Improved implicit mouse grabbing on Cocoa.

This improves 106121a74bca32a6411b9ca968ee415f8bdfbff1 which was incomplete and
didn't work properly for comboboxes (or in general - when a popup window opens
due to a mouse press).

Reviewed-by: Prasanth

4 files changed, 69 insertions, 42 deletions

diff --git a/src/gui/kernel/qcocoapanel_mac.mm b/src/gui/kernel/qcocoapanel_mac.mm
index a26d775..d201653 100644
--- a/src/gui/kernel/qcocoapanel_mac.mm
+++ b/src/gui/kernel/qcocoapanel_mac.mm
@@ -52,6 +52,7 @@
 QT_FORWARD_DECLARE_CLASS(QWidget);
 QT_BEGIN_NAMESPACE
 extern Qt::MouseButton cocoaButton2QtButton(NSInteger buttonNum); // qcocoaview.mm
+extern QPointer<QWidget> qt_button_down; //qapplication_mac.cpp
 QT_END_NAMESPACE
 QT_USE_NAMESPACE
 
@@ -132,38 +133,41 @@ QT_USE_NAMESPACE
     QT_MANGLE_NAMESPACE(QCocoaView) *view = static_cast<QT_MANGLE_NAMESPACE(QCocoaView) *>(qt_mac_nativeview_for(widget));
     Qt::MouseButton mouseButton = cocoaButton2QtButton([event buttonNumber]);
 
+    bool handled = false;
     // sometimes need to redirect mouse events to the popup.
     QWidget *popup = qAppInstance()->activePopupWidget();
-    if (popup && popup != widget) {
+    if (popup) {
         switch([event type])
         {
         case NSLeftMouseDown:
-            qt_mac_handleMouseEvent(view, event, QEvent::MouseButtonPress, mouseButton);
+            if (!qt_button_down)
+                qt_button_down = widget;
+            handled = qt_mac_handleMouseEvent(view, event, QEvent::MouseButtonPress, mouseButton);
             // 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.
             // (this is standard Qt behavior.)
             break;
         case NSRightMouseDown:
         case NSOtherMouseDown:
-            if (!qt_mac_handleMouseEvent(view, event, QEvent::MouseButtonPress, mouseButton))
-                [super sendEvent:event];
+            if (!qt_button_down)
+                qt_button_down = widget;
+            handled = qt_mac_handleMouseEvent(view, event, QEvent::MouseButtonPress, mouseButton);
             break;
         case NSLeftMouseUp:
         case NSRightMouseUp:
         case NSOtherMouseUp:
-            if (!qt_mac_handleMouseEvent(view, event, QEvent::MouseButtonRelease, mouseButton))
-                [super sendEvent:event];
+            handled = qt_mac_handleMouseEvent(view, event, QEvent::MouseButtonRelease, mouseButton);
+            qt_button_down = 0;
             break;
         case NSMouseMoved:
-            qt_mac_handleMouseEvent(view, event, QEvent::MouseMove, Qt::NoButton);
+            handled = qt_mac_handleMouseEvent(view, event, QEvent::MouseMove, Qt::NoButton);
             break;
         case NSLeftMouseDragged:
         case NSRightMouseDragged:
         case NSOtherMouseDragged:
             [QT_MANGLE_NAMESPACE(QCocoaView) currentMouseEvent]->view = view;
             [QT_MANGLE_NAMESPACE(QCocoaView) currentMouseEvent]->theEvent = event;
-            if (!qt_mac_handleMouseEvent(view, event, QEvent::MouseMove, mouseButton))
-                [super sendEvent:event];
+            handled = qt_mac_handleMouseEvent(view, event, QEvent::MouseMove, mouseButton);
             break;
         default:
             [super sendEvent:event];
@@ -172,8 +176,9 @@ QT_USE_NAMESPACE
     } else {
         [super sendEvent:event];
     }
-    qt_mac_dispatchNCMouseMessage(self, event, [self QT_MANGLE_NAMESPACE(qt_qwidget)], leftButtonIsRightButton);
 
+    if (!handled)
+        qt_mac_dispatchNCMouseMessage(self, event, [self QT_MANGLE_NAMESPACE(qt_qwidget)], leftButtonIsRightButton);
 
     [self release];
 }
diff --git a/src/gui/kernel/qcocoaview_mac.mm b/src/gui/kernel/qcocoaview_mac.mm
index 3da783f..a4da25f 100644
--- a/src/gui/kernel/qcocoaview_mac.mm
+++ b/src/gui/kernel/qcocoaview_mac.mm
@@ -708,9 +708,9 @@ extern "C" {
 
 - (void)mouseUp:(NSEvent *)theEvent
 {
-    qt_button_down = 0;
-
     qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseButtonRelease, Qt::LeftButton);
+
+    qt_button_down = 0;
 }
 
 - (void)rightMouseDown:(NSEvent *)theEvent
@@ -723,9 +723,9 @@ extern "C" {
 
 - (void)rightMouseUp:(NSEvent *)theEvent
 {
-    qt_button_down = 0;
-
     qt_mac_handleMouseEvent(self, theEvent, QEvent::MouseButtonRelease, Qt::RightButton);
+
+    qt_button_down = 0;
 }
 
 - (void)otherMouseDown:(NSEvent *)theEvent
@@ -739,10 +739,10 @@ extern "C" {
 
 - (void)otherMouseUp:(NSEvent *)theEvent
 {
-    qt_button_down = 0;
-
     Qt::MouseButton mouseButton = cocoaButton2QtButton([theEvent buttonNumber]);
     qt_mac_handleMouseEvent(self, theEvent,  QEvent::MouseButtonRelease, mouseButton);
+
+    qt_button_down = 0;
 }
 
 - (void)mouseDragged:(NSEvent *)theEvent
@@ -1442,6 +1442,9 @@ Qt::DropAction QDragManager::drag(QDrag *o)
                     pasteboard:pboard
                         source:dndParams.view
                      slideBack:YES];
+    // reset the implicit grab widget when drag ends because we will not
+    // receive the mouse release event when DND is active.
+    qt_button_down = 0;
     [dndParams.view release];
     [image release];
     dragPrivate()->executed_action = Qt::IgnoreAction;
diff --git a/src/gui/kernel/qcocoawindow_mac.mm b/src/gui/kernel/qcocoawindow_mac.mm
index 263f0ac..ee5952b 100644
--- a/src/gui/kernel/qcocoawindow_mac.mm
+++ b/src/gui/kernel/qcocoawindow_mac.mm
@@ -52,6 +52,7 @@
 QT_FORWARD_DECLARE_CLASS(QWidget);
 QT_BEGIN_NAMESPACE
 extern Qt::MouseButton cocoaButton2QtButton(NSInteger buttonNum); // qcocoaview.mm
+extern QPointer<QWidget> qt_button_down; //qapplication_mac.cpp
 QT_END_NAMESPACE
 QT_USE_NAMESPACE
 
@@ -146,40 +147,44 @@ QT_USE_NAMESPACE
     }
 
     [self retain];
+
+    bool handled = false;
     QT_MANGLE_NAMESPACE(QCocoaView) *view = static_cast<QT_MANGLE_NAMESPACE(QCocoaView) *>(qt_mac_nativeview_for(widget));
     Qt::MouseButton mouseButton = cocoaButton2QtButton([event buttonNumber]);
     // sometimes need to redirect mouse events to the popup.
     QWidget *popup = qAppInstance()->activePopupWidget();
-    if (popup && popup != widget) {
+    if (popup) {
         switch([event type])
         {
         case NSLeftMouseDown:
-            qt_mac_handleMouseEvent(view, event, QEvent::MouseButtonPress, mouseButton);
+            if (!qt_button_down)
+                qt_button_down = widget;
+            handled = qt_mac_handleMouseEvent(view, event, QEvent::MouseButtonPress, mouseButton);
             // 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. 
             // (this is standard Qt behavior.)
             break;
         case NSRightMouseDown:
         case NSOtherMouseDown:
-            if (!qt_mac_handleMouseEvent(view, event, QEvent::MouseButtonPress, mouseButton))
-                [super sendEvent:event];
+            if (!qt_button_down)
+                qt_button_down = widget;
+            handled = qt_mac_handleMouseEvent(view, event, QEvent::MouseButtonPress, mouseButton);
             break;
         case NSLeftMouseUp:
         case NSRightMouseUp:
         case NSOtherMouseUp:
-            if (!qt_mac_handleMouseEvent(view, event, QEvent::MouseButtonRelease, mouseButton))
-                [super sendEvent:event];
+            handled = qt_mac_handleMouseEvent(view, event, QEvent::MouseButtonRelease, mouseButton);
+            qt_button_down = 0;
             break;
         case NSMouseMoved:
-            qt_mac_handleMouseEvent(view, event, QEvent::MouseMove, Qt::NoButton);
+            handled = qt_mac_handleMouseEvent(view, event, QEvent::MouseMove, Qt::NoButton);
             break;
         case NSLeftMouseDragged:
         case NSRightMouseDragged:
         case NSOtherMouseDragged:
             [QT_MANGLE_NAMESPACE(QCocoaView) currentMouseEvent]->view = view;
             [QT_MANGLE_NAMESPACE(QCocoaView) currentMouseEvent]->theEvent = event;
-            if (!qt_mac_handleMouseEvent(view, event, QEvent::MouseMove, mouseButton))
-                [super sendEvent:event];
+            handled = qt_mac_handleMouseEvent(view, event, QEvent::MouseMove, mouseButton);
             break;
         default:
             [super sendEvent:event];
@@ -188,8 +193,9 @@ QT_USE_NAMESPACE
     } else {
         [super sendEvent:event];
     }
-    qt_mac_dispatchNCMouseMessage(self, event, [self QT_MANGLE_NAMESPACE(qt_qwidget)], leftButtonIsRightButton);
 
+    if (!handled)
+        qt_mac_dispatchNCMouseMessage(self, event, [self QT_MANGLE_NAMESPACE(qt_qwidget)], leftButtonIsRightButton);
 
     [self release];
 }
diff --git a/src/gui/kernel/qt_cocoa_helpers_mac.mm b/src/gui/kernel/qt_cocoa_helpers_mac.mm
index 2bf1465..ef680a4 100644
--- a/src/gui/kernel/qt_cocoa_helpers_mac.mm
+++ b/src/gui/kernel/qt_cocoa_helpers_mac.mm
@@ -139,6 +139,7 @@ void QMacWindowFader::performFade()
 extern bool qt_sendSpontaneousEvent(QObject *receiver, QEvent *event); // qapplication.cpp;
 extern Qt::MouseButton cocoaButton2QtButton(NSInteger buttonNum); // qcocoaview.mm
 extern QWidget * mac_mouse_grabber;
+extern QPointer<QWidget> qt_button_down; //qapplication_mac.cpp
 
 void macWindowFade(void * /*OSWindowRef*/ window, float durationSeconds)
 {
@@ -748,7 +749,11 @@ void qt_mac_dispatchNCMouseMessage(void * /* NSWindow* */eventWindow, void * /*
             NSRect frameRect = [window frame];
             if (fakeNCEvents || NSMouseInRect(globalPoint, frameRect, NO)) {
                 NSRect contentRect = [window contentRectForFrameRect:frameRect];
-                if (fakeNCEvents || !NSMouseInRect(globalPoint, contentRect, NO)) {
+                qglobalPoint = QPoint(flipPoint(globalPoint).toPoint());
+                QWidget *w = widgetToGetEvent->childAt(widgetToGetEvent->mapFromGlobal(qglobalPoint));
+                // check that the mouse pointer is on the non-client area and
+                // there are not widgets in it.
+                if (fakeNCEvents || (!NSMouseInRect(globalPoint, contentRect, NO) && !w)) {
                     qglobalPoint = QPoint(flipPoint(globalPoint).toPoint());
                     qlocalPoint = widgetToGetEvent->mapFromGlobal(qglobalPoint);
                     processThisEvent = true;
@@ -759,8 +764,11 @@ void qt_mac_dispatchNCMouseMessage(void * /* NSWindow* */eventWindow, void * /*
     // This is not an NC area mouse message.
     if (!processThisEvent)
         return;
+
     // If the window is frame less, generate fake mouse events instead. (floating QToolBar)
-    if (fakeNCEvents && (widgetToGetEvent->window()->windowFlags() & Qt::FramelessWindowHint))
+    // or if someone already got an explicit or implicit grab
+    if (mac_mouse_grabber || qt_button_down ||
+        (fakeNCEvents && (widgetToGetEvent->window()->windowFlags() & Qt::FramelessWindowHint)))
         fakeMouseEvents = true;
 
     Qt::MouseButton button;
@@ -838,8 +846,15 @@ void qt_mac_dispatchNCMouseMessage(void * /* NSWindow* */eventWindow, void * /*
             leftButtonIsRightButton = false;
         }
     }
+
     QMouseEvent qme(eventType, qlocalPoint, qglobalPoint, button, button, keyMods);
     qt_sendSpontaneousEvent(widgetToGetEvent, &qme);
+
+    // We don't need to set the implicit grab widget here because we won't
+    // reach this point if then event type is Press over a Qt widget.
+    // However we might need to unset it if the event is Release.
+    if (eventType == QEvent::MouseButtonRelease)
+        qt_button_down = 0;
 #endif
 }
 
@@ -873,15 +888,12 @@ bool qt_mac_handleMouseEvent(void * /* NSView * */view, void * /* NSEvent * */ev
     // Find the widget that *should* get the event (e.g., maybe it was a pop-up,
     // they always get the mouse event).
     QWidget *qwidget = [theView qt_qwidget];
-    QWidget *widgetToGetMouse = qwidget;
+    QWidget *widgetToGetMouse = 0;
+    NSView *tmpView = 0;
     QWidget *popup = qAppInstance()->activePopupWidget();
-    NSView *tmpView = theView;
-    if (mac_mouse_grabber  && mac_mouse_grabber != widgetToGetMouse) {
-        widgetToGetMouse = mac_mouse_grabber;
-        tmpView = qt_mac_nativeview_for(widgetToGetMouse);
-    }
+    QPoint qglobalPoint(flipPoint(globalPoint).toPoint());
 
-    if (popup && popup != qwidget->window()) {
+    if (popup) {
         widgetToGetMouse = popup;
         tmpView = qt_mac_nativeview_for(popup);
         windowPoint = [[tmpView window] convertScreenToBase:globalPoint];
@@ -901,13 +913,15 @@ bool qt_mac_handleMouseEvent(void * /* NSView * */view, void * /* NSEvent * */ev
         }
     } 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;
+        QPoint pos;
+        widgetToGetMouse = QApplicationPrivate::pickMouseReceiver(qwidget, qglobalPoint,
+                                                                  pos, eventType,
+                                                                  button, qt_button_down, 0);
+        if (widgetToGetMouse)
             tmpView = qt_mac_nativeview_for(widgetToGetMouse);
-        }
     }
+    if (!widgetToGetMouse)
+        return false;
 
     NSPoint localPoint = [tmpView convertPoint:windowPoint fromView:nil];
     QPoint qlocalPoint(localPoint.x, localPoint.y);
@@ -953,14 +967,13 @@ bool qt_mac_handleMouseEvent(void * /* NSView * */view, void * /* NSEvent * */ev
         break;
     }
     [QT_MANGLE_NAMESPACE(QCocoaView) currentMouseEvent]->localPoint = localPoint;
-    QPoint qglobalPoint(flipPoint(globalPoint).toPoint());
     QMouseEvent qme(eventType, qlocalPoint, qglobalPoint, button, buttons, keyMods);
     qt_sendSpontaneousEvent(widgetToGetMouse, &qme);
     if (eventType == QEvent::MouseButtonPress && button == Qt::RightButton) {
         QContextMenuEvent qcme(QContextMenuEvent::Mouse, qlocalPoint, qglobalPoint, keyMods);
         qt_sendSpontaneousEvent(widgetToGetMouse, &qcme);
     }
-    return qme.isAccepted();
+    return true;
 #endif
 }