Dont create native windows when setting up gestures.

The code used to create native window handle even before checking if the widget
subscribes to gestures, basically breaking alien widgets. Check the position of
the gesture instead when the WM_GESTURE message is received in the GID_BEGIN
state. This will work properly in most cases - but not always as the position
that we get with the WM_GESTURE message is the center point of the multitouch
gesture, which might be outside of the widget depending on positions of
fingers.

Reviewed-by: trustme

1 files changed, 65 insertions, 63 deletions

diff --git a/src/gui/kernel/qapplication_win.cpp b/src/gui/kernel/qapplication_win.cpp
index 7d9e6ea224..12cd879818 100644
--- a/src/gui/kernel/qapplication_win.cpp
+++ b/src/gui/kernel/qapplication_win.cpp
@@ -452,7 +452,7 @@ public:
     bool        translateConfigEvent(const MSG &msg);
     bool        translateCloseEvent(const MSG &msg);
     bool        translateTabletEvent(const MSG &msg, PACKET *localPacketBuf, int numPackets);
-    bool        translateGestureEvent(const MSG &msg);
+    bool        translateGestureEvent(const MSG &msg, const GESTUREINFO &gi);
     void        repolishStyle(QStyle &style);
     inline void showChildren(bool spontaneous) { d_func()->showChildren(spontaneous); }
     inline void hideChildren(bool spontaneous) { d_func()->hideChildren(spontaneous); }
@@ -848,6 +848,7 @@ void qt_init(QApplicationPrivate *priv, int)
         (PtrEndPanningFeedback)QLibrary::resolve(QLatin1String("uxtheme"),
                                                    "EndPanningFeedback");
 #endif
+    priv->gestureWidget = 0;
 }
 
 /*****************************************************************************
@@ -2513,10 +2514,38 @@ LRESULT CALLBACK QtWndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam
             }
             result = false;
             break;
-        case WM_GESTURE:
-            widget->translateGestureEvent(msg);
+        case WM_GESTURE: {
+            GESTUREINFO gi;
+            memset(&gi, 0, sizeof(GESTUREINFO));
+            gi.cbSize = sizeof(GESTUREINFO);
+
+            QApplicationPrivate *qAppPriv = QApplicationPrivate::instance();
+            BOOL bResult = false;
+            if (qAppPriv->GetGestureInfo)
+                bResult = qAppPriv->GetGestureInfo((HANDLE)msg.lParam, &gi);
+            if (bResult) {
+                if (gi.dwID == GID_BEGIN) {
+                    // find the alien widget for the gesture position.
+                    // This might not be accurate as the position is the center
+                    // point of two fingers for multi-finger gestures.
+                    QPoint pt(gi.ptsLocation.x, gi.ptsLocation.y);
+                    QWidget *w = widget->childAt(widget->mapFromGlobal(pt));
+                    qAppPriv->gestureWidget = w ? w : widget;
+                }
+                if (qAppPriv->gestureWidget)
+                    static_cast<QETWidget*>(qAppPriv->gestureWidget)->translateGestureEvent(msg, gi);
+                if (qAppPriv->CloseGestureInfoHandle)
+                    qAppPriv->CloseGestureInfoHandle((HANDLE)msg.lParam);
+                if (gi.dwID == GID_END)
+                    qAppPriv->gestureWidget = 0;
+            } else {
+                DWORD dwErr = GetLastError();
+                if (dwErr > 0)
+                    qWarning() << "translateGestureEvent: error = " << dwErr;
+            }
             result = true;
             break;
+        }
         default:
             result = false;                        // event was not processed
             break;
@@ -3725,69 +3754,42 @@ bool QETWidget::translateCloseEvent(const MSG &)
     return d_func()->close_helper(QWidgetPrivate::CloseWithSpontaneousEvent);
 }
 
-bool QETWidget::translateGestureEvent(const MSG &msg)
+bool QETWidget::translateGestureEvent(const MSG &, const GESTUREINFO &gi)
 {
-    GESTUREINFO gi;
-    memset(&gi, 0, sizeof(GESTUREINFO));
-    gi.cbSize = sizeof(GESTUREINFO);
+    const QPoint widgetPos = QPoint(gi.ptsLocation.x, gi.ptsLocation.y);
+    QWidget *alienWidget = !internalWinId() ? this : childAt(widgetPos);
+    if (alienWidget && alienWidget->internalWinId())
+        alienWidget = 0;
+    QWidget *widget = alienWidget ? alienWidget : this;
 
-    QApplicationPrivate *qAppPriv = QApplicationPrivate::instance();
-#if defined(Q_WS_WINCE_WM) && defined(QT_WINCE_GESTURES)
-#undef GID_ZOOM
-#define GID_ZOOM 0xf000
-#undef GID_ROTATE
-#define GID_ROTATE 0xf001
-#undef GID_TWOFINGERTAP
-#define GID_TWOFINGERTAP 0xf002
-#undef GID_ROLLOVER
-#define GID_ROLLOVER 0xf003
-#endif
-    BOOL bResult = false;
-    if (qAppPriv->GetGestureInfo)
-        bResult = qAppPriv->GetGestureInfo((HANDLE)msg.lParam, &gi);
-
-    if (bResult) {
-        const QPoint widgetPos = QPoint(gi.ptsLocation.x, gi.ptsLocation.y);
-        QWidget *alienWidget = !internalWinId() ? this : childAt(widgetPos);
-        if (alienWidget && alienWidget->internalWinId())
-            alienWidget = 0;
-        QWidget *widget = alienWidget ? alienWidget : this;
-
-        QNativeGestureEvent event;
-        event.sequenceId = gi.dwSequenceID;
-        event.position = QPoint(gi.ptsLocation.x, gi.ptsLocation.y);
-        event.argument = gi.ullArguments;
-
-        switch (gi.dwID) {
-        case GID_BEGIN:
-            event.gestureType = QNativeGestureEvent::GestureBegin;
-            break;
-        case GID_END:
-            event.gestureType = QNativeGestureEvent::GestureEnd;
-            break;
-        case GID_ZOOM:
-            event.gestureType = QNativeGestureEvent::Zoom;
-            break;
-        case GID_PAN:
-            event.gestureType = QNativeGestureEvent::Pan;
-            break;
-        case GID_ROTATE:
-            event.gestureType = QNativeGestureEvent::Rotate;
-            break;
-        case GID_TWOFINGERTAP:
-        case GID_ROLLOVER:
-        default:
-            break;
-        }
-        if (qAppPriv->CloseGestureInfoHandle)
-            qAppPriv->CloseGestureInfoHandle((HANDLE)msg.lParam);
-        if (event.gestureType != QNativeGestureEvent::None)
-            qt_sendSpontaneousEvent(widget, &event);
-    } else {
-        DWORD dwErr = GetLastError();
-        if (dwErr > 0)
-            qWarning() << "translateGestureEvent: error = " << dwErr;
+    QNativeGestureEvent event;
+    event.sequenceId = gi.dwSequenceID;
+    event.position = QPoint(gi.ptsLocation.x, gi.ptsLocation.y);
+    event.argument = gi.ullArguments;
+
+    switch (gi.dwID) {
+    case GID_BEGIN:
+        event.gestureType = QNativeGestureEvent::GestureBegin;
+        break;
+    case GID_END:
+        event.gestureType = QNativeGestureEvent::GestureEnd;
+        break;
+    case GID_ZOOM:
+        event.gestureType = QNativeGestureEvent::Zoom;
+        break;
+    case GID_PAN:
+        event.gestureType = QNativeGestureEvent::Pan;
+        break;
+    case GID_ROTATE:
+        event.gestureType = QNativeGestureEvent::Rotate;
+        break;
+    case GID_TWOFINGERTAP:
+    case GID_ROLLOVER:
+    default:
+        break;
     }
+    if (event.gestureType != QNativeGestureEvent::None)
+        qt_sendSpontaneousEvent(widget, &event);
     return true;
 }