Use brilliant workaround to show Windows 10 top border

Sine Striker

2023-12-24 46285db399f75154ad6c451e12f2cae2e59ace25

 src/widgets/widgetwindowagent_win.cpp

@@ -1,16 +1,17 @@
#include "widgetwindowagent_p.h"

#include <QWKCore/qwkconfig.h>
#include <QWKCore/qwkglobal.h>

#include <QtGui/QPainter>

#include <QWKCore/qwindowkit_windows.h>
#include <QWKCore/qwkconfig.h>
#include <QWKCore/private/nativeeventfilter_p.h>

namespace QWK {

#if QWINDOWKIT_CONFIG(ENABLE_WINDOWS_SYSTEM_BORDER)

    class WidgetBorderHandler;

    class WidgetBorderHandler : public QObject, public NativeEventFilter {
    public:
        explicit WidgetBorderHandler(QWidget *widget, AbstractWindowContext *ctx)
@@ -21,16 +22,21 @@
            updateGeometry();
        }

        inline bool isNormalWindow() const {
            return widget->windowState() &
                   (Qt::WindowMinimized | Qt::WindowMaximized | Qt::WindowFullScreen);
        }

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

@@ -61,6 +67,16 @@
                    break;
                }

                case WM_PAINT: {
                    // Let Qt paint first
                    m_dispatcher->resume(eventType, message, result);

                    // Upon receiving the WM_PAINT message, Qt will redraw the entire view, and we
                    // must wait for it to finish redrawing before drawing this top border area
                    ctx->virtual_hook(AbstractWindowContext::DrawWindows10BorderHook2, nullptr);
                    return true;
                }

                default:
                    break;
            }
@@ -70,23 +86,21 @@
        bool eventFilter(QObject *obj, QEvent *event) override {
            Q_UNUSED(obj)
            switch (event->type()) {
                case QEvent::Paint: {
                    if (widget->windowState() &
                        (Qt::WindowMinimized | Qt::WindowMaximized | Qt::WindowFullScreen))
                        break;

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

                    QPainter painter(widget);
                    void *args[] = {
                        &painter,
                        &rect,
                        &region,
                case QEvent::UpdateRequest: {
                    // Friend class helping to call `event`
                    class HackedWidget : public QWidget {
                    public:
                        friend class WidgetBorderHandler;
                    };
                    ctx->virtual_hook(AbstractWindowContext::DrawWindows10BorderHook, args);
                    break;

                    // Let the widget paint first
                    static_cast<HackedWidget *>(widget)->event(event);

                    // Due to the timer or user action, Qt will redraw some regions spontaneously,
                    // even if there is no WM_PAINT message, we must wait for it to finish redrawing
                    // and then update the upper border area
                    ctx->virtual_hook(AbstractWindowContext::DrawWindows10BorderHook2, nullptr);
                    return true;
                }

                case QEvent::WindowStateChange: {