xcb: Fix DnD for separate X screens

Recreate QShapedPixmapWindow when the cursor goes to
another X screen.

Change-Id: Ifd4c4281971b23abc45a9f6c0509832a45c31521
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>

4 files changed, 21 insertions, 16 deletions

diff --git a/src/gui/kernel/qshapedpixmapdndwindow.cpp b/src/gui/kernel/qshapedpixmapdndwindow.cpp
index 8f80789fb0..5736c41e25 100644
--- a/src/gui/kernel/qshapedpixmapdndwindow.cpp
+++ b/src/gui/kernel/qshapedpixmapdndwindow.cpp
@@ -38,8 +38,8 @@
 
 QT_BEGIN_NAMESPACE
 
-QShapedPixmapWindow::QShapedPixmapWindow()
-    : QWindow(),
+QShapedPixmapWindow::QShapedPixmapWindow(QScreen *screen)
+    : QWindow(screen),
       m_backingStore(0)
 {
     QSurfaceFormat format;
diff --git a/src/gui/kernel/qshapedpixmapdndwindow_p.h b/src/gui/kernel/qshapedpixmapdndwindow_p.h
index fc311cff92..7536c09165 100644
--- a/src/gui/kernel/qshapedpixmapdndwindow_p.h
+++ b/src/gui/kernel/qshapedpixmapdndwindow_p.h
@@ -55,7 +55,7 @@ class QShapedPixmapWindow : public QWindow
 {
     Q_OBJECT
 public:
-    QShapedPixmapWindow();
+    explicit QShapedPixmapWindow(QScreen *screen = 0);
     ~QShapedPixmapWindow();
 
     void render();
diff --git a/src/gui/kernel/qsimpledrag.cpp b/src/gui/kernel/qsimpledrag.cpp
index b02f1dd8bd..6acac4cade 100644
--- a/src/gui/kernel/qsimpledrag.cpp
+++ b/src/gui/kernel/qsimpledrag.cpp
@@ -203,25 +203,15 @@ void QBasicDrag::restoreCursor()
 
 void QBasicDrag::startDrag()
 {
-    // ### TODO Check if its really necessary to have m_drag_icon_window
-    // when QDrag is used without a pixmap - QDrag::setPixmap()
-    if (!m_drag_icon_window)
-        m_drag_icon_window = new QShapedPixmapWindow();
-
-    m_drag_icon_window->setPixmap(m_drag->pixmap());
-    m_drag_icon_window->setHotspot(m_drag->hotSpot());
-
+    QPoint pos;
 #ifndef QT_NO_CURSOR
-    QPoint pos = QCursor::pos();
+    pos = QCursor::pos();
     if (pos.x() == int(qInf())) {
         // ### fixme: no mouse pos registered. Get pos from touch...
         pos = QPoint();
     }
-    m_drag_icon_window->updateGeometry(pos);
 #endif
-
-    m_drag_icon_window->setVisible(true);
-
+    recreateShapedPixmapWindow(Q_NULLPTR, pos);
     enableEventFilter();
 }
 
@@ -229,6 +219,19 @@ void QBasicDrag::endDrag()
 {
 }
 
+void QBasicDrag::recreateShapedPixmapWindow(QScreen *screen, const QPoint &pos)
+{
+    delete m_drag_icon_window;
+    // ### TODO Check if its really necessary to have m_drag_icon_window
+    // when QDrag is used without a pixmap - QDrag::setPixmap()
+    m_drag_icon_window = new QShapedPixmapWindow(screen);
+
+    m_drag_icon_window->setPixmap(m_drag->pixmap());
+    m_drag_icon_window->setHotspot(m_drag->hotSpot());
+    m_drag_icon_window->updateGeometry(pos);
+    m_drag_icon_window->setVisible(true);
+}
+
 void QBasicDrag::cancel()
 {
     disableEventFilter();
diff --git a/src/gui/kernel/qsimpledrag_p.h b/src/gui/kernel/qsimpledrag_p.h
index a011475381..4c9edbae05 100644
--- a/src/gui/kernel/qsimpledrag_p.h
+++ b/src/gui/kernel/qsimpledrag_p.h
@@ -58,6 +58,7 @@ class QWindow;
 class QEventLoop;
 class QDropData;
 class QShapedPixmapWindow;
+class QScreen;
 
 class Q_GUI_EXPORT QBasicDrag : public QPlatformDrag, public QObject
 {
@@ -80,6 +81,7 @@ protected:
 
     void moveShapedPixmapWindow(const QPoint &deviceIndependentPosition);
     QShapedPixmapWindow *shapedPixmapWindow() const { return m_drag_icon_window; }
+    void recreateShapedPixmapWindow(QScreen *screen, const QPoint &pos);
     void updateCursor(Qt::DropAction action);
 
     bool canDrop() const { return m_can_drop; }