WIP: Fix foreign surface with qtwayland

src/client/qwaylanddisplay.cpp

@@ -84,6 +84,7 @@ Q_LOGGING_CATEGORY(lcQpaWayland, "qt.qpa.wayland"); // for general (uncategorize
 struct wl_surface *QWaylandDisplay::createSurface(void *handle)
 {
     struct wl_surface *surface = mCompositor.create_surface();
+    mAllSurfaces.push_back(surface);
     wl_surface_set_user_data(surface, handle);
     return surface;
 }
@@ -440,6 +441,15 @@ void QWaylandDisplay::handleWindowDestroyed(QWaylandWindow *window)
 {
     if (mActiveWindows.contains(window))
         handleWindowDeactivated(window);
+
+    ::wl_surface *surface = static_cast<::wl_surface *>(window);
+    int index = mAllSurfaces.indexOf(surface);
+
+    if (index != -1) {
+        // swap-erase
+        mAllSurfaces.replace(index, mAllSurfaces.back());
+        mAllSurfaces.pop_back();
+    }
 }
 
 void QWaylandDisplay::handleWaylandSync()
@@ -498,6 +508,11 @@ void QWaylandDisplay::setCursor(const QSharedPointer<QWaylandBuffer> &buffer, co
 }
 #endif // QT_CONFIG(cursor)
 
+bool QWaylandDisplay::ownSurface(struct wl_surface *surface)
+{
+    return mAllSurfaces.indexOf(surface) != -1;
+}
+
 }
 
 QT_END_NAMESPACE

src/client/qwaylanddisplay_p.h

@@ -181,6 +181,8 @@ class Q_WAYLAND_CLIENT_EXPORT QWaylandDisplay : public QObject, public QtWayland
     void handleKeyboardFocusChanged(QWaylandInputDevice *inputDevice);
     void handleWindowDestroyed(QWaylandWindow *window);
 
+    bool ownSurface(struct wl_surface *surface);
+
 public slots:
     void blockingReadEvents();
     void flushRequests();
@@ -225,6 +227,7 @@ public slots:
     QPointer<QWaylandWindow> mLastInputWindow;
     QPointer<QWaylandWindow> mLastKeyboardFocus;
     QVector<QWaylandWindow *> mActiveWindows;
+    QVector<::wl_surface *> mAllSurfaces;
     struct wl_callback *mSyncCallback = nullptr;
     static const wl_callback_listener syncCallbackListener;
 

src/client/qwaylandinputdevice.cpp

@@ -443,6 +443,13 @@ void QWaylandInputDevice::Pointer::pointer_enter(uint32_t serial, struct wl_surf
     if (!surface)
         return;
 
+    // If we don't own the surface, we just lost focus to a foreign surface
+    if (!mDisplay->ownSurface(surface)) {
+        // TODO: should we store the fact that we met a foreign surface?
+        mFocus = nullptr;
+        return;
+    }
+
     QWaylandWindow *window = QWaylandWindow::fromWlSurface(surface);
 #if QT_CONFIG(cursor)
     window->window()->setCursor(window->window()->cursor());
@@ -469,6 +476,11 @@ void QWaylandInputDevice::Pointer::pointer_leave(uint32_t time, struct wl_surfac
     if (!surface)
         return;
 
+    // In case we have to share the wayland display with an external user of
+    // wayland API, we might find a surface that doesn't belong to us.
+    if (!mDisplay->ownSurface(surface))
+        return;
+
     if (!QWaylandWindow::mouseGrab()) {
         QWaylandWindow *window = QWaylandWindow::fromWlSurface(surface);
         window->handleMouseLeave(mParent);
@@ -493,8 +505,10 @@ void QWaylandInputDevice::Pointer::pointer_motion(uint32_t time, wl_fixed_t surf
     QWaylandWindow *window = mFocus;
 
     if (!window) {
-        // We destroyed the pointer focus surface, but the server
-        // didn't get the message yet.
+        // Either:
+        // + we destroyed the pointer focus surface, but the server
+        //   didn't get the message yet.
+        // + the surface on which the movement happens doesn't belong to us.
         return;
     }
 
@@ -559,6 +573,7 @@ void QWaylandInputDevice::Pointer::pointer_button(uint32_t serial, uint32_t time
     if (state)
         mParent->mQDisplay->setLastInputDevice(mParent, serial, window);
 
+    // TODO: what to do when the focus is lost to a foreign window?
     QWaylandWindow *grab = QWaylandWindow::mouseGrab();
     if (grab && grab != mFocus) {
         QPointF pos = QPointF(-1, -1);
@@ -595,8 +610,10 @@ void QWaylandInputDevice::Pointer::pointer_axis(uint32_t time, uint32_t axis, in
     QPoint angleDelta;
 
     if (!window) {
-        // We destroyed the pointer focus surface, but the server
-        // didn't get the message yet.
+        // Either:
+        // + we destroyed the pointer focus surface, but the server
+        //   didn't get the message yet.
+        // + the surface on which the movement happens doesn't belong to us.
         return;
     }
 
@@ -657,6 +674,11 @@ void QWaylandInputDevice::Keyboard::keyboard_enter(uint32_t time, struct wl_surf
     if (!surface)
         return;
 
+    // If we don't own the surface, we don't handle the message.
+    if (!mDisplay->ownSurface(surface)) {
+        mFocus = nullptr;
+        return;
+    }
 
     QWaylandWindow *window = QWaylandWindow::fromWlSurface(surface);
     mFocus = window;
@@ -669,7 +691,8 @@ void QWaylandInputDevice::Keyboard::keyboard_leave(uint32_t time, struct wl_surf
     Q_UNUSED(time);
     Q_UNUSED(surface);
 
-    if (surface) {
+    if (surface && !mDisplay->ownSurface(surface))
+    {
         QWaylandWindow *window = QWaylandWindow::fromWlSurface(surface);
         window->unfocus();
     }
@@ -833,6 +856,9 @@ void QWaylandInputDevice::Touch::touch_down(uint32_t serial,
     if (!surface)
         return;
 
+    if (!mDisplay->ownSurface(surface))
+        return;
+
     mParent->mTime = time;
     mParent->mSerial = serial;
     mFocus = QWaylandWindow::fromWlSurface(surface);