Added ability to provide custom top bar mask to Window::SlideAnimation.

Telegram/SourceFiles/window/section_widget.cpp

@@ -157,6 +157,7 @@ void SectionWidget::showAnimated(
 	_showAnimation->setTopBarShadow(params.withTopBarShadow);
 	_showAnimation->setWithFade(params.withFade);
 	_showAnimation->setTopSkip(params.topSkip);
+	_showAnimation->setTopBarMask(params.topMask);
 	_showAnimation->start();
 
 	show();

Telegram/SourceFiles/window/section_widget.h

@@ -72,6 +72,7 @@ class SectionMemento;
 struct SectionSlideParams {
 	QPixmap oldContentCache;
 	int topSkip = 0;
+	QPixmap topMask;
 	bool withTopBarShadow = false;
 	bool withTabs = false;
 	bool withFade = false;

Telegram/SourceFiles/window/window_slide_animation.cpp

@@ -39,6 +39,45 @@ void SlideAnimation::paintContents(Painter &p) const {
 		const auto leftWidth = (leftWidthFull + leftCoord);
 		const auto rightWidth = rightWidthFull - rightCoord;
 
+		if (!_mask.isNull()) {
+			auto frame = QImage(
+				_mask.size(),
+				QImage::Format_ARGB32_Premultiplied);
+			frame.setDevicePixelRatio(_mask.devicePixelRatio());
+			frame.fill(Qt::transparent);
+			QPainter q(&frame);
+
+			if (leftWidth > 0) {
+				q.setOpacity(leftAlpha);
+				q.drawPixmap(
+					0,
+					0,
+					_cacheUnder,
+					(_cacheUnder.width() - leftWidth * cIntRetinaFactor()),
+					0,
+					leftWidth * cIntRetinaFactor(),
+					_topSkip * retina);
+			}
+
+			if (rightWidth > 0) {
+				q.setOpacity(rightAlpha);
+				q.drawPixmap(
+					rightCoord,
+					0,
+					_cacheOver,
+					0,
+					0,
+					rightWidth * cIntRetinaFactor(),
+					_topSkip * retina);
+			}
+
+			q.setOpacity(1.);
+			q.setCompositionMode(QPainter::CompositionMode_DestinationIn);
+			q.drawPixmap(0, 0, _mask);
+
+			p.drawImage(0, 0, frame);
+		}
+
 		if (leftWidth > 0) {
 			p.setOpacity(leftAlpha);
 			p.drawPixmap(
@@ -133,6 +172,10 @@ void SlideAnimation::setFinishedCallback(FinishedCallback &&callback) {
 	_finishedCallback = std::move(callback);
 }
 
+void SlideAnimation::setTopBarMask(const QPixmap &mask) {
+	_mask = mask;
+}
+
 void SlideAnimation::start() {
 	const auto fromLeft = (_direction == SlideDirection::FromLeft);
 	if (fromLeft) {

Telegram/SourceFiles/window/window_slide_animation.h

@@ -26,6 +26,7 @@ public:
 		const QPixmap &newContentCache);
 	void setTopBarShadow(bool enabled);
 	void setTopSkip(int skip);
+	void setTopBarMask(const QPixmap &mask);
 	void setWithFade(bool withFade);
 
 	using RepaintCallback = Fn<void()>;
@@ -50,6 +51,7 @@ private:
 
 	mutable Ui::Animations::Simple _animation;
 	QPixmap _cacheUnder, _cacheOver;
+	QPixmap _mask;
 
 	RepaintCallback _repaintCallback;
 	FinishedCallback _finishedCallback;