multicam: prioritize current clip under playhead

app/widget/multicam/multicamwidget.cpp

@@ -54,7 +54,6 @@ void MulticamWidget::SetMulticamNode(MultiCamNode *n)
 {
   node_ = n;
   display_->SetMulticamNode(n);
-  display_->update();
 }
 
 void MulticamWidget::SetClip(ClipBlock *clip)

app/widget/viewer/viewer.cpp

@@ -799,6 +799,14 @@ void ViewerWidget::UpdateTextureFromNode()
   }
 }
 
+void ViewerWidget::SetMulticamNode(MultiCamNode *n)
+{
+  auto_cacher()->SetMulticamNode(n);
+  if (!IsPlaying()) {
+    UpdateTextureFromNode();
+  }
+}
+
 void ViewerWidget::PlayInternal(int speed, bool in_to_out_only)
 {
   Q_ASSERT(speed != 0);

app/widget/viewer/viewer.h

@@ -109,10 +109,7 @@ public:
     playback_devices_.push_back(vw);
   }
 
-  void SetMulticamNode(MultiCamNode *n)
-  {
-    auto_cacher()->SetMulticamNode(n);
-  }
+  void SetMulticamNode(MultiCamNode *n);
 
 public slots:
   void Play(bool in_to_out_only);