Support application internal mouse grabbing for popup windows

Mouse grabbing is used to close a popup window when the user clicks on
another window. Wayland doesn't support mouse grabbing by
design and sends an event when the user clicks on a window of another
application. This patch fakes mouse grabbing for the windows of the
application the popup belongs to, so that it closes when the user
clicks on a window of the same application.

Change-Id: Iac210bed0ca0fc6d3ffdbdb76d069886de51cf04
Reviewed-by: Jan Arne Petersen <jan.petersen@kdab.com>
Reviewed-by: Pier Luigi Fiorini <pierluigi.fiorini@gmail.com>
Reviewed-by: Laszlo Agocs <laszlo.agocs@digia.com>
Reviewed-by: Andrew Knight <andrew.knight@digia.com>
Reviewed-by: Andy Nichols <andy.nichols@digia.com>

3 files changed, 47 insertions, 7 deletions

diff --git a/src/plugins/platforms/wayland_common/qwaylandinputdevice.cpp b/src/plugins/platforms/wayland_common/qwaylandinputdevice.cpp
index e081601d2..3fe6ca309 100644
--- a/src/plugins/platforms/wayland_common/qwaylandinputdevice.cpp
+++ b/src/plugins/platforms/wayland_common/qwaylandinputdevice.cpp
@@ -223,8 +223,11 @@ void QWaylandInputDevice::pointer_enter(uint32_t serial, struct wl_surface *surf
     mSerial = serial;
     mEnterSerial = serial;
 
-    window->handleMouseEnter(this);
-    window->handleMouse(this, mTime, mSurfacePos, mGlobalPos, mButtons, Qt::NoModifier);
+    QWaylandWindow *grab = QWaylandWindow::mouseGrab();
+    if (!grab) {
+        window->handleMouseEnter(this);
+        window->handleMouse(this, mTime, mSurfacePos, mGlobalPos, mButtons, Qt::NoModifier);
+    }
 }
 
 void QWaylandInputDevice::pointer_leave(uint32_t time, struct wl_surface *surface)
@@ -234,8 +237,10 @@ void QWaylandInputDevice::pointer_leave(uint32_t time, struct wl_surface *surfac
     if (!surface)
         return;
 
-    QWaylandWindow *window = QWaylandWindow::fromWlSurface(surface);
-    window->handleMouseLeave(this);
+    if (!QWaylandWindow::mouseGrab()) {
+        QWaylandWindow *window = QWaylandWindow::fromWlSurface(surface);
+        window->handleMouseLeave(this);
+    }
     mPointerFocus = 0;
     mButtons = Qt::NoButton;
 
@@ -264,7 +269,15 @@ void QWaylandInputDevice::pointer_motion(uint32_t time, wl_fixed_t surface_x, wl
     mGlobalPos = global;
     mTime = time;
 
-    window->handleMouse(this, time, mSurfacePos, mGlobalPos, mButtons, Qt::NoModifier);
+    QWaylandWindow *grab = QWaylandWindow::mouseGrab();
+    if (grab && grab != window) {
+        // We can't know the true position since we're getting events for another surface,
+        // so we just set it outside of the window boundaries.
+        pos = QPointF(-1, -1);
+        global = grab->window()->mapToGlobal(pos.toPoint());
+        grab->handleMouse(this, time, pos, global, mButtons, Qt::NoModifier);
+    } else
+        window->handleMouse(this, time, mSurfacePos, mGlobalPos, mButtons, Qt::NoModifier);
 }
 
 void QWaylandInputDevice::pointer_button(uint32_t serial, uint32_t time,
@@ -304,7 +317,12 @@ void QWaylandInputDevice::pointer_button(uint32_t serial, uint32_t time,
     mTime = time;
     mSerial = serial;
 
-    if (window)
+    QWaylandWindow *grab = QWaylandWindow::mouseGrab();
+    if (grab && grab != mPointerFocus) {
+        QPointF pos = QPointF(-1, -1);
+        QPointF global = grab->window()->mapToGlobal(pos.toPoint());
+        grab->handleMouse(this, time, pos, global, mButtons, Qt::NoModifier);
+    } else if (window)
         window->handleMouse(this, time, mSurfacePos, mGlobalPos, mButtons, Qt::NoModifier);
 }
 
diff --git a/src/plugins/platforms/wayland_common/qwaylandwindow.cpp b/src/plugins/platforms/wayland_common/qwaylandwindow.cpp
index 103865694..60b899cc0 100644
--- a/src/plugins/platforms/wayland_common/qwaylandwindow.cpp
+++ b/src/plugins/platforms/wayland_common/qwaylandwindow.cpp
@@ -61,6 +61,8 @@
 
 QT_BEGIN_NAMESPACE
 
+QWaylandWindow *QWaylandWindow::mMouseGrab = 0;
+
 QWaylandWindow::QWaylandWindow(QWindow *window)
     : QObject()
     , QPlatformWindow(window)
@@ -139,6 +141,10 @@ QWaylandWindow::~QWaylandWindow()
         if (w->transientParent() == parent)
             QWindowSystemInterface::handleCloseEvent(w);
     }
+
+    if (mMouseGrab == this) {
+        mMouseGrab = 0;
+    }
 }
 
 QWaylandWindow *QWaylandWindow::fromWlSurface(::wl_surface *surface)
@@ -183,7 +189,7 @@ void QWaylandWindow::setGeometry(const QRect &rect)
                 qBound(window()->minimumWidth(), rect.width(), window()->maximumWidth()),
                 qBound(window()->minimumHeight(), rect.height(), window()->maximumHeight())));
 
-    if (shellSurface() && window()->transientParent())
+    if (shellSurface() && window()->transientParent() && window()->type() != Qt::Popup)
         shellSurface()->updateTransientParent(window()->transientParent());
 
     if (mWindowDecoration && window()->isVisible())
@@ -582,4 +588,15 @@ void QWaylandWindow::restoreMouseCursor(QWaylandInputDevice *device)
     setMouseCursor(device, window()->cursor().shape());
 }
 
+bool QWaylandWindow::setMouseGrabEnabled(bool grab)
+{
+    if (window()->type() != Qt::Popup) {
+        qWarning("This plugin supports grabbing the mouse only for popup windows");
+        return false;
+    }
+
+    mMouseGrab = grab ? this : 0;
+    return true;
+}
+
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/wayland_common/qwaylandwindow.h b/src/plugins/platforms/wayland_common/qwaylandwindow.h
index 8fd104d0a..6e548b20a 100644
--- a/src/plugins/platforms/wayland_common/qwaylandwindow.h
+++ b/src/plugins/platforms/wayland_common/qwaylandwindow.h
@@ -162,6 +162,10 @@ public:
     QMutex *resizeMutex() { return &mResizeLock; }
     void doResize();
     void setCanResize(bool canResize);
+
+    bool setMouseGrabEnabled(bool grab);
+    static QWaylandWindow *mouseGrab() { return mMouseGrab; }
+
 public slots:
     void requestResize();
 
@@ -209,6 +213,7 @@ private:
     static void frameCallback(void *data, struct wl_callback *wl_callback, uint32_t time);
 
     static QMutex mFrameSyncMutex;
+    static QWaylandWindow *mMouseGrab;
 };
 
 inline QIcon QWaylandWindow::windowIcon() const