curveview: color code keyframe tracks when more than one is present

app/widget/curvewidget/curveview.cpp

@@ -92,9 +92,9 @@ void CurveView::drawBackground(QPainter *painter, const QRectF &rect)
   painter->drawLines(lines);
 
   // Draw keyframe lines
-  painter->setPen(QPen(palette().text().color(), qMax(1, fontMetrics().height() / 4)));
 
   for (int j=0;j<track_count_;j++) {
+    painter->setPen(QPen(GetKeyframeColor(j), qMax(1, fontMetrics().height() / 4)));
     QList<NodeKeyframe*> keys = GetKeyframesSortedByTime(j);
 
     if (!keys.isEmpty()) {
@@ -290,6 +290,17 @@ void CurveView::CreateBezierControlPoints(KeyframeViewItem* item)
   connect(bezier_out_pt, &QObject::destroyed, this, &CurveView::BezierControlPointDestroyed, Qt::DirectConnection);
 }
 
+QColor CurveView::GetKeyframeColor(int track) const
+{
+  if (track_count_) {
+    QColor c;
+    c.setHsvF(static_cast<double>(track) / static_cast<double>(track_count_), 0.5, 1.0);
+    return c;
+  }
+
+  return palette().text().color();
+}
+
 void CurveView::KeyframeValueChanged()
 {
   NodeKeyframe* key = static_cast<NodeKeyframe*>(sender());
@@ -338,6 +349,7 @@ void CurveView::AddKeyframe(NodeKeyframePtr key)
 {
   KeyframeViewItem* item = AddKeyframeInternal(key);
   SetItemYFromKeyframeValue(key.get(), item);
+  item->SetOverrideBrush(GetKeyframeColor(key->track()));
 
   connect(key.get(), &NodeKeyframe::ValueChanged, this, &CurveView::KeyframeValueChanged);
   connect(key.get(), &NodeKeyframe::TypeChanged, this, &CurveView::KeyframeTypeChanged);

app/widget/curvewidget/curveview.h

@@ -44,6 +44,8 @@ private:
 
   void CreateBezierControlPoints(KeyframeViewItem *item);
 
+  QColor GetKeyframeColor(int track) const;
+
   int text_padding_;
 
   int minimum_grid_space_;

app/widget/keyframeview/keyframeviewitem.cpp

@@ -12,7 +12,8 @@ KeyframeViewItem::KeyframeViewItem(NodeKeyframePtr key, QGraphicsItem *parent) :
   QGraphicsRectItem(parent),
   key_(key),
   scale_(1.0),
-  vert_center_(0)
+  vert_center_(0),
+  use_custom_brush_(false)
 {
   setFlag(QGraphicsItem::ItemIsSelectable);
 
@@ -24,6 +25,8 @@ KeyframeViewItem::KeyframeViewItem(NodeKeyframePtr key, QGraphicsItem *parent) :
   setRect(-half_sz, -half_sz, keyframe_size, keyframe_size);
 
   UpdatePos();
+
+  // Set default brush
 }
 
 void KeyframeViewItem::SetOverrideY(qreal vertical_center)
@@ -38,6 +41,12 @@ void KeyframeViewItem::SetScale(double scale)
   UpdatePos();
 }
 
+void KeyframeViewItem::SetOverrideBrush(const QBrush &b)
+{
+  use_custom_brush_ = true;
+  setBrush(b);
+}
+
 NodeKeyframePtr KeyframeViewItem::key() const
 {
   return key_;
@@ -51,6 +60,8 @@ void KeyframeViewItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *
 
   if (option->state & QStyle::State_Selected) {
     painter->setBrush(widget->palette().highlight());
+  } else if (use_custom_brush_) {
+    painter->setBrush(brush());
   } else {
     painter->setBrush(widget->palette().text());
   }

app/widget/keyframeview/keyframeviewitem.h

@@ -16,6 +16,8 @@ public:
 
   void SetScale(double scale);
 
+  void SetOverrideBrush(const QBrush& b);
+
   NodeKeyframePtr key() const;
 
 protected:
@@ -30,6 +32,8 @@ private:
 
   qreal vert_center_;
 
+  bool use_custom_brush_;
+
 private slots:
   void UpdatePos();