paramview: changed to static viewer-bound and fixed various scrolling issues

app/widget/keyframeview/keyframeview.cpp

@@ -23,7 +23,8 @@
 OLIVE_NAMESPACE_ENTER
 
 KeyframeView::KeyframeView(QWidget *parent) :
-  KeyframeViewBase(parent)
+  KeyframeViewBase(parent),
+  max_scroll_(0)
 {
   setAlignment(Qt::AlignLeft | Qt::AlignTop);
 }
@@ -35,6 +36,12 @@ void KeyframeView::wheelEvent(QWheelEvent *event)
   }
 }
 
+void KeyframeView::SceneRectUpdateEvent(QRectF &rect)
+{
+  rect.setY(0);
+  rect.setHeight(max_scroll_);
+}
+
 void KeyframeView::AddKeyframe(NodeKeyframePtr key, int y)
 {
   QPoint global_pt(0, y);

app/widget/keyframeview/keyframeview.h

@@ -31,12 +31,22 @@ class KeyframeView : public KeyframeViewBase
 public:
   KeyframeView(QWidget* parent = nullptr);
 
+  void SetMaxScroll(int i)
+  {
+    max_scroll_ = i;
+  }
+
 protected:
   virtual void wheelEvent(QWheelEvent* event) override;
 
+  virtual void SceneRectUpdateEvent(QRectF& rect) override;
+
 public slots:
   void AddKeyframe(NodeKeyframePtr key, int y);
 
+private:
+  int max_scroll_;
+
 };
 
 OLIVE_NAMESPACE_EXIT

app/widget/keyframeview/keyframeviewbase.cpp

@@ -101,14 +101,18 @@ void KeyframeViewBase::RemoveKeyframe(NodeKeyframePtr key)
 
 KeyframeViewItem *KeyframeViewBase::AddKeyframeInternal(NodeKeyframePtr key)
 {
-  KeyframeViewItem* item = new KeyframeViewItem(key);
-  item->SetTimeTarget(GetTimeTarget());
-  item->SetScale(GetScale());
-  item_map_.insert(key.get(), item);
-  scene()->addItem(item);
+  KeyframeViewItem* item = item_map_.value(key.get());
 
-  if (hidden_tracks_.contains(key->track())) {
-    item->setVisible(false);
+  if (!item) {
+    item = new KeyframeViewItem(key);
+    item->SetTimeTarget(GetTimeTarget());
+    item->SetScale(GetScale());
+    item_map_.insert(key.get(), item);
+    scene()->addItem(item);
+
+    if (hidden_tracks_.contains(key->track())) {
+      item->setVisible(false);
+    }
   }
 
   return item;