implemented node groups

app/dialog/CMakeLists.txt

@@ -23,6 +23,7 @@ add_subdirectory(diskcache)
 add_subdirectory(export)
 add_subdirectory(footagerelink)
 add_subdirectory(keyframeproperties)
+add_subdirectory(nodegroup)
 add_subdirectory(nodeproperties)
 add_subdirectory(preferences)
 add_subdirectory(progress)

app/dialog/nodegroup/CMakeLists.txt

@@ -0,0 +1,22 @@
+# Olive - Non-Linear Video Editor
+# Copyright (C) 2021 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/>.
+
+set(OLIVE_SOURCES
+  ${OLIVE_SOURCES}
+  dialog/nodegroup/nodegroupdialog.cpp
+  dialog/nodegroup/nodegroupdialog.h
+  PARENT_SCOPE
+)

app/dialog/nodegroup/nodegroupdialog.cpp

@@ -0,0 +1,99 @@
+/***
+
+  Olive - Non-Linear Video Editor
+  Copyright (C) 2021 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/>.
+
+***/
+
+#include "nodegroupdialog.h"
+
+#include <QDialogButtonBox>
+#include <QGridLayout>
+#include <QLabel>
+#include <QSplitter>
+
+#include "widget/nodeparamview/nodeparamview.h"
+#include "widget/nodeview/nodeview.h"
+
+namespace olive {
+
+#define super QDialog
+
+NodeGroupDialog::NodeGroupDialog(NodeGroup *group, QWidget *parent) :
+  super(parent),
+  group_(group),
+  parent_undo_(nullptr)
+{
+  QGridLayout *layout = new QGridLayout(this);
+
+  int row = 0;
+
+  layout->addWidget(new QLabel(tr("Name:")), row, 0);
+
+  name_edit_ = new QLineEdit();
+  layout->addWidget(name_edit_, row, 1);
+
+  row++;
+
+  QSplitter *splitter = new QSplitter(Qt::Horizontal);
+  layout->addWidget(splitter, row, 0, 1, 2);
+
+  NodeParamView *param_view = new NodeParamView(false);
+  param_view->SetCreateCheckBoxes(kCheckBoxesOnNonConnected);
+  splitter->addWidget(param_view);
+
+  NodeView *node_view = new NodeView();
+  node_view->SetContexts({group});
+  QMetaObject::invokeMethod(node_view, &NodeView::CenterOnItemsBoundingRect, Qt::QueuedConnection);
+  splitter->addWidget(node_view);
+
+  for (auto it=group->GetInputPassthroughs().cbegin(); it!=group->GetInputPassthroughs().cend(); it++) {
+    param_view->SetInputChecked(it.value(), true);
+  }
+
+  connect(node_view, &NodeView::NodesSelected, param_view, &NodeParamView::SelectNodes);
+  connect(node_view, &NodeView::NodesDeselected, param_view, &NodeParamView::DeselectNodes);
+  node_view->SelectAll();
+
+  row++;
+
+  QDialogButtonBox *btns = new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel);
+  btns->setCenterButtons(true);
+  connect(btns, &QDialogButtonBox::accepted, this, &NodeGroupDialog::accept);
+  connect(btns, &QDialogButtonBox::rejected, this, &NodeGroupDialog::reject);
+  layout->addWidget(btns, row, 0, 1, 2);
+
+  setWindowTitle(tr("Group Editor"));
+}
+
+void NodeGroupDialog::accept()
+{
+  MultiUndoCommand *command = new MultiUndoCommand();
+
+  if (name_edit_->text() != group_->GetCustomName()) {
+    command->add_child(new NodeGroupSetCustomNameCommand(group_, name_edit_->text()));
+  }
+
+  if (parent_undo_) {
+    parent_undo_->add_child(command);
+  } else {
+    Core::instance()->undo_stack()->push(command);
+  }
+
+  super::accept();
+}
+
+}

app/dialog/nodegroup/nodegroupdialog.h

@@ -18,26 +18,41 @@
 
 ***/
 
-#ifndef NODEGROUP_H
-#define NODEGROUP_H
+#ifndef NODEGROUPDIALOG_H
+#define NODEGROUPDIALOG_H
 
-#include "node.h"
+#include <QDialog>
+#include <QLineEdit>
+
+#include "node/group/group.h"
 
 namespace olive {
 
-class NodeGroup : public Node
+class NodeGroupDialog : public QDialog
 {
   Q_OBJECT
 public:
-  NodeGroup();
+  explicit NodeGroupDialog(NodeGroup *group, QWidget *parent = nullptr);
 
-  void SetNodes(Node *nodes);
+  void SetParentUndoCommand(MultiUndoCommand *c)
+  {
+    parent_undo_ = c;
+  }
+
+public slots:
+  virtual void accept() override;
+
+signals:
 
 private:
-  QVector<Node*> nodes_;
+  NodeGroup *group_;
+
+  QLineEdit *name_edit_;
+
+  MultiUndoCommand *parent_undo_;
 
 };
 
 }
 
-#endif // NODEGROUP_H
+#endif // NODEGROUPDIALOG_H

app/dialog/nodeproperties/nodepropertiesdialog.cpp

@@ -46,7 +46,7 @@ NodePropertiesDialog::NodePropertiesDialog(Node *node, const rational &timebase,
   label_edit_->setText(node->GetLabel());
   label_layout->addWidget(label_edit_);
 
-  NodeParamViewItem *item = new NodeParamViewItem(node);
+  NodeParamViewItem *item = new NodeParamViewItem(node, kNoCheckBoxes);
   item->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Fixed);
   item->SetTimebase(timebase);
   item->setTitleBarWidget(new QWidget());

app/node/CMakeLists.txt

@@ -20,6 +20,7 @@ add_subdirectory(color)
 add_subdirectory(distort)
 add_subdirectory(filter)
 add_subdirectory(generator)
+add_subdirectory(group)
 add_subdirectory(input)
 add_subdirectory(math)
 add_subdirectory(output)
@@ -34,8 +35,6 @@ set(OLIVE_SOURCES
   node/globals.h
   node/graph.cpp
   node/graph.h
-  node/group.cpp
-  node/group.h
   node/hashtraverser.cpp
   node/hashtraverser.h
   node/inputdragger.cpp

app/node/group.cpp

@@ -1,30 +0,0 @@
-/***
-
-  Olive - Non-Linear Video Editor
-  Copyright (C) 2021 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/>.
-
-***/
-
-#include "group.h"
-
-namespace olive {
-
-NodeGroup::NodeGroup()
-{
-
-}
-
-}

app/node/group/CMakeLists.txt

@@ -0,0 +1,22 @@
+# Olive - Non-Linear Video Editor
+# Copyright (C) 2021 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/>.
+
+set(OLIVE_SOURCES
+  ${OLIVE_SOURCES}
+  node/group/group.cpp
+  node/group/group.h
+  PARENT_SCOPE
+)

app/node/group/group.cpp

@@ -0,0 +1,177 @@
+/***
+
+  Olive - Non-Linear Video Editor
+  Copyright (C) 2021 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/>.
+
+***/
+
+#include "group.h"
+
+#include "node/graph.h"
+
+namespace olive {
+
+NodeGroup::NodeGroup() :
+  output_passthrough_(nullptr)
+{
+  graph_ = new NodeGraph();
+  graph_->setParent(this);
+}
+
+QString NodeGroup::Name() const
+{
+  if (custom_name_.isEmpty()) {
+    return tr("Group");
+  } else {
+    return custom_name_;
+  }
+}
+
+QString NodeGroup::id() const
+{
+  return QStringLiteral("org.olivevideoeditor.Olive.group");
+}
+
+QVector<Node::CategoryID> NodeGroup::Category() const
+{
+  return {kCategoryGeneral};
+}
+
+QString NodeGroup::Description() const
+{
+  return tr("A group of nodes that is represented as a single node.");
+}
+
+void NodeGroup::Retranslate()
+{
+  foreach (Node *n, graph_->nodes()) {
+    n->Retranslate();
+  }
+}
+
+void NodeGroup::AddNode(Node *node)
+{
+  node->setParent(graph_);
+}
+
+void NodeGroup::RemoveNode(Node *node, QObject *new_parent)
+{
+  if (node->parent() == graph_) {
+    node->setParent(new_parent);
+  }
+}
+
+void NodeGroup::AddInputPassthrough(const NodeInput &input)
+{
+  Q_ASSERT(graph_->nodes().contains(input.node()));
+
+  for (auto it=input_passthroughs_.cbegin(); it!=input_passthroughs_.cend(); it++) {
+    if (it.value() == input) {
+      // Already passing this input through
+      return;
+    }
+  }
+
+  // Add input
+  QString id = GetGroupInputIDFromInput(input);
+
+  AddInput(id, input.GetDataType(), input.GetDefaultValue(), input.GetFlags());
+
+  input_passthroughs_.insert(id, input);
+}
+
+void NodeGroup::RemoveInputPassthrough(const NodeInput &input)
+{
+  for (auto it=input_passthroughs_.cbegin(); it!=input_passthroughs_.cend(); it++) {
+    if (it.value() == input) {
+      RemoveInput(it.key());
+      input_passthroughs_.erase(it);
+      break;
+    }
+  }
+}
+
+void NodeGroup::SetOutputPassthrough(Node *node)
+{
+  Q_ASSERT(graph_->nodes().contains(node));
+
+  output_passthrough_ = node;
+}
+
+QString NodeGroup::GetGroupInputIDFromInput(const NodeInput &input)
+{
+  QCryptographicHash hash(QCryptographicHash::Sha1);
+
+  hash.addData(input.node()->GetUUID().toByteArray());
+
+  hash.addData(input.input().toUtf8());
+
+  hash.addData((const char*) &input.element(), sizeof(input.element()));
+
+  return QString::fromLatin1(hash.result().toHex());
+}
+
+bool NodeGroup::ContainsInputPassthrough(const NodeInput &input) const
+{
+  for (auto it=input_passthroughs_.cbegin(); it!=input_passthroughs_.cend(); it++) {
+    if (it.value() == input) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+void NodeAddToGroupCommand::redo()
+{
+  previous_parent_ = node_->parent();
+  group_->AddNode(node_);
+}
+
+void NodeAddToGroupCommand::undo()
+{
+  group_->RemoveNode(node_, previous_parent_);
+}
+
+void NodeGroupSetCustomNameCommand::redo()
+{
+  old_name_ = group_->GetCustomName();
+  group_->SetCustomName(new_name_);
+}
+
+void NodeGroupSetCustomNameCommand::undo()
+{
+  group_->SetCustomName(old_name_);
+}
+
+void NodeGroupAddInputPassthrough::redo()
+{
+  if (!group_->ContainsInputPassthrough(input_)) {
+    group_->AddInputPassthrough(input_);
+    actually_added_ = true;
+  } else {
+    actually_added_ = false;
+  }
+}
+
+void NodeGroupAddInputPassthrough::undo()
+{
+  if (actually_added_) {
+    group_->RemoveInputPassthrough(input_);
+  }
+}
+
+}

app/node/group/group.h

@@ -0,0 +1,176 @@
+/***
+
+  Olive - Non-Linear Video Editor
+  Copyright (C) 2021 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 NODEGROUP_H
+#define NODEGROUP_H
+
+#include "node/node.h"
+
+namespace olive {
+
+class NodeGroup : public Node
+{
+  Q_OBJECT
+public:
+  NodeGroup();
+
+  NODE_DEFAULT_DESTRUCTOR(NodeGroup)
+  NODE_COPY_FUNCTION(NodeGroup)
+
+  virtual QString Name() const override;
+  virtual QString id() const override;
+  virtual QVector<CategoryID> Category() const override;
+  virtual QString Description() const override;
+
+  virtual void Retranslate() override;
+
+  void AddNode(Node *node);
+
+  void RemoveNode(Node *node, QObject *new_parent = nullptr);
+
+  void AddInputPassthrough(const NodeInput &input);
+
+  void RemoveInputPassthrough(const NodeInput &input);
+
+  void SetOutputPassthrough(Node *node);
+
+  const QString &GetCustomName() const
+  {
+    return custom_name_;
+  }
+
+  void SetCustomName(const QString &name)
+  {
+    custom_name_ = name;
+
+    // NOTE: Not technically the right signal, but should achieve the right goal
+    emit LabelChanged(custom_name_);
+  }
+
+  void ClearCustomName()
+  {
+    custom_name_.clear();
+  }
+
+  static QString GetGroupInputIDFromInput(const NodeInput &input);
+
+  const QHash<QString, NodeInput> &GetInputPassthroughs() const
+  {
+    return input_passthroughs_;
+  }
+
+  bool ContainsInputPassthrough(const NodeInput &input) const;
+
+private:
+  NodeGraph *graph_;
+
+  QHash<QString, NodeInput> input_passthroughs_;
+
+  Node *output_passthrough_;
+
+  QString custom_name_;
+
+};
+
+class NodeAddToGroupCommand : public UndoCommand
+{
+public:
+  NodeAddToGroupCommand(Node *node, NodeGroup *group) :
+    node_(node),
+    group_(group)
+  {}
+
+  virtual Project * GetRelevantProject() const override
+  {
+    return node_->project();
+  }
+
+protected:
+  virtual void redo() override;
+
+  virtual void undo() override;
+
+private:
+  Node *node_;
+
+  NodeGroup *group_;
+
+  QObject *previous_parent_;
+
+};
+
+class NodeGroupSetCustomNameCommand : public UndoCommand
+{
+public:
+  NodeGroupSetCustomNameCommand(NodeGroup *group, const QString &name) :
+    group_(group),
+    new_name_(name)
+  {}
+
+  virtual Project * GetRelevantProject() const override
+  {
+    return group_->project();
+  }
+
+protected:
+  virtual void redo() override;
+
+  virtual void undo() override;
+
+private:
+  NodeGroup *group_;
+
+  QString old_name_;
+
+  QString new_name_;
+
+};
+
+class NodeGroupAddInputPassthrough : public UndoCommand
+{
+public:
+  NodeGroupAddInputPassthrough(NodeGroup *group, const NodeInput &input) :
+    group_(group),
+    input_(input),
+    actually_added_(false)
+  {}
+
+  virtual Project * GetRelevantProject() const override
+  {
+    return group_->project();
+  }
+
+protected:
+  virtual void redo() override;
+
+  virtual void undo() override;
+
+private:
+  NodeGroup *group_;
+
+  NodeInput input_;
+
+  bool actually_added_;
+
+};
+
+}
+
+#endif // NODEGROUP_H

app/node/node.cpp

@@ -49,6 +49,7 @@ Node::Node() :
   operation_stack_(0),
   cache_result_(false)
 {
+  uuid_ = QUuid::createUuid();
 }
 
 Node::~Node()
@@ -88,6 +89,8 @@ void Node::Load(QXmlStreamReader *reader, XMLNodeData& xml_node_data, uint versi
       xml_node_data.node_ptrs.insert(reader->readElementText().toULongLong(), this);
     } else if (reader->name() == QStringLiteral("label")) {
       SetLabel(reader->readElementText());
+    } else if (reader->name() == QStringLiteral("uuid")) {
+      SetUUID(QUuid::fromString(reader->readElementText()));
     } else if (reader->name() == QStringLiteral("color")) {
       override_color_ = reader->readElementText().toInt();
     } else if (reader->name() == QStringLiteral("links")) {
@@ -169,6 +172,7 @@ void Node::Save(QXmlStreamWriter *writer) const
 {
   writer->writeTextElement(QStringLiteral("ptr"), QString::number(reinterpret_cast<quintptr>(this)));
 
+  writer->writeTextElement(QStringLiteral("uuid"), uuid_.toString());
   writer->writeTextElement(QStringLiteral("label"), GetLabel());
   writer->writeTextElement(QStringLiteral("color"), QString::number(override_color_));
 
@@ -219,7 +223,16 @@ void Node::Save(QXmlStreamWriter *writer) const
 
 Project* Node::project() const
 {
-  return dynamic_cast<Project*>(parent());
+  QObject *t = this->parent();
+
+  while (t) {
+    if (Project *p = dynamic_cast<Project*>(t)) {
+      return p;
+    }
+    t = t->parent();
+  }
+
+  return nullptr;
 }
 
 QString Node::ShortName() const
@@ -1089,7 +1102,7 @@ NodeInputImmediate *Node::GetImmediate(const QString &input, int element) const
   return nullptr;
 }
 
-Node::InputFlags Node::GetInputFlags(const QString &input) const
+InputFlags Node::GetInputFlags(const QString &input) const
 {
   const Input* i = GetInternalInputData(input);
 
@@ -1343,7 +1356,7 @@ void Node::HashAddNodeSignature(QCryptographicHash &hash) const
   hash.addData(id().toUtf8());
 }
 
-void Node::InsertInput(const QString &id, NodeValue::Type type, const QVariant &default_value, Node::InputFlags flags, int index)
+void Node::InsertInput(const QString &id, NodeValue::Type type, const QVariant &default_value, InputFlags flags, int index)
 {
   if (id.isEmpty()) {
     qWarning() << "Rejected adding input with an empty ID on node" << this->id();

app/node/node.h

@@ -27,6 +27,7 @@
 #include <QObject>
 #include <QPainter>
 #include <QPointF>
+#include <QUuid>
 #include <QXmlStreamWriter>
 
 #include "codec/frame.h"
@@ -112,6 +113,9 @@ public:
 
   Project* project() const;
 
+  const QUuid &GetUUID() const {return uuid_;}
+  void SetUUID(const QUuid &uuid) {uuid_ = uuid;}
+
   /**
    * @brief Clear current node variables and replace them with
    */
@@ -935,38 +939,9 @@ public:
 
   };
 
+  InputFlags GetInputFlags(const QString& input) const;
+
 protected:
-  enum InputFlag {
-    /// By default, inputs are keyframable, connectable, and NOT arrays
-    kInputFlagNormal = 0x0,
-    kInputFlagArray = 0x1,
-    kInputFlagNotKeyframable = 0x2,
-    kInputFlagNotConnectable = 0x4,
-    kInputFlagHidden = 0x8
-  };
-
-  class InputFlags {
-  public:
-    explicit InputFlags()
-    {
-      f_ = kInputFlagNormal;
-    }
-
-    explicit InputFlags(uint64_t flags)
-    {
-      f_ = flags;
-    }
-
-    bool operator&(const InputFlag& f) const
-    {
-      return f_ & f;
-    }
-
-  private:
-    uint64_t f_;
-
-  };
-
   virtual void Hash(QCryptographicHash& hash, const NodeGlobals &globals, const VideoParams& video_params) const;
 
   void HashAddNodeSignature(QCryptographicHash &hash) const;
@@ -1216,8 +1191,6 @@ private:
     return input_ids_.indexOf(input);
   }
 
-  InputFlags GetInputFlags(const QString& input) const;
-
   Input* GetInternalInputData(const QString& input)
   {
     int i = GetInternalInputIndex(input);
@@ -1336,6 +1309,8 @@ private:
 
   PositionMap context_positions_;
 
+  QUuid uuid_;
+
 private slots:
   /**
    * @brief Slot when a keyframe's time changes to keep the keyframes correctly sorted by time

app/node/output/viewer/viewer.h

@@ -254,8 +254,6 @@ private:
 
   AudioPlaybackCache audio_playback_cache_;
 
-  int operation_stack_;
-
   VideoParams cached_video_params_;
 
   AudioParams cached_audio_params_;

app/node/param.cpp

@@ -69,6 +69,15 @@ bool NodeInput::IsArray() const
   }
 }
 
+InputFlags NodeInput::GetFlags() const
+{
+  if (IsValid()) {
+    return node_->GetInputFlags(input_);
+  } else {
+    return InputFlags(kInputFlagNormal);
+  }
+}
+
 Node *NodeInput::GetConnectedOutput() const
 {
   if (IsValid()) {
@@ -87,6 +96,15 @@ NodeValue::Type NodeInput::GetDataType() const
   }
 }
 
+QVariant NodeInput::GetDefaultValue() const
+{
+  if (IsValid()) {
+    return node_->GetDefaultValue(input_);
+  } else {
+    return QVariant();
+  }
+}
+
 QStringList NodeInput::GetComboBoxStrings() const
 {
   if (IsValid()) {

app/node/param.h

@@ -31,6 +31,37 @@ namespace olive {
 class Node;
 class NodeKeyframe;
 
+enum InputFlag {
+  /// By default, inputs are keyframable, connectable, and NOT arrays
+  kInputFlagNormal = 0x0,
+  kInputFlagArray = 0x1,
+  kInputFlagNotKeyframable = 0x2,
+  kInputFlagNotConnectable = 0x4,
+  kInputFlagHidden = 0x8
+};
+
+class InputFlags {
+public:
+  explicit InputFlags()
+  {
+    f_ = kInputFlagNormal;
+  }
+
+  explicit InputFlags(uint64_t flags)
+  {
+    f_ = flags;
+  }
+
+  bool operator&(const InputFlag& f) const
+  {
+    return f_ & f;
+  }
+
+private:
+  uint64_t f_;
+
+};
+
 struct NodeInputPair {
   bool operator==(const NodeInputPair& rhs) const
   {
@@ -98,7 +129,7 @@ public:
     return input_;
   }
 
-  int element() const
+  const int &element() const
   {
     return element_;
   }
@@ -123,10 +154,14 @@ public:
 
   bool IsArray() const;
 
+  InputFlags GetFlags() const;
+
   Node *GetConnectedOutput() const;
 
   NodeValue::Type GetDataType() const;
 
+  QVariant GetDefaultValue() const;
+
   QStringList GetComboBoxStrings() const;
 
   QVariant GetProperty(const QString& key) const;

app/render/previewautocacher.cpp

@@ -373,6 +373,9 @@ void PreviewAutoCacher::AddNode(Node *node)
   // Add to project
   copy->setParent(&copied_project_);
 
+  // Copy UUID
+  copy->SetUUID(node->GetUUID());
+
   // Insert into map
   InsertIntoCopyMap(node, copy);
 

app/render/previewautocacher.h

@@ -24,8 +24,9 @@
 #include <QtConcurrent/QtConcurrent>
 
 #include "config/config.h"
-#include "node/graph.h"
 #include "node/color/colormanager/colormanager.h"
+#include "node/graph.h"
+#include "node/group/group.h"
 #include "node/node.h"
 #include "node/output/viewer/viewer.h"
 #include "node/project/project.h"
@@ -172,6 +173,7 @@ private:
 
   QVector<QueuedJob> graph_update_queue_;
   QHash<Node*, Node*> copy_map_;
+  QHash<NodeGraph*, NodeGraph*> graph_map_;
   ViewerOutput* copied_viewer_node_;
   ColorManager* copied_color_manager_;
   QVector<Node*> created_nodes_;

app/widget/nodeparamview/nodeparamview.cpp

@@ -32,10 +32,12 @@ namespace olive {
 
 #define super TimeBasedWidget
 
-NodeParamView::NodeParamView(QWidget *parent) :
+NodeParamView::NodeParamView(bool create_keyframe_view, QWidget *parent) :
   super(true, false, parent),
   last_scroll_val_(0),
-  focused_node_(nullptr)
+  focused_node_(nullptr),
+  create_checkboxes_(kNoCheckBoxes),
+  time_target_(nullptr)
 {
   // Create horizontal layout to place scroll area in (and keyframe editing eventually)
   QHBoxLayout* layout = new QHBoxLayout(this);
@@ -46,16 +48,16 @@ NodeParamView::NodeParamView(QWidget *parent) :
   layout->addWidget(splitter);
 
   // Set up scroll area for params
-  QScrollArea* scroll_area = new QScrollArea();
-  scroll_area->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOn);
-  scroll_area->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
-  scroll_area->setWidgetResizable(true);
-  splitter->addWidget(scroll_area);
+  param_scroll_area_ = new QScrollArea();
+  param_scroll_area_->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOn);
+  param_scroll_area_->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+  param_scroll_area_->setWidgetResizable(true);
+  splitter->addWidget(param_scroll_area_);
 
   // Param widget
   param_widget_container_ = new NodeParamViewParamContainer();
   connect(param_widget_container_, &NodeParamViewParamContainer::Resized, this, &NodeParamView::UpdateGlobalScrollBar);
-  scroll_area->setWidget(param_widget_container_);
+  param_scroll_area_->setWidget(param_widget_container_);
 
   param_widget_area_ = new NodeParamViewDockArea();
 
@@ -74,56 +76,63 @@ NodeParamView::NodeParamView(QWidget *parent) :
 
   param_widget_container_layout->addStretch(INT_MAX);
 
-  // Set up keyframe view
-  QWidget* keyframe_area = new QWidget();
-  QVBoxLayout* keyframe_area_layout = new QVBoxLayout(keyframe_area);
-  keyframe_area_layout->setSpacing(0);
-  keyframe_area_layout->setMargin(0);
-
-  // Create ruler object
-  keyframe_area_layout->addWidget(ruler());
-
-  // Create keyframe view
-  keyframe_view_ = new KeyframeView();
-  keyframe_view_->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
-  ConnectTimelineView(keyframe_view_);
-  keyframe_area_layout->addWidget(keyframe_view_);
-
-  // Connect ruler and keyframe view together
-  connect(ruler(), &TimeRuler::TimeChanged, keyframe_view_, &KeyframeView::SetTime);
-  connect(keyframe_view_, &KeyframeView::TimeChanged, ruler(), &TimeRuler::SetTime);
-  connect(keyframe_view_, &KeyframeView::TimeChanged, this, &NodeParamView::SetTime);
-  connect(keyframe_view_, &KeyframeView::Dragged, this, &NodeParamView::KeyframeViewDragged);
-
-  // Connect keyframe view scaling to this
-  connect(keyframe_view_, &KeyframeView::ScaleChanged, this, &NodeParamView::SetScale);
-
-  splitter->addWidget(keyframe_area);
-
-  // Set both widgets to 50/50
-  splitter->setSizes({INT_MAX, INT_MAX});
-
   // Disable collapsing param view (but collapsing keyframe view is permitted)
   splitter->setCollapsible(0, false);
 
+  if (create_keyframe_view) {
+    // Set up keyframe view
+    QWidget* keyframe_area = new QWidget();
+    QVBoxLayout* keyframe_area_layout = new QVBoxLayout(keyframe_area);
+    keyframe_area_layout->setSpacing(0);
+    keyframe_area_layout->setMargin(0);
+
+    // Create ruler object
+    keyframe_area_layout->addWidget(ruler());
+
+    // Create keyframe view
+    keyframe_view_ = new KeyframeView();
+    keyframe_view_->setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
+    ConnectTimelineView(keyframe_view_);
+    keyframe_area_layout->addWidget(keyframe_view_);
+
+    // Connect ruler and keyframe view together
+    connect(ruler(), &TimeRuler::TimeChanged, keyframe_view_, &KeyframeView::SetTime);
+    connect(keyframe_view_, &KeyframeView::TimeChanged, ruler(), &TimeRuler::SetTime);
+    connect(keyframe_view_, &KeyframeView::TimeChanged, this, &NodeParamView::SetTime);
+    connect(keyframe_view_, &KeyframeView::Dragged, this, &NodeParamView::KeyframeViewDragged);
+
+    // Connect keyframe view scaling to this
+    connect(keyframe_view_, &KeyframeView::ScaleChanged, this, &NodeParamView::SetScale);
+
+    splitter->addWidget(keyframe_area);
+
+    // Set both widgets to 50/50
+    splitter->setSizes({INT_MAX, INT_MAX});
+  } else {
+    keyframe_view_ = nullptr;
+  }
+
   // Create global vertical scrollbar on the right
   vertical_scrollbar_ = new QScrollBar();
   vertical_scrollbar_->setMaximum(0);
   layout->addWidget(vertical_scrollbar_);
 
   // Connect scrollbars together
-  connect(keyframe_view_->verticalScrollBar(), &QScrollBar::valueChanged, vertical_scrollbar_, &QScrollBar::setValue);
-  connect(keyframe_view_->verticalScrollBar(), &QScrollBar::valueChanged, scroll_area->verticalScrollBar(), &QScrollBar::setValue);
-  connect(scroll_area->verticalScrollBar(), &QScrollBar::valueChanged, vertical_scrollbar_, &QScrollBar::setValue);
-  connect(scroll_area->verticalScrollBar(), &QScrollBar::valueChanged, keyframe_view_->verticalScrollBar(), &QScrollBar::setValue);
-  connect(vertical_scrollbar_, &QScrollBar::valueChanged, scroll_area->verticalScrollBar(), &QScrollBar::setValue);
-  connect(vertical_scrollbar_, &QScrollBar::valueChanged, keyframe_view_->verticalScrollBar(), &QScrollBar::setValue);
+  connect(param_scroll_area_->verticalScrollBar(), &QScrollBar::valueChanged, vertical_scrollbar_, &QScrollBar::setValue);
+  connect(vertical_scrollbar_, &QScrollBar::valueChanged, param_scroll_area_->verticalScrollBar(), &QScrollBar::setValue);
 
-  // TimeBasedWidget's scrollbar has extra functionality that we can take advantage of
-  keyframe_view_->setHorizontalScrollBar(scrollbar());
-  keyframe_view_->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOn);
+  if (keyframe_view_) {
+    connect(keyframe_view_->verticalScrollBar(), &QScrollBar::valueChanged, vertical_scrollbar_, &QScrollBar::setValue);
+    connect(keyframe_view_->verticalScrollBar(), &QScrollBar::valueChanged, param_scroll_area_->verticalScrollBar(), &QScrollBar::setValue);
+    connect(param_scroll_area_->verticalScrollBar(), &QScrollBar::valueChanged, keyframe_view_->verticalScrollBar(), &QScrollBar::setValue);
+    connect(vertical_scrollbar_, &QScrollBar::valueChanged, keyframe_view_->verticalScrollBar(), &QScrollBar::setValue);
 
-  connect(keyframe_view_->horizontalScrollBar(), &QScrollBar::valueChanged, ruler(), &TimeRuler::SetScroll);
+    // TimeBasedWidget's scrollbar has extra functionality that we can take advantage of
+    keyframe_view_->setHorizontalScrollBar(scrollbar());
+    keyframe_view_->setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOn);
+
+    connect(keyframe_view_->horizontalScrollBar(), &QScrollBar::valueChanged, ruler(), &TimeRuler::SetScroll);
+  }
 
   // Set a default scale - FIXME: Hardcoded
   SetScale(120);
@@ -192,6 +201,14 @@ void NodeParamView::DeselectNodes(const QVector<Node *> &nodes)
   }
 }
 
+void NodeParamView::SetInputChecked(const NodeInput &input, bool e)
+{
+  input_checked_.insert(input, e);
+  if (NodeParamViewItem *item = items_.value(input.node())) {
+    item->SetInputChecked(input, e);
+  }
+}
+
 void NodeParamView::resizeEvent(QResizeEvent *event)
 {
   super::resizeEvent(event);
@@ -205,17 +222,21 @@ void NodeParamView::ScaleChangedEvent(const double &scale)
 {
   super::ScaleChangedEvent(scale);
 
-  keyframe_view_->SetScale(scale);
+  if (keyframe_view_) {
+    keyframe_view_->SetScale(scale);
+  }
 }
 
 void NodeParamView::TimebaseChangedEvent(const rational &timebase)
 {
   super::TimebaseChangedEvent(timebase);
 
-  keyframe_view_->SetTimebase(timebase);
+  if (keyframe_view_) {
+    keyframe_view_->SetTimebase(timebase);
+  }
 
   foreach (NodeParamViewItem* item, items_) {
-      item->SetTimebase(timebase);
+    item->SetTimebase(timebase);
   }
 
   UpdateItemTime(GetTime());
@@ -225,29 +246,37 @@ void NodeParamView::TimeChangedEvent(const rational &time)
 {
   super::TimeChangedEvent(time);
 
-  keyframe_view_->SetTime(time);
+  if (keyframe_view_) {
+    keyframe_view_->SetTime(time);
+  }
 
   UpdateItemTime(time);
 }
 
 void NodeParamView::ConnectedNodeChangeEvent(ViewerOutput *n)
 {
-  // Set viewer as a time target
-  keyframe_view_->SetTimeTarget(n);
+  if (keyframe_view_) {
+    // Set viewer as a time target
+    keyframe_view_->SetTimeTarget(n);
+  }
 
   foreach (NodeParamViewItem* item, items_) {
     item->SetTimeTarget(n);
   }
+
+  time_target_ = n;
 }
 
 Node *NodeParamView::GetTimeTarget() const
 {
-  return keyframe_view_->GetTimeTarget();
+  return time_target_;
 }
 
 void NodeParamView::DeleteSelected()
 {
-  keyframe_view_->DeleteSelected();
+  if (keyframe_view_) {
+    keyframe_view_->DeleteSelected();
+  }
 }
 
 void NodeParamView::UpdateItemTime(const rational &time)
@@ -293,14 +322,16 @@ void NodeParamView::SignalNodeOrder()
 
 void NodeParamView::AddNode(Node *n)
 {
-  NodeParamViewItem* item = new NodeParamViewItem(n, param_widget_area_);
+  NodeParamViewItem* item = new NodeParamViewItem(n, create_checkboxes_, param_widget_area_);
 
   item->setAllowedAreas(Qt::LeftDockWidgetArea);
   item->setFeatures(QDockWidget::DockWidgetClosable | QDockWidget::DockWidgetMovable);
   item->SetExpanded(node_expanded_state_.value(n, true));
 
-  connect(n, &Node::KeyframeAdded, keyframe_view_, &KeyframeView::AddKeyframe);
-  connect(n, &Node::KeyframeRemoved, keyframe_view_, &KeyframeView::RemoveKeyframe);
+  if (keyframe_view_) {
+    connect(n, &Node::KeyframeAdded, keyframe_view_, &KeyframeView::AddKeyframe);
+    connect(n, &Node::KeyframeRemoved, keyframe_view_, &KeyframeView::RemoveKeyframe);
+  }
 
   connect(item, &NodeParamViewItem::RequestSetTime, this, &NodeParamView::SetTimeAndSignal);
   connect(item, &NodeParamViewItem::RequestSelectNode, this, &NodeParamView::RequestSelectNode);
@@ -310,6 +341,15 @@ void NodeParamView::AddNode(Node *n)
   connect(item, &NodeParamViewItem::ArrayExpandedChanged, this, &NodeParamView::QueueKeyframePositionUpdate);
   connect(item, &NodeParamViewItem::ExpandedChanged, this, &NodeParamView::QueueKeyframePositionUpdate);
   connect(item, &NodeParamViewItem::Moved, this, &NodeParamView::QueueKeyframePositionUpdate);
+  connect(item, &NodeParamViewItem::InputCheckedChanged, this, &NodeParamView::SetInputChecked);
+
+  if (create_checkboxes_) {
+    for (auto it=input_checked_.cbegin(); it!=input_checked_.cend(); it++) {
+      if (it.key().node() == n) {
+        item->SetInputChecked(it.key(), it.value());
+      }
+    }
+  }
 
   // Set time target
   item->SetTimeTarget(GetTimeTarget());
@@ -327,15 +367,19 @@ void NodeParamView::AddNode(Node *n)
     emit FocusedNodeChanged(focused_node_);
   }
 
-  keyframe_view_->AddKeyframesOfNode(n);
+  if (keyframe_view_) {
+    keyframe_view_->AddKeyframesOfNode(n);
+  }
 }
 
 void NodeParamView::RemoveNode(Node *n)
 {
-  keyframe_view_->RemoveKeyframesOfNode(n);
+  if (keyframe_view_) {
+    keyframe_view_->RemoveKeyframesOfNode(n);
 
-  disconnect(n, &Node::KeyframeAdded, keyframe_view_, &KeyframeView::AddKeyframe);
-  disconnect(n, &Node::KeyframeRemoved, keyframe_view_, &KeyframeView::RemoveKeyframe);
+    disconnect(n, &Node::KeyframeAdded, keyframe_view_, &KeyframeView::AddKeyframe);
+    disconnect(n, &Node::KeyframeRemoved, keyframe_view_, &KeyframeView::RemoveKeyframe);
+  }
 
   delete items_.take(n);
 
@@ -358,8 +402,10 @@ void NodeParamView::UpdateGlobalScrollBar()
 {
   int height_offscreen = param_widget_container_->height() - ruler()->height() + scrollbar()->height();
 
-  keyframe_view_->SetMaxScroll(height_offscreen);
-  vertical_scrollbar_->setRange(0, height_offscreen - keyframe_view_->height());
+  if (keyframe_view_) {
+    keyframe_view_->SetMaxScroll(height_offscreen);
+  }
+  vertical_scrollbar_->setRange(0, height_offscreen - param_scroll_area_->height());
 }
 
 void NodeParamView::PinNode(bool pin)
@@ -390,18 +436,20 @@ void NodeParamView::FocusChanged(QWidget* old, QWidget* now)
     item = dynamic_cast<NodeParamViewItem*>(parent);
 
     if (item) {
-      // Found it!
-      if (item->GetNode() != focused_node_) {
-        if (focused_node_) {
-          // De-focus current node
-          items_.value(focused_node_)->SetHighlighted(false);
+      if (item->parent() == param_widget_area_) {
+        // Found it!
+        if (item->GetNode() != focused_node_) {
+          if (focused_node_) {
+            // De-focus current node
+            items_.value(focused_node_)->SetHighlighted(false);
+          }
+
+          focused_node_ = item->GetNode();
+
+          item->SetHighlighted(true);
+
+          emit FocusedNodeChanged(focused_node_);
         }
-
-        focused_node_ = item->GetNode();
-
-        item->SetHighlighted(true);
-
-        emit FocusedNodeChanged(focused_node_);
       }
 
       break;
@@ -421,15 +469,17 @@ void NodeParamView::KeyframeViewDragged(int x, int y)
 
 void NodeParamView::UpdateElementY()
 {
-  for (auto it=items_.cbegin(); it!=items_.cend(); it++) {
-    foreach (const QString& input, it.key()->inputs()) {
-      int arr_sz = it.key()->InputArraySize(input);
+  if (keyframe_view_) {
+    for (auto it=items_.cbegin(); it!=items_.cend(); it++) {
+      foreach (const QString& input, it.key()->inputs()) {
+        int arr_sz = it.key()->InputArraySize(input);
 
-      for (int i=-1; i<arr_sz; i++) {
-        NodeInput ic = {it.key(), input, i};
+        for (int i=-1; i<arr_sz; i++) {
+          NodeInput ic = {it.key(), input, i};
 
-        int y = it.value()->GetElementY(ic);
-        keyframe_view_->SetElementY(ic, y);
+          int y = it.value()->GetElementY(ic);
+          keyframe_view_->SetElementY(ic, y);
+        }
       }
     }
   }

app/widget/nodeparamview/nodeparamview.h

@@ -58,11 +58,25 @@ class NodeParamView : public TimeBasedWidget
 {
   Q_OBJECT
 public:
-  NodeParamView(QWidget* parent = nullptr);
+  NodeParamView(bool create_keyframe_view, QWidget* parent = nullptr);
+  NodeParamView(QWidget* parent = nullptr) :
+    NodeParamView(true, parent)
+  {
+  }
 
   void SelectNodes(const QVector<Node *> &nodes);
   void DeselectNodes(const QVector<Node*>& nodes);
 
+  void SetCreateCheckBoxes(NodeParamViewCheckBoxBehavior e)
+  {
+    create_checkboxes_ = e;
+  }
+
+  bool IsInputChecked(const NodeInput &input) const
+  {
+    return input_checked_.value(input);
+  }
+
   const QMap<Node*, NodeParamViewItem*>& GetItemMap() const
   {
     return items_;
@@ -82,6 +96,9 @@ public:
     keyframe_view_->DeselectAll();
   }
 
+public slots:
+  void SetInputChecked(const NodeInput &input, bool e);
+
 signals:
   void RequestSelectNode(const QVector<Node*>& target);
 
@@ -117,10 +134,10 @@ private:
 
   int last_scroll_val_;
 
+  QScrollArea* param_scroll_area_;
+
   NodeParamViewParamContainer* param_widget_container_;
 
-  // This may look weird, but QMainWindow is just a QWidget with a fancy layout that allows
-  // docking windows
   NodeParamViewDockArea* param_widget_area_;
 
   QVector<Node*> pinned_nodes_;
@@ -131,6 +148,12 @@ private:
 
   Node* focused_node_;
 
+  NodeParamViewCheckBoxBehavior create_checkboxes_;
+
+  Node *time_target_;
+
+  QHash<NodeInput, bool> input_checked_;
+
 private slots:
   void UpdateGlobalScrollBar();
 

app/widget/nodeparamview/nodeparamviewdockarea.h

@@ -25,6 +25,8 @@
 
 namespace olive {
 
+// This may look weird, but QMainWindow is just a QWidget with a fancy layout that allows
+// for docking QDockWidgets
 class NodeParamViewDockArea : public QMainWindow
 {
   Q_OBJECT

app/widget/nodeparamview/nodeparamviewitem.cpp

@@ -38,12 +38,14 @@ const int NodeParamViewItemBody::kArrayInsertColumn = kKeyControlColumn-1;
 const int NodeParamViewItemBody::kArrayRemoveColumn = kArrayInsertColumn-1;
 const int NodeParamViewItemBody::kExtraButtonColumn = kKeyControlColumn-1;
 
-// 0 is for the array collapse button, 1 is for the main label, widgets start at 2
-const int NodeParamViewItemBody::kWidgetStartColumn = 2;
+const int NodeParamViewItemBody::kOptionalCheckBox = 0;
+const int NodeParamViewItemBody::kArrayCollapseBtnColumn = 1;
+const int NodeParamViewItemBody::kLabelColumn = 2;
+const int NodeParamViewItemBody::kWidgetStartColumn = 3;
 
 #define super QDockWidget
 
-NodeParamViewItem::NodeParamViewItem(Node *node, QWidget *parent) :
+NodeParamViewItem::NodeParamViewItem(Node *node, NodeParamViewCheckBoxBehavior create_checkboxes, QWidget *parent) :
   super(parent),
   node_(node),
   highlighted_(false)
@@ -55,10 +57,11 @@ NodeParamViewItem::NodeParamViewItem(Node *node, QWidget *parent) :
   this->setTitleBarWidget(title_bar_);
 
   // Create and add contents widget
-  body_ = new NodeParamViewItemBody(node_);
+  body_ = new NodeParamViewItemBody(node_, create_checkboxes);
   connect(body_, &NodeParamViewItemBody::RequestSelectNode, this, &NodeParamViewItem::RequestSelectNode);
   connect(body_, &NodeParamViewItemBody::RequestSetTime, this, &NodeParamViewItem::RequestSetTime);
   connect(body_, &NodeParamViewItemBody::ArrayExpandedChanged, this, &NodeParamViewItem::ArrayExpandedChanged);
+  connect(body_, &NodeParamViewItemBody::InputCheckedChanged, this, &NodeParamViewItem::InputCheckedChanged);
   connect(title_bar_, &NodeParamViewItemTitleBar::ExpandedStateChanged, this, &NodeParamViewItem::SetExpanded);
   connect(title_bar_, &NodeParamViewItemTitleBar::PinToggled, this, &NodeParamViewItem::PinToggled);
 
@@ -165,6 +168,11 @@ int NodeParamViewItem::GetElementY(const NodeInput &c) const
   }
 }
 
+void NodeParamViewItem::SetInputChecked(const NodeInput &input, bool e)
+{
+  body_->SetInputChecked(input, e);
+}
+
 void NodeParamViewItem::ToggleExpanded()
 {
   SetExpanded(!IsExpanded());
@@ -222,9 +230,10 @@ void NodeParamViewItemTitleBar::mouseDoubleClickEvent(QMouseEvent *event)
   collapse_btn_->click();
 }
 
-NodeParamViewItemBody::NodeParamViewItemBody(Node* node, QWidget *parent) :
+NodeParamViewItemBody::NodeParamViewItemBody(Node* node, NodeParamViewCheckBoxBehavior create_checkboxes, QWidget *parent) :
   QWidget(parent),
-  node_(node)
+  node_(node),
+  create_checkboxes_(create_checkboxes)
 {
   QGridLayout* root_layout = new QGridLayout(this);
 
@@ -277,11 +286,22 @@ void NodeParamViewItemBody::CreateWidgets(QGridLayout* layout, Node *node, const
   ui_objects.layout = layout;
   ui_objects.row = row;
 
+  // Create optional checkbox if requested
+  if (create_checkboxes_) {
+    ui_objects.optional_checkbox = new QCheckBox();
+    connect(ui_objects.optional_checkbox, &QCheckBox::clicked, this, &NodeParamViewItemBody::OptionalCheckBoxClicked);
+    layout->addWidget(ui_objects.optional_checkbox, row, kOptionalCheckBox);
+
+    if (create_checkboxes_ == kCheckBoxesOnNonConnected && input_ref.IsConnected()) {
+      ui_objects.optional_checkbox->setVisible(false);
+    }
+  }
+
   // Add descriptor label
   ui_objects.main_label = new QLabel();
 
-  // Label always goes into column 1 (array collapse button goes into 0 if applicable)
-  layout->addWidget(ui_objects.main_label, row, 1);
+  // Create input label
+  layout->addWidget(ui_objects.main_label, row, kLabelColumn);
 
   if (node->InputIsArray(input)) {
     if (element == -1) {
@@ -292,8 +312,8 @@ void NodeParamViewItemBody::CreateWidgets(QGridLayout* layout, Node *node, const
       // Default to collapsed
       array_collapse_btn->setChecked(false);
 
-      // Collapse button always goes into column 0
-      layout->addWidget(array_collapse_btn, row, 0);
+      // Add collapse button to layout
+      layout->addWidget(array_collapse_btn, row, kArrayCollapseBtnColumn);
 
       // Connect signal to show/hide array params when toggled
       connect(array_collapse_btn, &CollapseButton::toggled, this, &NodeParamViewItemBody::ArrayCollapseBtnPressed);
@@ -448,6 +468,11 @@ void NodeParamViewItemBody::UpdateUIForEdgeConnection(const NodeInput& input)
     if (ui_objects.key_control) {
       ui_objects.key_control->setVisible(!input.IsConnected());
     }
+
+    // Show/hide optional checkbox if requested
+    if (create_checkboxes_ == kCheckBoxesOnNonConnected) {
+      ui_objects.optional_checkbox->setVisible(!input.IsConnected());
+    }
   }
 }
 
@@ -575,6 +600,16 @@ void NodeParamViewItemBody::SetTimebase(const rational& timebase)
   }
 }
 
+void NodeParamViewItemBody::SetInputChecked(const NodeInput &input, bool e)
+{
+  if (input_ui_map_.contains(input)) {
+    QCheckBox *cb = input_ui_map_.value(input).optional_checkbox;
+    if (cb) {
+      cb->setChecked(e);
+    }
+  }
+}
+
 void NodeParamViewItemBody::ReplaceWidgets(const NodeInput &input)
 {
   InputUI ui = input_ui_map_.value(input);
@@ -588,12 +623,25 @@ void NodeParamViewItemBody::ShowSpeedDurationDialogForNode()
   sdd.exec();
 }
 
+void NodeParamViewItemBody::OptionalCheckBoxClicked(bool e)
+{
+  QCheckBox *cb = static_cast<QCheckBox*>(sender());
+
+  for (auto it=input_ui_map_.cbegin(); it!=input_ui_map_.cend(); it++) {
+    if (it.value().optional_checkbox == cb) {
+      emit InputCheckedChanged(it.key(), e);
+      break;
+    }
+  }
+}
+
 NodeParamViewItemBody::InputUI::InputUI() :
   main_label(nullptr),
   widget_bridge(nullptr),
   connected_label(nullptr),
   key_control(nullptr),
   extra_btn(nullptr),
+  optional_checkbox(nullptr),
   array_insert_btn(nullptr),
   array_remove_btn(nullptr)
 {

app/widget/nodeparamview/nodeparamviewitem.h

@@ -21,6 +21,7 @@
 #ifndef NODEPARAMVIEWITEM_H
 #define NODEPARAMVIEWITEM_H
 
+#include <QCheckBox>
 #include <QDockWidget>
 #include <QGridLayout>
 #include <QLabel>
@@ -38,6 +39,12 @@
 
 namespace olive {
 
+enum NodeParamViewCheckBoxBehavior {
+  kNoCheckBoxes,
+  kCheckBoxesOn,
+  kCheckBoxesOnNonConnected
+};
+
 class NodeParamViewItemTitleBar : public QWidget
 {
   Q_OBJECT
@@ -75,7 +82,7 @@ private:
 class NodeParamViewItemBody : public QWidget {
   Q_OBJECT
 public:
-  NodeParamViewItemBody(Node* node, QWidget* parent = nullptr);
+  NodeParamViewItemBody(Node* node, NodeParamViewCheckBoxBehavior create_checkboxes, QWidget* parent = nullptr);
 
   void SetTimeTarget(Node* target);
 
@@ -86,7 +93,9 @@ public:
   int GetElementY(NodeInput c) const;
 
   // Set the timebase of any timebased widgets contained here
-   void SetTimebase(const rational& timebase);
+  void SetTimebase(const rational& timebase);
+
+  void SetInputChecked(const NodeInput &input, bool e);
 
 signals:
   void RequestSetTime(const rational& time);
@@ -95,6 +104,8 @@ signals:
 
   void ArrayExpandedChanged(bool e);
 
+  void InputCheckedChanged(const NodeInput &input, bool e);
+
 private:
   void CreateWidgets(QGridLayout *layout, Node* node, const QString& input, int element, int row_index);
 
@@ -114,6 +125,7 @@ private:
     QGridLayout* layout;
     int row;
     QPushButton *extra_btn;
+    QCheckBox *optional_checkbox;
 
     NodeParamViewArrayButton* array_insert_btn;
     NodeParamViewArrayButton* array_remove_btn;
@@ -135,6 +147,8 @@ private:
 
   rational timebase_;
 
+  NodeParamViewCheckBoxBehavior create_checkboxes_;
+
   /**
    * @brief The column to place the keyframe controls in
    *
@@ -147,6 +161,9 @@ private:
   static const int kArrayRemoveColumn;
   static const int kExtraButtonColumn;
 
+  static const int kOptionalCheckBox;
+  static const int kArrayCollapseBtnColumn;
+  static const int kLabelColumn;
   static const int kWidgetStartColumn;
 
 private slots:
@@ -168,13 +185,15 @@ private slots:
 
   void ShowSpeedDurationDialogForNode();
 
+  void OptionalCheckBoxClicked(bool e);
+
 };
 
 class NodeParamViewItem : public QDockWidget
 {
   Q_OBJECT
 public:
-  NodeParamViewItem(Node* node, QWidget* parent = nullptr);
+  NodeParamViewItem(Node* node, NodeParamViewCheckBoxBehavior create_checkboxes, QWidget* parent = nullptr);
 
   void SetTimeTarget(Node* target);
 
@@ -196,6 +215,8 @@ public:
 
   int GetElementY(const NodeInput& c) const;
 
+  void SetInputChecked(const NodeInput &input, bool e);
+
 public slots:
   void SetExpanded(bool e);
 
@@ -214,6 +235,8 @@ signals:
 
   void Moved();
 
+  void InputCheckedChanged(const NodeInput &input, bool e);
+
 protected:
   virtual void changeEvent(QEvent *e) override;
 

app/widget/nodeview/nodeview.cpp

@@ -21,16 +21,18 @@
 #include "nodeview.h"
 
 #include <QInputDialog>
+#include <QMessageBox>
 #include <QMouseEvent>
 #include <QScrollBar>
 #include <QToolTip>
 
 #include "core.h"
+#include "dialog/nodegroup/nodegroupdialog.h"
 #include "nodeviewundo.h"
 #include "node/audio/volume/volume.h"
 #include "node/distort/transform/transformdistortnode.h"
 #include "node/factory.h"
-#include "node/group.h"
+#include "node/group/group.h"
 #include "node/traverser.h"
 #include "widget/menu/menushared.h"
 #include "widget/timebased/timebasedview.h"
@@ -638,6 +640,7 @@ void NodeView::UpdateSelectionCache()
   if (current_selection.isEmpty()) {
     // All nodes that were selected have been deselected, so we'll just set them all to `deselected`
     deselected = selected_nodes_;
+    selected_nodes_.clear();
   } else {
     foreach (Node* n, selected_nodes_) {
       bool still_selected = false;
@@ -649,20 +652,20 @@ void NodeView::UpdateSelectionCache()
         }
       }
 
-      if (still_selected) {
+      if (!still_selected) {
         deselected.append(n);
         selected_nodes_.removeOne(n);
       }
     }
   }
 
-  if (!selected.isEmpty()) {
-    emit NodesSelected(selected);
-  }
-
   if (!deselected.isEmpty()) {
     emit NodesDeselected(deselected);
   }
+
+  if (!selected.isEmpty()) {
+    emit NodesSelected(selected);
+  }
 }
 
 void NodeView::ShowContextMenu(const QPoint &pos)
@@ -1082,13 +1085,88 @@ void NodeView::PositionNewEdge(const QPoint &pos)
 
 void NodeView::GroupNodes()
 {
-  /*NodeGroup *group = new NodeGroup();
-  selected_nodes_*/
+  // Get items
+  QVector<NodeViewItem*> items = scene_.GetSelectedItems();
+  if (items.isEmpty()) {
+    return;
+  }
+
+  // Get node context
+  Node *context = items.first()->GetContext();
+  QPointF avg_pos = items.first()->GetNodePosition();
+  for (int i=1; i<items.size(); i++) {
+    if (items.at(i)->GetContext() != context) {
+      QMessageBox::critical(this, tr("Failed to group nodes"), tr("Nodes can only be grouped if they're in the same context."));
+      return;
+    }
+
+    avg_pos += items.at(i)->GetNodePosition();
+  }
+  avg_pos /= items.size();
+
+  // Create group
+  NodeGroup *group = new NodeGroup();
+
+  // Add group to graph and context
+  MultiUndoCommand *command = new MultiUndoCommand();
+
+  command->add_child(new NodeAddCommand(context->parent(), group));
+  command->add_child(new NodeSetPositionCommand(group, context, avg_pos));
+
+  // Add nodes to group
+  QVector<Node*> nodes_to_group = selected_nodes_;
+  DeselectAll();
+  foreach (Node *n, nodes_to_group) {
+    for (auto it=n->input_connections().cbegin(); it!=n->input_connections().cend(); it++) {
+      Node *output = it->second;
+      const NodeInput &input = it->first;
+
+      if (!nodes_to_group.contains(output)) {
+        command->add_child(new NodeEdgeRemoveCommand(output, input));
+        command->add_child(new NodeEdgeAddCommand(output, NodeInput(group, input.input(), input.element())));
+      }
+    }
+
+    for (auto it=n->output_connections().cbegin(); it!=n->output_connections().cend(); it++) {
+      Node *output = it->first;
+      const NodeInput &input = it->second;
+
+      if (!nodes_to_group.contains(input.node())) {
+        command->add_child(new NodeEdgeRemoveCommand(output, input));
+        command->add_child(new NodeEdgeAddCommand(group, input));
+      }
+    }
+
+    command->add_child(new NodeRemovePositionFromContextCommand(n, context));
+    command->add_child(new NodeAddToGroupCommand(n, group));
+    command->add_child(new NodeSetPositionCommand(n, group, scene_.context_map().value(context)->GetItemFromMap(n)->GetNodePosition()));
+
+    for (auto it=n->inputs().cbegin(); it!=n->inputs().cend(); it++) {
+      NodeInput input(n, *it, -1);
+
+      if (!input.IsConnected() || !nodes_to_group.contains(input.GetConnectedOutput())) {
+        command->add_child(new NodeGroupAddInputPassthrough(group, input));
+      }
+    }
+  }
+
+  // Do command
+  command->redo_now();
+
+  NodeGroupDialog ngd(group, this);
+  if (ngd.exec() == QDialog::Accepted) {
+    // Push to stack so it can be undone (MultiUndoCommand will ignore the request to redo again)
+    Core::instance()->undo_stack()->push(command);
+  } else {
+    // Undo command and delete
+    command->undo_now();
+    delete command;
+  }
 }
 
 void NodeView::UngroupNodes()
 {
-  //static_cast<NodeGroup*>(selected_nodes_.first());
+  //NodeGroup *group = static_cast<NodeGroup*>(selected_nodes_.first());
 }
 
 void NodeView::PasteNodesInternal(const QVector<Node *> &duplicate_nodes)

app/widget/nodeview/nodeview.h

@@ -45,7 +45,7 @@ class NodeView : public HandMovableView, public NodeCopyPasteService
 {
   Q_OBJECT
 public:
-  NodeView(QWidget* parent);
+  NodeView(QWidget* parent = nullptr);
 
   virtual ~NodeView() override;
 

app/widget/nodeview/nodeviewcontext.cpp

@@ -189,7 +189,9 @@ void NodeViewContext::DeleteSelected(NodeViewDeleteCommand *command)
 void NodeViewContext::Select(const QVector<Node *> &nodes)
 {
   foreach (Node *n, nodes) {
-    item_map_.value(n)->setSelected(true);
+    if (NodeViewItem *item = item_map_.value(n)) {
+      item->setSelected(true);
+    }
   }
 }
 

app/widget/nodeview/nodeviewcontext.h

@@ -36,6 +36,11 @@ public:
 
   QPointF MapScenePosToNodePosInContext(const QPointF &pos) const;
 
+  NodeViewItem *GetItemFromMap(Node *node) const
+  {
+    return item_map_.value(node);
+  }
+
   virtual void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr) override;
 
 public slots:

app/widget/nodeview/nodeviewitem.cpp

@@ -544,7 +544,7 @@ QPointF NodeViewItem::GetInputPoint(const QString &input, int element) const
   int index = node_inputs_.indexOf(input);
 
   if (index < 0 || index >= int(input_connectors_.size())) {
-    return QPointF();
+    return pos();
   }
 
   return input_connectors_[index]->scenePos();

app/window/mainwindow/mainwindow.cpp

@@ -467,15 +467,6 @@ void MainWindow::TimelinePanelSelectionChanged(const QVector<Block *> &blocks)
   }
 }
 
-void MainWindow::ProjectPanelSelectionChanged(const QVector<Node *> &nodes)
-{
-  ProjectPanel *panel = static_cast<ProjectPanel *>(sender());
-
-  if (PanelManager::instance()->CurrentlyFocused(false) == panel) {
-    node_panel_->Select(nodes, true);
-  }
-}
-
 void MainWindow::ShowWelcomeDialog()
 {
   if (Config::Current()[QStringLiteral("ShowWelcomeDialog")].toBool()) {
@@ -572,7 +563,6 @@ ProjectPanel *MainWindow::AppendProjectPanel()
 
   connect(panel, &PanelWidget::CloseRequested, this, &MainWindow::ProjectCloseRequested);
   connect(panel, &ProjectPanel::ProjectNameChanged, this, &MainWindow::UpdateTitle);
-  connect(panel, &ProjectPanel::SelectionChanged, this, &MainWindow::ProjectPanelSelectionChanged);
 
   return panel;
 }

app/window/mainwindow/mainwindow.h

@@ -193,8 +193,6 @@ private slots:
 
   void TimelinePanelSelectionChanged(const QVector<Block*> &blocks);
 
-  void ProjectPanelSelectionChanged(const QVector<Node*> &nodes);
-
   void ShowWelcomeDialog();
 
 };