node: split off traversing functions from renderer for usage elsewhere

Fixes issue where Viewer node wouldn't pick up correct length if a tracks
weren't in use.

app/widget/viewer/footageviewer.cpp

@@ -13,9 +13,13 @@ FootageViewerWidget::FootageViewerWidget(QWidget *parent) :
   audio_node_ = new AudioInput();
   viewer_node_ = new ViewerOutput();
 
+  waveform_view_ = new QWidget();
+  waveform_view_->setAutoFillBackground(true);
+  waveform_view_->setStyleSheet("background: black;");
+  stack()->addWidget(waveform_view_);
+
   NodeParam::ConnectEdge(video_node_->output(), viewer_node_->texture_input());
   NodeParam::ConnectEdge(audio_node_->output(), viewer_node_->samples_input());
-  NodeParam::ConnectEdge(video_node_->output(), viewer_node_->length_input());
 
   connect(gl_widget_, &ViewerGLWidget::DragStarted, this, &FootageViewerWidget::StartFootageDrag);
 }
@@ -55,6 +59,10 @@ void FootageViewerWidget::SetFootage(Footage *footage)
     if (video_stream) {
       video_node_->SetFootage(video_stream);
       viewer_node_->set_video_params(VideoParams(video_stream->width(), video_stream->height(), video_stream->frame_rate().flipped()));
+
+      stack()->setCurrentWidget(gl_widget_);
+    } else {
+      stack()->setCurrentWidget(waveform_view_);
     }
 
     if (audio_stream) {
@@ -79,7 +87,6 @@ void FootageViewerWidget::StartFootageDrag()
     return;
   }
 
-  qDebug() << "Drag start!";
   QDrag* drag = new QDrag(this);
   QMimeData* mimedata = new QMimeData();
 

app/widget/viewer/footageviewer.h

@@ -27,6 +27,8 @@ private:
 
   ViewerOutput* viewer_node_;
 
+  QWidget* waveform_view_;
+
 private slots:
   void StartFootageDrag();
 

app/widget/viewer/viewer.cpp

@@ -47,9 +47,13 @@ ViewerWidget::ViewerWidget(QWidget *parent) :
   QVBoxLayout* layout = new QVBoxLayout(this);
   layout->setMargin(0);
 
+  // Set up stacked widget to allow switching away from the viewer widget
+  stack_ = new QStackedWidget();
+  layout->addWidget(stack_);
+
   // Create main OpenGL-based view
   sizer_ = new ViewerSizer();
-  layout->addWidget(sizer_);
+  stack_->addWidget(sizer_);
 
   gl_widget_ = new ViewerGLWidget();
   connect(gl_widget_, &ViewerGLWidget::customContextMenuRequested, this, &ViewerWidget::ShowContextMenu);
@@ -111,7 +115,13 @@ void ViewerWidget::TimeChangedEvent(const int64_t &i)
 
 void ViewerWidget::ConnectNodeInternal(ViewerOutput *n)
 {
-  SetTimebase(n->video_params().time_base());
+  if (!n->video_params().time_base().isNull()) {
+    SetTimebase(n->video_params().time_base());
+  } else if (n->audio_params().sample_rate() > 0) {
+    SetTimebase(rational(1, n->audio_params().sample_rate()));
+  } else {
+    SetTimebase(rational());
+  }
 
   connect(n, &ViewerOutput::TimebaseChanged, this, &ViewerWidget::SetTimebase);
   connect(n, &ViewerOutput::SizeChanged, this, &ViewerWidget::SizeChangedSlot);
@@ -139,7 +149,7 @@ void ViewerWidget::DisconnectNodeInternal(ViewerOutput *n)
 {
   Pause();
 
-  SetTimebase(0);
+  SetTimebase(rational());
 
   disconnect(n, &ViewerOutput::TimebaseChanged, this, &ViewerWidget::SetTimebase);
   disconnect(n, &ViewerOutput::SizeChanged, this, &ViewerWidget::SizeChangedSlot);
@@ -171,6 +181,11 @@ void ViewerWidget::resizeEvent(QResizeEvent *event)
   }
 }
 
+QStackedWidget *ViewerWidget::stack() const
+{
+  return stack_;
+}
+
 void ViewerWidget::TogglePlayPause()
 {
   if (IsPlaying()) {
@@ -251,7 +266,11 @@ void ViewerWidget::PlayInternal(int speed)
 
   controls_->ShowPauseButton();
 
-  connect(gl_widget_, &ViewerGLWidget::frameSwapped, this, &ViewerWidget::PlaybackTimerUpdate);
+  if (stack_->currentWidget() == gl_widget_) {
+    connect(gl_widget_, &ViewerGLWidget::frameSwapped, this, &ViewerWidget::PlaybackTimerUpdate);
+  } else {
+    connect(AudioManager::instance(), &AudioManager::OutputNotified, this, &ViewerWidget::PlaybackTimerUpdate);
+  }
 }
 
 void ViewerWidget::PushScrubbedAudio()
@@ -387,7 +406,11 @@ void ViewerWidget::Pause()
     playback_speed_ = 0;
     controls_->ShowPlayButton();
 
-    disconnect(gl_widget_, &ViewerGLWidget::frameSwapped, this, &ViewerWidget::PlaybackTimerUpdate);
+    if (stack_->currentWidget() == gl_widget_) {
+      disconnect(gl_widget_, &ViewerGLWidget::frameSwapped, this, &ViewerWidget::PlaybackTimerUpdate);
+    } else {
+      disconnect(AudioManager::instance(), &AudioManager::OutputNotified, this, &ViewerWidget::PlaybackTimerUpdate);
+    }
   }
 }
 

app/widget/viewer/viewer.h

@@ -115,6 +115,8 @@ protected:
 
   virtual void resizeEvent(QResizeEvent *event) override;
 
+  QStackedWidget* stack() const;
+
   OpenGLBackend* video_renderer_;
   AudioBackend* audio_renderer_;
 
@@ -131,6 +133,8 @@ private:
 
   int CalculateDivider();
 
+  QStackedWidget* stack_;
+
   ViewerSizer* sizer_;
 
   PlaybackControls* controls_;