timeline: improved rubberband behavior

Improved rubberband responsiveness and show rubberband if dragging from a gap
(or other such immovable block).

app/widget/timelinewidget/timelinewidget.cpp

@@ -1427,16 +1427,19 @@ void TimelineWidget::RestoreSplitterState(const QByteArray &state)
   view_splitter_->restoreState(state);
 }
 
-void TimelineWidget::StartRubberBandSelect(bool enable_selecting, bool select_links)
+void TimelineWidget::StartRubberBandSelect(const QPoint &global_cursor_start)
 {
-  drag_origin_ = QCursor::pos();
+  drag_origin_ = global_cursor_start;
+
+  // Start rubberband at origin
+  QPoint local_origin = mapFromGlobal(drag_origin_);
+  rubberband_.setGeometry(QRect(local_origin.x(), local_origin.y(), 0, 0));
+
   rubberband_.show();
 
   // We don't touch any blocks that are already selected. If you want these to be deselected by
   // default, call DeselectAll() before calling StartRubberBandSelect()
   rubberband_old_selections_ = selections_;
-
-  MoveRubberBandSelect(enable_selecting, select_links);
 }
 
 void TimelineWidget::MoveRubberBandSelect(bool enable_selecting, bool select_links)

app/widget/timelinewidget/timelinewidget.h

@@ -138,7 +138,7 @@ public:
 
   void InsertGapsAt(const rational& time, const rational& length, QUndoCommand* command);
 
-  void StartRubberBandSelect(bool enable_selecting, bool select_links);
+  void StartRubberBandSelect(const QPoint& global_cursor_start);
   void MoveRubberBandSelect(bool enable_selecting, bool select_links);
   void EndRubberBandSelect();
 

app/widget/timelinewidget/tool/pointer.cpp

@@ -121,21 +121,38 @@ void PointerTool::MousePress(TimelineViewMouseEvent *event)
 
     parent()->SignalSelectedBlocks(selected_blocks);
 
-  } else if (event->GetButton() == Qt::LeftButton) {
+  }
 
-    // Start rubberband drag
-    parent()->StartRubberBandSelect(true, !(event->GetModifiers() & Qt::AltModifier));
-
-    rubberband_selecting_ = true;
+  can_rubberband_select_ =  (event->GetButton() == Qt::LeftButton                              // Only rubberband select from the primary mouse button
+                             && (!selectable_item || drag_movement_mode_ == Timeline::kNone)); // And if no item was selected OR the item isn't draggable
 
+  if (can_rubberband_select_) {
+    drag_global_start_ = QCursor::pos();
   }
 }
 
 void PointerTool::MouseMove(TimelineViewMouseEvent *event)
 {
-  if (rubberband_selecting_) {
+  if (can_rubberband_select_) {
+
+    if (!rubberband_selecting_) {
+
+      // If we clicked an item but are rubberband selecting anyway, deselect it now
+      if (clicked_item_) {
+        parent()->RemoveSelection(clicked_item_);
+        parent()->SignalDeselectedBlocks({clicked_item_->block()});
+        clicked_item_ = nullptr;
+      }
+
+      parent()->StartRubberBandSelect(drag_global_start_);
+
+      rubberband_selecting_ = true;
+
+    }
+
     // Process rubberband select
     parent()->MoveRubberBandSelect(true, !(event->GetModifiers() & Qt::AltModifier));
+
   } else {
     // Process drag
     if (!dragging_) {

app/widget/timelinewidget/tool/pointer.h

@@ -113,6 +113,7 @@ private:
   bool trimming_allowed_;
   bool track_movement_allowed_;
   bool gap_trimming_allowed_;
+  bool can_rubberband_select_;
   bool rubberband_selecting_;
 
   Timeline::TrackType drag_track_type_;
@@ -120,6 +121,8 @@ private:
 
   TimelineViewBlockItem* clicked_item_;
 
+  QPoint drag_global_start_;
+
 };
 
 }

app/widget/timelinewidget/tool/zoom.cpp

@@ -31,19 +31,21 @@ ZoomTool::ZoomTool(TimelineWidget *parent) :
 void ZoomTool::MousePress(TimelineViewMouseEvent *event)
 {
   Q_UNUSED(event)
+
+  drag_global_start_ = QCursor::pos();
 }
 
 void ZoomTool::MouseMove(TimelineViewMouseEvent *event)
 {
   Q_UNUSED(event)
 
-  if (dragging_) {
-    parent()->MoveRubberBandSelect(false, false);
-  } else {
-    parent()->StartRubberBandSelect(false, false);
+  if (!dragging_) {
+    parent()->StartRubberBandSelect(drag_global_start_);
 
     dragging_ = true;
   }
+
+  parent()->MoveRubberBandSelect(false, false);
 }
 
 void ZoomTool::MouseRelease(TimelineViewMouseEvent *event)

app/widget/timelinewidget/tool/zoom.h

@@ -34,6 +34,9 @@ public:
   virtual void MouseMove(TimelineViewMouseEvent *event) override;
   virtual void MouseRelease(TimelineViewMouseEvent *event) override;
 
+private:
+  QPoint drag_global_start_;
+
 };
 
 }