Cocoa: Mouse enter events on window activation.

This patch tells the window system that it should create a mouse enter
event if a window was activated when the mouse was inside. This wasn't
working and was a regression.

Task-number: QTBUG-35109

[ChangeLog][Cocoa] Fix enterEvent not being called on activate.

Change-Id: I4e4662b4a4c58dafa8d0a2c09458ab88f678d243
Reviewed-by: Liang Qi <liang.qi@digia.com>

src/plugins/platforms/cocoa/qnsview.h

@@ -93,6 +93,8 @@ QT_END_NAMESPACE
 - (BOOL)hasMask;
 - (BOOL)isOpaque;
 
+- (void)convertFromScreen:(NSPoint)mouseLocation toWindowPoint:(QPointF *)qtWindowPoint andScreenPoint:(QPointF *)qtScreenPoint;
+
 - (void)resetMouseButtons;
 
 - (void)handleMouseEvent:(NSEvent *)theEvent;

src/plugins/platforms/cocoa/qnswindowdelegate.h

@@ -53,6 +53,7 @@
 
 - (id)initWithQCocoaWindow: (QCocoaWindow *) cocoaWindow;
 
+- (void)windowDidBecomeKey:(NSNotification *)notification;
 - (void)windowDidResize:(NSNotification *)notification;
 - (void)windowDidMove:(NSNotification *)notification;
 - (void)windowWillMove:(NSNotification *)notification;

src/plugins/platforms/cocoa/qnswindowdelegate.mm

@@ -56,6 +56,17 @@
     return self;
 }
 
+- (void)windowDidBecomeKey:(NSNotification *)notification
+{
+    Q_UNUSED(notification);
+    if (m_cocoaWindow->m_windowUnderMouse) {
+        QPointF windowPoint;
+        QPointF screenPoint;
+        [m_cocoaWindow->m_qtView convertFromScreen:[NSEvent mouseLocation] toWindowPoint:&windowPoint andScreenPoint:&screenPoint];
+        QWindowSystemInterface::handleEnterEvent(m_cocoaWindow->m_enterLeaveTargetWindow, windowPoint, screenPoint);
+    }
+}
+
 - (void)windowDidResize:(NSNotification *)notification
 {
     Q_UNUSED(notification);