Fixes implicit grabbing in Qt/Cocoa

When delivering mouse events in Qt/Cocoa set the implicit mouse grabber and
deliver the event to it and do not try to propagate the event to the parent
view.

Reviewed-by: Prasanth
(cherry picked from commit aae81f370f6afede95064bc75eb7ee6ac13b1c30)

2 files changed, 29 insertions, 30 deletions

diff --git a/src/gui/kernel/qcocoaview_mac.mm b/src/gui/kernel/qcocoaview_mac.mm
index 72eedad..bf6bf4a 100644
--- a/src/gui/kernel/qcocoaview_mac.mm
+++ b/src/gui/kernel/qcocoaview_mac.mm
@@ -79,6 +79,7 @@ extern bool qt_sendSpontaneousEvent(QObject *, QEvent *); // qapplication.cpp
 extern OSViewRef qt_mac_nativeview_for(const QWidget *w); // qwidget_mac.mm
 extern const QStringList& qEnabledDraggedTypes(); // qmime_mac.cpp
 extern QPointer<QWidget> qt_mouseover; //qapplication_mac.mm
+extern QPointer<QWidget> qt_button_down; //qapplication_mac.cpp
 
 Qt::MouseButton cocoaButton2QtButton(NSInteger buttonNum)
 {
@@ -691,6 +692,9 @@ extern "C" {
 
 - (void)mouseDown:(NSEvent *)theEvent
 {
+    if (!qt_button_down)
+        qt_button_down = qwidget;
+
     qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseButtonPress, Qt::LeftButton);
     // Don't call super here. This prevents us from getting the mouseUp event,
     // which we need to send even if the mouseDown event was not accepted.
@@ -700,75 +704,62 @@ extern "C" {
 
 - (void)mouseUp:(NSEvent *)theEvent
 {
-    bool mouseOK = qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseButtonRelease, Qt::LeftButton);
+    qt_button_down = 0;
 
-    if (!mouseOK)
-        [super mouseUp:theEvent];
+    qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseButtonRelease, Qt::LeftButton);
 }
 
 - (void)rightMouseDown:(NSEvent *)theEvent
 {
-    bool mouseOK = qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseButtonPress, Qt::RightButton);
+    if (!qt_button_down)
+        qt_button_down = qwidget;
 
-    if (!mouseOK)
-        [super rightMouseDown:theEvent];
+    qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseButtonPress, Qt::RightButton);
 }
 
 - (void)rightMouseUp:(NSEvent *)theEvent
 {
-    bool mouseOK = qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseButtonRelease, Qt::RightButton);
+    qt_button_down = 0;
 
-    if (!mouseOK)
-        [super rightMouseUp:theEvent];
+    qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseButtonRelease, Qt::RightButton);
 }
 
 - (void)otherMouseDown:(NSEvent *)theEvent
 {
-    Qt::MouseButton mouseButton = cocoaButton2QtButton([theEvent buttonNumber]);
-    bool mouseOK = qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseButtonPress, mouseButton);
+    if (!qt_button_down)
+        qt_button_down = qwidget;
 
-    if (!mouseOK)
-        [super otherMouseDown:theEvent];
+    Qt::MouseButton mouseButton = cocoaButton2QtButton([theEvent buttonNumber]);
+    qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseButtonPress, mouseButton);
 }
 
 - (void)otherMouseUp:(NSEvent *)theEvent
 {
-    Qt::MouseButton mouseButton = cocoaButton2QtButton([theEvent buttonNumber]);
-    bool mouseOK = qt_mac_handleMouseEvent(self, theEvent,  QEvent::MouseButtonRelease, mouseButton);
-
-    if (!mouseOK)
-        [super otherMouseUp:theEvent];
+    qt_button_down = 0;
 
+    Qt::MouseButton mouseButton = cocoaButton2QtButton([theEvent buttonNumber]);
+    qt_mac_handleMouseEvent(self, theEvent,  QEvent::MouseButtonRelease, mouseButton);
 }
 
 - (void)mouseDragged:(NSEvent *)theEvent
 {
     qMacDnDParams()->view = self;
     qMacDnDParams()->theEvent = theEvent;
-    bool mouseOK = qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseMove, Qt::NoButton);
-
-    if (!mouseOK)
-        [super mouseDragged:theEvent];
+    qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseMove, Qt::NoButton);
 }
 
 - (void)rightMouseDragged:(NSEvent *)theEvent
 {
     qMacDnDParams()->view = self;
     qMacDnDParams()->theEvent = theEvent;
-    bool mouseOK = qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseMove, Qt::NoButton);
-
-    if (!mouseOK)
-        [super rightMouseDragged:theEvent];
+    qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseMove, Qt::NoButton);
 }
 
 - (void)otherMouseDragged:(NSEvent *)theEvent
 {
     qMacDnDParams()->view = self;
     qMacDnDParams()->theEvent = theEvent;
-    bool mouseOK = qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseMove, Qt::NoButton);
-
-    if (!mouseOK)
-        [super otherMouseDragged:theEvent];
+    qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseMove, Qt::NoButton);
 }
 
 - (void)scrollWheel:(NSEvent *)theEvent
diff --git a/src/gui/kernel/qt_cocoa_helpers_mac.mm b/src/gui/kernel/qt_cocoa_helpers_mac.mm
index c0fb8aa..2bf1465 100644
--- a/src/gui/kernel/qt_cocoa_helpers_mac.mm
+++ b/src/gui/kernel/qt_cocoa_helpers_mac.mm
@@ -899,6 +899,14 @@ bool qt_mac_handleMouseEvent(void * /* NSView * */view, void * /* NSEvent * */ev
             widgetToGetMouse =
                 [static_cast<QT_MANGLE_NAMESPACE(QCocoaView) *>(tmpView) qt_qwidget];
         }
+    } else {
+        extern QPointer<QWidget> qt_button_down; //qapplication_mac.cpp
+        if (!mac_mouse_grabber && qt_button_down) {
+            // if there is no explicit grabber, and the mouse was grabbed
+            // implicitely (i.e. a mousebutton was pressed)
+            widgetToGetMouse = qt_button_down;
+            tmpView = qt_mac_nativeview_for(widgetToGetMouse);
+        }
     }
 
     NSPoint localPoint = [tmpView convertPoint:windowPoint fromView:nil];