viewer: automatically update maximum scroll from media length

app/config/config.cpp

@@ -74,6 +74,7 @@ void Config::SetDefaults()
   config_map_["AutoscaleByDefault"] = false;
   config_map_["Autoscroll"] = AutoScroll::kPage;
   config_map_["DefaultViewerDivider"] = 2;
+  config_map_["AutoSelectDivider"] = false;
 
   config_map_["DiskCachePath"] = QStandardPaths::writableLocation(QStandardPaths::AppLocalDataLocation);
   config_map_["DiskCacheSize"] = 20.0;

app/widget/timebased/timebased.cpp

@@ -4,7 +4,8 @@
 
 TimeBasedWidget::TimeBasedWidget(bool ruler_text_visible, bool ruler_cache_status_visible, QWidget *parent) :
   QWidget(parent),
-  viewer_node_(nullptr)
+  viewer_node_(nullptr),
+  auto_max_scrollbar_(false)
 {
   ruler_ = new TimeRuler(ruler_text_visible, ruler_cache_status_visible, this);
   connect(ruler_, &TimeRuler::TimeChanged, this, &TimeBasedWidget::SetTimeAndSignal);
@@ -31,6 +32,8 @@ void TimeBasedWidget::ConnectViewerNode(ViewerOutput *node)
 {
   if (viewer_node_) {
     DisconnectNodeInternal(viewer_node_);
+
+    disconnect(viewer_node_, &ViewerOutput::LengthChanged, this, &TimeBasedWidget::UpdateMaximumScroll);
   }
 
   viewer_node_ = node;
@@ -39,9 +42,20 @@ void TimeBasedWidget::ConnectViewerNode(ViewerOutput *node)
 
   if (viewer_node_) {
     ConnectNodeInternal(viewer_node_);
+
+    connect(viewer_node_, &ViewerOutput::LengthChanged, this, &TimeBasedWidget::UpdateMaximumScroll);
   }
 }
 
+void TimeBasedWidget::UpdateMaximumScroll()
+{
+  if (!viewer_node_ || !auto_max_scrollbar_) {
+    return;
+  }
+
+  scrollbar_->setMaximum(qMax(0, qCeil(TimeToScene(viewer_node_->Length())) - width()));
+}
+
 TimeRuler *TimeBasedWidget::ruler() const
 {
   return ruler_;
@@ -66,6 +80,13 @@ void TimeBasedWidget::ScaleChangedEvent(const double &scale)
   TimelineScaledObject::ScaleChangedEvent(scale);
 
   ruler_->SetScale(scale);
+
+  UpdateMaximumScroll();
+}
+
+void TimeBasedWidget::SetAutoMaxScrollBar(bool e)
+{
+  auto_max_scrollbar_ = e;
 }
 
 void TimeBasedWidget::resizeEvent(QResizeEvent *event)
@@ -74,6 +95,8 @@ void TimeBasedWidget::resizeEvent(QResizeEvent *event)
 
   // Update horizontal scrollbar's page step to the width of the panel
   scrollbar()->setPageStep(scrollbar()->width());
+
+  UpdateMaximumScroll();
 }
 
 void TimeBasedWidget::SetTime(int64_t timestamp)

app/widget/timebased/timebased.h

@@ -66,6 +66,8 @@ protected:
 
   virtual void DisconnectNodeInternal(ViewerOutput*){}
 
+  void SetAutoMaxScrollBar(bool e);
+
   virtual void resizeEvent(QResizeEvent *event) override;
 
 signals:
@@ -80,6 +82,11 @@ private:
 
   QScrollBar* scrollbar_;
 
+  bool auto_max_scrollbar_;
+
+private slots:
+  void UpdateMaximumScroll();
+
 };
 
 #endif // TIMEBASEDWIDGET_H

app/widget/viewer/viewer.cpp

@@ -78,7 +78,7 @@ ViewerWidget::ViewerWidget(QWidget *parent) :
   connect(&playback_timer_, &QTimer::timeout, this, &ViewerWidget::PlaybackTimerUpdate);
 
   // FIXME: Magic number
-  ruler()->SetScale(48.0);
+  SetScale(48.0);
 
   // Start background renderers
   video_renderer_ = new OpenGLBackend(this);
@@ -89,6 +89,8 @@ ViewerWidget::ViewerWidget(QWidget *parent) :
   audio_renderer_ = new AudioBackend(this);
 
   connect(PixelService::instance(), &PixelService::FormatChanged, this, &ViewerWidget::UpdateRendererParameters);
+
+  SetAutoMaxScrollBar(true);
 }
 
 void ViewerWidget::TimeChangedEvent(const int64_t &i)
@@ -130,6 +132,8 @@ void ViewerWidget::ConnectNodeInternal(ViewerOutput *n)
     qWarning() << "Failed to find a suitable color manager for the connected viewer node";
   }
 
+  divider_ = CalculateDivider();
+
   UpdateRendererParameters();
 }
 
@@ -154,6 +158,18 @@ void ViewerWidget::ConnectedNodeChanged(ViewerOutput *n)
   audio_renderer_->SetViewerNode(n);
 }
 
+void ViewerWidget::resizeEvent(QResizeEvent *event)
+{
+  TimeBasedWidget::resizeEvent(event);
+
+  int new_div = CalculateDivider();
+  if (new_div != divider_) {
+    divider_ = new_div;
+
+    UpdateRendererParameters();
+  }
+}
+
 void ViewerWidget::TogglePlayPause()
 {
   if (IsPlaying()) {
@@ -259,6 +275,18 @@ void ViewerWidget::PushScrubbedAudio()
   }
 }
 
+int ViewerWidget::CalculateDivider()
+{
+  if (GetConnectedNode() && Config::Current()["AutoSelectDivider"].toBool()) {
+    int long_side_of_video = qMax(GetConnectedNode()->video_params().width(), GetConnectedNode()->video_params().height());
+    int long_side_of_widget = qMax(gl_widget_->width(), gl_widget_->height());
+
+    return qMax(1, long_side_of_video / long_side_of_widget);
+  }
+
+  return divider_;
+}
+
 void ViewerWidget::UpdateRendererParameters()
 {
   if (!GetConnectedNode()) {
@@ -279,7 +307,7 @@ void ViewerWidget::UpdateRendererParameters()
 
 void ViewerWidget::ShowContextMenu(const QPoint &pos)
 {
-  QMenu menu;
+  QMenu menu(this);
 
   // Color options
   if (gl_widget_->color_manager() && color_menu_enabled_) {

app/widget/viewer/viewer.h

@@ -122,6 +122,8 @@ protected:
   virtual void DisconnectNodeInternal(ViewerOutput *) override;
   virtual void ConnectedNodeChanged(ViewerOutput*n) override;
 
+  virtual void resizeEvent(QResizeEvent *event) override;
+
   OpenGLBackend* video_renderer_;
   AudioBackend* audio_renderer_;
 
@@ -134,6 +136,8 @@ private:
 
   void PushScrubbedAudio();
 
+  int CalculateDivider();
+
   ViewerSizer* sizer_;
 
   ViewerGLWidget* gl_widget_;