Make QCocoaWindow independent of NSWindow.

QCocoaWindow now gets resize events from QNSViev
and does not require a NSWindow. QWindow instances
can now be inserted in NSView hierarchies. This is
useful for Qt-as-a-plugin use cases and is needed to
implement QMacNativeWidget for Qt 5.

Change-Id: Ia95ea9c22a15a3e62d1e6543466cff07390c70a2
Reviewed-by: Morten Johan Sørvig <morten.sorvig@nokia.com>

5 files changed, 68 insertions, 16 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoanativeinterface.mm b/src/plugins/platforms/cocoa/qcocoanativeinterface.mm
index c6aa0d39e6..e48d588e5a 100644
--- a/src/plugins/platforms/cocoa/qcocoanativeinterface.mm
+++ b/src/plugins/platforms/cocoa/qcocoanativeinterface.mm
@@ -52,8 +52,15 @@
 
 void *QCocoaNativeInterface::nativeResourceForWindow(const QByteArray &resourceString, QWindow *window)
 {
+    if (!window->handle()) {
+        qWarning("QCocoaNativeInterface::nativeResourceForWindow: Native window has not been created.");
+        return 0;
+    }
+
     if (resourceString == "nsopenglcontext") {
         return static_cast<QCocoaWindow *>(window->handle())->currentContext()->nsOpenGLContext();
+    } else if (resourceString == "nsview") {
+        return static_cast<QCocoaWindow *>(window->handle())->m_contentView;
     }
     return 0;
 }
diff --git a/src/plugins/platforms/cocoa/qcocoawindow.h b/src/plugins/platforms/cocoa/qcocoawindow.h
index 9fa04a0ca2..2c5f6b5db0 100644
--- a/src/plugins/platforms/cocoa/qcocoawindow.h
+++ b/src/plugins/platforms/cocoa/qcocoawindow.h
@@ -65,6 +65,25 @@
 @end
 
 QT_BEGIN_NAMESPACE
+// QCocoaWindow
+//
+// QCocoaWindow is an NSView (not an NSWindow!) in the sense
+// that it relies on a NSView for all event handling and
+// graphics output and does not require a NSWindow, except for
+// for the window-related functions like setWindowTitle.
+//
+// As a consequence of this it is possible to embed the QCocoaWindow
+// in an NSView hierarchy by getting a pointer to the "backing"
+// NSView and not calling QCocoaWindow::show():
+//
+// QWindow *qtWindow = new MyWindow();
+// qtWindow->create();
+// QPlatformNativeInterface *platformNativeInterface = QGuiApplication::platformNativeInterface();
+// NSView *qtView = (NSView *)platformNativeInterface->nativeResourceForWindow("nsview", qtWindow);
+// [parentView addSubview:qtView];
+//
+// See the qt_on_cocoa manual tests for a working example, located
+// in tests/manual/cocoa at the time of writing.
 
 class QCocoaWindow : public QPlatformWindow
 {
@@ -97,12 +116,17 @@ protected:
     QRect windowGeometry() const;
     QCocoaWindow *parentCocoaWindow() const;
 
-private:
+// private:
+public: // for QNSView
     friend class QCocoaBackingStore;
-    NSWindow *m_nsWindow;
+    friend class QCocoaNativeInterface;
+
     QNSView *m_contentView;
+    QNSWindow *m_nsWindow;
+
     quint32 m_windowAttributes;
     quint32 m_windowClass;
+    bool m_inConstructor;
     QCocoaGLContext *m_glContext;
 };
 
diff --git a/src/plugins/platforms/cocoa/qcocoawindow.mm b/src/plugins/platforms/cocoa/qcocoawindow.mm
index 859aa87cce..27e8e9a2c9 100644
--- a/src/plugins/platforms/cocoa/qcocoawindow.mm
+++ b/src/plugins/platforms/cocoa/qcocoawindow.mm
@@ -81,6 +81,7 @@ QCocoaWindow::QCocoaWindow(QWindow *tlw)
     , m_windowAttributes(0)
     , m_windowClass(0)
     , m_glContext(0)
+    , m_inConstructor(true)
 {
     QCocoaAutoReleasePool pool;
 
@@ -97,7 +98,7 @@ QCocoaWindow::QCocoaWindow(QWindow *tlw)
     // QCocoaWindow is deleted by Qt.
     [m_nsWindow setReleasedWhenClosed : NO];
 
-    m_contentView = [[QNSView alloc] initWithQWindow:tlw];
+    m_contentView = [[QNSView alloc] initWithQWindow:tlw platformWindow:this];
 
     // ### Accept touch events by default.
     // Beware that enabling touch events has a negative impact on the overall performance.
@@ -107,6 +108,7 @@ QCocoaWindow::QCocoaWindow(QWindow *tlw)
     setGeometry(tlw->geometry());
 
     [m_nsWindow setContentView:m_contentView];
+    m_inConstructor = false;
 }
 
 QCocoaWindow::~QCocoaWindow()
@@ -124,8 +126,6 @@ void QCocoaWindow::setGeometry(const QRect &rect)
     QPlatformWindow::setGeometry(rect);
 
     NSRect bounds = qt_mac_flipRect(rect, window());
-
-    [[m_nsWindow contentView] setFrameSize:bounds.size];
     [m_nsWindow setContentSize : bounds.size];
     [m_nsWindow setFrameOrigin : bounds.origin];
 }
@@ -232,23 +232,17 @@ void QCocoaWindow::windowDidMove()
 {
     NSRect rect = [[m_nsWindow contentView]frame];
     NSRect windowRect = [m_nsWindow frame];
-
-    QRect geo(windowRect.origin.x, qt_mac_flipYCoordinate(windowRect.origin.y + rect.size.height), rect.size.width, rect.size.height);
-    setGeometry(geo);
-    QWindowSystemInterface::handleSynchronousGeometryChange(window(), geo);
+    [[m_nsWindow contentView] setFrameSize:rect.size];
 }
 
 void QCocoaWindow::windowDidResize()
 {
     NSRect rect = [[m_nsWindow contentView]frame];
     NSRect windowRect = [m_nsWindow frame];
-
-    QRect geo(windowRect.origin.x, qt_mac_flipYCoordinate(windowRect.origin.y + rect.size.height), rect.size.width, rect.size.height);
-    setGeometry(geo);
-    QWindowSystemInterface::handleSynchronousGeometryChange(window(), geo);
+    // Call setFrameSize which will trigger a frameDidChangeNotificatio on QNSView.
+    [[m_nsWindow contentView] setFrameSize:rect.size];
 }
 
-
 void QCocoaWindow::windowWillClose()
 {
     QWindowSystemInterface::handleSynchronousCloseEvent(window());
diff --git a/src/plugins/platforms/cocoa/qnsview.h b/src/plugins/platforms/cocoa/qnsview.h
index eddc1aa7e9..571449492d 100644
--- a/src/plugins/platforms/cocoa/qnsview.h
+++ b/src/plugins/platforms/cocoa/qnsview.h
@@ -47,15 +47,17 @@
 #include <QtGui/QImage>
 #include <QtGui/QAccessible>
 
+class QCocoaWindow;
 @interface QNSView : NSView {
     CGImageRef m_cgImage;
     QWindow *m_window;
+    QCocoaWindow *m_platformWindow;
     Qt::MouseButtons m_buttons;
     QAccessibleInterface *m_accessibleRoot;
 }
 
 - (id)init;
-- (id)initWithQWindow:(QWindow *)window;
+- (id)initWithQWindow:(QWindow *)window platformWindow:(QCocoaWindow *) platformWindow;
 
 - (void)setImage:(QImage *)image;
 - (void)drawRect:(NSRect)dirtyRect;
diff --git a/src/plugins/platforms/cocoa/qnsview.mm b/src/plugins/platforms/cocoa/qnsview.mm
index 82b4e54deb..1a1e02d2fd 100644
--- a/src/plugins/platforms/cocoa/qnsview.mm
+++ b/src/plugins/platforms/cocoa/qnsview.mm
@@ -44,6 +44,7 @@
 #include <Carbon/Carbon.h>
 
 #include "qnsview.h"
+#include "qcocoawindow.h"
 #include "qcocoahelpers.h"
 #include "qmultitouch_mac_p.h"
 
@@ -81,12 +82,14 @@ static QTouchDevice *touchDevice = 0;
     return self;
 }
 
-- (id)initWithQWindow:(QWindow *)window {
+- (id)initWithQWindow:(QWindow *)window platformWindow:(QCocoaWindow *) platformWindow
+{
     self = [self init];
     if (!self)
         return 0;
 
     m_window = window;
+    m_platformWindow = platformWindow;
     m_accessibleRoot = 0;
 
 #ifdef QT_COCOA_ENABLE_ACCESSIBILITY_INSPECTOR
@@ -106,9 +109,31 @@ static QTouchDevice *touchDevice = 0;
     m_accessibleRoot = window->accessibleRoot();
 #endif
 
+    [self setPostsFrameChangedNotifications : YES];
+    [[NSNotificationCenter defaultCenter] addObserver:self
+                                          selector:@selector(frameDidChangeNotification:)
+                                          name:NSViewFrameDidChangeNotification
+                                          object:self];
+
     return self;
 }
 
+- (void) frameDidChangeNotification: (NSNotification *) notification
+{
+    NSRect rect = [self frame];
+    NSRect windowRect = [[self window] frame];
+    QRect geo(windowRect.origin.x, qt_mac_flipYCoordinate(windowRect.origin.y + rect.size.height), rect.size.width, rect.size.height);
+
+    // Call setGeometry on QPlatformWindow. (not on QCocoaWindow,
+    // doing that will initiate a geometry change it and possibly create
+    // an infinite loop when this notification is triggered again.)
+    m_platformWindow->QPlatformWindow::setGeometry(geo);
+
+    // Send a geometry change event to Qt, if it's ready to handle events
+    if (!m_platformWindow->m_inConstructor)
+        QWindowSystemInterface::handleSynchronousGeometryChange(m_window, geo);
+}
+
 - (void) setImage:(QImage *)image
 {
     CGImageRelease(m_cgImage);