Add QCocoaWindowFunctions and add a function to find the clip offset

Change-Id: I0f9cd1f923867f6f24b3bc54e442a16b5d2a11e4
Reviewed-by: Tim Blechmann <tim@klingt.org>
Reviewed-by: Morten Johan Sørvig <morten.sorvig@theqtcompany.com>

src/platformheaders/cocoafunctions/cocoafunctions.pri

@@ -0,0 +1 @@
+HEADERS += $$PWD/qcocoawindowfunctions.h

src/platformheaders/cocoafunctions/qcocoawindowfunctions.h

@@ -0,0 +1,57 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL21$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file. Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** As a special exception, The Qt Company gives you certain additional
+** rights. These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QXCBWINDOWFUNCTIONS_H
+#define QXCBWINDOWFUNCTIONS_H
+
+#include <QtPlatformHeaders/QPlatformHeaderHelper>
+
+QT_BEGIN_NAMESPACE
+
+class QWindow;
+
+class QCocoaWindowFunctions {
+public:
+    typedef QPoint (*BottomLeftClippedByNSWindowOffset)(QWindow *window);
+    static const QByteArray bottomLeftClippedByNSWindowOffsetIdentifier() { return QByteArrayLiteral("CocoaBottomLeftClippedByNSWindowOffset"); }
+
+    static QPoint bottomLeftClippedByNSWindowOffset(QWindow *window)
+    {
+        return QPlatformHeaderHelper::callPlatformFunction<QPoint, BottomLeftClippedByNSWindowOffset>(bottomLeftClippedByNSWindowOffsetIdentifier(),window);
+    }
+};
+
+
+QT_END_NAMESPACE
+
+#endif // QXCBWINDOWFUNCTIONS_H

src/platformheaders/cocoafunctions/qcocoawindowfunctions.qdoc

@@ -0,0 +1,58 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:FDL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Free Documentation License Usage
+** Alternatively, this file may be used under the terms of the GNU Free
+** Documentation License version 1.3 as published by the Free Software
+** Foundation and appearing in the file included in the packaging of
+** this file. Please review the following information to ensure
+** the GNU Free Documentation License version 1.3 requirements
+** will be met: http://www.gnu.org/copyleft/fdl.html.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*!
+    \class QCocoaWindowFunctions
+    \inmodule QtPlatformHeaders
+
+    \brief The QCocoaWindowFunctions class is an inline class containing
+    miscellaneous functionality for NSWindow and NSView window specific functionality.
+
+    \note There is no binary compatibility guarantee for this class,
+    meaning that an application using it is only guaranteed to work with the Qt
+    version it was developed against.
+*/
+
+/*!
+    \typedef QCocoaWindowFunctions::BottomLeftClippedByNSWindowOffset
+
+    This is the typedef for the function returned by QGuiApplication::platformFunction when passed clippedByNSWindowIdentifier.
+*/
+
+/*!
+    \fn QByteArray QCocoaWindowFunctions::bottomLeftClippedByNSWindowOffsetIdentifier()
+
+    This function returnes the bytearray that can be used to query
+    QGuiApplication::platformFunction to retrieve the BottomLeftClippedByNSWindowOffset function.
+*/
+
+/*!
+    \fn QPoint QCocoaWindowFunctions::bottomLeftClippedByNSWindowOffset(QWindow *window)
+
+    This is a convenience function that can be used directly instead of resolving the function pointer.
+    \a window will be relayed to the function retrieved by QGuiApplication
+*/

src/platformheaders/platformheaders.pro

@@ -8,6 +8,7 @@ include(xcbfunctions/xcbfunctions.pri)
 include(eglfsfunctions/eglfsfunctions.pri)
 include(windowsfunctions/windowsfunctions.pri)
 include(helper/helper.pri)
+include(cocoafunctions/cocoafunctions.pri)
 
 QMAKE_DOCS = $$PWD/doc/qtplatformheaders.qdocconf
 

src/plugins/platforms/cocoa/qcocoanativeinterface.h

@@ -67,6 +67,8 @@ public:
     static void *nsOpenGLContextForContext(QOpenGLContext* context);
 #endif
 
+    QFunctionPointer platformFunction(const QByteArray &function) const Q_DECL_OVERRIDE;
+
 public Q_SLOTS:
     void onAppFocusWindowChanged(QWindow *window);
 

src/plugins/platforms/cocoa/qcocoanativeinterface.mm

@@ -58,6 +58,8 @@
 #include <qpa/qplatformprintersupport.h>
 #endif
 
+#include <QtPlatformHeaders/qcocoawindowfunctions.h>
+
 #include <Cocoa/Cocoa.h>
 
 QT_BEGIN_NAMESPACE
@@ -217,6 +219,14 @@ void *QCocoaNativeInterface::nsOpenGLContextForContext(QOpenGLContext* context)
 }
 #endif
 
+QFunctionPointer QCocoaNativeInterface::platformFunction(const QByteArray &function) const
+{
+    if (function == QCocoaWindowFunctions::bottomLeftClippedByNSWindowOffsetIdentifier())
+        return QFunctionPointer(QCocoaWindowFunctions::BottomLeftClippedByNSWindowOffset(QCocoaWindow::bottomLeftClippedByNSWindowOffsetStatic));
+
+    return Q_NULLPTR;
+}
+
 void QCocoaNativeInterface::addToMimeList(void *macPasteboardMime)
 {
     qt_mac_addToGlobalMimeList(reinterpret_cast<QMacInternalPasteboardMime *>(macPasteboardMime));

src/plugins/platforms/cocoa/qcocoawindow.h

@@ -227,6 +227,9 @@ public:
     void updateExposedGeometry();
     QWindow *childWindowAt(QPoint windowPoint);
     bool shouldRefuseKeyWindowAndFirstResponder();
+
+    static QPoint bottomLeftClippedByNSWindowOffsetStatic(QWindow *window);
+    QPoint bottomLeftClippedByNSWindowOffset() const;
 protected:
     void recreateWindow(const QPlatformWindow *parentWindow);
     QCocoaNSWindow *createNSWindow();

src/plugins/platforms/cocoa/qcocoawindow.mm

@@ -1839,6 +1839,25 @@ bool QCocoaWindow::shouldRefuseKeyWindowAndFirstResponder()
     return false;
 }
 
+QPoint QCocoaWindow::bottomLeftClippedByNSWindowOffsetStatic(QWindow *window)
+{
+    if (window->handle())
+        return static_cast<QCocoaWindow *>(window->handle())->bottomLeftClippedByNSWindowOffset();
+    return QPoint();
+}
+
+QPoint QCocoaWindow::bottomLeftClippedByNSWindowOffset() const
+{
+    if (!m_contentView)
+        return QPoint();
+    NSPoint origin = [m_contentView isFlipped] ?
+                        NSMakePoint(0, [m_contentView frame].size.height) :
+                        NSMakePoint(0, 0);
+    NSPoint windowPoint = [m_contentView convertPoint:origin toView:nil];
+
+    return QPoint(-std::min((int)windowPoint.x, 0), -std::min((int)windowPoint.y,0));
+}
+
 QMargins QCocoaWindow::frameMargins() const
 {
     NSRect frameW = [m_nsWindow frame];