Support blurred backgrounds.

Telegram/SourceFiles/window/themes/window_theme.cpp

@@ -150,6 +150,10 @@ bool WallPaper::isLocal() const {
 	return !document() && thumbnail();
 }
 
+bool WallPaper::isBlurred() const {
+	return _settings & MTPDwallPaperSettings::Flag::f_blur;
+}
+
 int WallPaper::patternIntensity() const {
 	return _intensity;
 }
@@ -482,6 +486,19 @@ QImage PreparePatternImage(
 	return image;
 }
 
+QImage PrepareBlurredBackground(QImage image) {
+	constexpr auto kSize = 900;
+	constexpr auto kRadius = 24;
+	if (image.width() > kSize || image.height() > kSize) {
+		image = image.scaled(
+			kSize,
+			kSize,
+			Qt::KeepAspectRatio,
+			Qt::SmoothTransformation);
+	}
+	return Images::BlurLargeImage(image, kRadius);
+}
+
 namespace details {
 
 WallPaper UninitializedWallPaper() {
@@ -973,6 +990,9 @@ void ChatBackground::setPreparedImage(QImage original, QImage prepared) {
 	Expects(prepared.width() > 0 && prepared.height() > 0);
 
 	_original = std::move(original);
+	if (!_paper.isPattern() && _paper.isBlurred()) {
+		prepared = Data::PrepareBlurredBackground(std::move(prepared));
+	}
 	if (adjustPaletteRequired()) {
 		adjustPaletteUsingBackground(prepared);
 	}

Telegram/SourceFiles/window/themes/window_theme.h

@@ -28,6 +28,7 @@ public:
 	[[nodiscard]] bool isCreator() const;
 	[[nodiscard]] bool isDark() const;
 	[[nodiscard]] bool isLocal() const;
+	[[nodiscard]] bool isBlurred() const;
 	[[nodiscard]] int patternIntensity() const;
 	[[nodiscard]] bool hasShareUrl() const;
 	[[nodiscard]] QString shareUrl() const;
@@ -89,6 +90,7 @@ QImage PreparePatternImage(
 	QColor bg,
 	QColor fg,
 	int intensity);
+QImage PrepareBlurredBackground(QImage image);
 
 namespace details {