Cocoa: Make QScreen::topLevelAt() work correctly

The QPlatformScreen::topLevelAt() default implementation
is flawed in that it does not check z-ordering but
simply returns the first window in the window list
that contains the test point.

Add QCocoaScreen::topLevelAt(). Use [NSApp orderedWindows]
to iterate through the window list in z order. Add
a NSWindow->QCococaWindow mapping hash to QCocoaIntegration
for getting the corresponding QWindow once a NSWindow
is found.

Task-number: QTBUG-37597
Change-Id: I7af70163a32528cb56f8d6caa037b98f580ee191
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>

1 files changed, 28 insertions, 0 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoaintegration.mm b/src/plugins/platforms/cocoa/qcocoaintegration.mm
index 9d5388d33b..c4398622e8 100644
--- a/src/plugins/platforms/cocoa/qcocoaintegration.mm
+++ b/src/plugins/platforms/cocoa/qcocoaintegration.mm
@@ -156,6 +156,24 @@ qreal QCocoaScreen::devicePixelRatio() const
     }
 }
 
+QWindow *QCocoaScreen::topLevelAt(const QPoint &point) const
+{
+    // Get a z-ordered list of windows. Iterate through it until
+    // we find a window which contains the point.
+    for (NSWindow *nsWindow in [NSApp orderedWindows]) {
+        QCocoaWindow *cocoaWindow = QCocoaIntegration::instance()->window(nsWindow);
+        if (!cocoaWindow)
+            continue;
+        QWindow *window = cocoaWindow->window();
+        if (!window->isTopLevel())
+             continue;
+        if (window->geometry().contains(point))
+            return window;
+    }
+
+    return QPlatformScreen::topLevelAt(point);
+}
+
 extern CGContextRef qt_mac_cg_context(const QPaintDevice *pdev);
 
 QPixmap QCocoaScreen::grabWindow(WId window, int x, int y, int width, int height) const
@@ -500,6 +518,16 @@ NSToolbar *QCocoaIntegration::toolbar(QWindow *window) const
     return mToolbars.value(window);
 }
 
+void QCocoaIntegration::setWindow(NSWindow* nsWindow, QCocoaWindow *window)
+{
+    mWindows.insert(nsWindow, window);
+}
+
+QCocoaWindow *QCocoaIntegration::window(NSWindow *window)
+{
+    return mWindows.value(window);
+}
+
 void QCocoaIntegration::clearToolbars()
 {
     QHash<QWindow *, NSToolbar *>::const_iterator it = mToolbars.constBegin();