OSX: a window can be de-maximized by resizing

After that, QWidget::isMaximized() should return false.

Task-number: QTBUG-37703
Change-Id: Ic8b0de63ab007066cd277f511dfaa969404ff069
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>

src/plugins/platforms/cocoa/qcocoawindow.h

@@ -183,6 +183,7 @@ public:
     void windowWillMove();
     void windowDidMove();
     void windowDidResize();
+    void windowDidEndLiveResize();
     bool windowShouldClose();
     bool windowIsPopupType(Qt::WindowType type = Qt::Widget) const;
 

src/plugins/platforms/cocoa/qcocoawindow.mm

@@ -1165,6 +1165,14 @@ void QCocoaWindow::windowDidResize()
     [m_qtView updateGeometry];
 }
 
+void QCocoaWindow::windowDidEndLiveResize()
+{
+    if (m_synchedWindowState == Qt::WindowMaximized && ![m_nsWindow isZoomed]) {
+        m_effectivelyMaximized = false;
+        [m_qtView notifyWindowStateChanged:Qt::WindowNoState];
+    }
+}
+
 bool QCocoaWindow::windowShouldClose()
 {
     bool accepted = false;

src/plugins/platforms/cocoa/qnswindowdelegate.mm

@@ -75,6 +75,14 @@
     }
 }
 
+- (void)windowDidEndLiveResize:(NSNotification *)notification
+{
+    Q_UNUSED(notification);
+    if (m_cocoaWindow) {
+        m_cocoaWindow->windowDidEndLiveResize();
+    }
+}
+
 - (void)windowWillMove:(NSNotification *)notification
 {
     Q_UNUSED(notification);