From c8a5a82994e513acb00ba0e1f0b882ccbb18a6db Mon Sep 17 00:00:00 2001
From: Sine Striker <trueful@163.com>
Date: 周二, 26 12月 2023 05:15:47 +0800
Subject: [PATCH] clean code
---
src/widgets/widgetwindowagent_win.cpp | 98 +++++++++++++++++++++++++++++++++---------------
1 files changed, 67 insertions(+), 31 deletions(-)
diff --git a/src/widgets/widgetwindowagent_win.cpp b/src/widgets/widgetwindowagent_win.cpp
index 2733f94..0f88e1c 100644
--- a/src/widgets/widgetwindowagent_win.cpp
+++ b/src/widgets/widgetwindowagent_win.cpp
@@ -9,6 +9,28 @@
namespace QWK {
#if QWINDOWKIT_CONFIG(ENABLE_WINDOWS_SYSTEM_BORDER)
+ // 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 redrawing.
+ //
+ // 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 redraw 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 NativeEventFilter, public SharedEventFilter {
public:
@@ -21,6 +43,8 @@
// Must extend top frame to client area
static QVariant defaultMargins = QVariant::fromValue(QMargins(0, 1, 0, 0));
ctx->setWindowAttribute(QStringLiteral("extra-margins"), defaultMargins);
+
+ // Enable dark mode by default, otherwise the frame borders are white
ctx->setWindowAttribute(QStringLiteral("dark-mode"), true);
ctx->installNativeEventFilter(this);
@@ -41,6 +65,37 @@
} else {
widget->setContentsMargins({});
}
+ }
+
+ inline void resumeWidgetEvent(QWidget *w, QEvent *event) {
+ // Friend class helping to call `event`
+ class HackedWidget : public QWidget {
+ public:
+ friend class QWK::WidgetBorderHandler;
+ };
+
+ // Let the widget paint first
+ static_cast<HackedWidget *>(w)->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 top border area.
+ ctx->virtual_hook(AbstractWindowContext::DrawWindows10BorderHook2, nullptr);
+ }
+
+ inline void resumeWindowEvent(QWindow *window, QEvent *event) {
+ // Friend class helping to call `event`
+ class HackedWindow : public QWindow {
+ public:
+ friend class QWK::WidgetBorderHandler;
+ };
+
+ // Let Qt paint first
+ static_cast<HackedWindow *>(window)->event(event);
+
+ // 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);
}
protected:
@@ -83,28 +138,22 @@
Q_UNUSED(obj)
auto window = widget->windowHandle();
+
+ // 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.
if (event->type() == QEvent::Expose) {
- // Qt will absolutely send a QExposeEvent 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.
auto ee = static_cast<QExposeEvent *>(event);
- if (isNormalWindow() && window->isExposed() && !ee->region().isNull()) {
- // Friend class helping to call `event`
- class HackedWindow : public QWindow {
- public:
- friend class QWK::WidgetBorderHandler;
- };
-
- // Let Qt paint first
- static_cast<HackedWindow *>(window)->event(event);
-
- // 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);
+ if (window->isExposed() && !ee->region().isNull()) {
+ resumeWindowEvent(window, event);
return true;
}
}
+
return false;
}
@@ -114,20 +163,7 @@
case QEvent::UpdateRequest: {
if (!isNormalWindow())
break;
-
- // Friend class helping to call `event`
- class HackedWidget : public QWidget {
- public:
- friend class QWK::WidgetBorderHandler;
- };
-
- // 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 top border area.
- ctx->virtual_hook(AbstractWindowContext::DrawWindows10BorderHook2, nullptr);
+ resumeWidgetEvent(widget, event);
return true;
}
--
Gitblit v1.9.1