Linux: fix the mouse grab issue, for real

Port previous workaround from 1.x to 2.0

And some minor tweaks.

Signed-off-by: Yuhang Zhao <2546789017@qq.com>

src/core/CMakeLists.txt

@@ -119,7 +119,7 @@ if(UNIX AND NOT APPLE)
     )
     target_link_libraries(${SUB_PROJ_NAME} PRIVATE
         ${GTK3_LIBRARIES}
-        X11::X11
+        X11::xcb
     )
     target_include_directories(${SUB_PROJ_NAME} PRIVATE
         ${GTK3_INCLUDE_DIRS}

src/core/utils_linux.cpp

@@ -28,7 +28,7 @@
 #include <QtCore/qregularexpression.h>
 #include <QtGui/qwindow.h>
 #include <gtk/gtk.h>
-#include <X11/Xlib.h>
+#include <xcb/xcb.h>
 
 FRAMELESSHELPER_BEGIN_NAMESPACE
 
@@ -113,6 +113,33 @@ template<typename T>
     return -1;
 }
 
+static inline void
+    emulateMouseButtonRelease(const WId windowId, const QPoint &globalPos, const QPoint &localPos)
+{
+    Q_ASSERT(windowId);
+    if (!windowId) {
+        return;
+    }
+    xcb_connection_t * const connection = QX11Info::connection();
+    Q_ASSERT(connection);
+    const quint32 rootWindow = QX11Info::appRootWindow(QX11Info::appScreen());
+    Q_ASSERT(rootWindow);
+    xcb_button_release_event_t xev;
+    memset(&xev, 0, sizeof(xev));
+    xev.response_type = XCB_BUTTON_RELEASE;
+    xev.time = XCB_CURRENT_TIME;
+    xev.root = rootWindow;
+    xev.root_x = globalPos.x();
+    xev.root_y = globalPos.y();
+    xev.event = windowId;
+    xev.event_x = localPos.x();
+    xev.event_y = localPos.y();
+    xev.same_screen = true;
+    xcb_send_event(connection, false, rootWindow, XCB_EVENT_MASK_BUTTON_RELEASE,
+                   reinterpret_cast<const char *>(&xev));
+    xcb_flush(connection);
+}
+
 [[maybe_unused]] static inline void
     doStartSystemMoveResize(const WId windowId, const QPoint &globalPos, const int edges)
 {
@@ -123,7 +150,7 @@ template<typename T>
     }
     xcb_connection_t * const connection = QX11Info::connection();
     Q_ASSERT(connection);
-    static const xcb_atom_t moveResize = [connection]() -> xcb_atom_t {
+    static const xcb_atom_t netMoveResize = [connection]() -> xcb_atom_t {
         const xcb_intern_atom_cookie_t cookie = xcb_intern_atom(connection, false,
                              qstrlen(WM_MOVERESIZE_OPERATION_NAME), WM_MOVERESIZE_OPERATION_NAME);
         xcb_intern_atom_reply_t * const reply = xcb_intern_atom_reply(connection, cookie, nullptr);
@@ -138,17 +165,20 @@ template<typename T>
     xcb_client_message_event_t xev;
     memset(&xev, 0, sizeof(xev));
     xev.response_type = XCB_CLIENT_MESSAGE;
-    xev.type = moveResize;
+    xev.type = netMoveResize;
     xev.window = windowId;
     xev.format = 32;
     xev.data.data32[0] = globalPos.x();
     xev.data.data32[1] = globalPos.y();
     xev.data.data32[2] = edges;
     xev.data.data32[3] = XCB_BUTTON_INDEX_1;
+    // First we need to ungrab the pointer that may have been
+    // automatically grabbed by Qt on ButtonPressEvent.
     xcb_ungrab_pointer(connection, XCB_CURRENT_TIME);
     xcb_send_event(connection, false, rootWindow,
                    (XCB_EVENT_MASK_SUBSTRUCTURE_REDIRECT | XCB_EVENT_MASK_SUBSTRUCTURE_NOTIFY),
                    reinterpret_cast<const char *>(&xev));
+    xcb_flush(connection);
 }
 
 SystemTheme Utils::getSystemTheme()
@@ -163,15 +193,17 @@ void Utils::startSystemMove(QWindow *window, const QPoint &globalPos)
     if (!window) {
         return;
     }
+    const WId windowId = window->winId();
+    const qreal dpr = window->devicePixelRatio();
+    const QPoint deviceGlobalPos = QPointF(QPointF(globalPos) * dpr).toPoint();
+    const QPoint logicalLocalPos = window->mapFromGlobal(globalPos);
+    const QPoint deviceLocalPos = QPointF(QPointF(logicalLocalPos) * dpr).toPoint();
+    // Before we start the dragging we need to tell Qt that the mouse is released.
+    emulateMouseButtonRelease(windowId, deviceGlobalPos, deviceLocalPos);
 #if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
-    Q_UNUSED(globalPos);
     window->startSystemMove();
 #else
-    // Qt always gives us logical coordinates, however, the native APIs
+    doStartSystemMoveResize(windowId, deviceGlobalPos, _NET_WM_MOVERESIZE_MOVE);
-    // are expecting device coordinates.
-    const qreal dpr = window->devicePixelRatio();
-    const QPoint globalPos2 = QPointF(QPointF(globalPos) * dpr).toPoint();
-    doStartSystemMoveResize(window->winId(), globalPos2, _NET_WM_MOVERESIZE_MOVE);
 #endif
 }
 
@@ -184,19 +216,21 @@ void Utils::startSystemResize(QWindow *window, const Qt::Edges edges, const QPoi
     if (edges == Qt::Edges{}) {
         return;
     }
+    const WId windowId = window->winId();
+    const qreal dpr = window->devicePixelRatio();
+    const QPoint deviceGlobalPos = QPointF(QPointF(globalPos) * dpr).toPoint();
+    const QPoint logicalLocalPos = window->mapFromGlobal(globalPos);
+    const QPoint deviceLocalPos = QPointF(QPointF(logicalLocalPos) * dpr).toPoint();
+    // Before we start the resizing we need to tell Qt that the mouse is released.
+    emulateMouseButtonRelease(windowId, deviceGlobalPos, deviceLocalPos);
 #if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
-    Q_UNUSED(globalPos);
     window->startSystemResize(edges);
 #else
     const int section = qtEdgesToWmMoveOrResizeOperation(edges);
     if (section < 0) {
         return;
     }
-    // Qt always gives us logical coordinates, however, the native APIs
+    doStartSystemMoveResize(windowId, deviceGlobalPos, section);
-    // are expecting device coordinates.
-    const qreal dpr = window->devicePixelRatio();
-    const QPoint globalPos2 = QPointF(QPointF(globalPos) * dpr).toPoint();
-    doStartSystemMoveResize(window->winId(), globalPos2, section);
 #endif
 }
 

src/core/utils_mac.mm

@@ -209,8 +209,10 @@ void Utils::startSystemResize(QWindow *window, const Qt::Edges edges, const QPoi
     }
 #if (QT_VERSION >= QT_VERSION_CHECK(5, 15, 0))
     Q_UNUSED(globalPos);
+    // Actually Qt doesn't implement this function, it will do nothing and always returns false.
     window->startSystemResize(edges);
 #else
+    // ### TODO
     Q_UNUSED(globalPos);
 #endif
 }

src/quick/framelessquickwindow.cpp

@@ -342,6 +342,7 @@ void FramelessQuickWindowPrivate::setOptions(const QuickGlobal::Options value)
     if (m_quickOptions == value) {
         return;
     }
+    // ### TODO: re-evaluate some usable options.
     m_quickOptions = value;
     m_settings.options = optionsQuickToCore(m_quickOptions);
     Q_EMIT q->optionsChanged();
@@ -367,17 +368,14 @@ bool FramelessQuickWindowPrivate::eventFilter(QObject *object, QEvent *event)
         const auto showEvent = static_cast<QShowEvent *>(event);
         showEventHandler(showEvent);
     } break;
-#ifdef Q_OS_WINDOWS
     case QEvent::MouseMove: {
         const auto mouseEvent = static_cast<QMouseEvent *>(event);
         mouseMoveEventHandler(mouseEvent);
     } break;
-#else
     case QEvent::MouseButtonPress: {
         const auto mouseEvent = static_cast<QMouseEvent *>(event);
         mousePressEventHandler(mouseEvent);
     } break;
-#endif
     case QEvent::MouseButtonRelease: {
         const auto mouseEvent = static_cast<QMouseEvent *>(event);
         mouseReleaseEventHandler(mouseEvent);
@@ -640,31 +638,6 @@ bool FramelessQuickWindowPrivate::shouldIgnoreMouseEvents(const QPoint &pos) con
     return (isNormal() && withinFrameBorder);
 }
 
-void FramelessQuickWindowPrivate::doStartSystemMove2(QMouseEvent *event)
-{
-    Q_ASSERT(event);
-    if (!event) {
-        return;
-    }
-    if (m_settings.options & Option::DisableDragging) {
-        return;
-    }
-#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
-    const QPoint scenePos = event->scenePosition().toPoint();
-    const QPoint globalPos = event->globalPosition().toPoint();
-#else
-    const QPoint scenePos = event->windowPos().toPoint();
-    const QPoint globalPos = event->screenPos().toPoint();
-#endif
-    if (shouldIgnoreMouseEvents(scenePos)) {
-        return;
-    }
-    if (!isInTitleBarDraggableArea(scenePos)) {
-        return;
-    }
-    startSystemMove2(globalPos);
-}
-
 bool FramelessQuickWindowPrivate::shouldDrawFrameBorder() const
 {
 #ifdef Q_OS_WINDOWS
@@ -702,28 +675,41 @@ void FramelessQuickWindowPrivate::showEventHandler(QShowEvent *event)
 
 void FramelessQuickWindowPrivate::mouseMoveEventHandler(QMouseEvent *event)
 {
-#ifdef Q_OS_WINDOWS
     Q_ASSERT(event);
     if (!event) {
         return;
     }
-    doStartSystemMove2(event);
+    if (!m_mouseLeftButtonPressed) {
+        return;
+    }
+    if (m_settings.options & Option::DisableDragging) {
+        return;
+    }
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
+    const QPoint scenePos = event->scenePosition().toPoint();
+    const QPoint globalPos = event->globalPosition().toPoint();
 #else
-    Q_UNUSED(event);
+    const QPoint scenePos = event->windowPos().toPoint();
+    const QPoint globalPos = event->screenPos().toPoint();
 #endif
+    if (shouldIgnoreMouseEvents(scenePos)) {
+        return;
+    }
+    if (!isInTitleBarDraggableArea(scenePos)) {
+        return;
+    }
+    startSystemMove2(globalPos);
 }
 
 void FramelessQuickWindowPrivate::mousePressEventHandler(QMouseEvent *event)
 {
-#ifdef Q_OS_WINDOWS
-    Q_UNUSED(event);
-#else
     Q_ASSERT(event);
     if (!event) {
         return;
     }
-    doStartSystemMove2(event);
+    if (event->button() == Qt::LeftButton) {
-#endif
+        m_mouseLeftButtonPressed = true;
+    }
 }
 
 void FramelessQuickWindowPrivate::mouseReleaseEventHandler(QMouseEvent *event)
@@ -732,10 +718,14 @@ void FramelessQuickWindowPrivate::mouseReleaseEventHandler(QMouseEvent *event)
     if (!event) {
         return;
     }
-    if (m_settings.options & Option::DisableSystemMenu) {
+    const Qt::MouseButton button = event->button();
+    if (button == Qt::LeftButton) {
+        m_mouseLeftButtonPressed = false;
+    }
+    if (button != Qt::RightButton) {
         return;
     }
-    if (event->button() != Qt::RightButton) {
+    if (m_settings.options & Option::DisableSystemMenu) {
         return;
     }
 #if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))

src/quick/framelessquickwindow_p.h

@@ -97,7 +97,6 @@ private:
     Q_NODISCARD bool isInSystemButtons(const QPoint &pos, QuickGlobal::SystemButtonType *button) const;
     Q_NODISCARD bool isInTitleBarDraggableArea(const QPoint &pos) const;
     Q_NODISCARD bool shouldIgnoreMouseEvents(const QPoint &pos) const;
-    void doStartSystemMove2(QMouseEvent *event);
     Q_NODISCARD bool shouldDrawFrameBorder() const;
 
 private Q_SLOTS:
@@ -116,6 +115,7 @@ private:
     QPointer<QQuickItem> m_titleBarItem = nullptr;
     QList<QQuickItem *> m_hitTestVisibleItems = {};
     QuickGlobal::Options m_quickOptions = {};
+    bool m_mouseLeftButtonPressed = false;
 };
 
 FRAMELESSHELPER_END_NAMESPACE

src/quick/quickstandardtitlebar.cpp

@@ -146,6 +146,9 @@ void QuickStandardTitleBar::updateTitleBarColor()
 #ifdef Q_OS_WINDOWS
             backgroundColor = Utils::getDwmColorizationColor();
 #endif
+#ifdef Q_OS_LINUX
+            backgroundColor = Utils::getWmThemeColor();
+#endif
 #ifdef Q_OS_MACOS
             backgroundColor = Utils::getControlsAccentColor();
 #endif

src/widgets/framelesswidgetshelper.cpp

@@ -277,28 +277,41 @@ void FramelessWidgetsHelper::paintEventHandler(QPaintEvent *event)
 
 void FramelessWidgetsHelper::mouseMoveEventHandler(QMouseEvent *event)
 {
-#ifdef Q_OS_WINDOWS
     Q_ASSERT(event);
     if (!event) {
         return;
     }
-    doStartSystemMove2(event);
+    if (!m_mouseLeftButtonPressed) {
+        return;
+    }
+    if (m_settings.options & Option::DisableDragging) {
+        return;
+    }
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
+    const QPoint scenePos = event->scenePosition().toPoint();
+    const QPoint globalPos = event->globalPosition().toPoint();
 #else
-    Q_UNUSED(event);
+    const QPoint scenePos = event->windowPos().toPoint();
+    const QPoint globalPos = event->screenPos().toPoint();
 #endif
+    if (shouldIgnoreMouseEvents(scenePos)) {
+        return;
+    }
+    if (!isInTitleBarDraggableArea(scenePos)) {
+        return;
+    }
+    startSystemMove2(globalPos);
 }
 
 void FramelessWidgetsHelper::mousePressEventHandler(QMouseEvent *event)
 {
-#ifdef Q_OS_WINDOWS
-    Q_UNUSED(event);
-#else
     Q_ASSERT(event);
     if (!event) {
         return;
     }
-    doStartSystemMove2(event);
+    if (event->button() == Qt::LeftButton) {
-#endif
+        m_mouseLeftButtonPressed = true;
+    }
 }
 
 void FramelessWidgetsHelper::mouseReleaseEventHandler(QMouseEvent *event)
@@ -307,10 +320,14 @@ void FramelessWidgetsHelper::mouseReleaseEventHandler(QMouseEvent *event)
     if (!event) {
         return;
     }
-    if (m_settings.options & Option::DisableSystemMenu) {
+    const Qt::MouseButton button = event->button();
+    if (button == Qt::LeftButton) {
+        m_mouseLeftButtonPressed = false;
+    }
+    if (button != Qt::RightButton) {
         return;
     }
-    if (event->button() != Qt::RightButton) {
+    if (m_settings.options & Option::DisableSystemMenu) {
         return;
     }
 #if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
@@ -667,31 +684,6 @@ bool FramelessWidgetsHelper::shouldIgnoreMouseEvents(const QPoint &pos) const
     return (isNormal() && withinFrameBorder);
 }
 
-void FramelessWidgetsHelper::doStartSystemMove2(QMouseEvent *event)
-{
-    Q_ASSERT(event);
-    if (!event) {
-        return;
-    }
-    if (m_settings.options & Option::DisableDragging) {
-        return;
-    }
-#if (QT_VERSION >= QT_VERSION_CHECK(6, 0, 0))
-    const QPoint scenePos = event->scenePosition().toPoint();
-    const QPoint globalPos = event->globalPosition().toPoint();
-#else
-    const QPoint scenePos = event->windowPos().toPoint();
-    const QPoint globalPos = event->screenPos().toPoint();
-#endif
-    if (shouldIgnoreMouseEvents(scenePos)) {
-        return;
-    }
-    if (!isInTitleBarDraggableArea(scenePos)) {
-        return;
-    }
-    startSystemMove2(globalPos);
-}
-
 void FramelessWidgetsHelper::updateContentsMargins()
 {
 #ifdef Q_OS_WINDOWS
@@ -706,29 +698,26 @@ void FramelessWidgetsHelper::updateSystemTitleBarStyleSheet()
     }
     const bool active = q->isActiveWindow();
     const bool dark = Utils::shouldAppsUseDarkMode();
-#ifdef Q_OS_WINDOWS
     const bool colorizedTitleBar = Utils::isTitleBarColorized();
-#else
-    constexpr const bool colorizedTitleBar = false;
-#endif
     const QColor systemTitleBarWidgetBackgroundColor = [active, colorizedTitleBar, dark]() -> QColor {
-#ifndef Q_OS_WINDOWS
-        Q_UNUSED(colorizedTitleBar);
-#endif
         if (active) {
-#ifdef Q_OS_WINDOWS
             if (colorizedTitleBar) {
+#ifdef Q_OS_WINDOWS
                 return Utils::getDwmColorizationColor();
-            } else {
 #endif
+#ifdef Q_OS_LINUX
+                return Utils::getWmThemeColor();
+#endif
+#ifdef Q_OS_MACOS
+                return Utils::getControlsAccentColor();
+#endif
+            } else {
                 if (dark) {
                     return kDefaultBlackColor;
                 } else {
                     return kDefaultWhiteColor;
                 }
-#ifdef Q_OS_WINDOWS
             }
-#endif
         } else {
             if (dark) {
                 return kDefaultSystemDarkColor;
@@ -841,17 +830,14 @@ bool FramelessWidgetsHelper::eventFilter(QObject *object, QEvent *event)
         const auto paintEvent = static_cast<QPaintEvent *>(event);
         paintEventHandler(paintEvent);
     } break;
-#ifdef Q_OS_WINDOWS
     case QEvent::MouseMove: {
         const auto mouseEvent = static_cast<QMouseEvent *>(event);
         mouseMoveEventHandler(mouseEvent);
     } break;
-#else
     case QEvent::MouseButtonPress: {
         const auto mouseEvent = static_cast<QMouseEvent *>(event);
         mousePressEventHandler(mouseEvent);
     } break;
-#endif
     case QEvent::MouseButtonRelease: {
         const auto mouseEvent = static_cast<QMouseEvent *>(event);
         mouseReleaseEventHandler(mouseEvent);

src/widgets/framelesswidgetshelper_p.h

@@ -94,7 +94,6 @@ private:
     Q_NODISCARD bool isInTitleBarDraggableArea(const QPoint &pos) const;
     Q_NODISCARD bool shouldDrawFrameBorder() const;
     Q_NODISCARD bool shouldIgnoreMouseEvents(const QPoint &pos) const;
-    void doStartSystemMove2(QMouseEvent *event);
 
 private Q_SLOTS:
     void updateContentsMargins();
@@ -119,6 +118,7 @@ private:
     Global::UserSettings m_settings = {};
     Global::SystemParameters m_params = {};
     bool m_windowExposed = false;
+    bool m_mouseLeftButtonPressed = false;
 };
 
 FRAMELESSHELPER_END_NAMESPACE