From 2d08f989b16dad059d42c94e3a2cdccdbd3c379e Mon Sep 17 00:00:00 2001
From: Sine Striker <trueful@163.com>
Date: 周一, 04 12月 2023 03:38:52 +0800
Subject: [PATCH] Add more comments
---
src/core/contexts/win32windowcontext.cpp | 83 +++++++++++++++++++++++++++--------------
1 files changed, 54 insertions(+), 29 deletions(-)
diff --git a/src/core/contexts/win32windowcontext.cpp b/src/core/contexts/win32windowcontext.cpp
index a2f885b..a901cae 100644
--- a/src/core/contexts/win32windowcontext.cpp
+++ b/src/core/contexts/win32windowcontext.cpp
@@ -17,24 +17,6 @@
static WNDPROC g_qtWindowProc = nullptr; // Original Qt window proc function
- static bool g_lastMessageHandled = false;
-
- static LRESULT g_lastMessageResult = false;
-
- class WindowsNativeEventFilter : public QAbstractNativeEventFilter {
- public:
- bool nativeEventFilter(const QByteArray &eventType, void *message,
- QT_NATIVE_EVENT_RESULT_TYPE *result) override {
- if (g_lastMessageHandled) {
- *result = static_cast<QT_NATIVE_EVENT_RESULT_TYPE>(g_lastMessageResult);
- return true;
- }
- return false;
- }
- };
-
- static WindowsNativeEventFilter *g_nativeFilter = nullptr;
-
static inline QPoint fromNativeLocalPosition(const QWindow *window, const QPoint &point) {
#if 1
return QHighDpi::fromNativeLocalPosition(point, window);
@@ -105,6 +87,44 @@
return true;
}
+ // https://github.com/qt/qtbase/blob/e26a87f1ecc40bc8c6aa5b889fce67410a57a702/src/plugins/platforms/windows/qwindowscontext.cpp#L1556
+ // In QWindowsContext::windowsProc(), the messages will be passed to all global native event
+ // filters, but because we have already filtered the messages in the hook WndProc function for
+ // convenience, Qt does not know we may have already process the messages and thus will call
+ // DefWindowProc(). Consequently, we have to add a global native filter that forwards the result
+ // of the hook function, telling Qt whether we have filtered the events before. Since Qt only
+ // handles Windows window messages in the main thread, it is safe to do so.
+ class WindowsNativeEventFilter : public QAbstractNativeEventFilter {
+ public:
+ bool nativeEventFilter(const QByteArray &eventType, void *message,
+ QT_NATIVE_EVENT_RESULT_TYPE *result) override {
+ if (lastMessageHandled) {
+ *result = static_cast<QT_NATIVE_EVENT_RESULT_TYPE>(lastMessageResult);
+ return true;
+ }
+ return false;
+ }
+
+ static bool lastMessageHandled;
+ static LRESULT lastMessageResult;
+ static WindowsNativeEventFilter *instance;
+
+ static inline void install() {
+ instance = new WindowsNativeEventFilter();
+ qApp->installNativeEventFilter(instance);
+ }
+
+ static inline void uninstall() {
+ qApp->removeNativeEventFilter(instance);
+ delete instance;
+ instance = nullptr;
+ }
+ };
+
+ bool WindowsNativeEventFilter::lastMessageHandled = false;
+ LRESULT WindowsNativeEventFilter::lastMessageResult = 0;
+ WindowsNativeEventFilter *WindowsNativeEventFilter::instance = nullptr;
+
// https://github.com/qt/qtbase/blob/e26a87f1ecc40bc8c6aa5b889fce67410a57a702/src/plugins/platforms/windows/qwindowscontext.cpp#L1025
// We can see from the source code that Qt will filter out some messages first and then send the
// unfiltered messages to the event dispatcher. To activate the Snap Layout feature on Windows
@@ -171,7 +191,9 @@
}
// Try hooked procedure and save result
- g_lastMessageHandled = ctx->windowProc(hWnd, message, wParam, lParam, &g_lastMessageResult);
+ auto &handled = WindowsNativeEventFilter::lastMessageHandled;
+ auto &result = WindowsNativeEventFilter::lastMessageResult;
+ handled = ctx->windowProc(hWnd, message, wParam, lParam, &result);
// TODO: Determine whether to show system menu
// ...
@@ -190,11 +212,9 @@
if (auto hWnd = reinterpret_cast<HWND>(windowId); hWnd) {
g_wndProcHash->remove(hWnd);
- // Remove event filter if the last window is destroyed
+ // Remove event filter if the all windows has been destroyed
if (g_wndProcHash->empty()) {
- qApp->removeNativeEventFilter(g_nativeFilter);
- delete g_nativeFilter;
- g_nativeFilter = nullptr;
+ WindowsNativeEventFilter::uninstall();
}
}
}
@@ -214,9 +234,8 @@
::SetWindowLongPtrW(hWnd, GWLP_WNDPROC, reinterpret_cast<LONG_PTR>(QWKHookedWndProc));
// Install global native event filter
- if (!g_nativeFilter) {
- g_nativeFilter = new WindowsNativeEventFilter();
- qApp->installNativeEventFilter(g_nativeFilter);
+ if (!WindowsNativeEventFilter::instance) {
+ WindowsNativeEventFilter::install();
}
// Cache window ID
@@ -411,7 +430,7 @@
}
bool Win32WindowContext::snapLayoutHandler(HWND hWnd, UINT message, WPARAM wParam,
- LPARAM lParam, LRESULT *result) {
+ LPARAM lParam, LRESULT *result) {
switch (message) {
case WM_MOUSELEAVE: {
if (!isTaggedMessage(wParam)) {
@@ -429,6 +448,9 @@
GET_Y_LPARAM(dwScreenPos)));
auto dummy = CoreWindowAgent::Unknown;
if (isInSystemButtons(qtScenePos, &dummy)) {
+ // We must record whether the last WM_MOUSELEAVE was filtered, because if
+ // Qt does not receive this message it will not call TrackMouseEvent()
+ // again, resulting in the client area not responding to any mouse event.
mouseLeaveBlocked = true;
*result = FALSE;
return true;
@@ -439,7 +461,10 @@
}
case WM_MOUSEMOVE: {
- if ((lastHitTestResult != WindowPart::ChromeButton) && mouseLeaveBlocked) {
+ // At appropriate time, we will call TrackMouseEvent() for Qt. Simultaneously,
+ // we unset `mouseLeaveBlocked` mark and pretend as if Qt has received
+ // WM_MOUSELEAVE.
+ if (lastHitTestResult != WindowPart::ChromeButton && mouseLeaveBlocked) {
mouseLeaveBlocked = false;
std::ignore = requestForMouseLeaveMessage(hWnd, false);
}
@@ -479,7 +504,7 @@
// comes, so we reset it when we receive a WM_NCMOUSEMOVE.
// If the mouse is entering the client area, there must be a WM_NCHITTEST
- // setting it to `Client` before the WM_NCMOUSELEAVE comes; If the mouse is
+ // setting it to `Client` before the WM_NCMOUSELEAVE comes; if the mouse is
// leaving the window, current window part remains as `Outside`.
lastHitTestResult = WindowPart::Outside;
}
--
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