Clip the Meter Widgets to the visible portion of the Video Window (#3462)

When the video widget is scrolled, the MeterWidget windows appeared on
top of the Main Window user interface. Now the visible portion of the
Video Window is tracked and used as a clipping region. This avoids
blocking the controls on bottom toolbar.

src/Train/MeterWidget.cpp

@@ -70,6 +70,7 @@ void MeterWidget::SetRelativePos(float RelativePosX, float RelativePosY)
 
 void MeterWidget::AdjustSizePos()
 {
+    // Compute the size and position relative to its parent
     QPoint p;
     if (m_container->windowFlags() & Qt::Window)
         p = m_container->pos();
@@ -80,6 +81,11 @@ void MeterWidget::AdjustSizePos()
     m_PosY = p.y() + m_container->height() * m_RelativePosY - m_Height/2;
     move(m_PosX, m_PosY);
     adjustSize();
+
+    // Translate the Video Container visible region to our coordinate for clipping
+    QPoint vp = m_VideoContainer->pos();
+    videoContainerRegion = m_VideoContainer->visibleRegion();
+    videoContainerRegion.translate(mapFromGlobal(m_VideoContainer->mapToGlobal(vp)) - vp);
 }
 
 void MeterWidget::ComputeSize()
@@ -116,6 +122,7 @@ void MeterWidget::paintEvent(QPaintEvent* paintevent)
 
         //painter
         QPainter painter(this);
+        painter.setClipRegion(videoContainerRegion);
         painter.setRenderHint(QPainter::Antialiasing);
 
         painter.setPen(m_OutlinePen);
@@ -151,6 +158,7 @@ void TextMeterWidget::paintEvent(QPaintEvent* paintevent)
 
     //painter
     QPainter painter(this);
+    painter.setClipRegion(videoContainerRegion);
     painter.setRenderHint(QPainter::Antialiasing);
 
     //draw background
@@ -196,6 +204,7 @@ void CircularIndicatorMeterWidget::paintEvent(QPaintEvent* paintevent)
 
     //painter
     QPainter painter(this);
+    painter.setClipRegion(videoContainerRegion);
     painter.setRenderHint(QPainter::Antialiasing);
     // define scale and location
     painter.translate(m_Width / 2, m_Height / 2);
@@ -242,6 +251,7 @@ void CircularBargraphMeterWidget::paintEvent(QPaintEvent* paintevent)
 
     //painter
     QPainter painter(this);
+    painter.setClipRegion(videoContainerRegion);
     painter.setRenderHint(QPainter::Antialiasing);
 
     //draw bargraph
@@ -277,6 +287,7 @@ void NeedleMeterWidget::paintEvent(QPaintEvent* paintevent)
 
     //painter
     QPainter painter(this);
+    painter.setClipRegion(videoContainerRegion);
     painter.setRenderHint(QPainter::Antialiasing);
 
     //draw background
@@ -339,6 +350,7 @@ void ElevationMeterWidget::paintEvent(QPaintEvent* paintevent)
 
     //painter
     QPainter painter(this);
+    painter.setClipRegion(videoContainerRegion);
     painter.setRenderHint(QPainter::Antialiasing);
 
     // Find min/max

src/Train/MeterWidget.h

@@ -54,6 +54,8 @@ class MeterWidget : public QWidget
     QString  m_Name;
     QWidget* m_container;
     QString  m_Source;
+    QWidget* m_VideoContainer;
+    QRegion  videoContainerRegion;
     float    m_RelativeWidth, m_RelativeHeight;
     float    m_RelativePosX, m_RelativePosY;
     int      m_PosX, m_PosY, m_Width, m_Height;

src/Train/VideoLayoutParser.cpp

@@ -50,6 +50,7 @@ void VideoLayoutParser::SetDefaultValues()
         meterWidget->m_BackgroundColor = QColor(100,100,100,0);
         meterWidget->m_MainFont = QFont(meterWidget->font().family(), 64);
         meterWidget->m_AltFont = QFont(meterWidget->font().family(), 48);
+        meterWidget->m_VideoContainer = VideoContainer;
     }
 }