Fix Ui::RpWidget geometry constraints.

ui/platform/ui_platform_window.cpp

@@ -146,6 +146,7 @@ DefaultWindowHelper::DefaultWindowHelper(not_null<RpWidget*> window)
 }
 
 void DefaultWindowHelper::init() {
+	_title->show(); // Be consistent with _nativeFrame == false.
 	window()->setWindowFlag(Qt::FramelessWindowHint);
 
 	if (WindowExtentsSupported()) {
@@ -327,24 +328,18 @@ void DefaultWindowHelper::setNativeFrame(bool enabled) {
 }
 
 void DefaultWindowHelper::setMinimumSize(QSize size) {
-	const auto sizeWithMargins = size
+	const auto sizeWithMargins = size.grownBy(bodyPadding());
-		.grownBy({ 0, _title->isVisible() ? _title->height() : 0, 0, 0 })
-		.grownBy(resizeArea());
 	window()->setMinimumSize(sizeWithMargins);
 }
 
 void DefaultWindowHelper::setFixedSize(QSize size) {
-	const auto sizeWithMargins = size
+	const auto sizeWithMargins = size.grownBy(bodyPadding());
-		.grownBy({ 0, _title->isVisible() ? _title->height() : 0, 0, 0 })
-		.grownBy(resizeArea());
 	window()->setFixedSize(sizeWithMargins);
 	_title->setResizeEnabled(false);
 }
 
 void DefaultWindowHelper::setGeometry(QRect rect) {
-	window()->setGeometry(rect
+	window()->setGeometry(rect.marginsAdded(bodyPadding()));
-		.marginsAdded({ 0, _title->isVisible() ? _title->height() : 0, 0, 0 })
-		.marginsAdded(resizeArea()));
 }
 
 void DefaultWindowHelper::paintBorders(QPainter &p) {
@@ -404,6 +399,14 @@ void DefaultWindowHelper::updateWindowExtents() {
 	}
 }
 
+int DefaultWindowHelper::titleHeight() const {
+	return _title->isHidden() ? 0 : _title->height();
+}
+
+QMargins DefaultWindowHelper::bodyPadding() const {
+	return resizeArea() + QMargins{ 0, titleHeight(), 0, 0 };
+}
+
 void DefaultWindowHelper::updateCursor(Qt::Edges edges) {
 	if (((edges & Qt::LeftEdge) && (edges & Qt::TopEdge))
 		|| ((edges & Qt::RightEdge) && (edges & Qt::BottomEdge))) {

ui/platform/ui_platform_window.h

@@ -84,6 +84,8 @@ private:
 	void paintBorders(QPainter &p);
 	void updateWindowExtents();
 	void updateCursor(Qt::Edges edges);
+	[[nodiscard]] int titleHeight() const;
+	[[nodiscard]] QMargins bodyPadding() const;
 
 	const not_null<DefaultTitleWidget*> _title;
 	const not_null<RpWidget*> _body;

ui/platform/win/ui_window_win.cpp

@@ -151,7 +151,6 @@ WindowHelper::WindowHelper(not_null<RpWidget*> window)
 , _shadow(std::in_place, window, st::windowShadowFg->c) {
 	Expects(_handle != nullptr);
 
-	GetNativeFilter()->registerWindow(_handle, this);
 	init();
 }
 
@@ -186,13 +185,11 @@ void WindowHelper::setNativeFrame(bool enabled) {
 }
 
 void WindowHelper::setMinimumSize(QSize size) {
-	const auto titleHeight = _title->isVisible() ? _title->height() : 0;
+	window()->setMinimumSize(size.width(), titleHeight() + size.height());
-	window()->setMinimumSize(size.width(), titleHeight + size.height());
 }
 
 void WindowHelper::setFixedSize(QSize size) {
-	const auto titleHeight = _title->isVisible() ? _title->height() : 0;
+	window()->setFixedSize(size.width(), titleHeight() + size.height());
-	window()->setFixedSize(size.width(), titleHeight + size.height());
 	_title->setResizeEnabled(false);
 	if (_shadow) {
 		_shadow->setResizeEnabled(false);
@@ -200,8 +197,7 @@ void WindowHelper::setFixedSize(QSize size) {
 }
 
 void WindowHelper::setGeometry(QRect rect) {
-	const auto titleHeight = _title->isVisible() ? _title->height() : 0;
+	window()->setGeometry(rect.marginsAdded({ 0, titleHeight(), 0, 0 }));
-	window()->setGeometry(rect.marginsAdded({ 0, titleHeight, 0, 0 }));
 }
 
 void WindowHelper::showFullScreen() {
@@ -221,6 +217,9 @@ void WindowHelper::showNormal() {
 }
 
 void WindowHelper::init() {
+	_title->show(); // Be consistent with _nativeFrame == false.
+	GetNativeFilter()->registerWindow(_handle, this);
+
 	style::PaletteChanged(
 	) | rpl::start_with_next([=] {
 		if (_shadow) {
@@ -429,7 +428,8 @@ bool WindowHelper::handleNativeEvent(
 			p.y - r.top + _marginsDelta.top());
 		if (!window()->rect().contains(mapped)) {
 			*result = HTTRANSPARENT;
-		} else if (!_title->isVisible() || !_title->geometry().contains(mapped)) {
+		} else if (_title->isHidden()
+			|| !_title->geometry().contains(mapped)) {
 			*result = HTCLIENT;
 		} else switch (_title->hitTest(_title->pos() + mapped)) {
 		case HitTestResult::Client:
@@ -502,6 +502,10 @@ bool WindowHelper::fixedSize() const {
 	return window()->minimumSize() == window()->maximumSize();
 }
 
+int WindowHelper::titleHeight() const {
+	return _title->isHidden() ? 0 : _title->height();
+}
+
 void WindowHelper::updateMargins() {
 	if (_updatingMargins) return;
 

ui/platform/win/ui_window_win.h

@@ -47,6 +47,7 @@ private:
 		LRESULT *result);
 	[[nodiscard]] bool fixedSize() const;
 
+	[[nodiscard]] int titleHeight() const;
 	static not_null<NativeFilter*> GetNativeFilter();
 
 	const HWND _handle = nullptr;