sola/qwindowkit.git

			@@ -1,72 +1,132 @@
			// Copyright (C) 2023-2024 Stdware Collections (https://www.github.com/stdware)
			// Copyright (C) 2021-2023 wangwenx190 (Yuhang Zhao)
			// SPDX-License-Identifier: Apache-2.0

			#include "widgetwindowagent_p.h"

			#include <QtCore/QDebug>
			#include <QtCore/QDateTime>
			#include <QtGui/QPainter>

			#include <QWKCore/private/eventobserver_p.h>
			#include <QtCore/private/qcoreapplication_p.h>

			#include <QWKCore/qwindowkit_windows.h>
			#include <QWKCore/private/qwkglobal_p.h>
			#include <QWKCore/private/windows10borderhandler_p.h>

			namespace QWK {

			class WidgetBorderHandler : public QObject, public EventObserver {
			Q_OBJECT
			#if QWINDOWKIT_CONFIG(ENABLE_WINDOWS_SYSTEM_BORDERS)
			// https://github.com/qt/qtbase/blob/e26a87f1ecc40bc8c6aa5b889fce67410a57a702/src/plugins/platforms/windows/qwindowsbackingstore.cpp#L42
			// In QtWidgets applications, when repainting happens, QPA at the last calls
			// QWindowsBackingStore::flush() to draw the contents of the buffer to the screen, we need to
			// call GDI drawing the top border after that.

			// After debugging, we know that there are two situations that will lead to repaint.
			//
			// 1. Windows sends a WM_PAINT message, after which Qt immediately generates a QExposeEvent or
			// QResizeEvent and send it to the corresponding QWidgetWindow instance, calling "flush" at the
			// end of its handler.
			//
			// 2. When a timer or user input triggers Qt to repaint spontaneously, the corresponding
			// QWidget receives a QEvent::UpdateRequest event and also calls "flush" at the end of its
			// handler.
			//
			// The above two cases are mutually exclusive, so we just need to intercept the two events
			// separately and draw the border area after the "flush" is called.

			// https://github.com/qt/qtbase/blob/e26a87f1ecc40bc8c6aa5b889fce67410a57a702/src/plugins/platforms/windows/qwindowswindow.cpp#L2440
			// Note that we can not draw the border right after WM_PAINT comes or right before the WndProc
			// returns, because Qt calls BeginPaint() and EndPaint() itself. We should make sure that we
			// draw the top border between these two calls, otherwise some display exceptions may arise.

			class WidgetBorderHandler : public QObject, public Windows10BorderHandler {
			public:
			explicit WidgetBorderHandler(QWidget widget, AbstractWindowContext ctx,
			QObject *parent = nullptr)
			: QObject(parent), widget(widget), ctx(ctx) {
			: QObject(parent), Windows10BorderHandler(ctx), widget(widget) {
			widget->installEventFilter(this);

			ctx->addObserver(this);
			updateGeometry();
			// First update
			if (ctx->windowId()) {
			setupNecessaryAttributes();
			}
			WidgetBorderHandler::updateGeometry();
			}

			void updateGeometry() {
			if (widget->windowState() & (Qt::WindowMaximized \| Qt::WindowFullScreen)) {
			widget->setContentsMargins({});
			} else {
			widget->setContentsMargins({
			0,
			ctx->property("borderThickness").toInt(),
			0,
			0,
			});
			void updateGeometry() override {
			widget->setContentsMargins(isNormalWindow() ? QMargins(0, borderThickness(), 0, 0)
			: QMargins());
			}

			bool isWindowActive() const override {
			return widget->isActiveWindow();
			}

			inline void forwardEventToWidgetAndDraw(QWidget w, QEvent event) {
			// https://github.com/qt/qtbase/blob/e26a87f1ecc40bc8c6aa5b889fce67410a57a702/src/widgets/kernel/qapplication.cpp#L3286
			// Deliver the event
			if (!forwardObjectEventFilters(ctx, w, event)) {
			// Let the widget paint first
			std::ignore = static_cast<QObject *>(w)->event(event);
			QCoreApplicationPrivate::setEventSpontaneous(event, false);
			}

			// Due to the timer or user action, Qt will repaint some regions spontaneously,
			// even if there is no WM_PAINT message, we must wait for it to finish painting
			// and then update the top border area.
			drawBorder();
			}

			inline void forwardEventToWindowAndDraw(QWindow window, QEvent event) {
			// https://github.com/qt/qtbase/blob/e26a87f1ecc40bc8c6aa5b889fce67410a57a702/src/widgets/kernel/qapplication.cpp#L3286
			// Deliver the event;
			if (!forwardObjectEventFilters(ctx, window, event)) {
			// Let Qt paint first
			std::ignore = static_cast<QObject *>(window)->event(event);
			QCoreApplicationPrivate::setEventSpontaneous(event, false);
			}

			// Upon receiving the WM_PAINT message, Qt will repaint the entire view, and we
			// must wait for it to finish painting before drawing this top border area.
			drawBorder();
			}

			protected:
			bool observe(QEvent *event) override {
			bool sharedEventFilter(QObject obj, QEvent event) override {
			Q_UNUSED(obj)

			switch (event->type()) {
			case QEvent::UpdateLater: {
			widget->update();
			case QEvent::Expose: {
			// Qt will absolutely send a QExposeEvent or QResizeEvent to the QWindow when it
			// receives a WM_PAINT message. When the control flow enters the expose handler,
			// Qt must have already called BeginPaint() and it's the best time for us to
			// draw the top border.

			// Since a QExposeEvent will be sent immediately after the QResizeEvent, we can
			// simply ignore it.
			auto ee = static_cast<QExposeEvent *>(event);
			auto window = widget->windowHandle();
			if (window->isExposed() && isNormalWindow() && !ee->region().isNull()) {
			forwardEventToWindowAndDraw(window, event);
			return true;
			}
			break;
			}

			case QEvent::ScreenChangeInternal: {
			updateGeometry();
			break;
			}

			default:
			break;
			}
			return false;
			return Windows10BorderHandler::sharedEventFilter(obj, event);
			}

			bool eventFilter(QObject obj, QEvent event) override {
			Q_UNUSED(obj)

			switch (event->type()) {
			case QEvent::Paint: {
			if (widget->windowState() & (Qt::WindowMaximized \| Qt::WindowFullScreen))
			case QEvent::UpdateRequest: {
			if (!isNormalWindow())
			break;

			auto paintEvent = static_cast<QPaintEvent *>(event);
			auto rect = paintEvent->rect();
			auto region = paintEvent->region();

			QPainter painter(widget);
			void *args[] = {
			&painter,
			&rect,
			&region,
			};
			ctx->virtual_hook(AbstractWindowContext::DrawWindows10BorderHook, args);
			forwardEventToWidgetAndDraw(widget, event);
			return true;
			}

			@@ -88,17 +148,15 @@
			}

			QWidget *widget;
			AbstractWindowContext *ctx;
			};

			void WidgetWindowAgentPrivate::setupWindows10BorderWorkaround() {
			// Install painting hook
			auto ctx = context.get();
			if (ctx->property("needBorderPainter").toBool()) {
			std::ignore = new WidgetBorderHandler(hostWidget, ctx, ctx);
			if (ctx->windowAttribute(QStringLiteral("win10-border-needed")).toBool()) {
			borderHandler = std::make_unique<WidgetBorderHandler>(hostWidget, ctx);
			}
			}
			#endif

			}

			#include "widgetwindowagent_win.moc"