timelinescaledobject: implemented minimum scale

Used by Viewer to keep TimeRuler and WaveformView within restrictions.

app/widget/timelinewidget/timelinescaledobject.cpp

@@ -3,8 +3,11 @@
 #include <cfloat>
 #include <QtMath>
 
+#include "common/clamp.h"
+
 TimelineScaledObject::TimelineScaledObject() :
   scale_(1.0),
+  min_scale_(0),
   max_scale_(DBL_MAX)
 {
 
@@ -64,6 +67,15 @@ void TimelineScaledObject::SetMaximumScale(const double &max)
   }
 }
 
+void TimelineScaledObject::SetMinimumScale(const double &min)
+{
+  min_scale_ = min;
+
+  if (GetScale() < min_scale_) {
+    SetScale(min_scale_);
+  }
+}
+
 const double& TimelineScaledObject::GetScale() const
 {
   return scale_;
@@ -73,7 +85,7 @@ void TimelineScaledObject::SetScale(const double& scale)
 {
   Q_ASSERT(scale > 0);
 
-  scale_ = qMin(scale, max_scale_);
+  scale_ = clamp(scale, min_scale_, max_scale_);
 
   ScaleChangedEvent(scale_);
 }

app/widget/timelinewidget/timelinescaledobject.h

@@ -32,6 +32,8 @@ protected:
 
   void SetMaximumScale(const double& max);
 
+  void SetMinimumScale(const double& min);
+
 private:
   rational timebase_;
 
@@ -39,6 +41,8 @@ private:
 
   double scale_;
 
+  double min_scale_;
+
   double max_scale_;
 
 };

app/widget/viewer/viewer.cpp

@@ -202,6 +202,8 @@ void ViewerWidget::resizeEvent(QResizeEvent *event)
 
     UpdateRendererParameters();
   }
+
+  UpdateMinimumScale();
 }
 
 void ViewerWidget::TogglePlayPause()
@@ -324,6 +326,15 @@ int ViewerWidget::CalculateDivider()
   return divider_;
 }
 
+void ViewerWidget::UpdateMinimumScale()
+{
+  if (!GetConnectedNode()) {
+    return;
+  }
+
+  SetMinimumScale(static_cast<double>(ruler()->width()) / GetConnectedNode()->Length().toDouble());
+}
+
 void ViewerWidget::UpdateStack()
 {
   if (!GetConnectedNode() || GetConnectedNode()->texture_input()->IsConnected()) {
@@ -554,6 +565,7 @@ void ViewerWidget::LengthChangedSlot(const rational &length)
 {
   controls_->SetEndTime(Timecode::time_to_timestamp(length, timebase()));
   ruler()->SetCacheStatusLength(length);
+  UpdateMinimumScale();
 }
 
 void ViewerWidget::ColorDisplayChanged(QAction* action)

app/widget/viewer/viewer.h

@@ -134,6 +134,8 @@ private:
 
   int CalculateDivider();
 
+  void UpdateMinimumScale();
+
   QStackedWidget* stack_;
 
   ViewerSizer* sizer_;