Add a function to determine whether a Qt window is main.

Unlike other operating systems, OS X has two distinct concepts for
window activation that affect behavior and drawing - key and main.

The key window is what Qt calls "active".

The differences between key and main windows are documented here:
https://developer.apple.com/library/mac/#documentation/Cocoa/Conceptual/WinPanel/Concepts/ChangingMainKeyWindow.html

Change-Id: I2071f163e4774bbbcddbac24078086caa4466443
Reviewed-by: Shawn Rutledge <shawn.rutledge@digia.com>

2 files changed, 35 insertions, 0 deletions

diff --git a/src/macextras/qmacfunctions.h b/src/macextras/qmacfunctions.h
index aa694a7..4b7500a 100644
--- a/src/macextras/qmacfunctions.h
+++ b/src/macextras/qmacfunctions.h
@@ -73,6 +73,8 @@ class QMenuBar;
 class QPixmap;
 class QString;
 class QUrl;
+class QWidget;
+class QWindow;
 
 namespace QtMacExtras
 {
@@ -97,6 +99,12 @@ Q_MACEXTRAS_EXPORT NSMenu* toNSMenu(QMenu *menu);
 Q_MACEXTRAS_EXPORT NSMenu* toNSMenu(QMenuBar *menubar);
 
 Q_MACEXTRAS_EXPORT void setDockMenu(QMenu *menu);
+
+#if QT_VERSION >= QT_VERSION_CHECK(5, 0, 0)
+Q_MACEXTRAS_EXPORT bool isMainWindow(QWindow *window);
+#endif
+
+Q_MACEXTRAS_EXPORT bool isMainWindow(QWidget *widget);
 #endif
 }
 
diff --git a/src/macextras/qmacfunctions_mac.mm b/src/macextras/qmacfunctions_mac.mm
index a78792a..5fdd407 100644
--- a/src/macextras/qmacfunctions_mac.mm
+++ b/src/macextras/qmacfunctions_mac.mm
@@ -46,6 +46,7 @@
 QT_BEGIN_NAMESPACE
 
 #if QT_VERSION > QT_VERSION_CHECK(5, 0, 0)
+#include <QtGui/QWindow>
 #include <QtWidgets/QMenu>
 #include <QtWidgets/QMenuBar>
 #include <qpa/qplatformmenu.h>
@@ -110,6 +111,32 @@ void setDockMenu(QMenu *menu)
     }
 }
 
+#if QT_VERSION >= QT_VERSION_CHECK(5, 0, 0)
+bool isMainWindow(QWindow *window)
+{
+    NSWindow *macWindow = static_cast<NSWindow*>(
+        QGuiApplication::platformNativeInterface()->nativeResourceForWindow("nswindow", window));
+    if (!macWindow)
+        return false;
+
+    return [macWindow isMainWindow];
+}
+#endif
+
+bool isMainWindow(QWidget *widget)
+{
+    if (!widget)
+        return false;
+
+#if QT_VERSION >= QT_VERSION_CHECK(5, 0, 0)
+    return isMainWindow(widget->windowHandle());
+#else
+    NSWindow *macWindow =
+            reinterpret_cast<NSWindow*>([reinterpret_cast<NSView*>(widget->window()->winId()) window]);
+    return [macWindow isMainWindow];
+#endif
+}
+
 CGContextRef currentCGContext()
 {
     return reinterpret_cast<CGContextRef>([[NSGraphicsContext currentContext] graphicsPort]);