add subtitle track when switching to add tool

Fixes #1709

app/core.cpp

@@ -264,6 +264,7 @@ const QString &Core::GetSelectedTransition() const
 void Core::SetSelectedAddableObject(const Tool::AddableObject &obj)
 {
   addable_object_ = obj;
+  emit AddableObjectChanged(addable_object_);
 }
 
 void Core::SetSelectedTransitionObject(const QString &obj)

app/core.h

@@ -440,6 +440,11 @@ signals:
    */
   void ToolChanged(const Tool::Item& tool);
 
+  /**
+   * @brief Signal emitted when addable object changes through SetSelectedAddableObject
+   */
+  void AddableObjectChanged(Tool::AddableObject o);
+
   /**
    * @brief Signal emitted when the snapping setting is changed
    */

app/widget/timelinewidget/timelinewidget.cpp

@@ -62,7 +62,8 @@ TimelineWidget::TimelineWidget(QWidget *parent) :
   super(true, true, parent),
   rubberband_(QRubberBand::Rectangle, this),
   active_tool_(nullptr),
-  use_audio_time_units_(false)
+  use_audio_time_units_(false),
+  subtitle_show_command_(nullptr)
 {
   QVBoxLayout* vert_layout = new QVBoxLayout(this);
   vert_layout->setSpacing(0);
@@ -182,6 +183,7 @@ TimelineWidget::TimelineWidget(QWidget *parent) :
   SetAutoSetTimebase(false);
 
   connect(Core::instance(), &Core::ToolChanged, this, &TimelineWidget::ToolChanged);
+  connect(Core::instance(), &Core::AddableObjectChanged, this, &TimelineWidget::AddableObjectChanged);
 }
 
 TimelineWidget::~TimelineWidget()
@@ -192,6 +194,8 @@ TimelineWidget::~TimelineWidget()
   Clear();
 
   qDeleteAll(tools_);
+
+  delete subtitle_show_command_;
 }
 
 void TimelineWidget::Clear()
@@ -849,17 +853,6 @@ void TimelineWidget::ViewMouseMoved(TimelineViewMouseEvent *event)
 
       if (hover_tool) {
         hover_tool->HoverMove(event);
-
-        // Special cast for subtitle adding - ensure section is visible
-        if (dynamic_cast<AddTool*>(hover_tool)
-            && Core::instance()->GetSelectedAddableObject() == Tool::kAddableSubtitle) {
-          QList<int> sz = view_splitter_->sizes();
-          int &subtitle_section_height = sz[Track::kSubtitle];
-          if (subtitle_section_height == 0) {
-            subtitle_section_height = height() / Track::kCount;
-            view_splitter_->setSizes(sz);
-          }
-        }
       }
     }
   }
@@ -1103,6 +1096,41 @@ void TimelineWidget::ToolChanged()
   HideSnaps();
   SetViewBeamCursor(TimelineCoordinate(0, Track::kNone, -1));
   SetViewTransitionOverlay(nullptr, nullptr);
+
+  AddableObjectChanged();
+}
+
+void TimelineWidget::AddableObjectChanged()
+{
+  // Special cast for subtitle adding - ensure section is visible
+  if (Core::instance()->tool() == Tool::kAdd && Core::instance()->GetSelectedAddableObject() == Tool::kAddableSubtitle) {
+    if (!subtitle_show_command_) {
+      // Determine if we need to do anything
+      QList<int> sz = view_splitter_->sizes();
+      bool should_adjust_splitter = (sz[Track::kSubtitle] == 0);
+      bool should_add_sub_track = (sequence() && sequence()->track_list(Track::kSubtitle)->GetTrackCount() == 0);
+
+      if (should_adjust_splitter || should_add_sub_track) {
+        // Create command
+        subtitle_show_command_ = new MultiUndoCommand();
+
+        if (should_adjust_splitter) {
+          sz[Track::kSubtitle] = height() / Track::kCount;
+          subtitle_show_command_->add_child(new SetSplitterSizesCommand(view_splitter_, sz));
+        }
+
+        if (should_add_sub_track) {
+          subtitle_show_command_->add_child(new TimelineAddTrackCommand(sequence()->track_list(Track::kSubtitle)));
+        }
+
+        subtitle_show_command_->redo_now();
+      }
+    }
+  } else if (subtitle_show_command_) {
+    subtitle_show_command_->undo_now();
+    delete subtitle_show_command_;
+    subtitle_show_command_ = nullptr;
+  }
 }
 
 void TimelineWidget::SetViewWaveformsEnabled(bool e)
@@ -1785,4 +1813,15 @@ bool TimelineWidget::SnapPoint(QVector<rational> start_times, rational* movement
   return true;
 }
 
+void TimelineWidget::SetSplitterSizesCommand::redo()
+{
+  old_sizes_ = splitter_->sizes();
+  splitter_->setSizes(new_sizes_);
+}
+
+void TimelineWidget::SetSplitterSizesCommand::undo()
+{
+  splitter_->setSizes(old_sizes_);
+}
+
 }

app/widget/timelinewidget/timelinewidget.h

@@ -216,6 +216,18 @@ public:
    */
   void SignalDeselectedAllBlocks();
 
+  MultiUndoCommand *TakeSubtitleSectionCommand()
+  {
+    // Copy pointer
+    MultiUndoCommand *c = subtitle_show_command_;
+
+    // Set to null
+    subtitle_show_command_ = nullptr;
+
+    // Return command
+    return c;
+  }
+
   class SetSelectionsCommand : public UndoCommand {
   public:
     SetSelectionsCommand(TimelineWidget* timeline, const TimelineWidgetSelections& now, const TimelineWidgetSelections& old, bool process_block_changes) :
@@ -317,6 +329,32 @@ private:
 
   QSplitter* view_splitter_;
 
+  MultiUndoCommand *subtitle_show_command_;
+
+  class SetSplitterSizesCommand : public UndoCommand
+  {
+  public:
+    SetSplitterSizesCommand(QSplitter *splitter, const QList<int> &sizes) :
+      splitter_(splitter),
+      new_sizes_(sizes)
+    {}
+
+    virtual Project* GetRelevantProject() const override
+    {
+      return nullptr;
+    }
+
+  protected:
+    virtual void redo() override;
+    virtual void undo() override;
+
+  private:
+    QSplitter *splitter_;
+    QList<int> new_sizes_;
+    QList<int> old_sizes_;
+
+  };
+
   void CenterOn(qreal scene_pos);
 
   void UpdateViewTimebases();
@@ -361,6 +399,8 @@ private slots:
 
   void ToolChanged();
 
+  void AddableObjectChanged();
+
   void SetViewWaveformsEnabled(bool e);
 
   void FrameRateChanged();

app/widget/timelinewidget/tool/add.cpp

@@ -98,6 +98,10 @@ void AddTool::MouseRelease(TimelineViewMouseEvent *event)
     if (!ghost_->GetAdjustedLength().isNull()) {
       MultiUndoCommand* command = new MultiUndoCommand();
 
+      if (MultiUndoCommand *subtitle_section_command = parent()->TakeSubtitleSectionCommand()) {
+        command->add_child(subtitle_section_command);
+      }
+
       ClipBlock* clip;
       if (Core::instance()->GetSelectedAddableObject() == olive::Tool::kAddableSubtitle) {
         clip = new SubtitleBlock();