timeline: show transition tool overlay

app/widget/timelinewidget/timelinewidget.cpp

@@ -1076,6 +1076,8 @@ void TimelineWidget::ViewTimestampChanged(int64_t ts)
 void TimelineWidget::ToolChanged()
 {
   HideSnaps();
+  SetViewBeamCursor(TimelineCoordinate(0, Track::kNone, -1));
+  SetViewTransitionOverlay(nullptr, nullptr);
 }
 
 void TimelineWidget::SetViewWaveformsEnabled(bool e)
@@ -1147,6 +1149,13 @@ void TimelineWidget::SetViewBeamCursor(const TimelineCoordinate &coord)
   }
 }
 
+void TimelineWidget::SetViewTransitionOverlay(ClipBlock *out, ClipBlock *in)
+{
+  foreach (TimelineAndTrackView* tview, views_) {
+    tview->view()->SetTransitionOverlay(out, in);
+  }
+}
+
 void TimelineWidget::SetBlockLinksSelected(Block* block, bool selected)
 {
   foreach (Block* link, block->block_links()) {

app/widget/timelinewidget/timelinewidget.h

@@ -138,6 +138,7 @@ public:
   Track* GetTrackFromReference(const Track::Reference& ref) const;
 
   void SetViewBeamCursor(const TimelineCoordinate& coord);
+  void SetViewTransitionOverlay(ClipBlock *out, ClipBlock *in);
 
   const QVector<TimelineViewGhostItem*>& GetGhostItems() const
   {

app/widget/timelinewidget/tool/transition.cpp

@@ -34,64 +34,49 @@ TransitionTool::TransitionTool(TimelineWidget *parent) :
 {
 }
 
+void TransitionTool::HoverMove(TimelineViewMouseEvent *event)
+{
+  ClipBlock *primary = nullptr;
+  ClipBlock *secondary = nullptr;
+  Timeline::MovementMode trim_mode;
+  rational transition_start_point;
+
+  GetBlocksAtCoord(event->GetCoordinates(), &primary, &secondary, &trim_mode, &transition_start_point);
+
+  if (trim_mode == Timeline::kTrimIn) {
+    std::swap(primary, secondary);
+  }
+
+  parent()->SetViewTransitionOverlay(primary, secondary);
+}
+
 void TransitionTool::MousePress(TimelineViewMouseEvent *event)
 {
-  const Track::Reference& track = event->GetTrack();
+  ClipBlock *primary, *secondary;
-  Track* t = parent()->GetTrackFromReference(track);
-  rational cursor_frame = event->GetFrame();
-
-  if (!t || t->IsLocked()) {
-    return;
-  }
-
-  Block* block_at_time = t->BlockAtTime(event->GetFrame());
-  if (!dynamic_cast<ClipBlock*>(block_at_time)) {
-    return;
-  }
-
-  // Determine which side of the clip the transition belongs to
-  rational transition_start_point;
   Timeline::MovementMode trim_mode;
-  rational halfway_point = block_at_time->in() + block_at_time->length() / 2;
+  rational transition_start_point;
-  rational tenth_point = block_at_time->in() + block_at_time->length() / 10;
+  if (!GetBlocksAtCoord(event->GetCoordinates(), &primary, &secondary, &trim_mode, &transition_start_point)) {
-  Block* other_block = nullptr;
+    return;
-  if (cursor_frame < halfway_point) {
-    transition_start_point = block_at_time->in();
-    trim_mode = Timeline::kTrimIn;
-
-    if (cursor_frame < tenth_point
-        && dynamic_cast<ClipBlock*>(block_at_time->previous())) {
-      other_block = block_at_time->previous();
-    }
-  } else {
-    transition_start_point = block_at_time->out();
-    trim_mode = Timeline::kTrimOut;
-    dual_transition_ = (cursor_frame > block_at_time->length() - tenth_point);
-
-    if (cursor_frame > block_at_time->length() - tenth_point
-        && dynamic_cast<ClipBlock*>(block_at_time->next())) {
-      other_block = block_at_time->next();
-    }
   }
 
   // Create ghost
   ghost_ = new TimelineViewGhostItem();
-  ghost_->SetTrack(track);
+  ghost_->SetTrack(event->GetTrack());
   ghost_->SetIn(transition_start_point);
   ghost_->SetOut(transition_start_point);
   ghost_->SetMode(trim_mode);
-  ghost_->SetData(TimelineViewGhostItem::kAttachedBlock, Node::PtrToValue(block_at_time));
+  ghost_->SetData(TimelineViewGhostItem::kAttachedBlock, Node::PtrToValue(primary));
 
-  dual_transition_ = (other_block);
+  dual_transition_ = (secondary);
-  if (other_block)
+  if (secondary)
-    ghost_->SetData(TimelineViewGhostItem::kReferenceBlock, Node::PtrToValue(other_block));
+    ghost_->SetData(TimelineViewGhostItem::kReferenceBlock, Node::PtrToValue(secondary));
 
   parent()->AddGhost(ghost_);
 
   snap_points_.append(transition_start_point);
 
   // Set the drag start point
-  drag_start_point_ = cursor_frame;
+  drag_start_point_ = event->GetFrame();
 }
 
 void TransitionTool::MouseMove(TimelineViewMouseEvent *event)
@@ -175,4 +160,52 @@ void TransitionTool::MouseRelease(TimelineViewMouseEvent *event)
   }
 }
 
+bool TransitionTool::GetBlocksAtCoord(const TimelineCoordinate &coord, ClipBlock **primary, ClipBlock **secondary, Timeline::MovementMode *ptrim_mode, rational *start_point)
+{
+  const Track::Reference& track = coord.GetTrack();
+  Track* t = parent()->GetTrackFromReference(track);
+  rational cursor_frame = coord.GetFrame();
+
+  if (!t || t->IsLocked()) {
+    return false;
+  }
+
+  Block* block_at_time = t->BlockAtTime(coord.GetFrame());
+  if (!dynamic_cast<ClipBlock*>(block_at_time)) {
+    return false;
+  }
+
+  // Determine which side of the clip the transition belongs to
+  rational transition_start_point;
+  Timeline::MovementMode trim_mode;
+  rational halfway_point = block_at_time->in() + block_at_time->length() / 2;
+  rational tenth_point = block_at_time->in() + block_at_time->length() / 10;
+  Block* other_block = nullptr;
+  if (cursor_frame < halfway_point) {
+    transition_start_point = block_at_time->in();
+    trim_mode = Timeline::kTrimIn;
+
+    if (cursor_frame < tenth_point
+        && dynamic_cast<ClipBlock*>(block_at_time->previous())) {
+      other_block = block_at_time->previous();
+    }
+  } else {
+    transition_start_point = block_at_time->out();
+    trim_mode = Timeline::kTrimOut;
+    dual_transition_ = (cursor_frame > block_at_time->length() - tenth_point);
+
+    if (cursor_frame > block_at_time->length() - tenth_point
+        && dynamic_cast<ClipBlock*>(block_at_time->next())) {
+      other_block = block_at_time->next();
+    }
+  }
+
+  *primary = static_cast<ClipBlock*>(block_at_time);
+  *secondary = static_cast<ClipBlock*>(other_block);
+  *ptrim_mode = trim_mode;
+  *start_point = transition_start_point;
+
+  return true;
+}
+
 }

app/widget/timelinewidget/tool/transition.h

@@ -30,11 +30,17 @@ class TransitionTool : public AddTool
 public:
   TransitionTool(TimelineWidget* parent);
 
+  virtual void HoverMove(TimelineViewMouseEvent *event) override;
+
   virtual void MousePress(TimelineViewMouseEvent *event) override;
   virtual void MouseMove(TimelineViewMouseEvent *event) override;
   virtual void MouseRelease(TimelineViewMouseEvent *event) override;
+
 private:
+  bool GetBlocksAtCoord(const TimelineCoordinate &coord, ClipBlock **primary, ClipBlock **secondary, Timeline::MovementMode *trim_mode, rational *start_point);
+
   bool dual_transition_;
+
 };
 
 }

app/widget/timelinewidget/view/timelineview.cpp

@@ -44,7 +44,9 @@ TimelineView::TimelineView(Qt::Alignment vertical_alignment, QWidget *parent) :
   ghosts_(nullptr),
   show_beam_cursor_(false),
   connected_track_list_(nullptr),
-  show_waveforms_(true)
+  show_waveforms_(true),
+  transition_overlay_out_(nullptr),
+  transition_overlay_in_(nullptr)
 {
   Q_ASSERT(vertical_alignment == Qt::AlignTop || vertical_alignment == Qt::AlignBottom);
   setAlignment(Qt::AlignLeft | vertical_alignment);
@@ -474,6 +476,31 @@ void TimelineView::DrawBlocks(QPainter *painter, bool foreground)
             painter->setPen(shadow_color);
             painter->drawLines(lines);
           }
+
+          if (transition_overlay_out_ == block || transition_overlay_in_ == block) {
+            QRectF transition_overlay_rect = r;
+
+            qreal transition_overlay_width = TimeToScene(block->length()) * 0.5;
+            if (transition_overlay_out_ && transition_overlay_in_) {
+              // This is a dual transition, use the smallest width
+              Block *other_block = (transition_overlay_out_ == block) ? transition_overlay_in_ : transition_overlay_out_;
+
+              qreal other_width = TimeToScene(other_block->length()) * 0.5;
+
+              transition_overlay_width = qMin(transition_overlay_width, other_width);
+            }
+
+            if (transition_overlay_out_ == block) {
+              transition_overlay_rect.setLeft(transition_overlay_rect.right() - transition_overlay_width);
+            } else {
+              transition_overlay_rect.setRight(transition_overlay_rect.left() + transition_overlay_width);
+            }
+
+            painter->setPen(Qt::NoPen);
+            painter->setBrush(QColor(0, 0, 0, 64));
+
+            painter->drawRect(transition_overlay_rect);
+          }
         }
 
       }
@@ -573,6 +600,29 @@ void TimelineView::SetBeamCursor(const TimelineCoordinate &coord)
   }
 }
 
+void TimelineView::SetTransitionOverlay(ClipBlock *out, ClipBlock *in)
+{
+  if (transition_overlay_out_ != out || transition_overlay_in_ != in) {
+    Track::Type type = Track::kNone;
+
+    if (out) {
+      type = out->track()->type();
+    } else if (in) {
+      type = in->track()->type();
+    }
+
+    if (type == this->connected_track_list_->type()) {
+      transition_overlay_out_ = out;
+      transition_overlay_in_ = in;
+    } else {
+      transition_overlay_out_ = nullptr;
+      transition_overlay_in_ = nullptr;
+    }
+
+    viewport()->update();
+  }
+}
+
 int TimelineView::SceneToTrack(double y)
 {
   int track = -1;

app/widget/timelinewidget/view/timelineview.h

@@ -55,6 +55,7 @@ public:
   void ConnectTrackList(TrackList* list);
 
   void SetBeamCursor(const TimelineCoordinate& coord);
+  void SetTransitionOverlay(ClipBlock *out, ClipBlock *in);
 
   void SetSelectionList(QHash<Track::Reference, TimeRangeList>* s)
   {
@@ -141,6 +142,9 @@ private:
 
   bool show_waveforms_;
 
+  ClipBlock *transition_overlay_out_;
+  ClipBlock *transition_overlay_in_;
+
 private slots:
   void TrackListChanged();