correctly connect timeline and trackview so they vertically scroll in tandem

with each other

app/widget/curvewidget/curveview.cpp

@@ -10,7 +10,6 @@ CurveView::CurveView(QWidget *parent) :
 {
   setAlignment(Qt::AlignLeft | Qt::AlignVCenter);
   setDragMode(RubberBandDrag);
-  setViewportUpdateMode(FullViewportUpdate);
   SetYAxisEnabled(true);
 
   text_padding_ = QFontMetricsWidth(fontMetrics(), QStringLiteral("i"));

app/widget/timelinewidget/timelineandtrackview.cpp

@@ -1,6 +1,7 @@
 #include "timelineandtrackview.h"
 
 #include <QHBoxLayout>
+#include <QScrollBar>
 
 TimelineAndTrackView::TimelineAndTrackView(const TrackType &type, Qt::Alignment vertical_alignment, QWidget *parent) :
   QWidget(parent)
@@ -19,6 +20,9 @@ TimelineAndTrackView::TimelineAndTrackView(const TrackType &type, Qt::Alignment
   view_ = new TimelineView(type, vertical_alignment);
   splitter_->addWidget(view_);
 
+  connect(view_->verticalScrollBar(), &QScrollBar::valueChanged, this, &TimelineAndTrackView::ViewValueChanged);
+  connect(track_view_->verticalScrollBar(), &QScrollBar::valueChanged, this, &TimelineAndTrackView::TracksValueChanged);
+
   splitter_->setSizes({1, width()});
 }
 
@@ -36,3 +40,13 @@ TrackView *TimelineAndTrackView::track_view() const
 {
   return track_view_;
 }
+
+void TimelineAndTrackView::ViewValueChanged(int v)
+{
+  track_view_->verticalScrollBar()->setValue(v - view_->verticalScrollBar()->minimum());
+}
+
+void TimelineAndTrackView::TracksValueChanged(int v)
+{
+  view_->verticalScrollBar()->setValue(view_->verticalScrollBar()->minimum() + v);
+}

app/widget/timelinewidget/timelineandtrackview.h

@@ -27,6 +27,11 @@ private:
 
   TrackView* track_view_;
 
+private slots:
+  void ViewValueChanged(int v);
+
+  void TracksValueChanged(int v);
+
 };
 
 #endif // TIMELINEANDTRACKVIEW_H

app/widget/timelinewidget/trackview/trackview.cpp

@@ -13,6 +13,8 @@ TrackView::TrackView(Qt::Alignment vertical_alignment, QWidget *parent) :
   list_(nullptr),
   alignment_(vertical_alignment)
 {
+  setAlignment(Qt::AlignLeft | alignment_);
+
   QWidget* central = new QWidget();
   setWidget(central);
   setWidgetResizable(true);
@@ -31,6 +33,11 @@ TrackView::TrackView(Qt::Alignment vertical_alignment, QWidget *parent) :
   splitter_ = new TrackViewSplitter(alignment_);
   splitter_->setChildrenCollapsible(false);
   layout->addWidget(splitter_);
+
+  if (alignment_ == Qt::AlignTop) {
+    layout->addStretch();
+  }
+
   connect(splitter_, SIGNAL(TrackHeightChanged(int, int)), this, SLOT(TrackHeightChanged(int, int)));
   setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
   setVerticalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
@@ -67,6 +74,13 @@ void TrackView::DisconnectTrackList()
   ConnectTrackList(nullptr);
 }
 
+void TrackView::resizeEvent(QResizeEvent *e)
+{
+  QScrollArea::resizeEvent(e);
+
+  splitter_->SetSpacerHeight(height()/2);
+}
+
 void TrackView::ScrollbarRangeChanged(int, int max)
 {
   if (max != last_scrollbar_max_) {
@@ -74,6 +88,7 @@ void TrackView::ScrollbarRangeChanged(int, int max)
     int new_val = max - ba_val;
 
     verticalScrollBar()->setValue(new_val);
+    emit verticalScrollBar()->valueChanged(new_val);
 
     last_scrollbar_max_ = max;
   }

app/widget/timelinewidget/trackview/trackview.h

@@ -18,6 +18,9 @@ public:
   void ConnectTrackList(TrackList* list);
   void DisconnectTrackList();
 
+protected:
+  virtual void resizeEvent(QResizeEvent *e) override;
+
 private:
   QList<TrackViewItem*> items_;
 
@@ -29,8 +32,6 @@ private:
 
   int last_scrollbar_max_;
 
-  QWidget* top_spacer_;
-
 private slots:
   void ScrollbarRangeChanged(int min, int max);
 

app/widget/timelinewidget/trackview/trackviewsplitter.cpp

@@ -3,16 +3,20 @@
 #include <QDebug>
 #include <QPainter>
 
+#include "node/output/track/track.h"
+
 TrackViewSplitter::TrackViewSplitter(Qt::Alignment vertical_alignment, QWidget* parent) :
   QSplitter(Qt::Vertical, parent),
-  alignment_(vertical_alignment)
+  alignment_(vertical_alignment),
+  spacer_height_(0)
 {
   setHandleWidth(1);
 
   int initial_height = 0;
 
   // Add empty spacer so we get a splitter handle after the last element
-  addWidget(new QWidget());
+  QWidget* spacer = new QWidget();
+  addWidget(spacer);
 
   setFixedHeight(initial_height);
 }
@@ -42,18 +46,15 @@ void TrackViewSplitter::HandleReceiver(TrackViewSplitterHandle *h, int diff)
   // Transform element size by diff
   int new_ele_sz = old_ele_sz + diff;
 
-  // Validate it with the widget's minimum size
-  new_ele_sz = qMax(new_ele_sz, widget(ele_id)->minimumHeight());
-
-  // Correct diff
-  diff = new_ele_sz - old_ele_sz;
-
-  SetTrackHeight(ele_id, new_ele_sz);
+  // Limit by track minimum height
+  new_ele_sz = qMax(new_ele_sz, TrackOutput::GetTrackHeightMinimum());
 
   if (alignment_ == Qt::AlignBottom) {
     ele_id = count() - ele_id - 1;
   }
 
+  SetTrackHeight(ele_id, new_ele_sz);
+
   emit TrackHeightChanged(ele_id, new_ele_sz);
 }
 
@@ -67,8 +68,6 @@ void TrackViewSplitter::SetTrackHeight(int index, int h)
 
   int old_ele_sz = element_sizes.at(index);
 
-  qDebug() << "Old ele sz" << old_ele_sz << "vs h" << h;
-
   int diff = h - old_ele_sz;
 
   // Set new size on element
@@ -79,14 +78,24 @@ void TrackViewSplitter::SetTrackHeight(int index, int h)
   setFixedHeight(height() + diff);
 }
 
-void TrackViewSplitter::SetHeightWithSizes(const QList<int> &sizes)
+void TrackViewSplitter::SetHeightWithSizes(QList<int> sizes)
 {
   int start_height = 0;
 
+  // Add spacer height too
+  if (alignment_ == Qt::AlignBottom) {
+    sizes.replace(0, spacer_height_);
+  } else {
+    sizes.replace(count() - 1, spacer_height_);
+  }
+
   foreach (int s, sizes) {
     start_height += s + handleWidth();
   }
 
+  // The spacer doesn't need a handle width
+  start_height -= handleWidth();
+
   setFixedHeight(start_height);
   setSizes(sizes);
 }
@@ -119,6 +128,12 @@ void TrackViewSplitter::Remove(int index)
   SetHeightWithSizes(sz);
 }
 
+void TrackViewSplitter::SetSpacerHeight(int height)
+{
+  spacer_height_ = height;
+  SetHeightWithSizes(sizes());
+}
+
 QSplitterHandle *TrackViewSplitter::createHandle()
 {
   return new TrackViewSplitterHandle(orientation(), this);

app/widget/timelinewidget/trackview/trackviewsplitter.h

@@ -30,11 +30,13 @@ public:
 
   void HandleReceiver(TrackViewSplitterHandle* h, int diff);
 
-  void SetHeightWithSizes(const QList<int>& sizes);
+  void SetHeightWithSizes(QList<int> sizes);
 
   void Insert(int index, int height, QWidget* item);
   void Remove(int index);
 
+  void SetSpacerHeight(int height);
+
 public slots:
   void SetTrackHeight(int index, int h);
 
@@ -46,6 +48,9 @@ protected:
 
 private:
   Qt::Alignment alignment_;
+
+  int spacer_height_;
+
 };
 
 #endif // TRACKVIEWSPLITTER_H

app/widget/timelinewidget/view/timelineview.cpp

@@ -151,6 +151,34 @@ void TimelineView::dropEvent(QDropEvent *event)
   emit DragDropped(&timeline_event);
 }
 
+void TimelineView::drawBackground(QPainter *painter, const QRectF &rect)
+{
+  if (!connected_track_list_) {
+    return;
+  }
+
+  painter->setPen(palette().base().color());
+
+  int line_y = 0;
+
+  foreach (TrackOutput* track, connected_track_list_->Tracks()) {
+    line_y += track->GetTrackHeight();
+
+    // One px gap between tracks
+    line_y++;
+
+    int this_line_y;
+
+    if (alignment() & Qt::AlignTop) {
+      this_line_y = line_y;
+    } else {
+      this_line_y = -line_y;
+    }
+
+    painter->drawLine(qRound(rect.left()), this_line_y, qRound(rect.right()), this_line_y);
+  }
+}
+
 Stream::Type TimelineView::TrackTypeToStreamType(TrackType track_type)
 {
   switch (track_type) {
@@ -188,10 +216,13 @@ int TimelineView::GetTrackY(int track_index)
 
   for (int i=0;i<track_index;i++) {
     y += GetTrackHeight(i);
+
+    // One px line between each track
+    y++;
   }
 
   if (alignment() & Qt::AlignBottom) {
-    y = -y;
+    y = -y + 1;
   }
 
   return y;
@@ -219,7 +250,15 @@ void TimelineView::SetScrollCoordinates(const QPoint &pt)
 
 void TimelineView::ConnectTrackList(TrackList *list)
 {
+  if (connected_track_list_) {
+    disconnect(connected_track_list_, SIGNAL(TrackHeightChanged(int, int)), viewport(), SLOT(update()));
+  }
+
   connected_track_list_ = list;
+
+  if (connected_track_list_) {
+    connect(connected_track_list_, SIGNAL(TrackHeightChanged(int, int)), viewport(), SLOT(update()));
+  }
 }
 
 int TimelineView::SceneToTrack(double y)

app/widget/timelinewidget/view/timelineview.h

@@ -83,6 +83,8 @@ protected:
   virtual void dragLeaveEvent(QDragLeaveEvent *event) override;
   virtual void dropEvent(QDropEvent *event) override;
 
+  virtual void drawBackground(QPainter *painter, const QRectF &rect) override;
+
 private:
   TrackType ConnectedTrackType();
   Stream::Type TrackTypeToStreamType(TrackType track_type);

app/widget/timelinewidget/view/timelineviewbase.cpp

@@ -22,6 +22,8 @@ TimelineViewBase::TimelineViewBase(QWidget *parent) :
   // Set default scale
   SetScale(1.0);
 
+  setViewportUpdateMode(FullViewportUpdate);
+
   connect(&scene_, SIGNAL(changed(const QList<QRectF>&)), this, SLOT(UpdateSceneRect()));
 }
 
@@ -113,6 +115,13 @@ void TimelineViewBase::UpdateSceneRect()
   QRectF bounding_rect = scene_.itemsBoundingRect();
 
   if (limit_y_axis_) {
+    // Make a gap of half the viewport height
+    if (alignment() & Qt::AlignBottom) {
+      bounding_rect.setTop(bounding_rect.top() - height()/2);
+    } else {
+      bounding_rect.setBottom(bounding_rect.bottom() + height()/2);
+    }
+
     // Ensure the scene height is always AT LEAST the height of the view
     // The scrollbar appears to have a 1px margin on the top and bottom, hence the -2
     int minimum_height = height() - horizontalScrollBar()->height() - 2;

app/widget/timelinewidget/view/timelineviewblockitem.cpp

@@ -64,7 +64,7 @@ void TimelineViewBlockItem::UpdateRect()
   double item_width = TimeToScene(block_->length());
 
   // -1 on width and height so we don't overlap any adjacent clips
-  setRect(0, y_, item_width - 1, height_ - 1);
+  setRect(0, y_, item_width - 1, height_);
   setPos(item_left, 0.0);
 
   setToolTip(QCoreApplication::translate("TimelineViewBlockItem",