Allow fixed windows with custom title bar.

ui/platform/mac/ui_window_mac.h

@@ -20,7 +20,8 @@ public:
 
 	not_null<RpWidget*> body() override;
 	void setTitle(const QString &title) override;
-	void setSizeMin(QSize size) override;
+	void setMinimumSize(QSize size) override;
+	void setFixedSize(QSize size) override;
 	void setGeometry(QRect rect) override;
 
 private:

ui/platform/mac/ui_window_mac.mm

@@ -204,12 +204,18 @@ void WindowHelper::toggleCustomTitle(bool visible) {
 	_window->setWindowTitle(visible ? QString() : _title->text());
 }
 
-void WindowHelper::setSizeMin(QSize size) {
+void WindowHelper::setMinimumSize(QSize size) {
 	_window->setMinimumSize(
 		size.width(),
 		(_title ? _title->height() : 0) + size.height());
 }
 
+void WindowHelper::setFixedSize(QSize size) {
+	_window->setFixedSize(
+		size.width(),
+		(_title ? _title->height() : 0) + size.height());
+}
+
 void WindowHelper::setGeometry(QRect rect) {
 	_window->setGeometry(
 		rect.marginsAdded({ 0, (_title ? _title->height() : 0), 0, 0 }));

ui/platform/ui_platform_window.h

@@ -16,7 +16,8 @@ class BasicWindowHelper {
 public:
 	[[nodiscard]] virtual not_null<RpWidget*> body() = 0;
 	virtual void setTitle(const QString &title) = 0;
-	virtual void setSizeMin(QSize size) = 0;
+	virtual void setMinimumSize(QSize size) = 0;
+	virtual void setFixedSize(QSize size) = 0;
 	virtual void setGeometry(QRect rect) = 0;
 	virtual ~BasicWindowHelper() = default;
 

ui/platform/win/ui_window_shadow_win.cpp

@@ -514,6 +514,10 @@ void WindowShadow::updateWindow(int i, POINT *p, SIZE *s) {
 	}
 }
 
+void WindowShadow::setResizeEnabled(bool enabled) {
+	_resizeEnabled = enabled;
+}
+
 LRESULT CALLBACK WindowShadow::WindowCallback(
 		HWND hwnd,
 		UINT msg,
@@ -540,6 +544,9 @@ LRESULT WindowShadow::windowCallback(
 		return 0;
 
 	case WM_NCHITTEST: {
+		if (!_resizeEnabled) {
+			return HTTRANSPARENT;
+		}
 		const auto xPos = GET_X_LPARAM(lParam);
 		const auto yPos = GET_Y_LPARAM(lParam);
 		if (hwnd == _handles[0]) {

ui/platform/win/ui_window_shadow_win.h

@@ -43,6 +43,7 @@ public:
 	void setColor(QColor color);
 	void update(Changes changes, WINDOWPOS *pos = nullptr);
 	void updateWindow(int i, POINT *p, SIZE *s = nullptr);
+	void setResizeEnabled(bool enabled);
 
 private:
 	enum class Direction {
@@ -90,6 +91,7 @@ private:
 	std::vector<BYTE> _colors;
 
 	bool _hidden = true;
+	bool _resizeEnabled = true;
 
 	HWND _handles[4] = { nullptr };
 	HDC _contexts[4] = { nullptr };

ui/platform/win/ui_window_title_win.cpp

@@ -38,6 +38,11 @@ not_null<RpWidget*> TitleWidget::window() const {
 	return static_cast<RpWidget*>(parentWidget());
 }
 
+void TitleWidget::setResizeEnabled(bool enabled) {
+	_resizeEnabled = enabled;
+	updateControlsVisibility();
+}
+
 void TitleWidget::init() {
 	_minimize->setClickedCallback([=] {
 		window()->setWindowState(Qt::WindowMinimized);
@@ -85,7 +90,10 @@ void TitleWidget::paintEvent(QPaintEvent *e) {
 void TitleWidget::updateControlsPosition() {
 	auto right = 0;
 	_close->moveToRight(right, 0); right += _close->width();
-	_maximizeRestore->moveToRight(right, 0); right += _maximizeRestore->width();
+	_maximizeRestore->moveToRight(right, 0);
+	if (_resizeEnabled) {
+		right += _maximizeRestore->width();
+	}
 	_minimize->moveToRight(right, 0);
 }
 
@@ -95,6 +103,7 @@ void TitleWidget::resizeEvent(QResizeEvent *e) {
 }
 
 void TitleWidget::updateControlsVisibility() {
+	_maximizeRestore->setVisible(_resizeEnabled);
 	updateControlsPosition();
 	update();
 }

ui/platform/win/ui_window_title_win.h

@@ -39,7 +39,8 @@ public:
 	explicit TitleWidget(not_null<RpWidget*> parent);
 
 	void setText(const QString &text);
-	HitTestResult hitTest(QPoint point) const;
+	[[nodiscard]] HitTestResult hitTest(QPoint point) const;
+	void setResizeEnabled(bool enabled);
 
 protected:
 	void paintEvent(QPaintEvent *e) override;
@@ -61,6 +62,7 @@ private:
 
 	bool _maximizedState = false;
 	bool _activeState = false;
+	bool _resizeEnabled = true;
 
 };
 

ui/platform/win/ui_window_win.cpp

@@ -99,10 +99,16 @@ void WindowHelper::setTitle(const QString &title) {
 	_window->setWindowTitle(title);
 }
 
-void WindowHelper::setSizeMin(QSize size) {
+void WindowHelper::setMinimumSize(QSize size) {
 	_window->setMinimumSize(size.width(), _title->height() + size.height());
 }
 
+void WindowHelper::setFixedSize(QSize size) {
+	_window->setFixedSize(size.width(), _title->height() + size.height());
+	_title->setResizeEnabled(false);
+	_shadow.setResizeEnabled(false);
+}
+
 void WindowHelper::setGeometry(QRect rect) {
 	_window->setGeometry(rect.marginsAdded({ 0, _title->height(), 0, 0 }));
 }
@@ -133,10 +139,20 @@ void WindowHelper::init() {
 
 	_menu = GetSystemMenu(_handle, FALSE);
 	updateSystemMenu();
+
+	const auto handleStateChanged = [=](Qt::WindowState state) {
+		updateSystemMenu(state);
+		if (fixedSize() && (state & Qt::WindowMaximized)) {
+			crl::on_main(_window.get(), [=] {
+				_window->setWindowState(
+					_window->windowState() & ~Qt::WindowMaximized);
+			});
+		}
+	};
 	Ui::Connect(
 		_window->windowHandle(),
 		&QWindow::windowStateChanged,
-		[=](Qt::WindowState state) { updateSystemMenu(state); });
+		handleStateChanged);
 }
 
 bool WindowHelper::handleNativeEvent(
@@ -189,6 +205,16 @@ bool WindowHelper::handleNativeEvent(
 		return true;
 	}
 
+	case WM_NCLBUTTONDBLCLK:
+	case WM_NCMBUTTONDBLCLK:
+	case WM_NCRBUTTONDBLCLK:
+	case WM_NCXBUTTONDBLCLK: {
+		if (!fixedSize()) {
+			return false;
+		}
+		if (result) *result = 0;
+	} return true;
+
 	case WM_NCACTIVATE: {
 		if (IsCompositionEnabled()) {
 			const auto res = DefWindowProc(_handle, msg, wParam, -1);
@@ -288,7 +314,7 @@ bool WindowHelper::handleNativeEvent(
 	} return true;
 
 	case WM_SYSCOMMAND: {
-		if (wParam == SC_MOUSEMENU) {
+		if (wParam == SC_MOUSEMENU && !fixedSize()) {
 			POINTS p = MAKEPOINTS(lParam);
 			updateSystemMenu(_window->windowHandle()->windowState());
 			TrackPopupMenu(
@@ -313,7 +339,9 @@ bool WindowHelper::handleNativeEvent(
 			_window->setWindowState(Qt::WindowMinimized);
 			return true;
 		case SC_MAXIMIZE:
-			_window->setWindowState(Qt::WindowMaximized);
+			if (!fixedSize()) {
+				_window->setWindowState(Qt::WindowMaximized);
+			}
 			return true;
 		case SC_RESTORE:
 			_window->setWindowState(Qt::WindowNoState);
@@ -325,6 +353,10 @@ bool WindowHelper::handleNativeEvent(
 	return false;
 }
 
+bool WindowHelper::fixedSize() const {
+	return _window->minimumSize() == _window->maximumSize();
+}
+
 void WindowHelper::updateMargins() {
 	if (_updatingMargins) return;
 

ui/platform/win/ui_window_win.h

@@ -23,7 +23,8 @@ public:
 
 	not_null<RpWidget*> body() override;
 	void setTitle(const QString &title) override;
-	void setSizeMin(QSize size) override;
+	void setMinimumSize(QSize size) override;
+	void setFixedSize(QSize size) override;
 	void setGeometry(QRect rect) override;
 
 private:
@@ -39,6 +40,7 @@ private:
 		WPARAM wParam,
 		LPARAM lParam,
 		LRESULT *result);
+	[[nodiscard]] bool fixedSize() const;
 
 	static not_null<NativeFilter*> GetNativeFilter();
 

ui/widgets/window.cpp

@@ -34,11 +34,19 @@ void Window::setTitle(const QString &title) {
 	}
 }
 
-void Window::setSizeMin(QSize size) {
+void Window::setMinimumSize(QSize size) {
 	if (_helper) {
-		_helper->setSizeMin(size);
+		_helper->setMinimumSize(size);
 	} else {
-		setMinimumSize(size);
+		RpWidget::setMinimumSize(size);
+	}
+}
+
+void Window::setFixedSize(QSize size) {
+	if (_helper) {
+		_helper->setFixedSize(size);
+	} else {
+		RpWidget::setFixedSize(size);
 	}
 }
 

ui/widgets/window.h

@@ -22,7 +22,8 @@ public:
 	[[nodiscard]] not_null<const RpWidget*> body() const;
 
 	void setTitle(const QString &title);
-	void setSizeMin(QSize size);
+	void setMinimumSize(QSize size);
+	void setFixedSize(QSize size);
 	void setGeometry(QRect rect);
 
 private: