draw passthrough overlay on overview ...

on top of all overview items and put 'Passthrough' QLabel on top.
Any mouse events are still passed to the overview widget.
Skin style:
The cover color is picked from skin node <PassthroughOverlayColor>
in the Overview widget (default #bb000000), the default label style
can be adjusted in qss (#PassthroughLabel).

src/waveform/renderers/waveformsignalcolors.cpp

@@ -67,8 +67,7 @@ bool WaveformSignalColors::setup(const QDomNode &node, const SkinContext& contex
     m_passthroughOverlayColor = context.selectColor(node, "PassthroughOverlayColor");
     m_passthroughOverlayColor = WSkinColor::getCorrectColor(m_passthroughOverlayColor).toRgb();
     if (!m_passthroughOverlayColor.isValid()) {
-        // TODO(ronso0): set a default color
-        m_passthroughOverlayColor = Qt::transparent;
+        m_passthroughOverlayColor = WSkinColor::getCorrectColor(QColor(187, 0, 0, 0)).toRgb();
     }
 
     m_bgColor = context.selectColor(node, "BgColor");

src/widget/woverview.cpp

@@ -17,7 +17,6 @@
 #include <QMouseEvent>
 #include <QPaintEvent>
 #include <QPainter>
-#include <QPixmap>
 #include <QUrl>
 #include <QtDebug>
 
@@ -94,6 +93,17 @@ WOverview::WOverview(
             this, &WOverview::onTrackAnalyzerProgress);
 
     connect(m_pCueMenuPopup.get(), &WCueMenuPopup::aboutToHide, this, &WOverview::slotCueMenuPopupAboutToHide);
+
+    m_pPassthroughLabel = new QLabel(this);
+    m_pPassthroughLabel->setObjectName("PassthroughLabel");
+    m_pPassthroughLabel->setAlignment(Qt::AlignLeft|Qt::AlignVCenter);
+    m_pPassthroughLabel->setText("Passthrough");
+    m_pPassthroughLabel->hide();
+    m_pPassThroughLayout = new QVBoxLayout(this);
+    m_pPassThroughLayout->setContentsMargins(0,0,0,0);
+    m_pPassThroughLayout->setAlignment(Qt::AlignLeft|Qt::AlignVCenter);
+    m_pPassThroughLayout->addWidget(m_pPassthroughLabel);
+    setLayout(m_pPassThroughLayout);
 }
 
 void WOverview::setup(const QDomNode& node, const SkinContext& context) {
@@ -135,6 +145,8 @@ void WOverview::setup(const QDomNode& node, const SkinContext& context) {
         m_endOfTrackColor = WSkinColor::getCorrectColor(m_endOfTrackColor);
     }
 
+    m_passthroughOverlayColor = m_signalColors.getPlayedOverlayColor();
+
     // setup hotcues and cue and loop(s)
     m_marks.setup(m_group, node, context, m_signalColors);
 
@@ -243,11 +255,6 @@ void WOverview::onConnectedControlChanged(double dParameter, double dValue) {
 void WOverview::slotWaveformSummaryUpdated() {
     //qDebug() << "WOverview::slotWaveformSummaryUpdated()";
 
-    // Do not draw the waveform when passthrough is enabled
-    if (m_bPassthroughEnabled) {
-        return;
-    }
-
     TrackPointer pTrack(m_pCurrentTrack);
     if (!pTrack) {
         return;
@@ -563,11 +570,6 @@ void WOverview::paintEvent(QPaintEvent* pEvent) {
         painter.drawPixmap(rect(), m_backgroundPixmap);
     }
 
-    if (m_bPassthroughEnabled) {
-        paintText(tr("Passthrough"), &painter);
-        return;
-    }
-
     if (m_pCurrentTrack) {
         // Refer to util/ScopePainter.h to understand the semantics of
         // ScopePainter.
@@ -589,7 +591,15 @@ void WOverview::paintEvent(QPaintEvent* pEvent) {
             drawMarkLabels(&painter, offset, gain);
         }
     }
+
+    if (m_bPassthroughEnabled) {
+        drawPassthroughOverlay(&painter);
+        m_pPassthroughLabel->show();
+    } else {
+        m_pPassthroughLabel->hide();
+    }
 }
+
 void WOverview::drawEndOfTrackBackground(QPainter* pPainter) {
     if (m_endOfTrack) {
         PainterScope painterScope(pPainter);
@@ -1077,6 +1087,13 @@ void WOverview::drawMarkLabels(QPainter* pPainter, const float offset, const flo
     }
 }
 
+void WOverview::drawPassthroughOverlay(QPainter* pPainter) {
+    if (!m_waveformSourceImage.isNull() && m_passthroughOverlayColor.alpha() > 0) {
+        // Overlay the entire overview-waveform with a skin defined color
+        pPainter->fillRect(rect(), m_passthroughOverlayColor);
+    }
+}
+
 void WOverview::paintText(const QString& text, QPainter* pPainter) {
     PainterScope painterScope(pPainter);
     QColor lowColor = m_signalColors.getLowColor();

src/widget/woverview.h

@@ -117,6 +117,7 @@ class WOverview : public WWidget, public TrackDropTarget {
     void drawPickupPosition(QPainter* pPainter);
     void drawTimeRuler(QPainter* pPainter);
     void drawMarkLabels(QPainter* pPainter, const float offset, const float gain);
+    void drawPassthroughOverlay(QPainter* pPainter);
     void paintText(const QString& text, QPainter* pPainter);
     double samplePositionToSeconds(double sample);
     inline int valueToPosition(double value) const {
@@ -170,6 +171,9 @@ class WOverview : public WWidget, public TrackDropTarget {
     QColor m_labelTextColor;
     QColor m_labelBackgroundColor;
     QColor m_endOfTrackColor;
+    QColor m_passthroughOverlayColor;
+    QLabel* m_pPassthroughLabel;
+    QVBoxLayout* m_pPassThroughLayout;
 
     // All WaveformMarks
     WaveformMarkSet m_marks;