!=item_map_.constEnd(); i++) {
     if (i.value()->isSelected()) {
-      new NodeParamRemoveKeyframeCommand(i.key(), command);
+      command->add_child(new NodeParamRemoveKeyframeCommand(i.key()));
     }
   }
 
@@ -307,46 +307,42 @@ void KeyframeViewBase::mouseReleaseEvent(QMouseEvent *event)
 
     if (dragging_) {
       if (dragging_bezier_point_) {
-        QUndoCommand* command = new QUndoCommand();
+        MultiUndoCommand* command = new MultiUndoCommand();
 
         // Create undo command with the current bezier point and the old one
-        new KeyframeSetBezierControlPoint(dragging_bezier_point_->key(),
+        command->add_child(new KeyframeSetBezierControlPoint(dragging_bezier_point_->key(),
                                                              dragging_bezier_point_->mode(),
                                                              dragging_bezier_point_->key()->bezier_control(dragging_bezier_point_->mode()),
-                                          dragging_bezier_point_start_,
-                                          command);
+                                                             dragging_bezier_point_start_));
 
         if (!(event->modifiers() & Qt::ControlModifier)) {
           auto opposing_type = NodeKeyframe::get_opposing_bezier_type(dragging_bezier_point_->mode());
 
-          new KeyframeSetBezierControlPoint(dragging_bezier_point_->key(),
+          command->add_child(new KeyframeSetBezierControlPoint(dragging_bezier_point_->key(),
                                                                opposing_type,
                                                                dragging_bezier_point_->key()->bezier_control(opposing_type),
-                                            dragging_bezier_point_opposing_start_,
-                                            command);
+                                                               dragging_bezier_point_opposing_start_));
         }
 
         dragging_bezier_point_ = nullptr;
 
         Core::instance()->undo_stack()->push(command);
       } else if (!selected_keys_.isEmpty()) {
-        QUndoCommand* command = new QUndoCommand();
+        MultiUndoCommand* command = new MultiUndoCommand();
 
         foreach (const KeyframeItemAndTime& keypair, selected_keys_) {
           NodeKeyframe* item = keypair.key->key();
 
           // Commit movement
-          new NodeParamSetKeyframeTimeCommand(item,
+          command->add_child(new NodeParamSetKeyframeTimeCommand(item,
                                                                  item->time(),
-                                              keypair.time,
-                                              command);
+                                                                 keypair.time));
 
           // Commit value if we're setting a value
           if (IsYAxisEnabled()) {
-            new NodeParamSetKeyframeValueCommand(item,
+            command->add_child(new NodeParamSetKeyframeValueCommand(item,
                                                                     item->value(),
-                                                 keypair.value,
-                                                 command);
+                                                                    keypair.value));
           }
         }
 
@@ -497,11 +493,10 @@ void KeyframeViewBase::ShowContextMenu()
         new_type = NodeKeyframe::kLinear;
       }
 
-      QUndoCommand* command = new QUndoCommand();
+      MultiUndoCommand* command = new MultiUndoCommand();
       foreach (QGraphicsItem* item, items) {
-        new KeyframeSetTypeCommand(static_cast<KeyframeViewItem*>(item)->key(),
-                                   new_type,
-                                   command);
+        command->add_child(new KeyframeSetTypeCommand(static_cast<KeyframeViewItem*>(item)->key(),
+                                                      new_type));
       }
       Core::instance()->undo_stack()->pushIfHasChildren(command);
     }

app/widget/keyframeview/keyframeviewundo.cpp

@@ -26,8 +26,7 @@
 
 namespace olive {
 
-KeyframeSetTypeCommand::KeyframeSetTypeCommand(NodeKeyframe* key, NodeKeyframe::Type type, QUndoCommand *parent) :
-  UndoCommand(parent),
+KeyframeSetTypeCommand::KeyframeSetTypeCommand(NodeKeyframe* key, NodeKeyframe::Type type) :
   key_(key),
   old_type_(key->type()),
   new_type_(type)
@@ -39,18 +38,17 @@ Project *KeyframeSetTypeCommand::GetRelevantProject() const
   return key_->parent()->parent()->parent()->project();
 }
 
-void KeyframeSetTypeCommand::redo_internal()
+void KeyframeSetTypeCommand::redo()
 {
   key_->set_type(new_type_);
 }
 
-void KeyframeSetTypeCommand::undo_internal()
+void KeyframeSetTypeCommand::undo()
 {
   key_->set_type(old_type_);
 }
 
-KeyframeSetBezierControlPoint::KeyframeSetBezierControlPoint(NodeKeyframe* key, NodeKeyframe::BezierType mode, const QPointF& point, QUndoCommand *parent) :
-  UndoCommand(parent),
+KeyframeSetBezierControlPoint::KeyframeSetBezierControlPoint(NodeKeyframe* key, NodeKeyframe::BezierType mode, const QPointF& point) :
   key_(key),
   mode_(mode),
   old_point_(key->bezier_control(mode_)),
@@ -58,8 +56,7 @@ KeyframeSetBezierControlPoint::KeyframeSetBezierControlPoint(NodeKeyframe* key,
 {
 }
 
-KeyframeSetBezierControlPoint::KeyframeSetBezierControlPoint(NodeKeyframe* key, NodeKeyframe::BezierType mode, const QPointF &new_point, const QPointF &old_point, QUndoCommand *parent) :
-  UndoCommand(parent),
+KeyframeSetBezierControlPoint::KeyframeSetBezierControlPoint(NodeKeyframe* key, NodeKeyframe::BezierType mode, const QPointF &new_point, const QPointF &old_point) :
   key_(key),
   mode_(mode),
   old_point_(old_point),
@@ -72,12 +69,12 @@ Project *KeyframeSetBezierControlPoint::GetRelevantProject() const
   return key_->parent()->parent()->parent()->project();
 }
 
-void KeyframeSetBezierControlPoint::redo_internal()
+void KeyframeSetBezierControlPoint::redo()
 {
   key_->set_bezier_control(mode_, new_point_);
 }
 
-void KeyframeSetBezierControlPoint::undo_internal()
+void KeyframeSetBezierControlPoint::undo()
 {
   key_->set_bezier_control(mode_, old_point_);
 }

app/widget/keyframeview/keyframeviewundo.h

@@ -28,13 +28,12 @@ namespace olive {
 
 class KeyframeSetTypeCommand : public UndoCommand {
 public:
-  KeyframeSetTypeCommand(NodeKeyframe* key, NodeKeyframe::Type type, QUndoCommand* parent = nullptr);
+  KeyframeSetTypeCommand(NodeKeyframe* key, NodeKeyframe::Type type);
 
   virtual Project* GetRelevantProject() const override;
 
-protected:
-  virtual void redo_internal() override;
-  virtual void undo_internal() override;
+  virtual void redo() override;
+  virtual void undo() override;
 
 private:
   NodeKeyframe* key_;
@@ -47,14 +46,13 @@ private:
 
 class KeyframeSetBezierControlPoint : public UndoCommand {
 public:
-  KeyframeSetBezierControlPoint(NodeKeyframe* key, NodeKeyframe::BezierType mode, const QPointF& point, QUndoCommand* parent = nullptr);
-  KeyframeSetBezierControlPoint(NodeKeyframe* key, NodeKeyframe::BezierType mode, const QPointF& new_point, const QPointF& old_point, QUndoCommand* parent = nullptr);
+  KeyframeSetBezierControlPoint(NodeKeyframe* key, NodeKeyframe::BezierType mode, const QPointF& point);
+  KeyframeSetBezierControlPoint(NodeKeyframe* key, NodeKeyframe::BezierType mode, const QPointF& new_point, const QPointF& old_point);
 
   virtual Project* GetRelevantProject() const override;
 
-protected:
-  virtual void redo_internal() override;
-  virtual void undo_internal() override;
+  virtual void redo() override;
+  virtual void undo() override;
 
 private:
   NodeKeyframe* key_;

app/widget/menu/menushared.cpp

@@ -118,8 +118,8 @@ void MenuShared::AddItemsForNewMenu(Menu *m)
 
 void MenuShared::AddItemsForEditMenu(Menu *m, bool for_clips)
 {
-  m->addAction(Core::instance()->undo_stack()->createUndoAction(m));
-  m->addAction(Core::instance()->undo_stack()->createRedoAction(m));
+  m->addAction(Core::instance()->undo_stack()->GetUndoAction());
+  m->addAction(Core::instance()->undo_stack()->GetRedoAction());
 
   m->addSeparator();
 

app/widget/nodeparamview/nodeparamviewarraywidget.cpp

@@ -38,6 +38,13 @@ NodeParamViewArrayWidget::NodeParamViewArrayWidget(NodeInput *array, QWidget* pa
   UpdateCounter();
 }
 
+void NodeParamViewArrayWidget::mouseDoubleClickEvent(QMouseEvent *event)
+{
+  QWidget::mouseDoubleClickEvent(event);
+
+  emit DoubleClicked();
+}
+
 void NodeParamViewArrayWidget::UpdateCounter()
 {
   count_lbl_->setText(tr("%1 element(s)").arg(array_->ArraySize()));

app/widget/nodeparamview/nodeparamviewarraywidget.h

@@ -56,6 +56,12 @@ class NodeParamViewArrayWidget : public QWidget
 public:
   NodeParamViewArrayWidget(NodeInput* array, QWidget* parent = nullptr);
 
+signals:
+  void DoubleClicked();
+
+protected:
+  virtual void mouseDoubleClickEvent(QMouseEvent* event) override;
+
 private:
   NodeInput* array_;
 

app/widget/nodeparamview/nodeparamviewitem.cpp

@@ -258,15 +258,14 @@ void NodeParamViewItemBody::CreateWidgets(QGridLayout* layout, NodeInput *input,
       // Default to collapsed
       array_collapse_btn->setChecked(false);
 
-      // Add data
-      array_collapse_btn->setProperty("input", Node::PtrToValue(input));
-
       // Collapse button always goes into column 0
       layout->addWidget(array_collapse_btn, row, 0);
 
       // Connect signal to show/hide array params when toggled
       connect(array_collapse_btn, &CollapseButton::toggled, this, &NodeParamViewItemBody::ArrayCollapseBtnPressed);
 
+      array_collapse_buttons_.insert(input, array_collapse_btn);
+
     } else {
 
       NodeParamViewArrayButton* insert_element_btn = new NodeParamViewArrayButton(NodeParamViewArrayButton::kAdd);
@@ -286,6 +285,7 @@ void NodeParamViewItemBody::CreateWidgets(QGridLayout* layout, NodeInput *input,
 
   // Create a widget/input bridge for this input
   ui_objects.widget_bridge = new NodeParamViewWidgetBridge(input, element, this);
+  connect(ui_objects.widget_bridge, &NodeParamViewWidgetBridge::ArrayWidgetDoubleClicked, this, &NodeParamViewItemBody::ToggleArrayExpanded);
 
   // 0 is for the array collapse button, 1 is for the main label, widgets start at 2
   const int widget_start = 2;
@@ -372,7 +372,7 @@ void NodeParamViewItemBody::SignalAllKeyframes()
 
     foreach (const NodeKeyframeTrack& track, input->GetKeyframeTracks(i.key().element)) {
       foreach (NodeKeyframe* key, track) {
-        InputAddedKeyframeInternal(input, key);
+        InputAddedKeyframeInternal(input, i.key().element, key);
       }
     }
   }
@@ -406,7 +406,7 @@ void NodeParamViewItemBody::InputKeyframeEnableChanged(bool e, int element)
     foreach (NodeKeyframe* key, track) {
       if (e) {
         // Add a keyframe item for each keyframe
-        InputAddedKeyframeInternal(input, key);
+        InputAddedKeyframeInternal(input, element, key);
       } else {
         // Remove each keyframe item
         emit KeyframeRemoved(key);
@@ -420,13 +420,13 @@ void NodeParamViewItemBody::InputAddedKeyframe(NodeKeyframe* key)
   // Get NodeInput that emitted this signal
   NodeInput* input = static_cast<NodeInput*>(sender());
 
-  InputAddedKeyframeInternal(input, key);
+  InputAddedKeyframeInternal(input, key->element(), key);
 }
 
-void NodeParamViewItemBody::InputAddedKeyframeInternal(NodeInput *input, NodeKeyframe* keyframe)
+void NodeParamViewItemBody::InputAddedKeyframeInternal(NodeInput *input, int element, NodeKeyframe* keyframe)
 {
   // Find its row in the parameters
-  QLabel* lbl = input_ui_map_.value(input).main_label;
+  QLabel* lbl = input_ui_map_.value({input, element}).main_label;
 
   // Find label's Y position
   QPoint lbl_center = lbl->rect().center();
@@ -439,7 +439,7 @@ void NodeParamViewItemBody::InputAddedKeyframeInternal(NodeInput *input, NodeKey
 
 void NodeParamViewItemBody::ArrayCollapseBtnPressed(bool checked)
 {
-  NodeInput* input = Node::ValueToPtr<NodeInput>(sender()->property("input"));
+  NodeInput* input = array_collapse_buttons_.key(static_cast<CollapseButton*>(sender()));
 
   array_ui_.value(input).widget->setVisible(checked);
 }
@@ -486,7 +486,7 @@ void NodeParamViewItemBody::ArrayAppendClicked()
 {
   for (auto it=array_ui_.cbegin(); it!=array_ui_.cend(); it++) {
     if (it.value().append_btn == sender()) {
-      it.key()->ArrayAppend();
+      it.key()->ArrayAppend(true);
       break;
     }
   }
@@ -498,7 +498,7 @@ void NodeParamViewItemBody::ArrayInsertClicked()
     if (it.value().array_insert_btn == sender()) {
       // Found our input and element
       const Node::InputConnection& ic = it.key();
-      ic.input->ArrayInsert(ic.element);
+      ic.input->ArrayInsert(ic.element, true);
       break;
     }
   }
@@ -510,12 +510,25 @@ void NodeParamViewItemBody::ArrayRemoveClicked()
     if (it.value().array_remove_btn == sender()) {
       // Found our input and element
       const Node::InputConnection& ic = it.key();
-      ic.input->ArrayRemove(ic.element);
+      ic.input->ArrayRemove(ic.element, true);
       break;
     }
   }
 }
 
+void NodeParamViewItemBody::ToggleArrayExpanded()
+{
+  NodeParamViewWidgetBridge* bridge = static_cast<NodeParamViewWidgetBridge*>(sender());
+
+  for (auto it=input_ui_map_.cbegin(); it!=input_ui_map_.cend(); it++) {
+    if (it.value().widget_bridge == bridge) {
+      CollapseButton* b = array_collapse_buttons_.value(it.key().input);
+      b->setChecked(!b->isChecked());
+      return;
+    }
+  }
+}
+
 NodeParamViewItemBody::InputUI::InputUI() :
   main_label(nullptr),
   widget_bridge(nullptr),

app/widget/nodeparamview/nodeparamviewitem.h

@@ -97,7 +97,7 @@ private:
 
   void UpdateUIForEdgeConnection(NodeInput* input, int element);
 
-  void InputAddedKeyframeInternal(NodeInput* input, NodeKeyframe* keyframe);
+  void InputAddedKeyframeInternal(NodeInput* input, int element, NodeKeyframe* keyframe);
 
   struct InputUI {
     InputUI();
@@ -121,6 +121,8 @@ private:
 
   QHash<NodeInput*, ArrayUI> array_ui_;
 
+  QHash<NodeInput*, CollapseButton*> array_collapse_buttons_;
+
   /**
    * @brief The column to place the keyframe controls in
    *
@@ -149,6 +151,8 @@ private slots:
 
   void ArrayRemoveClicked();
 
+  void ToggleArrayExpanded();
+
 };
 
 class NodeParamViewItem : public QDockWidget

app/widget/nodeparamview/nodeparamviewkeyframecontrol.cpp

@@ -145,7 +145,7 @@ void NodeParamViewKeyframeControl::ToggleKeyframe(bool e)
 
   QVector<NodeKeyframe*> keys = input_->GetKeyframesAtTime(node_time, element_);
 
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   int nb_tracks = input_->GetNumberOfKeyframeTracks();
 
@@ -158,20 +158,19 @@ void NodeParamViewKeyframeControl::ToggleKeyframe(bool e)
                                            i,
                                            element_);
 
-      new NodeParamInsertKeyframeCommand(input_, key, command);
+      command->add_child(new NodeParamInsertKeyframeCommand(input_, key));
     }
   } else if (!e && !keys.isEmpty()) {
     // Remove all keyframes at this time
     foreach (NodeKeyframe* key, keys) {
-      new NodeParamRemoveKeyframeCommand(key, command);
+      command->add_child(new NodeParamRemoveKeyframeCommand(key));
 
       if (input_->GetKeyframeTracks(key->track()).size() == 1) {
         // If this was the last keyframe on this track, set the standard value to the value at this time too
-        new NodeParamSetStandardValueCommand(input_,
+        command->add_child(new NodeParamSetStandardValueCommand(input_,
                                                                 key->track(),
                                                                 element_,
-                                             input_->GetValueAtTimeForTrack(node_time, key->track(), element_),
-                                             command);
+                                                                input_->GetValueAtTimeForTrack(node_time, key->track(), element_)));
       }
     }
   }
@@ -228,11 +227,11 @@ void NodeParamViewKeyframeControl::KeyframeEnableChanged(bool e)
     return;
   }
 
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   if (e) {
     // Enable keyframing
-    new NodeParamSetKeyframingCommand(input_, element_, true, command);
+    command->add_child(new NodeParamSetKeyframingCommand(input_, element_, true));
 
     // Create one keyframe across all tracks here
     const QVector<QVariant>& key_vals = input_->GetSplitStandardValue(element_);
@@ -244,7 +243,7 @@ void NodeParamViewKeyframeControl::KeyframeEnableChanged(bool e)
                                            i,
                                            element_);
 
-      new NodeParamInsertKeyframeCommand(input_, key, command);
+      command->add_child(new NodeParamInsertKeyframeCommand(input_, key));
     }
   } else {
     // Confirm the user wants to clear all keyframes
@@ -259,17 +258,17 @@ void NodeParamViewKeyframeControl::KeyframeEnableChanged(bool e)
       // Delete all keyframes
       foreach (const NodeKeyframeTrack& track, input_->GetKeyframeTracks(element_)) {
         for (int i=track.size()-1;i>=0;i--) {
-          new NodeParamRemoveKeyframeCommand(track.at(i), command);
+          command->add_child(new NodeParamRemoveKeyframeCommand(track.at(i)));
         }
       }
 
       // Update standard value
       for (int i=0;i<stored_vals.size();i++) {
-        new NodeParamSetStandardValueCommand(input_, i, element_, stored_vals.at(i), command);
+        command->add_child(new NodeParamSetStandardValueCommand(input_, i, element_, stored_vals.at(i)));
       }
 
       // Disable keyframing
-      new NodeParamSetKeyframingCommand(input_, element_, false, command);
+      command->add_child(new NodeParamSetKeyframingCommand(input_, element_, false));
 
     } else {
       // Disable action has effectively been ignored

app/widget/nodeparamview/nodeparamviewundo.cpp

@@ -25,8 +25,7 @@
 
 namespace olive {
 
-NodeParamSetKeyframingCommand::NodeParamSetKeyframingCommand(NodeInput *input, int element, bool setting, QUndoCommand *parent) :
-  UndoCommand(parent),
+NodeParamSetKeyframingCommand::NodeParamSetKeyframingCommand(NodeInput *input, int element, bool setting) :
   input_(input),
   setting_(setting),
   element_(element)
@@ -39,26 +38,24 @@ Project *NodeParamSetKeyframingCommand::GetRelevantProject() const
   return input_->parent()->parent()->project();
 }
 
-void NodeParamSetKeyframingCommand::redo_internal()
+void NodeParamSetKeyframingCommand::redo()
 {
   input_->SetIsKeyframing(setting_, element_);
 }
 
-void NodeParamSetKeyframingCommand::undo_internal()
+void NodeParamSetKeyframingCommand::undo()
 {
   input_->SetIsKeyframing(!setting_, element_);
 }
 
-NodeParamSetKeyframeValueCommand::NodeParamSetKeyframeValueCommand(NodeKeyframe* key, const QVariant& value, QUndoCommand* parent) :
-  UndoCommand(parent),
+NodeParamSetKeyframeValueCommand::NodeParamSetKeyframeValueCommand(NodeKeyframe* key, const QVariant& value) :
   key_(key),
   old_value_(key_->value()),
   new_value_(value)
 {
 }
 
-NodeParamSetKeyframeValueCommand::NodeParamSetKeyframeValueCommand(NodeKeyframe* key, const QVariant &new_value, const QVariant &old_value, QUndoCommand *parent) :
-  UndoCommand(parent),
+NodeParamSetKeyframeValueCommand::NodeParamSetKeyframeValueCommand(NodeKeyframe* key, const QVariant &new_value, const QVariant &old_value) :
   key_(key),
   old_value_(old_value),
   new_value_(new_value)
@@ -71,18 +68,17 @@ Project *NodeParamSetKeyframeValueCommand::GetRelevantProject() const
   return key_->parent()->parent()->parent()->project();
 }
 
-void NodeParamSetKeyframeValueCommand::redo_internal()
+void NodeParamSetKeyframeValueCommand::redo()
 {
   key_->set_value(new_value_);
 }
 
-void NodeParamSetKeyframeValueCommand::undo_internal()
+void NodeParamSetKeyframeValueCommand::undo()
 {
   key_->set_value(old_value_);
 }
 
-NodeParamInsertKeyframeCommand::NodeParamInsertKeyframeCommand(NodeInput *input, NodeKeyframe* keyframe, QUndoCommand* parent) :
-  UndoCommand(parent),
+NodeParamInsertKeyframeCommand::NodeParamInsertKeyframeCommand(NodeInput *input, NodeKeyframe* keyframe) :
   input_(input),
   keyframe_(keyframe)
 {
@@ -94,18 +90,17 @@ Project *NodeParamInsertKeyframeCommand::GetRelevantProject() const
   return input_->parent()->parent()->project();
 }
 
-void NodeParamInsertKeyframeCommand::redo_internal()
+void NodeParamInsertKeyframeCommand::redo()
 {
   keyframe_->setParent(input_);
 }
 
-void NodeParamInsertKeyframeCommand::undo_internal()
+void NodeParamInsertKeyframeCommand::undo()
 {
   keyframe_->setParent(&memory_manager_);
 }
 
-NodeParamRemoveKeyframeCommand::NodeParamRemoveKeyframeCommand(NodeKeyframe* keyframe, QUndoCommand *parent) :
-  UndoCommand(parent),
+NodeParamRemoveKeyframeCommand::NodeParamRemoveKeyframeCommand(NodeKeyframe* keyframe) :
   input_(keyframe->parent()),
   keyframe_(keyframe)
 {
@@ -116,27 +111,25 @@ Project *NodeParamRemoveKeyframeCommand::GetRelevantProject() const
   return input_->parent()->parent()->project();
 }
 
-void NodeParamRemoveKeyframeCommand::redo_internal()
+void NodeParamRemoveKeyframeCommand::redo()
 {
   // Removes from input
   keyframe_->setParent(&memory_manager_);
 }
 
-void NodeParamRemoveKeyframeCommand::undo_internal()
+void NodeParamRemoveKeyframeCommand::undo()
 {
   keyframe_->setParent(input_);
 }
 
-NodeParamSetKeyframeTimeCommand::NodeParamSetKeyframeTimeCommand(NodeKeyframe* key, const rational &time, QUndoCommand *parent) :
-  UndoCommand(parent),
+NodeParamSetKeyframeTimeCommand::NodeParamSetKeyframeTimeCommand(NodeKeyframe* key, const rational &time) :
   key_(key),
   old_time_(key->time()),
   new_time_(time)
 {
 }
 
-NodeParamSetKeyframeTimeCommand::NodeParamSetKeyframeTimeCommand(NodeKeyframe* key, const rational &new_time, const rational &old_time, QUndoCommand *parent) :
-  UndoCommand(parent),
+NodeParamSetKeyframeTimeCommand::NodeParamSetKeyframeTimeCommand(NodeKeyframe* key, const rational &new_time, const rational &old_time) :
   key_(key),
   old_time_(old_time),
   new_time_(new_time)
@@ -148,18 +141,17 @@ Project *NodeParamSetKeyframeTimeCommand::GetRelevantProject() const
   return key_->parent()->parent()->parent()->project();
 }
 
-void NodeParamSetKeyframeTimeCommand::redo_internal()
+void NodeParamSetKeyframeTimeCommand::redo()
 {
   key_->set_time(new_time_);
 }
 
-void NodeParamSetKeyframeTimeCommand::undo_internal()
+void NodeParamSetKeyframeTimeCommand::undo()
 {
   key_->set_time(old_time_);
 }
 
-NodeParamSetStandardValueCommand::NodeParamSetStandardValueCommand(NodeInput *input, int track, int element, const QVariant &value, QUndoCommand *parent) :
-  UndoCommand(parent),
+NodeParamSetStandardValueCommand::NodeParamSetStandardValueCommand(NodeInput *input, int track, int element, const QVariant &value) :
   input_(input),
   element_(element),
   track_(track),
@@ -168,8 +160,7 @@ NodeParamSetStandardValueCommand::NodeParamSetStandardValueCommand(NodeInput *in
 {
 }
 
-NodeParamSetStandardValueCommand::NodeParamSetStandardValueCommand(NodeInput *input, int track, int element, const QVariant &new_value, const QVariant &old_value, QUndoCommand *parent) :
-  UndoCommand(parent),
+NodeParamSetStandardValueCommand::NodeParamSetStandardValueCommand(NodeInput *input, int track, int element, const QVariant &new_value, const QVariant &old_value) :
   input_(input),
   element_(element),
   track_(track),
@@ -183,14 +174,19 @@ Project *NodeParamSetStandardValueCommand::GetRelevantProject() const
   return input_->parent()->parent()->project();
 }
 
-void NodeParamSetStandardValueCommand::redo_internal()
+void NodeParamSetStandardValueCommand::redo()
 {
   input_->SetStandardValueOnTrack(new_value_, track_, element_);
 }
 
-void NodeParamSetStandardValueCommand::undo_internal()
+void NodeParamSetStandardValueCommand::undo()
 {
   input_->SetStandardValueOnTrack(old_value_, track_, element_);
 }
 
+Project *NodeParamArrayInsertCommand::GetRelevantProject() const
+{
+  return input_->parent()->parent()->project();
+}
+
 }

app/widget/nodeparamview/nodeparamviewundo.h

@@ -26,15 +26,15 @@
 
 namespace olive {
 
-class NodeParamSetKeyframingCommand : public UndoCommand {
+class NodeParamSetKeyframingCommand : public UndoCommand
+{
 public:
-  NodeParamSetKeyframingCommand(NodeInput* input, int element, bool setting, QUndoCommand* parent = nullptr);
+  NodeParamSetKeyframingCommand(NodeInput* input, int element, bool setting);
 
   virtual Project* GetRelevantProject() const override;
 
-protected:
-  virtual void redo_internal() override;
-  virtual void undo_internal() override;
+  virtual void redo() override;
+  virtual void undo() override;
 
 private:
   NodeInput* input_;
@@ -43,15 +43,15 @@ private:
 
 };
 
-class NodeParamInsertKeyframeCommand : public UndoCommand {
+class NodeParamInsertKeyframeCommand : public UndoCommand
+{
 public:
-  NodeParamInsertKeyframeCommand(NodeInput* input, NodeKeyframe* keyframe, QUndoCommand *parent = nullptr);
+  NodeParamInsertKeyframeCommand(NodeInput* input, NodeKeyframe* keyframe);
 
   virtual Project* GetRelevantProject() const override;
 
-protected:
-  virtual void redo_internal() override;
-  virtual void undo_internal() override;
+  virtual void redo() override;
+  virtual void undo() override;
 
 private:
   NodeInput* input_;
@@ -62,15 +62,15 @@ private:
 
 };
 
-class NodeParamRemoveKeyframeCommand : public UndoCommand {
+class NodeParamRemoveKeyframeCommand : public UndoCommand
+{
 public:
-  NodeParamRemoveKeyframeCommand(NodeKeyframe* keyframe, QUndoCommand *parent = nullptr);
+  NodeParamRemoveKeyframeCommand(NodeKeyframe* keyframe);
 
   virtual Project* GetRelevantProject() const override;
 
-protected:
-  virtual void redo_internal() override;
-  virtual void undo_internal() override;
+  virtual void redo() override;
+  virtual void undo() override;
 
 private:
   NodeInput* input_;
@@ -81,16 +81,16 @@ private:
 
 };
 
-class NodeParamSetKeyframeTimeCommand : public UndoCommand {
+class NodeParamSetKeyframeTimeCommand : public UndoCommand
+{
 public:
-  NodeParamSetKeyframeTimeCommand(NodeKeyframe* key, const rational& time, QUndoCommand* parent = nullptr);
-  NodeParamSetKeyframeTimeCommand(NodeKeyframe* key, const rational& new_time, const rational& old_time, QUndoCommand* parent = nullptr);
+  NodeParamSetKeyframeTimeCommand(NodeKeyframe* key, const rational& time);
+  NodeParamSetKeyframeTimeCommand(NodeKeyframe* key, const rational& new_time, const rational& old_time);
 
   virtual Project* GetRelevantProject() const override;
 
-protected:
-  virtual void redo_internal() override;
-  virtual void undo_internal() override;
+  virtual void redo() override;
+  virtual void undo() override;
 
 private:
   NodeKeyframe* key_;
@@ -100,16 +100,16 @@ private:
 
 };
 
-class NodeParamSetKeyframeValueCommand : public UndoCommand {
+class NodeParamSetKeyframeValueCommand : public UndoCommand
+{
 public:
-  NodeParamSetKeyframeValueCommand(NodeKeyframe* key, const QVariant& value, QUndoCommand* parent = nullptr);
-  NodeParamSetKeyframeValueCommand(NodeKeyframe* key, const QVariant& new_value, const QVariant& old_value, QUndoCommand* parent = nullptr);
+  NodeParamSetKeyframeValueCommand(NodeKeyframe* key, const QVariant& value);
+  NodeParamSetKeyframeValueCommand(NodeKeyframe* key, const QVariant& new_value, const QVariant& old_value);
 
   virtual Project* GetRelevantProject() const override;
 
-protected:
-  virtual void redo_internal() override;
-  virtual void undo_internal() override;
+  virtual void redo() override;
+  virtual void undo() override;
 
 private:
   NodeKeyframe* key_;
@@ -119,16 +119,16 @@ private:
 
 };
 
-class NodeParamSetStandardValueCommand : public UndoCommand {
+class NodeParamSetStandardValueCommand : public UndoCommand
+{
 public:
-  NodeParamSetStandardValueCommand(NodeInput* input, int track, int element, const QVariant& value, QUndoCommand* parent = nullptr);
-  NodeParamSetStandardValueCommand(NodeInput* input, int track, int element, const QVariant& new_value, const QVariant& old_value, QUndoCommand* parent = nullptr);
+  NodeParamSetStandardValueCommand(NodeInput* input, int track, int element, const QVariant& value);
+  NodeParamSetStandardValueCommand(NodeInput* input, int track, int element, const QVariant& new_value, const QVariant& old_value);
 
   virtual Project* GetRelevantProject() const override;
 
-protected:
-  virtual void redo_internal() override;
-  virtual void undo_internal() override;
+  virtual void redo() override;
+  virtual void undo() override;
 
 private:
   NodeInput* input_;
@@ -140,6 +140,33 @@ private:
 
 };
 
+class NodeParamArrayInsertCommand : public UndoCommand
+{
+public:
+  NodeParamArrayInsertCommand(NodeInput* input, int index) :
+    input_(input),
+    index_(index)
+  {
+  }
+
+  virtual Project* GetRelevantProject() const override;
+
+  virtual void redo() override
+  {
+    input_->ArrayInsert(index_);
+  }
+
+  virtual void undo() override
+  {
+    input_->ArrayRemove(index_);
+  }
+
+private:
+  NodeInput* input_;
+  int index_;
+
+};
+
 }
 
 #endif // NODEPARAMVIEWUNDO_H

app/widget/nodeparamview/nodeparamviewwidgetbridge.cpp

@@ -70,6 +70,7 @@ void NodeParamViewWidgetBridge::CreateWidgets()
   if (input_->IsArray() && element_ == -1) {
 
     NodeParamViewArrayWidget* w = new NodeParamViewArrayWidget(input_);
+    connect(w, &NodeParamViewArrayWidget::DoubleClicked, this, &NodeParamViewWidgetBridge::ArrayWidgetDoubleClicked);
     widgets_.append(w);
 
   } else {
@@ -190,14 +191,14 @@ void NodeParamViewWidgetBridge::CreateWidgets()
 
 void NodeParamViewWidgetBridge::SetInputValue(const QVariant &value, int track)
 {
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   SetInputValueInternal(value, track, command);
 
   Core::instance()->undo_stack()->pushIfHasChildren(command);
 }
 
-void NodeParamViewWidgetBridge::SetInputValueInternal(const QVariant &value, int track, QUndoCommand *command)
+void NodeParamViewWidgetBridge::SetInputValueInternal(const QVariant &value, int track, MultiUndoCommand *command)
 {
   rational node_time = GetCurrentTimeAsNodeTime();
 
@@ -205,7 +206,7 @@ void NodeParamViewWidgetBridge::SetInputValueInternal(const QVariant &value, int
     NodeKeyframe* existing_key = input_->GetKeyframeAtTimeOnTrack(node_time, track, element_);
 
     if (existing_key) {
-      new NodeParamSetKeyframeValueCommand(existing_key, value, command);
+      command->add_child(new NodeParamSetKeyframeValueCommand(existing_key, value));
     } else {
       // No existing key, create a new one
       NodeKeyframe* new_key = new NodeKeyframe(node_time,
@@ -214,10 +215,10 @@ void NodeParamViewWidgetBridge::SetInputValueInternal(const QVariant &value, int
                                                track,
                                                element_);
 
-      new NodeParamInsertKeyframeCommand(input_, new_key, command);
+      command->add_child(new NodeParamInsertKeyframeCommand(input_, new_key));
     }
   } else {
-    new NodeParamSetStandardValueCommand(input_, track, element_, value, command);
+    command->add_child(new NodeParamSetStandardValueCommand(input_, track, element_, value));
   }
 }
 
@@ -231,13 +232,11 @@ void NodeParamViewWidgetBridge::ProcessSlider(SliderBase *slider, const QVariant
 
     // While we're dragging, we block the input's normal signalling and create our own
     if (!dragger_.IsStarted()) {
-      dragger_.Start(input_, node_time, slider_track);
+      dragger_.Start(input_, node_time, slider_track, element_);
     }
 
     dragger_.Drag(value);
 
-    //input_->parentNode()->InvalidateVisible(input_, input_);
-
   } else if (dragger_.IsStarted()) {
 
     // We were dragging and just stopped
@@ -245,8 +244,10 @@ void NodeParamViewWidgetBridge::ProcessSlider(SliderBase *slider, const QVariant
     dragger_.End();
 
   } else {
+
     // No drag was involved, we can just push the value
     SetInputValue(value, slider_track);
+
   }
 }
 
@@ -321,7 +322,7 @@ void NodeParamViewWidgetBridge::WidgetCallback()
     // Sender is a ColorButton
     ManagedColor c = static_cast<ColorButton*>(sender())->GetColor();
 
-    QUndoCommand* command = new QUndoCommand();
+    MultiUndoCommand* command = new MultiUndoCommand();
 
     SetInputValueInternal(c.red(), 0, command);
     SetInputValueInternal(c.green(), 1, command);
@@ -394,7 +395,7 @@ void NodeParamViewWidgetBridge::CreateSliders(int count)
 
 void NodeParamViewWidgetBridge::UpdateWidgetValues()
 {
-  if (input_->IsArray()) {
+  if (input_->IsArray() && element_ == -1) {
     return;
   }
 
@@ -428,7 +429,7 @@ void NodeParamViewWidgetBridge::UpdateWidgetValues()
   }
   case NodeValue::kVec2:
   {
-    QVector2D vec2 = input_->GetValueAtTime(node_time, -1).value<QVector2D>();
+    QVector2D vec2 = input_->GetValueAtTime(node_time, element_).value<QVector2D>();
     QVector2D offset = input_->property("offset").value<QVector2D>();
 
     static_cast<FloatSlider*>(widgets_.at(0))->SetValue(static_cast<double>(vec2.x() + offset.x()));
@@ -510,9 +511,11 @@ rational NodeParamViewWidgetBridge::GetCurrentTimeAsNodeTime() const
   return GetAdjustedTime(GetTimeTarget(), input_->parent(), time_, true);
 }
 
-void NodeParamViewWidgetBridge::InputValueChanged(const TimeRange &range)
+void NodeParamViewWidgetBridge::InputValueChanged(const TimeRange &range, int element)
 {
-  if (!dragger_.IsStarted() && range.in() <= time_ && range.out() >= time_) {
+  if (element == element_
+      && !dragger_.IsStarted()
+      && range.in() <= time_ && range.out() >= time_) {
     // We'll need to update the widgets because the values have changed on our current time
     UpdateWidgetValues();
   }

app/widget/nodeparamview/nodeparamviewwidgetbridge.h

@@ -47,12 +47,15 @@ public:
 
   const QList<QWidget*>& widgets() const;
 
+signals:
+  void ArrayWidgetDoubleClicked();
+
 private:
   void CreateWidgets();
 
   void SetInputValue(const QVariant& value, int track);
 
-  void SetInputValueInternal(const QVariant& value, int track, QUndoCommand* command);
+  void SetInputValueInternal(const QVariant& value, int track, MultiUndoCommand *command);
 
   void ProcessSlider(SliderBase* slider, const QVariant& value);
 
@@ -77,7 +80,7 @@ private:
 private slots:
   void WidgetCallback();
 
-  void InputValueChanged(const TimeRange& range);
+  void InputValueChanged(const TimeRange& range, int element);
 
   void PropertyChanged(const QString& key, const QVariant& value);
 

app/widget/nodeview/nodeview.cpp

@@ -118,13 +118,13 @@ void NodeView::DeleteSelected()
     return;
   }
 
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   {
     QVector<NodeViewEdge *> selected_edges = scene_.GetSelectedEdges();
 
     foreach (NodeViewEdge* edge, selected_edges) {
-      new NodeEdgeRemoveCommand(edge->output(), edge->input(), edge->element(), command);
+      command->add_child(new NodeEdgeRemoveCommand(edge->output(), edge->input(), edge->element()));
     }
   }
 
@@ -141,7 +141,7 @@ void NodeView::DeleteSelected()
 
     if (!selected_nodes.isEmpty()) {
       foreach (Node* node, selected_nodes) {
-        new NodeRemoveAndDisconnectCommand(node, command);
+        command->add_child(new NodeRemoveAndDisconnectCommand(node));
       }
     }
   }
@@ -292,7 +292,7 @@ void NodeView::Paste()
     return;
   }
 
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   QVector<Node*> pasted_nodes = PasteNodesFromClipboard(graph_, command);
 
@@ -315,7 +315,7 @@ void NodeView::Duplicate()
     return;
   }
 
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   QVector<Node*> duplicated_nodes = Node::CopyDependencyGraph(selected, command);
 
@@ -536,14 +536,14 @@ void NodeView::mouseReleaseEvent(QMouseEvent *event)
 
       if (drop_edge_) {
         // We have everything we need to place the node in between
-        QUndoCommand* command = new QUndoCommand();
+        MultiUndoCommand* command = new MultiUndoCommand();
 
         // Remove old edge
-        new NodeEdgeRemoveCommand(drop_edge_->output(), drop_edge_->input(), drop_edge_->element(), command);
+        command->add_child(new NodeEdgeRemoveCommand(drop_edge_->output(), drop_edge_->input(), drop_edge_->element()));
 
         // Place new edges
-        new NodeEdgeAddCommand(drop_edge_->output(), drop_input_, -1, command);
-        new NodeEdgeAddCommand(dropping_node, drop_edge_->input(), drop_edge_->element(), command);
+        command->add_child(new NodeEdgeAddCommand(drop_edge_->output(), drop_input_, -1));
+        command->add_child(new NodeEdgeAddCommand(dropping_node, drop_edge_->input(), drop_edge_->element()));
 
         Core::instance()->undo_stack()->push(command);
       }

app/widget/nodeview/nodeviewitem.h

@@ -24,7 +24,6 @@
 #include <QFontMetrics>
 #include <QGraphicsRectItem>
 #include <QLinearGradient>
-#include <QUndoCommand>
 #include <QWidget>
 
 #include "node/node.h"

app/widget/nodeview/nodeviewundo.cpp

@@ -25,22 +25,41 @@
 
 namespace olive {
 
-NodeEdgeAddCommand::NodeEdgeAddCommand(Node *output, NodeInput *input, int element, QUndoCommand *parent) :
-  UndoCommand(parent),
+NodeEdgeAddCommand::NodeEdgeAddCommand(Node *output, NodeInput *input, int element) :
   output_(output),
   input_(input),
-  element_(element)
+  element_(element),
+  remove_command_(nullptr)
 {
 }
 
-void NodeEdgeAddCommand::redo_internal()
+NodeEdgeAddCommand::~NodeEdgeAddCommand()
 {
+  delete remove_command_;
+}
+
+void NodeEdgeAddCommand::redo()
+{
+  if (input_->IsConnected(element_)) {
+    if (!remove_command_) {
+      remove_command_ = new NodeEdgeRemoveCommand(input_->GetConnectedNode(element_),
+                                                  input_,
+                                                  element_);
+    }
+
+    remove_command_->redo();
+  }
+
   Node::ConnectEdge(output_, input_, element_);
 }
 
-void NodeEdgeAddCommand::undo_internal()
+void NodeEdgeAddCommand::undo()
 {
   Node::DisconnectEdge(output_, input_, element_);
+
+  if (remove_command_) {
+    remove_command_->undo();
+  }
 }
 
 Project *NodeEdgeAddCommand::GetRelevantProject() const
@@ -48,20 +67,19 @@ Project *NodeEdgeAddCommand::GetRelevantProject() const
   return output_->parent()->project();
 }
 
-NodeEdgeRemoveCommand::NodeEdgeRemoveCommand(Node *output, NodeInput *input, int element, QUndoCommand *parent) :
-  UndoCommand(parent),
+NodeEdgeRemoveCommand::NodeEdgeRemoveCommand(Node *output, NodeInput *input, int element) :
   output_(output),
   input_(input),
   element_(element)
 {
 }
 
-void NodeEdgeRemoveCommand::redo_internal()
+void NodeEdgeRemoveCommand::redo()
 {
   Node::DisconnectEdge(output_, input_, element_);
 }
 
-void NodeEdgeRemoveCommand::undo_internal()
+void NodeEdgeRemoveCommand::undo()
 {
   Node::ConnectEdge(output_, input_, element_);
 }
@@ -71,8 +89,7 @@ Project *NodeEdgeRemoveCommand::GetRelevantProject() const
   return output_->parent()->project();
 }
 
-NodeAddCommand::NodeAddCommand(NodeGraph *graph, Node *node, QUndoCommand *parent) :
-  UndoCommand(parent),
+NodeAddCommand::NodeAddCommand(NodeGraph *graph, Node *node) :
   graph_(graph),
   node_(node)
 {
@@ -80,12 +97,12 @@ NodeAddCommand::NodeAddCommand(NodeGraph *graph, Node *node, QUndoCommand *paren
   node_->setParent(&memory_manager_);
 }
 
-void NodeAddCommand::redo_internal()
+void NodeAddCommand::redo()
 {
   node_->setParent(graph_);
 }
 
-void NodeAddCommand::undo_internal()
+void NodeAddCommand::undo()
 {
   node_->setParent(&memory_manager_);
 }
@@ -95,8 +112,7 @@ Project *NodeAddCommand::GetRelevantProject() const
   return graph_->project();
 }
 
-NodeCopyInputsCommand::NodeCopyInputsCommand(Node *src, Node *dest, bool include_connections, QUndoCommand *parent) :
-  QUndoCommand(parent),
+NodeCopyInputsCommand::NodeCopyInputsCommand(Node *src, Node *dest, bool include_connections) :
   src_(src),
   dest_(dest),
   include_connections_(include_connections)
@@ -110,21 +126,21 @@ void NodeCopyInputsCommand::redo()
 
 void NodeRemoveAndDisconnectCommand::prep()
 {
-  command_ = new QUndoCommand();
+  command_ = new MultiUndoCommand();
 
   // If this is a block, remove all links
   if (node_->HasLinks()) {
-    new NodeUnlinkAllCommand(node_, command_);
+    command_->add_child(new NodeUnlinkAllCommand(node_));
   }
 
   // Disconnect everything
   foreach (const Node::InputConnection& conn, node_->edges()) {
-    new NodeEdgeRemoveCommand(node_, conn.input, conn.element, command_);
+    command_->add_child(new NodeEdgeRemoveCommand(node_, conn.input, conn.element));
   }
 
   foreach (NodeInput* input, node_->inputs()) {
     for (auto it=input->edges().cbegin(); it!=input->edges().cend(); it++) {
-      new NodeEdgeRemoveCommand(it->second, input, it->first, command_);
+      command_->add_child(new NodeEdgeRemoveCommand(it->second, input, it->first));
     }
   }
 }

app/widget/nodeview/nodeviewundo.h

@@ -21,8 +21,6 @@
 #ifndef NODEVIEWUNDO_H
 #define NODEVIEWUNDO_H
 
-#include <QUndoCommand>
-
 #include "node/graph.h"
 #include "node/node.h"
 #include "undo/undocommand.h"
@@ -30,19 +28,18 @@
 namespace olive {
 
 /**
- * @brief An undoable command for connecting two NodeParams together
+ * @brief An undoable command for disconnecting two NodeParams
  *
- * Can be considered a QUndoCommand wrapper for NodeParam::ConnectEdge()/
+ * Can be considered a UndoCommand wrapper for NodeParam::DisonnectEdge()/
  */
-class NodeEdgeAddCommand : public UndoCommand {
+class NodeEdgeRemoveCommand : public UndoCommand {
 public:
-  NodeEdgeAddCommand(Node* output, NodeInput* input, int element, QUndoCommand* parent = nullptr);
+  NodeEdgeRemoveCommand(Node* output, NodeInput* input, int element);
 
   virtual Project* GetRelevantProject() const override;
 
-protected:
-  virtual void redo_internal() override;
-  virtual void undo_internal() override;
+  virtual void redo() override;
+  virtual void undo() override;
 
 private:
   Node* output_;
@@ -52,36 +49,38 @@ private:
 };
 
 /**
- * @brief An undoable command for disconnecting two NodeParams
+ * @brief An undoable command for connecting two NodeParams together
  *
- * Can be considered a QUndoCommand wrapper for NodeParam::DisonnectEdge()/
+ * Can be considered a UndoCommand wrapper for NodeParam::ConnectEdge()/
  */
-class NodeEdgeRemoveCommand : public UndoCommand {
+class NodeEdgeAddCommand : public UndoCommand {
 public:
-  NodeEdgeRemoveCommand(Node* output, NodeInput* input, int element, QUndoCommand* parent = nullptr);
+  NodeEdgeAddCommand(Node* output, NodeInput* input, int element);
+
+  virtual ~NodeEdgeAddCommand() override;
 
   virtual Project* GetRelevantProject() const override;
 
-protected:
-  virtual void redo_internal() override;
-  virtual void undo_internal() override;
+  virtual void redo() override;
+  virtual void undo() override;
 
 private:
   Node* output_;
   NodeInput* input_;
   int element_;
 
+  NodeEdgeRemoveCommand* remove_command_;
+
 };
 
 class NodeAddCommand : public UndoCommand {
 public:
-  NodeAddCommand(NodeGraph* graph, Node* node, QUndoCommand* parent = nullptr);
+  NodeAddCommand(NodeGraph* graph, Node* node);
 
   virtual Project* GetRelevantProject() const override;
 
-protected:
-  virtual void redo_internal() override;
-  virtual void undo_internal() override;
+  virtual void redo() override;
+  virtual void undo() override;
 
 private:
   QObject memory_manager_;
@@ -92,8 +91,7 @@ private:
 
 class NodeRemoveAndDisconnectCommand : public UndoCommand {
 public:
-  NodeRemoveAndDisconnectCommand(Node* node, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  NodeRemoveAndDisconnectCommand(Node* node) :
     node_(node),
     graph_(nullptr),
     command_(nullptr),
@@ -115,8 +113,7 @@ public:
     }
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     if (!prepped_) {
       prep();
@@ -129,7 +126,7 @@ protected:
     node_->setParent(&memory_manager_);
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     node_->setParent(graph_);
     graph_ = nullptr;
@@ -145,7 +142,7 @@ private:
   Node* node_;
   NodeGraph* graph_;
 
-  QUndoCommand* command_;
+  MultiUndoCommand* command_;
 
   bool prepped_;
 
@@ -153,8 +150,7 @@ private:
 
 class NodeRemoveWithExclusiveDependenciesAndDisconnect : public UndoCommand {
 public:
-  NodeRemoveWithExclusiveDependenciesAndDisconnect(Node* node, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  NodeRemoveWithExclusiveDependenciesAndDisconnect(Node* node) :
     node_(node),
     command_(nullptr),
     prepped_(false)
@@ -175,8 +171,7 @@ public:
     }
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     if (!prepped_) {
       prep();
@@ -186,7 +181,7 @@ protected:
     command_->redo();
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     command_->undo();
   }
@@ -194,33 +189,35 @@ protected:
 private:
   void prep()
   {
-    command_ = new QUndoCommand();
+    command_ = new MultiUndoCommand();
 
-    new NodeRemoveAndDisconnectCommand(node_, command_);
+    command_->add_child(new NodeRemoveAndDisconnectCommand(node_));
 
     // Remove exclusive dependencies
     QVector<Node*> deps = node_->GetExclusiveDependencies();
     foreach (Node* d, deps) {
-      new NodeRemoveAndDisconnectCommand(d, command_);
+      command_->add_child(new NodeRemoveAndDisconnectCommand(d));
     }
   }
 
   Node* node_;
-  QUndoCommand* command_;
+  MultiUndoCommand* command_;
   bool prepped_;
 
 };
 
-class NodeCopyInputsCommand : public QUndoCommand {
+class NodeCopyInputsCommand : public UndoCommand {
 public:
   NodeCopyInputsCommand(Node* src,
                         Node* dest,
-                        bool include_connections,
-                        QUndoCommand* parent = nullptr);
+                        bool include_connections);
 
-protected:
   virtual void redo() override;
 
+  virtual void undo() override {}
+
+  virtual Project* GetRelevantProject() const override {return nullptr;}
+
 private:
   Node* src_;
 
@@ -232,8 +229,7 @@ private:
 
 class NodeLinkCommand : public UndoCommand {
 public:
-  NodeLinkCommand(Node* a, Node* b, bool link, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  NodeLinkCommand(Node* a, Node* b, bool link) :
     a_(a),
     b_(b),
     link_(link)
@@ -245,8 +241,7 @@ public:
     return a_->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     if (link_) {
       done_ = Node::Link(a_, b_);
@@ -255,7 +250,7 @@ protected:
     }
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     if (done_) {
       if (link_) {
@@ -276,8 +271,7 @@ private:
 
 class NodeUnlinkAllCommand : public UndoCommand {
 public:
-  NodeUnlinkAllCommand(Node* node, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  NodeUnlinkAllCommand(Node* node) :
     node_(node)
   {
   }
@@ -287,8 +281,7 @@ public:
     return node_->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     unlinked_ = node_->links();
 
@@ -297,7 +290,7 @@ protected:
     }
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     foreach (Node* link, unlinked_) {
       Node::Link(node_, link);
@@ -313,16 +306,15 @@ private:
 
 };
 
-class NodeLinkManyCommand : public UndoCommand {
+class NodeLinkManyCommand : public MultiUndoCommand {
 public:
-  NodeLinkManyCommand(const QVector<Node*> nodes, bool link, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  NodeLinkManyCommand(const QVector<Node*> nodes, bool link) :
     nodes_(nodes)
   {
     foreach (Node* a, nodes_) {
       foreach (Node* b, nodes_) {
         if (a != b) {
-          new NodeLinkCommand(a, b, link, this);
+          add_child(new NodeLinkCommand(a, b, link));
         }
       }
     }

app/widget/projectexplorer/projectexplorer.cpp

@@ -571,7 +571,7 @@ void ProjectExplorer::DeleteSelected()
     return;
   }
 
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   foreach (Item* item, selected) {
     // Verify whether this item is in use anywhere
@@ -629,7 +629,7 @@ void ProjectExplorer::DeleteSelected()
         if (msgbox.clickedButton() == offline_btn || msgbox.clickedButton() == delete_clip_btn) {
 
           // For safety, even if we're deleting clips, we'll offline the footage nodes too
-          new OfflineFootageCommand(footage_nodes, command);
+          command->add_child(new OfflineFootageCommand(footage_nodes));
 
         }
 
@@ -676,7 +676,7 @@ void ProjectExplorer::DeleteSelected()
       break;
     }
 
-    new ProjectViewModel::RemoveItemCommand(&model_, item, command);
+    command->add_child(new ProjectViewModel::RemoveItemCommand(&model_, item));
   }
 
   Core::instance()->undo_stack()->pushIfHasChildren(command);

app/widget/projectexplorer/projectexplorerundo.h

@@ -31,8 +31,7 @@ namespace olive {
  */
 class OfflineFootageCommand : public UndoCommand {
 public:
-  OfflineFootageCommand(const QVector<MediaInput*>& media,  QUndoCommand* parent = nullptr) :
-    UndoCommand(parent)
+  OfflineFootageCommand(const QVector<MediaInput*>& media)
   {
     foreach (MediaInput* i, media) {
       stream_data_.insert(i, i->stream());
@@ -46,15 +45,14 @@ public:
     return project_;
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     for (auto it=stream_data_.cbegin(); it!=stream_data_.cend(); it++) {
       it.key()->SetStream(nullptr);
     }
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     for (auto it=stream_data_.cbegin(); it!=stream_data_.cend(); it++) {
       it.key()->SetStream(it.value());

app/widget/timebased/timebasedwidget.cpp

@@ -21,7 +21,6 @@
 #include "timebasedwidget.h"
 
 #include <QInputDialog>
-#include <QUndoCommand>
 
 #include "common/autoscroll.h"
 #include "common/timecodefunctions.h"
@@ -435,11 +434,11 @@ void TimeBasedWidget::SetPoint(Timeline::MovementMode m, const rational& time)
     return;
   }
 
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   // Enable workarea if it isn't already enabled
   if (!points_->workarea()->enabled()) {
-    new WorkareaSetEnabledCommand(GetTimelinePointsProject(), points_, true, command);
+    command->add_child(new WorkareaSetEnabledCommand(GetTimelinePointsProject(), points_, true));
   }
 
   // Determine our new range
@@ -464,7 +463,7 @@ void TimeBasedWidget::SetPoint(Timeline::MovementMode m, const rational& time)
   }
 
   // Set workarea
-  new WorkareaSetRangeCommand(GetTimelinePointsProject(), points_, TimeRange(in_point, out_point), command);
+  command->add_child(new WorkareaSetRangeCommand(GetTimelinePointsProject(), points_, TimeRange(in_point, out_point)));
 
   Core::instance()->undo_stack()->push(command);
 }
@@ -647,12 +646,12 @@ Project *TimeBasedWidget::MarkerAddCommand::GetRelevantProject() const
   return project_;
 }
 
-void TimeBasedWidget::MarkerAddCommand::redo_internal()
+void TimeBasedWidget::MarkerAddCommand::redo()
 {
   added_marker_ = marker_list_->AddMarker(range_, name_);
 }
 
-void TimeBasedWidget::MarkerAddCommand::undo_internal()
+void TimeBasedWidget::MarkerAddCommand::undo()
 {
   marker_list_->RemoveMarker(added_marker_);
 }

app/widget/timebased/timebasedwidget.h

@@ -152,9 +152,8 @@ private:
 
     virtual Project* GetRelevantProject() const override;
 
-  protected:
-    virtual void redo_internal() override;
-    virtual void undo_internal() override;
+    virtual void redo() override;
+    virtual void undo() override;
 
   private:
     Project* project_;

app/widget/timelinewidget/timelineundo.h

@@ -21,8 +21,6 @@
 #ifndef TIMELINEUNDOABLE_H
 #define TIMELINEUNDOABLE_H
 
-#include <QUndoCommand>
-
 #include "config/config.h"
 #include "core.h"
 #include "node/block/block.h"
@@ -46,22 +44,21 @@ inline bool NodeCanBeRemoved(Node* n)
   return n->edges().empty();
 }
 
-inline QUndoCommand* CreateRemoveCommand(Node* n)
+inline UndoCommand* CreateRemoveCommand(Node* n)
 {
   return new NodeRemoveWithExclusiveDependenciesAndDisconnect(n);
 }
 
-inline QUndoCommand* CreateAndRunRemoveCommand(Node* n)
+inline UndoCommand* CreateAndRunRemoveCommand(Node* n)
 {
-  QUndoCommand* command = CreateRemoveCommand(n);
+  UndoCommand* command = CreateRemoveCommand(n);
   command->redo();
   return command;
 }
 
 class BlockResizeCommand : public UndoCommand {
 public:
-  BlockResizeCommand(Block* block, rational new_length, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  BlockResizeCommand(Block* block, rational new_length) :
     block_(block),
     new_length_(new_length)
   {
@@ -72,14 +69,13 @@ public:
     return block_->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     old_length_ = block_->length();
     block_->set_length_and_media_out(new_length_);
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     block_->set_length_and_media_out(old_length_);
   }
@@ -93,8 +89,7 @@ private:
 
 class BlockResizeWithMediaInCommand : public UndoCommand {
 public:
-  BlockResizeWithMediaInCommand(Block* block, rational new_length, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  BlockResizeWithMediaInCommand(Block* block, rational new_length) :
     block_(block),
     new_length_(new_length)
   {
@@ -105,14 +100,13 @@ public:
     return block_->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     old_length_ = block_->length();
     block_->set_length_and_media_in(new_length_);
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     block_->set_length_and_media_in(old_length_);
   }
@@ -135,8 +129,7 @@ private:
  */
 class BlockTrimCommand : public UndoCommand {
 public:
-  BlockTrimCommand(Track *track, Block* block, rational new_length, Timeline::MovementMode mode, QUndoCommand* command = nullptr) :
-    UndoCommand(command),
+  BlockTrimCommand(Track *track, Block* block, rational new_length, Timeline::MovementMode mode) :
     prepped_(false),
     track_(track),
     block_(block),
@@ -177,8 +170,7 @@ public:
     remove_block_from_graph_ = e;
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     if (!prepped_) {
       prep();
@@ -245,7 +237,7 @@ protected:
     track_->InvalidateCache(invalidate_range, track_->block_input());
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     if (doing_nothing_) {
       return;
@@ -360,7 +352,7 @@ private:
   bool needs_adjacent_;
   bool we_created_adjacent_;
   bool we_removed_adjacent_;
-  QUndoCommand* deleted_adjacent_command_;
+  UndoCommand* deleted_adjacent_command_;
 
   bool trim_is_a_roll_edit_;
   bool remove_block_from_graph_;
@@ -371,8 +363,7 @@ private:
 
 class BlockSetMediaInCommand : public UndoCommand {
 public:
-  BlockSetMediaInCommand(Block* block, rational new_media_in, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  BlockSetMediaInCommand(Block* block, rational new_media_in) :
     block_(block),
     new_media_in_(new_media_in)
   {
@@ -383,14 +374,13 @@ public:
     return block_->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     old_media_in_ = block_->media_in();
     block_->set_media_in(new_media_in_);
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     block_->set_media_in(old_media_in_);
   }
@@ -403,8 +393,7 @@ private:
 
 class TrackRippleRemoveBlockCommand : public UndoCommand {
 public:
-  TrackRippleRemoveBlockCommand(Track* track, Block* block, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  TrackRippleRemoveBlockCommand(Track* track, Block* block) :
     track_(track),
     block_(block)
   {
@@ -415,14 +404,13 @@ public:
     return track_->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     before_ = block_->previous();
     track_->RippleRemoveBlock(block_);
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     track_->InsertBlockAfter(block_, before_);
   }
@@ -438,8 +426,7 @@ private:
 
 class TrackPrependBlockCommand : public UndoCommand {
 public:
-  TrackPrependBlockCommand(Track* track, Block* block, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  TrackPrependBlockCommand(Track* track, Block* block) :
     track_(track),
     block_(block)
   {
@@ -450,13 +437,12 @@ public:
     return track_->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     track_->PrependBlock(block_);
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     track_->RippleRemoveBlock(block_);
   }
@@ -468,8 +454,7 @@ private:
 
 class TrackInsertBlockAfterCommand : public UndoCommand {
 public:
-  TrackInsertBlockAfterCommand(Track* track, Block* block, Block* before, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  TrackInsertBlockAfterCommand(Track* track, Block* block, Block* before) :
     track_(track),
     block_(block),
     before_(before)
@@ -481,13 +466,12 @@ public:
     return block_->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     track_->InsertBlockAfter(block_, before_);
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     track_->RippleRemoveBlock(block_);
   }
@@ -502,8 +486,7 @@ private:
 
 class BlockSplitCommand : public UndoCommand {
 public:
-  BlockSplitCommand(Block* block, rational point, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  BlockSplitCommand(Block* block, rational point) :
     block_(block),
     point_(point),
     reconnect_tree_command_(nullptr)
@@ -528,8 +511,7 @@ public:
     return static_cast<Block*>(added_nodes_.first());
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     old_length_ = block_->length();
 
@@ -571,8 +553,8 @@ protected:
     if (!reconnect_tree_command_) {
       if (copy_dependencies_too) {
         // Create equivalent connections among our copied dependency tree
-        reconnect_tree_command_ = new QUndoCommand();
-        Node::CopyDependencyGraph(src_nodes_, added_nodes_, reconnect_tree_command_);
+        reconnect_tree_command_ = new MultiUndoCommand();
+        Node::CopyDependencyGraph(src_nodes_, added_nodes_, static_cast<MultiUndoCommand*>(reconnect_tree_command_));
       } else {
         reconnect_tree_command_ = new NodeCopyInputsCommand(block_, new_block(), true);
       }
@@ -613,7 +595,7 @@ protected:
     track->EndOperation();
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     Track* track = block_->track();
 
@@ -646,7 +628,7 @@ private:
 
   QObject memory_manager_;
 
-  QUndoCommand* reconnect_tree_command_;
+  UndoCommand* reconnect_tree_command_;
 
   NodeInput* moved_transition_;
 
@@ -657,8 +639,7 @@ private:
 
 class BlockSplitPreservingLinksCommand : public UndoCommand {
 public:
-  BlockSplitPreservingLinksCommand(const QVector<Block *> &blocks, const QList<rational>& times, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  BlockSplitPreservingLinksCommand(const QVector<Block *> &blocks, const QList<rational>& times) :
     blocks_(blocks),
     times_(times)
   {
@@ -674,8 +655,7 @@ public:
     return blocks_.first()->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     if (commands_.isEmpty()) {
       QVector< QVector<Block*> > split_blocks(times_.size());
@@ -736,7 +716,7 @@ protected:
     }
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     for (int i=commands_.size()-1; i>=0; i--) {
       commands_.at(i)->undo();
@@ -748,14 +728,13 @@ private:
 
   QList<rational> times_;
 
-  QVector<QUndoCommand*> commands_;
+  QVector<UndoCommand*> commands_;
 
 };
 
 class TrackSplitAtTimeCommand : public UndoCommand {
 public:
-  TrackSplitAtTimeCommand(Track* track, rational point, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  TrackSplitAtTimeCommand(Track* track, rational point) :
     prepped_(false),
     track_(track),
     point_(point),
@@ -773,8 +752,7 @@ public:
     return track_->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     if (!prepped_) {
       // Find Block that contains this time
@@ -792,7 +770,7 @@ protected:
     }
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     if (command_) {
       command_->undo();
@@ -806,7 +784,7 @@ private:
 
   rational point_;
 
-  QUndoCommand* command_;
+  UndoCommand* command_;
 
 };
 
@@ -819,8 +797,7 @@ private:
  */
 class TrackRippleRemoveAreaCommand : public UndoCommand {
 public:
-  TrackRippleRemoveAreaCommand(Track* track, const TimeRange& range, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  TrackRippleRemoveAreaCommand(Track* track, const TimeRange& range) :
     prepped_(false),
     track_(track),
     range_(range),
@@ -858,8 +835,7 @@ public:
     return nullptr;
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     if (!prepped_) {
       prep();
@@ -900,7 +876,7 @@ protected:
           }
         }
 
-        foreach (QUndoCommand* c, remove_block_commands_) {
+        foreach (UndoCommand* c, remove_block_commands_) {
           c->redo();
         }
       }
@@ -911,7 +887,7 @@ protected:
     track_->InvalidateCache(TimeRange(range_.in(), RATIONAL_MAX));
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     // Begin operations
     track_->BeginOperation();
@@ -1028,14 +1004,13 @@ private:
   Block* insert_previous_;
 
   BlockSplitCommand* splice_split_command_;
-  QVector<QUndoCommand*> remove_block_commands_;
+  QVector<UndoCommand*> remove_block_commands_;
 
 };
 
 class TrackListRippleRemoveAreaCommand : public UndoCommand {
 public:
-  TrackListRippleRemoveAreaCommand(TrackList* list, rational in, rational out, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  TrackListRippleRemoveAreaCommand(TrackList* list, rational in, rational out) :
     list_(list),
     in_(in),
     out_(out)
@@ -1052,8 +1027,7 @@ public:
     return static_cast<ViewerOutput*>(list_->parent())->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     // Code that's only run on the first redo
     if (commands_.isEmpty()) {
@@ -1096,7 +1070,7 @@ protected:
     }
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     if (all_tracks_unlocked_) {
       // We can optimize here by simply shifting the whole cache forward instead of re-caching
@@ -1138,17 +1112,15 @@ private:
 
 };
 
-class TimelineRippleRemoveAreaCommand : public UndoCommand {
+class TimelineRippleRemoveAreaCommand : public MultiUndoCommand {
 public:
-  TimelineRippleRemoveAreaCommand(ViewerOutput* timeline, rational in, rational out, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  TimelineRippleRemoveAreaCommand(ViewerOutput* timeline, rational in, rational out) :
     timeline_(timeline)
   {
     for (int i=0; i<Track::kCount; i++) {
-      new TrackListRippleRemoveAreaCommand(timeline->track_list(static_cast<Track::Type>(i)),
+      add_child(new TrackListRippleRemoveAreaCommand(timeline->track_list(static_cast<Track::Type>(i)),
                                                      in,
-                                           out,
-                                           this);
+                                                     out));
     }
   }
 
@@ -1173,8 +1145,7 @@ public:
                              const QHash<Track*, RippleInfo>& info,
                              const rational& ripple_movement,
                              const Timeline::MovementMode& movement_mode,
-                             QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+                             UndoCommand* parent = nullptr) :
     track_list_(track_list),
     info_(info),
     ripple_movement_(ripple_movement),
@@ -1188,13 +1159,12 @@ public:
     return static_cast<ViewerOutput*>(track_list_->parent())->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     ripple(true);
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     ripple(false);
   }
@@ -1385,8 +1355,7 @@ private:
 
 class TimelineAddTrackCommand : public UndoCommand {
 public:
-  TimelineAddTrackCommand(TrackList *timeline, QUndoCommand* command = nullptr) :
-    UndoCommand(command),
+  TimelineAddTrackCommand(TrackList *timeline) :
     timeline_(timeline)
   {
     track_ = new Track();
@@ -1415,8 +1384,7 @@ public:
     return timeline_->GetParentGraph()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     // Add track
     track_->setParent(timeline_->GetParentGraph());
@@ -1444,7 +1412,7 @@ protected:
     }
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     // Remove merge if applicable
     if (merge_) {
@@ -1490,8 +1458,7 @@ private:
  */
 class TrackPlaceBlockCommand : public UndoCommand {
 public:
-  TrackPlaceBlockCommand(TrackList *timeline, int track, Block* block, rational in, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  TrackPlaceBlockCommand(TrackList *timeline, int track, Block* block, rational in) :
     timeline_(timeline),
     track_index_(track),
     in_(in),
@@ -1512,8 +1479,7 @@ public:
     return timeline_->GetParentGraph()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     // Determine if we need to add tracks
     if (track_index_ >= timeline_->GetTracks().size()) {
@@ -1560,7 +1526,7 @@ protected:
     }
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     Track* t = timeline_->GetTrackAt(track_index_);
 
@@ -1600,8 +1566,7 @@ private:
  */
 class TrackReplaceBlockCommand : public UndoCommand {
 public:
-  TrackReplaceBlockCommand(Track* track, Block* old, Block* replace, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  TrackReplaceBlockCommand(Track* track, Block* old, Block* replace) :
     track_(track),
     old_(old),
     replace_(replace)
@@ -1613,13 +1578,12 @@ public:
     return track_->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     track_->ReplaceBlock(old_, replace_);
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     track_->ReplaceBlock(replace_, old_);
   }
@@ -1633,8 +1597,7 @@ private:
 
 class TrackReplaceBlockWithGapCommand : public UndoCommand {
 public:
-  TrackReplaceBlockWithGapCommand(Track* track, Block* block, QUndoCommand* command = nullptr) :
-    UndoCommand(command),
+  TrackReplaceBlockWithGapCommand(Track* track, Block* block) :
     track_(track),
     block_(block),
     existing_gap_(nullptr),
@@ -1648,8 +1611,7 @@ public:
     return block_->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     track_->BeginOperation();
 
@@ -1721,7 +1683,7 @@ protected:
     track_->InvalidateCache(invalidate_range, track_->block_input());
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     track_->BeginOperation();
 
@@ -1793,8 +1755,7 @@ private:
 
 class TimelineRippleDeleteGapsAtRegionsCommand : public UndoCommand {
 public:
-  TimelineRippleDeleteGapsAtRegionsCommand(ViewerOutput* vo, const TimeRangeList& regions, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  TimelineRippleDeleteGapsAtRegionsCommand(ViewerOutput* vo, const TimeRangeList& regions) :
     timeline_(vo),
     regions_(regions)
   {
@@ -1810,8 +1771,7 @@ public:
     return timeline_->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     if (commands_.isEmpty()) {
       foreach (const TimeRange& range, regions_) {
@@ -1849,12 +1809,12 @@ protected:
       }
     }
 
-    foreach (QUndoCommand* c, commands_) {
+    foreach (UndoCommand* c, commands_) {
       c->redo();
     }
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     for (int i=commands_.size()-1;i>=0;i--) {
       commands_.at(i)->undo();
@@ -1865,14 +1825,13 @@ private:
   ViewerOutput* timeline_;
   TimeRangeList regions_;
 
-  QVector<QUndoCommand*> commands_;
+  QVector<UndoCommand*> commands_;
 
 };
 
 class WorkareaSetEnabledCommand : public UndoCommand {
 public:
-  WorkareaSetEnabledCommand(Project *project, TimelinePoints* points, bool enabled, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  WorkareaSetEnabledCommand(Project *project, TimelinePoints* points, bool enabled) :
     project_(project),
     points_(points),
     old_enabled_(points_->workarea()->enabled()),
@@ -1885,13 +1844,12 @@ public:
     return project_;
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     points_->workarea()->set_enabled(new_enabled_);
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     points_->workarea()->set_enabled(old_enabled_);
   }
@@ -1909,8 +1867,7 @@ private:
 
 class WorkareaSetRangeCommand : public UndoCommand {
 public:
-  WorkareaSetRangeCommand(Project *project, TimelinePoints* points, const TimeRange& range, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  WorkareaSetRangeCommand(Project *project, TimelinePoints* points, const TimeRange& range) :
     project_(project),
     points_(points),
     old_range_(points_->workarea()->range()),
@@ -1923,13 +1880,12 @@ public:
     return project_;
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     points_->workarea()->set_range(new_range_);
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     points_->workarea()->set_range(old_range_);
   }
@@ -1947,8 +1903,7 @@ private:
 
 class BlockEnableDisableCommand : public UndoCommand {
 public:
-  BlockEnableDisableCommand(Block* block, bool enabled, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  BlockEnableDisableCommand(Block* block, bool enabled) :
     block_(block),
     old_enabled_(block_->is_enabled()),
     new_enabled_(enabled)
@@ -1960,13 +1915,12 @@ public:
     return block_->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     block_->set_enabled(new_enabled_);
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     block_->set_enabled(old_enabled_);
   }
@@ -1982,8 +1936,7 @@ private:
 
 class TrackSlideCommand : public UndoCommand {
 public:
-  TrackSlideCommand(Track* track, const QList<Block*>& moving_blocks, Block* in_adjacent, Block* out_adjacent, const rational& movement, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  TrackSlideCommand(Track* track, const QList<Block*>& moving_blocks, Block* in_adjacent, Block* out_adjacent, const rational& movement) :
     prepped_(false),
     track_(track),
     blocks_(moving_blocks),
@@ -2007,8 +1960,7 @@ public:
     return track_->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     if (!prepped_) {
       prep();
@@ -2073,7 +2025,7 @@ protected:
     track_->InvalidateCache(invalidate_range, track_->block_input());
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     // Make sure all movement blocks' old positions are invalidated
     TimeRange invalidate_range(blocks_.first()->in(), blocks_.last()->out());
@@ -2145,10 +2097,10 @@ private:
 
   bool we_created_in_adjacent_;
   Block* in_adjacent_;
-  QUndoCommand* in_adjacent_remove_command_;
+  UndoCommand* in_adjacent_remove_command_;
   bool we_created_out_adjacent_;
   Block* out_adjacent_;
-  QUndoCommand* out_adjacent_remove_command_;
+  UndoCommand* out_adjacent_remove_command_;
 
   QObject memory_manager_;
 
@@ -2156,8 +2108,7 @@ private:
 
 class TrackListInsertGaps : public UndoCommand {
 public:
-  TrackListInsertGaps(TrackList* track_list, const rational& point, const rational& length, QUndoCommand* parent = nullptr) :
-    UndoCommand(parent),
+  TrackListInsertGaps(TrackList* track_list, const rational& point, const rational& length) :
     prepped_(false),
     track_list_(track_list),
     point_(point),
@@ -2176,8 +2127,7 @@ public:
     return static_cast<ViewerOutput*>(track_list_->parent())->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     if (!prepped_) {
       prep();
@@ -2221,7 +2171,7 @@ protected:
     }
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     if (all_tracks_unlocked_) {
       // Optimize by shifting over since we have a constant amount of time being inserted
@@ -2340,8 +2290,7 @@ private:
 
 class TransitionRemoveCommand : public UndoCommand {
 public:
-  TransitionRemoveCommand(TransitionBlock* block, QUndoCommand *parent = nullptr) :
-    UndoCommand(parent),
+  TransitionRemoveCommand(TransitionBlock* block, UndoCommand *parent = nullptr) :
     block_(block)
   {
   }
@@ -2351,8 +2300,7 @@ public:
     return track_->parent()->project();
   }
 
-protected:
-  virtual void redo_internal() override
+  virtual void redo() override
   {
     track_ = block_->track();
     out_block_ = block_->connected_out_block();
@@ -2387,7 +2335,7 @@ protected:
     track_->InvalidateCache(invalidate_range, track_->block_input());
   }
 
-  virtual void undo_internal() override
+  virtual void undo() override
   {
     track_->BeginOperation();
 

app/widget/timelinewidget/timelinewidget.cpp

@@ -421,7 +421,7 @@ void TimelineWidget::SplitAtPlayhead()
 
 void TimelineWidget::ReplaceBlocksWithGaps(const QVector<Block *> &blocks,
                                            bool remove_from_graph,
-                                           QUndoCommand *command)
+                                           MultiUndoCommand *command)
 {
   foreach (Block* b, blocks) {
     if (b->type() == Block::kGap) {
@@ -432,10 +432,10 @@ void TimelineWidget::ReplaceBlocksWithGaps(const QVector<Block *> &blocks,
 
     Track* original_track = b->track();
 
-    new TrackReplaceBlockWithGapCommand(original_track, b, command);
+    command->add_child(new TrackReplaceBlockWithGapCommand(original_track, b));
 
     if (remove_from_graph) {
-      new NodeRemoveWithExclusiveDependenciesAndDisconnect(b, command);
+      command->add_child(new NodeRemoveWithExclusiveDependenciesAndDisconnect(b));
     }
   }
 }
@@ -454,7 +454,7 @@ void TimelineWidget::DeleteSelected(bool ripple)
     return;
   }
 
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   QVector<Block*> clips_to_delete;
   QVector<TransitionBlock*> transitions_to_delete;
@@ -469,16 +469,16 @@ void TimelineWidget::DeleteSelected(bool ripple)
 
   // For transitions, remove them but extend their attached blocks to fill their place
   foreach (TransitionBlock* transition, transitions_to_delete) {
-    new TransitionRemoveCommand(transition, command);
+    command->add_child(new TransitionRemoveCommand(transition));
 
-    new NodeRemoveWithExclusiveDependenciesAndDisconnect(transition, command);
+    command->add_child(new NodeRemoveWithExclusiveDependenciesAndDisconnect(transition));
   }
 
   // Replace clips with gaps (effectively deleting them)
   ReplaceBlocksWithGaps(clips_to_delete, true, command);
 
   // Remove all selections
-  new SetSelectionsCommand(this, TimelineWidgetSelections(), GetSelections(), command);
+  command->add_child(new SetSelectionsCommand(this, TimelineWidgetSelections(), GetSelections()));
 
   // Insert ripple command now that it's all cleaned up gaps
   if (ripple) {
@@ -488,7 +488,7 @@ void TimelineWidget::DeleteSelected(bool ripple)
       range_list.insert(TimeRange(b->in(), b->out()));
     }
 
-    new TimelineRippleDeleteGapsAtRegionsCommand(GetConnectedNode(), range_list, command);
+    command->add_child(new TimelineRippleDeleteGapsAtRegionsCommand(GetConnectedNode(), range_list));
   }
 
   Core::instance()->undo_stack()->pushIfHasChildren(command);
@@ -593,7 +593,7 @@ void TimelineWidget::Paste(bool insert)
     return;
   }
 
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   QVector<BlockPasteData> paste_data;
   QVector<Node*> pasted = PasteNodesFromClipboard(GetConnectedNode()->parent(), command, &paste_data);
@@ -614,11 +614,10 @@ void TimelineWidget::Paste(bool insert)
 
   foreach (const BlockPasteData& bpd, paste_data) {
     qDebug() << "Placing" << bpd.block;
-    new TrackPlaceBlockCommand(GetConnectedNode()->track_list(bpd.track_type),
+    command->add_child(new TrackPlaceBlockCommand(GetConnectedNode()->track_list(bpd.track_type),
                                                   bpd.track_index,
                                                   bpd.block,
-                               paste_start + bpd.in,
-                               command);
+                                                  paste_start + bpd.in));
   }
 
   Core::instance()->undo_stack()->pushIfHasChildren(command);
@@ -632,14 +631,13 @@ void TimelineWidget::DeleteInToOut(bool ripple)
     return;
   }
 
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   if (ripple) {
 
-    new TimelineRippleRemoveAreaCommand(GetConnectedNode(),
+    command->add_child(new TimelineRippleRemoveAreaCommand(GetConnectedNode(),
                                                            GetConnectedTimelinePoints()->workarea()->in(),
-                                        GetConnectedTimelinePoints()->workarea()->out(),
-                                        command);
+                                                           GetConnectedTimelinePoints()->workarea()->out()));
 
   } else {
     QVector<Track*> unlocked_tracks = GetConnectedNode()->GetUnlockedTracks();
@@ -649,23 +647,20 @@ void TimelineWidget::DeleteInToOut(bool ripple)
 
       gap->set_length_and_media_out(GetConnectedTimelinePoints()->workarea()->length());
 
-      new NodeAddCommand(static_cast<NodeGraph*>(track->parent()),
-                         gap,
-                         command);
+      command->add_child(new NodeAddCommand(static_cast<NodeGraph*>(track->parent()),
+                                            gap));
 
-      new TrackPlaceBlockCommand(GetConnectedNode()->track_list(track->type()),
+      command->add_child(new TrackPlaceBlockCommand(GetConnectedNode()->track_list(track->type()),
                                                     track->Index(),
                                                     gap,
-                                 GetConnectedTimelinePoints()->workarea()->in(),
-                                 command);
+                                                    GetConnectedTimelinePoints()->workarea()->in()));
     }
   }
 
   // Clear workarea after this
-  new WorkareaSetEnabledCommand(GetTimelinePointsProject(),
+  command->add_child(new WorkareaSetEnabledCommand(GetTimelinePointsProject(),
                                                    GetConnectedTimelinePoints(),
-                                false,
-                                command);
+                                                   false));
 
   if (ripple) {
     SetTimeAndSignal(Timecode::time_to_timestamp(GetConnectedTimelinePoints()->workarea()->in(),
@@ -683,12 +678,11 @@ void TimelineWidget::ToggleSelectedEnabled()
     return;
   }
 
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   foreach (Block* i, items) {
-    new BlockEnableDisableCommand(i,
-                                  !i->is_enabled(),
-                                  command);
+    command->add_child(new BlockEnableDisableCommand(i,
+                                                     !i->is_enabled()));
   }
 
   Core::instance()->undo_stack()->pushIfHasChildren(command);
@@ -701,13 +695,12 @@ void TimelineWidget::SetColorLabel(int index)
   }
 }
 
-void TimelineWidget::InsertGapsAt(const rational &earliest_point, const rational &insert_length, QUndoCommand *command)
+void TimelineWidget::InsertGapsAt(const rational &earliest_point, const rational &insert_length, MultiUndoCommand *command)
 {
   for (int i=0;i<Track::kCount;i++) {
-    new TrackListInsertGaps(GetConnectedNode()->track_list(static_cast<Track::Type>(i)),
+    command->add_child(new TrackListInsertGaps(GetConnectedNode()->track_list(static_cast<Track::Type>(i)),
                                                earliest_point,
-                            insert_length,
-                            command);
+                                               insert_length));
   }
 }
 
@@ -1238,7 +1231,7 @@ void TimelineWidget::EditTo(Timeline::MovementMode mode)
     return;
   }
 
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   foreach (const Timeline::EditToInfo& info, tracks) {
     if (info.nearest_block
@@ -1253,11 +1246,10 @@ void TimelineWidget::EditTo(Timeline::MovementMode mode)
       }
       new_len = info.nearest_block->length() - new_len;
 
-      new BlockTrimCommand(info.track,
+      command->add_child(new BlockTrimCommand(info.track,
                                               info.nearest_block,
                                               new_len,
-                           mode,
-                           command);
+                                              mode));
     }
   }
 

app/widget/timelinewidget/timelinewidget.h

@@ -104,7 +104,7 @@ public:
 
   void RestoreSplitterState(const QByteArray& state);
 
-  static void ReplaceBlocksWithGaps(const QVector<Block *> &blocks, bool remove_from_graph, QUndoCommand* command);
+  static void ReplaceBlocksWithGaps(const QVector<Block *> &blocks, bool remove_from_graph, MultiUndoCommand *command);
 
   /**
    * @brief Retrieve the QGraphicsItem at a particular scene position
@@ -136,7 +136,7 @@ public:
     return ghost_items_;
   }
 
-  void InsertGapsAt(const rational& time, const rational& length, QUndoCommand* command);
+  void InsertGapsAt(const rational& time, const rational& length, MultiUndoCommand *command);
 
   void StartRubberBandSelect(const QPoint& global_cursor_start);
   void MoveRubberBandSelect(bool enable_selecting, bool select_links);
@@ -197,17 +197,15 @@ public:
    */
   void SignalDeselectedAllBlocks();
 
-  class SetSelectionsCommand : public QUndoCommand {
+  class SetSelectionsCommand : public UndoCommand {
   public:
-    SetSelectionsCommand(TimelineWidget* timeline, const TimelineWidgetSelections& now, const TimelineWidgetSelections& old, QUndoCommand* parent = nullptr) :
-      QUndoCommand(parent),
+    SetSelectionsCommand(TimelineWidget* timeline, const TimelineWidgetSelections& now, const TimelineWidgetSelections& old) :
       timeline_(timeline),
       old_(old),
       now_(now)
     {
     }
 
-  protected:
     virtual void redo() override
     {
       timeline_->SetSelections(now_);
@@ -218,6 +216,8 @@ public:
       timeline_->SetSelections(old_);
     }
 
+    virtual Project* GetRelevantProject() const override {return nullptr;}
+
   private:
     TimelineWidget* timeline_;
     TimelineWidgetSelections old_;

app/widget/timelinewidget/tool/add.cpp

@@ -91,7 +91,7 @@ void AddTool::MouseRelease(TimelineViewMouseEvent *event)
 
   if (ghost_) {
     if (!ghost_->GetAdjustedLength().isNull()) {
-      QUndoCommand* command = new QUndoCommand();
+      MultiUndoCommand* command = new MultiUndoCommand();
 
       ClipBlock* clip = new ClipBlock();
       clip->set_length_and_media_out(ghost_->GetAdjustedLength());
@@ -99,15 +99,13 @@ void AddTool::MouseRelease(TimelineViewMouseEvent *event)
 
       NodeGraph* graph = static_cast<NodeGraph*>(parent()->GetConnectedNode()->parent());
 
-      new NodeAddCommand(graph,
-                         clip,
-                         command);
+      command->add_child(new NodeAddCommand(graph,
+                                            clip));
 
-      new TrackPlaceBlockCommand(parent()->GetConnectedNode()->track_list(track.type()),
+      command->add_child(new TrackPlaceBlockCommand(parent()->GetConnectedNode()->track_list(track.type()),
                                                     track.index(),
                                                     clip,
-                                 ghost_->GetAdjustedIn(),
-                                 command);
+                                                    ghost_->GetAdjustedIn()));
 
       switch (Core::instance()->GetSelectedAddableObject()) {
       case olive::Tool::kAddableEmpty:
@@ -117,22 +115,20 @@ void AddTool::MouseRelease(TimelineViewMouseEvent *event)
       {
         Node* solid = new SolidGenerator();
 
-        new NodeAddCommand(graph,
-                           solid,
-                           command);
+        command->add_child(new NodeAddCommand(graph,
+                                              solid));
 
-        new NodeEdgeAddCommand(solid, clip->texture_input(), -1, command);
+        command->add_child(new NodeEdgeAddCommand(solid, clip->texture_input(), -1));
         break;
       }
       case olive::Tool::kAddableTitle:
       {
         Node* text = new TextGenerator();
 
-        new NodeAddCommand(graph,
-                           text,
-                           command);
+        command->add_child(new NodeAddCommand(graph,
+                                              text));
 
-        new NodeEdgeAddCommand(text, clip->texture_input(), -1, command);
+        command->add_child(new NodeEdgeAddCommand(text, clip->texture_input(), -1));
         break;
       }
       case olive::Tool::kAddableBars:

app/widget/timelinewidget/tool/import.cpp

@@ -306,7 +306,7 @@ void ImportTool::PrepGhosts(const rational& frame, const int& track_index)
 
 void ImportTool::DropGhosts(bool insert)
 {
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   NodeGraph* dst_graph = nullptr;
   ViewerOutput* viewer_node = nullptr;
@@ -383,10 +383,9 @@ void ImportTool::DropGhosts(bool insert)
         if (sequence_is_valid) {
           new_sequence->add_default_nodes();
 
-          new ProjectViewModel::AddItemCommand(Core::instance()->GetActiveProjectModel(),
+          command->add_child(new ProjectViewModel::AddItemCommand(Core::instance()->GetActiveProjectModel(),
                                                                   Core::instance()->GetSelectedFolderInActiveProject(),
-                                               new_sequence,
-                                               command);
+                                                                  new_sequence));
 
           FootageToGhosts(0, dragged_footage_, new_sequence->video_params().time_base(), 0);
 
@@ -422,44 +421,43 @@ void ImportTool::DropGhosts(bool insert)
       clip->set_media_in(ghost->GetMediaIn());
       clip->set_length_and_media_out(ghost->GetLength());
       clip->SetLabel(footage_stream->footage()->name());
-      new NodeAddCommand(dst_graph, clip, command);
+      command->add_child(new NodeAddCommand(dst_graph, clip));
 
       switch (footage_stream->type()) {
       case Stream::kVideo:
       {
         MediaInput* video_input = new MediaInput();
         video_input->SetStream(footage_stream);
-        new NodeAddCommand(dst_graph, video_input, command);
+        command->add_child(new NodeAddCommand(dst_graph, video_input));
 
         TransformDistortNode* transform = new TransformDistortNode();
-        new NodeAddCommand(dst_graph, transform, command);
+        command->add_child(new NodeAddCommand(dst_graph, transform));
 
-        new NodeEdgeAddCommand(video_input, transform->texture_input(), -1, command);
-        new NodeEdgeAddCommand(transform, clip->texture_input(), -1, command);
+        command->add_child(new NodeEdgeAddCommand(video_input, transform->texture_input(), -1));
+        command->add_child(new NodeEdgeAddCommand(transform, clip->texture_input(), -1));
         break;
       }
       case Stream::kAudio:
       {
         MediaInput* audio_input = new MediaInput();
         audio_input->SetStream(footage_stream);
-        new NodeAddCommand(dst_graph, audio_input, command);
+        command->add_child(new NodeAddCommand(dst_graph, audio_input));
 
         VolumeNode* volume_node = new VolumeNode();
-        new NodeAddCommand(dst_graph, volume_node, command);
+        command->add_child(new NodeAddCommand(dst_graph, volume_node));
 
-        new NodeEdgeAddCommand(audio_input, volume_node->samples_input(), -1, command);
-        new NodeEdgeAddCommand(volume_node, clip->texture_input(), -1, command);
+        command->add_child(new NodeEdgeAddCommand(audio_input, volume_node->samples_input(), -1));
+        command->add_child(new NodeEdgeAddCommand(volume_node, clip->texture_input(), -1));
         break;
       }
       default:
         break;
       }
 
-      new TrackPlaceBlockCommand(viewer_node->track_list(ghost->GetAdjustedTrack().type()),
+      command->add_child(new TrackPlaceBlockCommand(viewer_node->track_list(ghost->GetAdjustedTrack().type()),
                                                     ghost->GetAdjustedTrack().index(),
                                                     clip,
-                                 ghost->GetAdjustedIn(),
-                                 command);
+                                                    ghost->GetAdjustedIn()));
 
       block_items.replace(i, clip);
 

app/widget/timelinewidget/tool/pointer.cpp

@@ -563,7 +563,7 @@ void PointerTool::FinishDrag(TimelineViewMouseEvent *event)
     return;
   }
 
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   if (!blocks_trimming.isEmpty()) {
     foreach (const GhostBlockPair& p, blocks_trimming) {
@@ -574,10 +574,11 @@ void PointerTool::FinishDrag(TimelineViewMouseEvent *event)
         BlockTrimCommand* c = new BlockTrimCommand(parent()->GetTrackFromReference(ghost->GetAdjustedTrack()),
                                                    p.block,
                                                    ghost->GetAdjustedLength(),
-                                                   ghost->GetMode(),
-                                                   command);
+                                                   ghost->GetMode());
 
         c->SetTrimIsARollEdit(ghost->GetData(TimelineViewGhostItem::kTrimIsARollEdit).toBool());
+
+        command->add_child(c);
       }
     }
 
@@ -590,7 +591,7 @@ void PointerTool::FinishDrag(TimelineViewMouseEvent *event)
       } else {
         new_sel.TrimOut(reference_ghost->GetOutAdjustment());
       }
-      new TimelineWidget::SetSelectionsCommand(parent(), new_sel, parent()->GetSelections(), command);
+      command->add_child(new TimelineWidget::SetSelectionsCommand(parent(), new_sel, parent()->GetSelections()));
     }
   }
 
@@ -632,11 +633,10 @@ void PointerTool::FinishDrag(TimelineViewMouseEvent *event)
         } else {
           copy = block->copy();
 
-          new NodeAddCommand(static_cast<NodeGraph*>(block->parent()),
-                             copy,
-                             command);
+          command->add_child(new NodeAddCommand(static_cast<NodeGraph*>(block->parent()),
+                                                copy));
 
-          new NodeCopyInputsCommand(block, copy, true, command);
+          command->add_child(new NodeCopyInputsCommand(block, copy, true));
         }
 
         // Place the copy instead of the original block
@@ -644,18 +644,17 @@ void PointerTool::FinishDrag(TimelineViewMouseEvent *event)
       }
 
       const Track::Reference& track_ref = p.ghost->GetAdjustedTrack();
-      new TrackPlaceBlockCommand(parent()->GetConnectedNode()->track_list(track_ref.type()),
+      command->add_child(new TrackPlaceBlockCommand(parent()->GetConnectedNode()->track_list(track_ref.type()),
                                                     track_ref.index(),
                                                     block,
-                                 p.ghost->GetAdjustedIn(),
-                                 command);
+                                                    p.ghost->GetAdjustedIn()));
     }
 
     // Adjust selections
     TimelineWidgetSelections new_sel = parent()->GetSelections();
     new_sel.ShiftTime(blocks_moving.first().ghost->GetInAdjustment());
     new_sel.ShiftTracks(drag_track_type_, blocks_moving.first().ghost->GetTrackAdjustment());
-    new TimelineWidget::SetSelectionsCommand(parent(), new_sel, parent()->GetSelections(), command);
+    command->add_child(new TimelineWidget::SetSelectionsCommand(parent(), new_sel, parent()->GetSelections()));
   }
 
   if (!blocks_sliding.isEmpty()) {
@@ -706,18 +705,17 @@ void PointerTool::FinishDrag(TimelineViewMouseEvent *event)
     if (!movement.isNull()) {
       QHash<Track::Reference, QList<Block*> >::const_iterator i;
       for (i=slide_info.constBegin(); i!=slide_info.constEnd(); i++) {
-        new TrackSlideCommand(parent()->GetTrackFromReference(i.key()),
+        command->add_child(new TrackSlideCommand(parent()->GetTrackFromReference(i.key()),
                               i.value(),
                               in_adjacents.value(i.key()),
                               out_adjacents.value(i.key()),
-                              movement,
-                              command);
+                              movement));
       }
 
       // Adjust selections
       TimelineWidgetSelections new_sel = parent()->GetSelections();
       new_sel.ShiftTime(movement);
-      new TimelineWidget::SetSelectionsCommand(parent(), new_sel, parent()->GetSelections(), command);
+      command->add_child(new TimelineWidget::SetSelectionsCommand(parent(), new_sel, parent()->GetSelections()));
     }
   }
 

app/widget/timelinewidget/tool/ripple.cpp

@@ -132,7 +132,7 @@ void RippleTool::FinishDrag(TimelineViewMouseEvent *event)
       info_list[track->type()].insert(track, info);
     }
 
-    QUndoCommand* command = new QUndoCommand();
+    MultiUndoCommand* command = new MultiUndoCommand();
 
     rational movement;
 
@@ -144,15 +144,14 @@ void RippleTool::FinishDrag(TimelineViewMouseEvent *event)
 
     for (int i=0;i<info_list.size();i++) {
       if (!info_list.at(i).isEmpty()) {
-        new TrackListRippleToolCommand(parent()->GetConnectedNode()->track_list(static_cast<Track::Type>(i)),
+        command->add_child(new TrackListRippleToolCommand(parent()->GetConnectedNode()->track_list(static_cast<Track::Type>(i)),
                                                           info_list.at(i),
                                                           movement,
-                                       drag_movement_mode(),
-                                       command);
+                                                          drag_movement_mode()));
       }
     }
 
-    if (command->childCount() > 0) {
+    if (command->child_count() > 0) {
       TimelineWidgetSelections new_sel = parent()->GetSelections();
       TimelineViewGhostItem* reference_ghost = parent()->GetGhostItems().first();
       if (drag_movement_mode() == Timeline::kTrimIn) {
@@ -160,7 +159,7 @@ void RippleTool::FinishDrag(TimelineViewMouseEvent *event)
       } else {
         new_sel.TrimOut(reference_ghost->GetOutAdjustment());
       }
-      new TimelineWidget::SetSelectionsCommand(parent(), new_sel, parent()->GetSelections(), command);
+      command->add_child(new TimelineWidget::SetSelectionsCommand(parent(), new_sel, parent()->GetSelections()));
 
       Core::instance()->undo_stack()->push(command);
     } else {

app/widget/timelinewidget/tool/slip.cpp

@@ -68,13 +68,13 @@ void SlipTool::FinishDrag(TimelineViewMouseEvent *event)
 {
   Q_UNUSED(event)
 
-  QUndoCommand* command = new QUndoCommand();
+  MultiUndoCommand* command = new MultiUndoCommand();
 
   // Find earliest point to ripple around
   foreach (TimelineViewGhostItem* ghost, parent()->GetGhostItems()) {
     Block* b = Node::ValueToPtr<Block>(ghost->GetData(TimelineViewGhostItem::kAttachedBlock));
 
-    new BlockSetMediaInCommand(b, ghost->GetAdjustedMediaIn(), command);
+    command->add_child(new BlockSetMediaInCommand(b, ghost->GetAdjustedMediaIn()));
   }
 
   Core::instance()->undo_stack()->pushIfHasChildren(command);

app/widget/timelinewidget/tool/tool.cpp

@@ -128,7 +128,7 @@ void TimelineTool::GetGhostData(rational *earliest_point, rational *latest_point
   }
 }
 
-void TimelineTool::InsertGapsAtGhostDestination(QUndoCommand *command)
+void TimelineTool::InsertGapsAtGhostDestination(olive::MultiUndoCommand *command)
 {
   rational earliest_point, latest_point;
 

app/widget/timelinewidget/tool/tool.h

@@ -75,7 +75,7 @@ protected:
 
   void GetGhostData(rational *earliest_point, rational *latest_point);
 
-  void InsertGapsAtGhostDestination(QUndoCommand* command);
+  void InsertGapsAtGhostDestination(MultiUndoCommand* command);
 
   QVector<rational> snap_points_;
 

app/widget/timelinewidget/tool/transition.cpp

@@ -120,18 +120,16 @@ void TransitionTool::MouseRelease(TimelineViewMouseEvent *event)
         transition = static_cast<TransitionBlock*>(NodeFactory::CreateFromID(Core::instance()->GetSelectedTransition()));
       }
 
-      QUndoCommand* command = new QUndoCommand();
+      MultiUndoCommand* command = new MultiUndoCommand();
 
       // Place transition in place
-      new NodeAddCommand(static_cast<NodeGraph*>(parent()->GetConnectedNode()->parent()),
-                         transition,
-                         command);
+      command->add_child(new NodeAddCommand(static_cast<NodeGraph*>(parent()->GetConnectedNode()->parent()),
+                                            transition));
 
-      new TrackPlaceBlockCommand(parent()->GetConnectedNode()->track_list(track.type()),
+      command->add_child(new TrackPlaceBlockCommand(parent()->GetConnectedNode()->track_list(track.type()),
                                                     track.index(),
                                                     transition,
-                                 ghost_->GetAdjustedIn(),
-                                 command);
+                                                    ghost_->GetAdjustedIn()));
 
       if (dual_transition_) {
         transition->set_length_and_media_out(ghost_->GetAdjustedLength());
@@ -148,15 +146,13 @@ void TransitionTool::MouseRelease(TimelineViewMouseEvent *event)
         Block* in_block = (ghost_->GetMode() == Timeline::kTrimIn) ? active_block : friend_block;
 
         // Connect block to transition
-        new NodeEdgeAddCommand(out_block,
+        command->add_child(new NodeEdgeAddCommand(out_block,
                                                   transition->out_block_input(),
-                               -1,
-                               command);
+                                                  -1));
 
-        new NodeEdgeAddCommand(in_block,
+        command->add_child(new NodeEdgeAddCommand(in_block,
                                                   transition->in_block_input(),
-                               -1,
-                               command);
+                                                  -1));
       } else {
         Block* block_to_transition = Node::ValueToPtr<Block>(ghost_->GetData(TimelineViewGhostItem::kAttachedBlock));
         NodeInput* transition_input_to_connect;
@@ -170,10 +166,9 @@ void TransitionTool::MouseRelease(TimelineViewMouseEvent *event)
         }
 
         // Connect block to transition
-        new NodeEdgeAddCommand(block_to_transition,
+        command->add_child(new NodeEdgeAddCommand(block_to_transition,
                                                   transition_input_to_connect,
-                               -1,
-                               command);
+                                                  -1));
       }
 
       Core::instance()->undo_stack()->push(command);

app/window/mainwindow/mainmenu.cpp

@@ -75,10 +75,10 @@ MainMenu::MainMenu(MainWindow *parent) :
   //
   edit_menu_ = new Menu(this);
 
-  edit_undo_item_ = Core::instance()->undo_stack()->createUndoAction(this);
+  edit_undo_item_ = Core::instance()->undo_stack()->GetUndoAction();
   Menu::ConformItem(edit_undo_item_, "undo", "Ctrl+Z");
   edit_menu_->addAction(edit_undo_item_);
-  edit_redo_item_ = Core::instance()->undo_stack()->createRedoAction(this);
+  edit_redo_item_ = Core::instance()->undo_stack()->GetRedoAction();
   Menu::ConformItem(edit_redo_item_, "redo", "Ctrl+Shift+Z");
   edit_menu_->addAction(edit_redo_item_);