macOS: Move QMacCGContext helper into QtGui

The implementation was duplicated and spread out between QMacStyle,
QMacPaintEngine, and the Cocoa platform plugin.

Moving it into QtGui allows using it on other Apple platform.

Change-Id: Iadcbd71998204887e116271c575037789b6e2163
Reviewed-by: Jake Petroules <jake.petroules@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@theqtcompany.com>

12 files changed, 415 insertions, 541 deletions

diff --git a/src/gui/painting/painting.pri b/src/gui/painting/painting.pri
index c47060a2ad..a61865a0b6 100644
--- a/src/gui/painting/painting.pri
+++ b/src/gui/painting/painting.pri
@@ -99,6 +99,11 @@ SOURCES += \
         painting/qplatformbackingstore.cpp \
         painting/qpathsimplifier.cpp
 
+darwin {
+    HEADERS += painting/qcoregraphics_p.h
+    SOURCES += painting/qcoregraphics.mm
+}
+
 SSE2_SOURCES += painting/qdrawhelper_sse2.cpp
 SSSE3_SOURCES += painting/qdrawhelper_ssse3.cpp
 SSE4_1_SOURCES += painting/qdrawhelper_sse4.cpp \
diff --git a/src/gui/painting/qcoregraphics.mm b/src/gui/painting/qcoregraphics.mm
new file mode 100644
index 0000000000..fa5c9b61b2
--- /dev/null
+++ b/src/gui/painting/qcoregraphics.mm
@@ -0,0 +1,289 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the QtGui module 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qcoregraphics_p.h"
+
+#include <private/qcore_mac_p.h>
+#include <qpa/qplatformpixmap.h>
+
+#include <QtGui/private/qpaintengine_p.h>
+#include <QtCore/qdebug.h>
+#include <QtCore/qcoreapplication.h>
+
+QT_BEGIN_NAMESPACE
+
+
+// ---------------------- Color Management ----------------------
+
+static CGColorSpaceRef m_genericColorSpace = 0;
+static QHash<uint32_t, CGColorSpaceRef> m_displayColorSpaceHash;
+static bool m_postRoutineRegistered = false;
+
+static void qt_mac_cleanUpMacColorSpaces()
+{
+    if (m_genericColorSpace) {
+        CFRelease(m_genericColorSpace);
+        m_genericColorSpace = 0;
+    }
+    QHash<uint32_t, CGColorSpaceRef>::const_iterator it = m_displayColorSpaceHash.constBegin();
+    while (it != m_displayColorSpaceHash.constEnd()) {
+        if (it.value())
+            CFRelease(it.value());
+        ++it;
+    }
+    m_displayColorSpaceHash.clear();
+}
+
+static CGColorSpaceRef qt_mac_displayColorSpace(const QWindow *window)
+{
+    CGColorSpaceRef colorSpace = 0;
+    uint32_t displayID = 0;
+
+#ifdef Q_OS_MACOS
+    if (window == 0) {
+        displayID = CGMainDisplayID();
+    } else {
+        displayID = CGMainDisplayID();
+        /*
+        ### get correct display
+        const QRect &qrect = window->geometry();
+        CGRect rect = CGRectMake(qrect.x(), qrect.y(), qrect.width(), qrect.height());
+        CGDisplayCount throwAway;
+        CGDisplayErr dErr = CGGetDisplaysWithRect(rect, 1, &displayID, &throwAway);
+        if (dErr != kCGErrorSuccess)
+            return macDisplayColorSpace(0); // fall back on main display
+        */
+    }
+    if ((colorSpace = m_displayColorSpaceHash.value(displayID)))
+        return colorSpace;
+
+    colorSpace = CGDisplayCopyColorSpace(displayID);
+#else
+    Q_UNUSED(window);
+#endif
+
+    if (colorSpace == 0)
+        colorSpace = CGColorSpaceCreateDeviceRGB();
+
+    m_displayColorSpaceHash.insert(displayID, colorSpace);
+    if (!m_postRoutineRegistered) {
+        m_postRoutineRegistered = true;
+        qAddPostRoutine(qt_mac_cleanUpMacColorSpaces);
+    }
+    return colorSpace;
+}
+
+CGColorSpaceRef qt_mac_colorSpaceForDeviceType(const QPaintDevice *paintDevice)
+{
+    Q_UNUSED(paintDevice);
+
+    // FIXME: Move logic into each paint device once Qt has support for color spaces
+    return qt_mac_displayColorSpace(0);
+
+    // The following code seems to take care of QWidget, but in reality doesn't, as
+    // qt_mac_displayColorSpace ignores the argument and always uses the main display.
+#if 0
+    bool isWidget = (paintDevice->devType() == QInternal::Widget);
+    return qt_mac_displayColorSpace(isWidget ? static_cast<const QWidget *>(paintDevice)->window() : 0);
+#endif
+}
+
+CGColorSpaceRef qt_mac_genericColorSpace()
+{
+#if 0
+    if (!m_genericColorSpace) {
+        if (QSysInfo::MacintoshVersion >= QSysInfo::MV_10_4) {
+            m_genericColorSpace = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);
+        } else
+        {
+            m_genericColorSpace = CGColorSpaceCreateDeviceRGB();
+        }
+        if (!m_postRoutineRegistered) {
+            m_postRoutineRegistered = true;
+            qAddPostRoutine(QCoreGraphicsPaintEngine::cleanUpMacColorSpaces);
+        }
+    }
+    return m_genericColorSpace;
+#else
+    // Just return the main display colorspace for the moment.
+    return qt_mac_displayColorSpace(0);
+#endif
+}
+
+// ---------------------- Geometry Helpers ----------------------
+
+void qt_mac_clip_cg(CGContextRef hd, const QRegion &rgn, CGAffineTransform *orig_xform)
+{
+    CGAffineTransform old_xform = CGAffineTransformIdentity;
+    if (orig_xform) { //setup xforms
+        old_xform = CGContextGetCTM(hd);
+        CGContextConcatCTM(hd, CGAffineTransformInvert(old_xform));
+        CGContextConcatCTM(hd, *orig_xform);
+    }
+
+    //do the clipping
+    CGContextBeginPath(hd);
+    if (rgn.isEmpty()) {
+        CGContextAddRect(hd, CGRectMake(0, 0, 0, 0));
+    } else {
+        for (const QRect &r : rgn) {
+            CGRect mac_r = CGRectMake(r.x(), r.y(), r.width(), r.height());
+            CGContextAddRect(hd, mac_r);
+        }
+    }
+    CGContextClip(hd);
+
+    if (orig_xform) {//reset xforms
+        CGContextConcatCTM(hd, CGAffineTransformInvert(CGContextGetCTM(hd)));
+        CGContextConcatCTM(hd, old_xform);
+    }
+}
+
+// move to QRegion?
+void qt_mac_scale_region(QRegion *region, qreal scaleFactor)
+{
+    if (!region || !region->rectCount())
+        return;
+
+    QVector<QRect> scaledRects;
+    scaledRects.reserve(region->rectCount());
+
+    for (const QRect &rect : *region)
+        scaledRects.append(QRect(rect.topLeft() * scaleFactor, rect.size() * scaleFactor));
+
+    region->setRects(&scaledRects[0], scaledRects.count());
+}
+
+// ---------------------- QMacCGContext ----------------------
+
+QMacCGContext::QMacCGContext(QPaintDevice *paintDevice) : context(0)
+{
+    // In Qt 5, QWidget and QPixmap (and QImage) paint devices are all QImages under the hood.
+    QImage *image = 0;
+    if (paintDevice->devType() == QInternal::Image) {
+        image = static_cast<QImage *>(paintDevice);
+    } else if (paintDevice->devType() == QInternal::Pixmap) {
+
+        const QPixmap *pm = static_cast<const QPixmap*>(paintDevice);
+        QPlatformPixmap *data = const_cast<QPixmap *>(pm)->data_ptr().data();
+        if (data && data->classId() == QPlatformPixmap::RasterClass) {
+            image = data->buffer();
+        } else {
+            qDebug("QMacCGContext: Unsupported pixmap class");
+        }
+    } else if (paintDevice->devType() == QInternal::Widget) {
+        // TODO test: image = static_cast<QImage *>(static_cast<const QWidget *>(paintDevice)->backingStore()->paintDevice());
+        qDebug("QMacCGContext: not implemented: Widget class");
+    }
+
+    if (!image)
+        return; // Context type not supported.
+
+    CGColorSpaceRef colorspace = qt_mac_colorSpaceForDeviceType(paintDevice);
+    uint flags = kCGImageAlphaPremultipliedFirst;
+    flags |= kCGBitmapByteOrder32Host;
+
+    context = CGBitmapContextCreate(image->bits(), image->width(), image->height(),
+                                8, image->bytesPerLine(), colorspace, flags);
+    CGContextTranslateCTM(context, 0, image->height());
+    CGContextScaleCTM(context, 1, -1);
+}
+
+QMacCGContext::QMacCGContext(QPainter *painter) : context(0)
+{
+    QPaintEngine *paintEngine = painter->paintEngine();
+
+    // Handle the case of QMacPrintEngine, which has an internal QCoreGraphicsPaintEngine
+    while (QPaintEngine *aggregateEngine = QPaintEnginePrivate::get(paintEngine)->aggregateEngine())
+        paintEngine = aggregateEngine;
+
+    paintEngine->syncState();
+
+    if (Qt::HANDLE handle = QPaintEnginePrivate::get(paintEngine)->nativeHandle()) {
+        context = static_cast<CGContextRef>(handle);
+        return;
+    }
+
+    int devType = painter->device()->devType();
+    if (paintEngine->type() == QPaintEngine::Raster
+            && (devType == QInternal::Widget ||
+                devType == QInternal::Pixmap ||
+                devType == QInternal::Image)) {
+
+        CGColorSpaceRef colorspace = qt_mac_colorSpaceForDeviceType(paintEngine->paintDevice());
+        uint flags = kCGImageAlphaPremultipliedFirst;
+#ifdef kCGBitmapByteOrder32Host //only needed because CGImage.h added symbols in the minor version
+        flags |= kCGBitmapByteOrder32Host;
+#endif
+        const QImage *image = static_cast<const QImage *>(paintEngine->paintDevice());
+
+        context = CGBitmapContextCreate((void *)image->bits(), image->width(), image->height(),
+                                        8, image->bytesPerLine(), colorspace, flags);
+
+        // Invert y axis
+        CGContextTranslateCTM(context, 0, image->height());
+        CGContextScaleCTM(context, 1, -1);
+
+        const qreal devicePixelRatio = image->devicePixelRatio();
+
+        if (devType == QInternal::Widget) {
+            // Set the clip rect which is an intersection of the system clip
+            // and the painter clip. To make matters more interesting these
+            // are in device pixels and device-independent pixels, respectively.
+            QRegion clip = painter->paintEngine()->systemClip(); // get system clip in device pixels
+            QTransform native = painter->deviceTransform();      // get device transform. dx/dy is in device pixels
+
+            if (painter->hasClipping()) {
+                QRegion r = painter->clipRegion();               // get painter clip, which is in device-independent pixels
+                qt_mac_scale_region(&r, devicePixelRatio); // scale painter clip to device pixels
+                r.translate(native.dx(), native.dy());
+                if (clip.isEmpty())
+                    clip = r;
+                else
+                    clip &= r;
+            }
+            qt_mac_clip_cg(context, clip, 0); // clip in device pixels
+
+            // Scale the context so that painting happens in device-independent pixels
+            CGContextScaleCTM(context, devicePixelRatio, devicePixelRatio);
+            CGContextTranslateCTM(context, native.dx() / devicePixelRatio, native.dy() / devicePixelRatio);
+        } else {
+            // Scale to paint in device-independent pixels
+            CGContextScaleCTM(context, devicePixelRatio, devicePixelRatio);
+        }
+    } else {
+        qDebug() << "QMacCGContext:: Unsupported painter devtype type" << devType;
+    }
+}
+
+QT_END_NAMESPACE
diff --git a/src/gui/painting/qcoregraphics_p.h b/src/gui/painting/qcoregraphics_p.h
new file mode 100644
index 0000000000..b6ea5474ec
--- /dev/null
+++ b/src/gui/painting/qcoregraphics_p.h
@@ -0,0 +1,99 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the QtGui module 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 QCOREGRAPHICS_P_H
+#define QCOREGRAPHICS_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtGui/private/qtguiglobal_p.h>
+#include <QtGui/qregion.h>
+
+#include <CoreGraphics/CoreGraphics.h>
+
+QT_BEGIN_NAMESPACE
+
+Q_GUI_EXPORT CGColorSpaceRef qt_mac_genericColorSpace();
+Q_GUI_EXPORT CGColorSpaceRef qt_mac_colorSpaceForDeviceType(const QPaintDevice *paintDevice);
+
+Q_GUI_EXPORT void qt_mac_clip_cg(CGContextRef hd, const QRegion &rgn, CGAffineTransform *orig_xform);
+
+class Q_GUI_EXPORT QMacCGContext
+{
+public:
+    inline QMacCGContext() { context = 0; }
+    QMacCGContext(QPaintDevice *pdev);
+    QMacCGContext(QPainter *p);
+    inline QMacCGContext(CGContextRef cg, bool takeOwnership = false) {
+        context = cg;
+        if (!takeOwnership)
+            CGContextRetain(context);
+    }
+    inline QMacCGContext(const QMacCGContext &copy) : context(0) { *this = copy; }
+    inline ~QMacCGContext() {
+        if (context)
+            CGContextRelease(context);
+    }
+    inline bool isNull() const { return context; }
+    inline operator CGContextRef() { return context; }
+    inline QMacCGContext &operator=(const QMacCGContext &copy) {
+        if (context)
+            CGContextRelease(context);
+        context = copy.context;
+        CGContextRetain(context);
+        return *this;
+    }
+    inline QMacCGContext &operator=(CGContextRef cg) {
+        if (context)
+            CGContextRelease(context);
+        context = cg;
+        CGContextRetain(context); //we do not take ownership
+        return *this;
+    }
+
+private:
+    CGContextRef context;
+};
+
+QT_END_NAMESPACE
+
+#endif // QCOREGRAPHICS_P_H
diff --git a/src/gui/painting/qpaintengine_p.h b/src/gui/painting/qpaintengine_p.h
index 1a1df547bb..9d511f9bad 100644
--- a/src/gui/painting/qpaintengine_p.h
+++ b/src/gui/painting/qpaintengine_p.h
@@ -118,6 +118,11 @@ public:
     virtual void systemStateChanged() { }
 
     void drawBoxTextItem(const QPointF &p, const QTextItemInt &ti);
+
+    static QPaintEnginePrivate *get(QPaintEngine *paintEngine) { return paintEngine->d_func(); }
+
+    virtual QPaintEngine *aggregateEngine() { return 0; }
+    virtual Qt::HANDLE nativeHandle() { return 0; }
 };
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/cocoa/qcocoahelpers.h b/src/plugins/platforms/cocoa/qcocoahelpers.h
index 9b061bbae8..272b443b68 100644
--- a/src/plugins/platforms/cocoa/qcocoahelpers.h
+++ b/src/plugins/platforms/cocoa/qcocoahelpers.h
@@ -95,9 +95,6 @@ Qt::DropActions qt_mac_mapNSDragOperations(NSDragOperation nsActions);
 
 // Misc
 void qt_mac_transformProccessToForegroundApplication();
-CGColorSpaceRef qt_mac_genericColorSpace();
-CGColorSpaceRef qt_mac_displayColorSpace(const QWidget *widget);
-CGColorSpaceRef qt_mac_colorSpaceForDeviceType(const QPaintDevice *paintDevice);
 QString qt_mac_applicationName();
 
 int qt_mac_flipYCoordinate(int y);
@@ -143,8 +140,6 @@ public:
     }
 };
 
-CGContextRef qt_mac_cg_context(QPaintDevice *pdev);
-
 template<typename T>
 T qt_mac_resolveOption(const T &fallback, const QByteArray &environment)
 {
diff --git a/src/plugins/platforms/cocoa/qcocoahelpers.mm b/src/plugins/platforms/cocoa/qcocoahelpers.mm
index 6920f75887..21ffd8599f 100644
--- a/src/plugins/platforms/cocoa/qcocoahelpers.mm
+++ b/src/plugins/platforms/cocoa/qcocoahelpers.mm
@@ -47,6 +47,7 @@
 #include <qpa/qplatformscreen.h>
 #include <private/qguiapplication_p.h>
 #include <private/qwindow_p.h>
+#include <QtGui/private/qcoregraphics_p.h>
 
 #ifndef QT_NO_WIDGETS
 #include <QtWidgets/QWidget>
@@ -402,97 +403,6 @@ void qt_mac_transformProccessToForegroundApplication()
         [[NSApplication sharedApplication] setActivationPolicy:NSApplicationActivationPolicyRegular];
     }
 }
-static CGColorSpaceRef m_genericColorSpace = 0;
-static QHash<CGDirectDisplayID, CGColorSpaceRef> m_displayColorSpaceHash;
-static bool m_postRoutineRegistered = false;
-
-CGColorSpaceRef qt_mac_genericColorSpace()
-{
-#if 0
-    if (!m_genericColorSpace) {
-        if (QSysInfo::MacintoshVersion >= QSysInfo::MV_10_4) {
-            m_genericColorSpace = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);
-        } else
-        {
-            m_genericColorSpace = CGColorSpaceCreateDeviceRGB();
-        }
-        if (!m_postRoutineRegistered) {
-            m_postRoutineRegistered = true;
-            qAddPostRoutine(QCoreGraphicsPaintEngine::cleanUpMacColorSpaces);
-        }
-    }
-    return m_genericColorSpace;
-#else
-    // Just return the main display colorspace for the moment.
-    return qt_mac_displayColorSpace(0);
-#endif
-}
-
-/*
-    Ideally, we should pass the widget in here, and use CGGetDisplaysWithRect() etc.
-    to support multiple displays correctly.
-*/
-CGColorSpaceRef qt_mac_displayColorSpace(const QWidget *widget)
-{
-    CGColorSpaceRef colorSpace;
-
-    CGDirectDisplayID displayID;
-    if (widget == 0) {
-        displayID = CGMainDisplayID();
-    } else {
-        displayID = CGMainDisplayID();
-        /*
-        ### get correct display
-        const QRect &qrect = widget->window()->geometry();
-        CGRect rect = CGRectMake(qrect.x(), qrect.y(), qrect.width(), qrect.height());
-        CGDisplayCount throwAway;
-        CGDisplayErr dErr = CGGetDisplaysWithRect(rect, 1, &displayID, &throwAway);
-        if (dErr != kCGErrorSuccess)
-            return macDisplayColorSpace(0); // fall back on main display
-        */
-    }
-    if ((colorSpace = m_displayColorSpaceHash.value(displayID)))
-        return colorSpace;
-
-    colorSpace = CGDisplayCopyColorSpace(displayID);
-    if (colorSpace == 0)
-        colorSpace = CGColorSpaceCreateDeviceRGB();
-
-    m_displayColorSpaceHash.insert(displayID, colorSpace);
-    if (!m_postRoutineRegistered) {
-        m_postRoutineRegistered = true;
-        void qt_mac_cleanUpMacColorSpaces();
-        qAddPostRoutine(qt_mac_cleanUpMacColorSpaces);
-    }
-    return colorSpace;
-}
-
-void qt_mac_cleanUpMacColorSpaces()
-{
-    if (m_genericColorSpace) {
-        CFRelease(m_genericColorSpace);
-        m_genericColorSpace = 0;
-    }
-    QHash<CGDirectDisplayID, CGColorSpaceRef>::const_iterator it = m_displayColorSpaceHash.constBegin();
-    while (it != m_displayColorSpaceHash.constEnd()) {
-        if (it.value())
-            CFRelease(it.value());
-        ++it;
-    }
-    m_displayColorSpaceHash.clear();
-}
-
-CGColorSpaceRef qt_mac_colorSpaceForDeviceType(const QPaintDevice *paintDevice)
-{
-#ifdef QT_NO_WIDGETS
-    Q_UNUSED(paintDevice)
-    return qt_mac_displayColorSpace(0);
-#else
-    bool isWidget = (paintDevice->devType() == QInternal::Widget);
-    return qt_mac_displayColorSpace(isWidget ? static_cast<const QWidget *>(paintDevice): 0);
-#endif
-
-}
 
 QString qt_mac_applicationName()
 {
@@ -599,49 +509,6 @@ QString qt_mac_removeAmpersandEscapes(QString s)
     return QPlatformTheme::removeMnemonics(s).trimmed();
 }
 
-/*! \internal
-
- Returns the CoreGraphics CGContextRef of the paint device. 0 is
- returned if it can't be obtained. It is the caller's responsibility to
- CGContextRelease the context when finished using it.
-
- \warning This function is only available on \macos.
- \warning This function is duplicated in qmacstyle_mac.mm
- */
-CGContextRef qt_mac_cg_context(QPaintDevice *pdev)
-{
-    // In Qt 5, QWidget and QPixmap (and QImage) paint devices are all QImages under the hood.
-    QImage *image = 0;
-    if (pdev->devType() == QInternal::Image) {
-        image = static_cast<QImage *>(pdev);
-    } else if (pdev->devType() == QInternal::Pixmap) {
-
-        const QPixmap *pm = static_cast<const QPixmap*>(pdev);
-        QPlatformPixmap *data = const_cast<QPixmap *>(pm)->data_ptr().data();
-        if (data && data->classId() == QPlatformPixmap::RasterClass) {
-            image = data->buffer();
-        } else {
-            qDebug("qt_mac_cg_context: Unsupported pixmap class");
-        }
-    } else if (pdev->devType() == QInternal::Widget) {
-        // TODO test: image = static_cast<QImage *>(static_cast<const QWidget *>(pdev)->backingStore()->paintDevice());
-        qDebug("qt_mac_cg_context: not implemented: Widget class");
-    }
-
-    if (!image)
-        return 0; // Context type not supported.
-
-    CGColorSpaceRef colorspace = qt_mac_colorSpaceForDeviceType(pdev);
-    uint flags = kCGImageAlphaPremultipliedFirst;
-    flags |= kCGBitmapByteOrder32Host;
-    CGContextRef ret = 0;
-    ret = CGBitmapContextCreate(image->bits(), image->width(), image->height(),
-                                8, image->bytesPerLine(), colorspace, flags);
-    CGContextTranslateCTM(ret, 0, image->height());
-    CGContextScaleCTM(ret, 1, -1);
-    return ret;
-}
-
 QPixmap qt_mac_toQPixmap(const NSImage *image, const QSizeF &size)
 {
     const NSSize pixmapSize = NSMakeSize(size.width(), size.height());
@@ -669,9 +536,8 @@ QImage qt_mac_toQImage(CGImageRef image)
     QImage ret(w, h, QImage::Format_ARGB32_Premultiplied);
     ret.fill(Qt::transparent);
     CGRect rect = CGRectMake(0, 0, w, h);
-    CGContextRef ctx = qt_mac_cg_context(&ret);
+    QMacCGContext ctx(&ret);
     qt_mac_drawCGImage(ctx, &rect, image);
-    CGContextRelease(ctx);
     return ret;
 }
 
diff --git a/src/plugins/platforms/cocoa/qcocoaintegration.mm b/src/plugins/platforms/cocoa/qcocoaintegration.mm
index 1793bd404e..f3f720654e 100644
--- a/src/plugins/platforms/cocoa/qcocoaintegration.mm
+++ b/src/plugins/platforms/cocoa/qcocoaintegration.mm
@@ -58,6 +58,8 @@
 #include <qpa/qplatforminputcontextfactory_p.h>
 #include <QtCore/qcoreapplication.h>
 
+#include <QtGui/private/qcoregraphics_p.h>
+
 #include <IOKit/graphics/IOGraphicsLib.h>
 
 static void initResources()
@@ -199,8 +201,6 @@ QWindow *QCocoaScreen::topLevelAt(const QPoint &point) const
     return window;
 }
 
-extern CGContextRef qt_mac_cg_context(const QPaintDevice *pdev);
-
 QPixmap QCocoaScreen::grabWindow(WId window, int x, int y, int width, int height) const
 {
     // TODO window should be handled
@@ -251,9 +251,8 @@ QPixmap QCocoaScreen::grabWindow(WId window, int x, int y, int width, int height
         QPixmap pix(w, h);
         pix.fill(Qt::transparent);
         CGRect rect = CGRectMake(0, 0, w, h);
-        CGContextRef ctx = qt_mac_cg_context(&pix);
+        QMacCGContext ctx(&pix);
         qt_mac_drawCGImage(ctx, &rect, image);
-        CGContextRelease(ctx);
 
         QPainter painter(&windowPixmap);
         painter.drawPixmap(0, 0, pix);
diff --git a/src/plugins/platforms/cocoa/qcocoatheme.mm b/src/plugins/platforms/cocoa/qcocoatheme.mm
index 95175871a4..d0879ed457 100644
--- a/src/plugins/platforms/cocoa/qcocoatheme.mm
+++ b/src/plugins/platforms/cocoa/qcocoatheme.mm
@@ -56,6 +56,7 @@
 
 #include <QtCore/qfileinfo.h>
 #include <QtGui/private/qguiapplication_p.h>
+#include <QtGui/private/qcoregraphics_p.h>
 #include <QtGui/qpainter.h>
 #include <QtPlatformSupport/private/qcoretextfontdatabase_p.h>
 #include <QtPlatformSupport/private/qabstractfileiconengine_p.h>
@@ -197,7 +198,7 @@ QPixmap qt_mac_convert_iconref(const IconRef icon, int width, int height)
 
     CGRect rect = CGRectMake(0, 0, width, height);
 
-    CGContextRef ctx = qt_mac_cg_context(&ret);
+    QMacCGContext ctx(&ret);
     CGAffineTransform old_xform = CGContextGetCTM(ctx);
     CGContextConcatCTM(ctx, CGAffineTransformInvert(old_xform));
     CGContextConcatCTM(ctx, CGAffineTransformIdentity);
@@ -205,7 +206,6 @@ QPixmap qt_mac_convert_iconref(const IconRef icon, int width, int height)
     ::RGBColor b;
     b.blue = b.green = b.red = 255*255;
     PlotIconRefInContext(ctx, &rect, kAlignNone, kTransformNone, &b, kPlotIconRefNormalFlags, icon);
-    CGContextRelease(ctx);
     return ret;
 }
 
diff --git a/src/plugins/platforms/cocoa/qpaintengine_mac.mm b/src/plugins/platforms/cocoa/qpaintengine_mac.mm
index 759c4d26a5..7e241e3ae6 100644
--- a/src/plugins/platforms/cocoa/qpaintengine_mac.mm
+++ b/src/plugins/platforms/cocoa/qpaintengine_mac.mm
@@ -63,6 +63,7 @@
 #include <private/qpainter_p.h>
 #include <private/qpainterpath_p.h>
 #include <private/qtextengine_p.h>
+#include <private/qcoregraphics_p.h>
 
 #include "qcocoahelpers.h"
 
@@ -74,84 +75,6 @@ QT_BEGIN_NAMESPACE
   QCoreGraphicsPaintEngine utility functions
  *****************************************************************************/
 
-static void qt_mac_clip_cg(CGContextRef hd, const QRegion &rgn, CGAffineTransform *orig_xform)
-{
-    CGAffineTransform old_xform = CGAffineTransformIdentity;
-    if (orig_xform) { //setup xforms
-        old_xform = CGContextGetCTM(hd);
-        CGContextConcatCTM(hd, CGAffineTransformInvert(old_xform));
-        CGContextConcatCTM(hd, *orig_xform);
-    }
-
-    //do the clipping
-    CGContextBeginPath(hd);
-    if (rgn.isEmpty()) {
-        CGContextAddRect(hd, CGRectMake(0, 0, 0, 0));
-    } else {
-        for (const QRect &r : rgn) {
-            CGRect mac_r = CGRectMake(r.x(), r.y(), r.width(), r.height());
-            CGContextAddRect(hd, mac_r);
-        }
-    }
-    CGContextClip(hd);
-
-    if (orig_xform) {//reset xforms
-        CGContextConcatCTM(hd, CGAffineTransformInvert(CGContextGetCTM(hd)));
-        CGContextConcatCTM(hd, old_xform);
-    }
-}
-
-// Implemented for qt_mac_p.h
-QMacCGContext::QMacCGContext(QPainter *p)
-{
-    QPaintEngine *pe = p->paintEngine();
-#ifndef QT_NO_PRINTER
-    if (pe->type() == QPaintEngine::MacPrinter)
-        pe = static_cast<QMacPrintEngine*>(pe)->paintEngine();
-#endif
-    pe->syncState();
-    context = 0;
-    if (pe->type() == QPaintEngine::CoreGraphics)
-        context = static_cast<QCoreGraphicsPaintEngine*>(pe)->handle();
-
-    int devType = p->device()->devType();
-    if (pe->type() == QPaintEngine::Raster
-            && (devType == QInternal::Widget || devType == QInternal::Pixmap || devType == QInternal::Image)) {
-
-        CGColorSpaceRef colorspace = qt_mac_colorSpaceForDeviceType(pe->paintDevice());
-        uint flags = kCGImageAlphaPremultipliedFirst;
-#ifdef kCGBitmapByteOrder32Host //only needed because CGImage.h added symbols in the minor version
-        flags |= kCGBitmapByteOrder32Host;
-#endif
-        const QImage *image = (const QImage *) pe->paintDevice();
-
-        context = CGBitmapContextCreate((void *) image->bits(), image->width(), image->height(),
-                                        8, image->bytesPerLine(), colorspace, flags);
-
-        CGContextTranslateCTM(context, 0, image->height());
-        CGContextScaleCTM(context, 1, -1);
-
-        if (devType == QInternal::Widget) {
-            QRegion clip = p->paintEngine()->systemClip();
-            QTransform native = p->deviceTransform();
-
-            if (p->hasClipping()) {
-                QRegion r = p->clipRegion();
-                r.translate(native.dx(), native.dy());
-                if (clip.isEmpty())
-                    clip = r;
-                else
-                    clip &= r;
-            }
-            qt_mac_clip_cg(context, clip, 0);
-
-            CGContextTranslateCTM(context, native.dx(), native.dy());
-        }
-    } else {
-        CGContextRetain(context);
-    }
-}
-
 void qt_mac_cgimage_data_free(void *, const void *memoryToFree, size_t)
 {
     free(const_cast<void *>(memoryToFree));
@@ -453,7 +376,7 @@ static void qt_mac_draw_pattern(void *info, CGContextRef c)
             const QColor c0(0, 0, 0, 0), c1(255, 255, 255, 255);
             QPixmap pm(w*QMACPATTERN_MASK_MULTIPLIER, h*QMACPATTERN_MASK_MULTIPLIER);
             pm.fill(c0);
-            CGContextRef pm_ctx = qt_mac_cg_context(&pm);
+            QMacCGContext pm_ctx(&pm);
             CGContextSetFillColorWithColor(c, cgColorForQColor(c1, pat->pdev));
             CGRect rect = CGRectMake(0, 0, w, h);
             for (int x = 0; x < QMACPATTERN_MASK_MULTIPLIER; ++x) {
@@ -543,7 +466,8 @@ QCoreGraphicsPaintEngine::begin(QPaintDevice *pdev)
     d->cosmeticPenSize = 1;
     d->current.clipEnabled = false;
     d->pixelSize = QPoint(1,1);
-    d->hd = qt_mac_cg_context(pdev);
+    QMacCGContext ctx(pdev);
+    d->hd = CGContextRetain(ctx);
     if (d->hd) {
         d->saveGraphicsState();
         d->orig_xform = CGContextGetCTM(d->hd);
diff --git a/src/plugins/platforms/cocoa/qprintengine_mac_p.h b/src/plugins/platforms/cocoa/qprintengine_mac_p.h
index e3cad3fd57..ee98275b63 100644
--- a/src/plugins/platforms/cocoa/qprintengine_mac_p.h
+++ b/src/plugins/platforms/cocoa/qprintengine_mac_p.h
@@ -149,6 +149,9 @@ public:
     PMPageFormat format() const { return static_cast<PMPageFormat>([printInfo PMPageFormat]); }
     PMPrintSession session() const { return static_cast<PMPrintSession>([printInfo PMPrintSession]); }
     PMPrintSettings settings() const { return static_cast<PMPrintSettings>([printInfo PMPrintSettings]); }
+
+    QPaintEngine *aggregateEngine() Q_DECL_OVERRIDE { return paintEngine; }
+    Qt::HANDLE nativeHandle() Q_DECL_OVERRIDE { return q_func()->handle(); }
 };
 
 QT_END_NAMESPACE
diff --git a/src/plugins/platforms/cocoa/qt_mac_p.h b/src/plugins/platforms/cocoa/qt_mac_p.h
index 902cf5c636..ce17919e8c 100644
--- a/src/plugins/platforms/cocoa/qt_mac_p.h
+++ b/src/plugins/platforms/cocoa/qt_mac_p.h
@@ -90,44 +90,6 @@ public:
     }
 };
 
-class QMacCGContext
-{
-    CGContextRef context;
-public:
-    QMacCGContext(QPainter *p); //qpaintengine_mac.mm
-    inline QMacCGContext() { context = 0; }
-    inline QMacCGContext(QPaintDevice *pdev) {
-        extern CGContextRef qt_mac_cg_context(QPaintDevice *);
-        context = qt_mac_cg_context(pdev);
-    }
-    inline QMacCGContext(CGContextRef cg, bool takeOwnership=false) {
-        context = cg;
-        if(!takeOwnership)
-            CGContextRetain(context);
-    }
-    inline QMacCGContext(const QMacCGContext &copy) : context(0) { *this = copy; }
-    inline ~QMacCGContext() {
-        if(context)
-            CGContextRelease(context);
-    }
-    inline bool isNull() const { return context; }
-    inline operator CGContextRef() { return context; }
-    inline QMacCGContext &operator=(const QMacCGContext &copy) {
-        if(context)
-            CGContextRelease(context);
-        context = copy.context;
-        CGContextRetain(context);
-        return *this;
-    }
-    inline QMacCGContext &operator=(CGContextRef cg) {
-        if(context)
-            CGContextRelease(context);
-        context = cg;
-        CGContextRetain(context); //we do not take ownership
-        return *this;
-    }
-};
-
 class QMacInternalPasteboardMime;
 class QMimeData;
 
diff --git a/src/widgets/styles/qmacstyle_mac.mm b/src/widgets/styles/qmacstyle_mac.mm
index 6aa5845a2c..1f17810fc9 100644
--- a/src/widgets/styles/qmacstyle_mac.mm
+++ b/src/widgets/styles/qmacstyle_mac.mm
@@ -96,6 +96,7 @@
 #include <private/qstyleanimation_p.h>
 #include <qpa/qplatformfontdatabase.h>
 #include <qpa/qplatformtheme.h>
+#include <QtGui/private/qcoregraphics_p.h>
 
 QT_USE_NAMESPACE
 
@@ -520,47 +521,6 @@ static QString qt_mac_removeMnemonics(const QString &original)
     return returnText;
 }
 
-static CGContextRef qt_mac_cg_context(const QPaintDevice *pdev);
-
-namespace {
-class QMacCGContext
-{
-    CGContextRef context;
-public:
-    QMacCGContext(QPainter *p);
-    inline QMacCGContext() { context = 0; }
-    inline QMacCGContext(const QPaintDevice *pdev) {
-        context = qt_mac_cg_context(pdev);
-    }
-    inline QMacCGContext(CGContextRef cg, bool takeOwnership=false) {
-        context = cg;
-        if (!takeOwnership)
-            CGContextRetain(context);
-    }
-    inline QMacCGContext(const QMacCGContext &copy) : context(0) { *this = copy; }
-    inline ~QMacCGContext() {
-        if (context)
-            CGContextRelease(context);
-    }
-    inline bool isNull() const { return context; }
-    inline operator CGContextRef() { return context; }
-    inline QMacCGContext &operator=(const QMacCGContext &copy) {
-        if (context)
-            CGContextRelease(context);
-        context = copy.context;
-        CGContextRetain(context);
-        return *this;
-    }
-    inline QMacCGContext &operator=(CGContextRef cg) {
-        if (context)
-            CGContextRelease(context);
-        context = cg;
-        CGContextRetain(context); //we do not take ownership
-        return *this;
-    }
-};
-} // anonymous namespace
-
 OSStatus qt_mac_shape2QRegionHelper(int inMessage, HIShapeRef, const CGRect *inRect, void *inRefcon)
 {
     QRegion *region = static_cast<QRegion *>(inRefcon);
@@ -581,7 +541,6 @@ OSStatus qt_mac_shape2QRegionHelper(int inMessage, HIShapeRef, const CGRect *inR
     return noErr;
 }
 
-
 /*!
     \internal
      Create's a mutable shape, it's the caller's responsibility to release.
@@ -611,86 +570,6 @@ QRegion qt_mac_fromHIShapeRef(HIShapeRef shape)
     return returnRegion;
 }
 
-CGColorSpaceRef m_genericColorSpace = 0;
-static QHash<CGDirectDisplayID, CGColorSpaceRef> m_displayColorSpaceHash;
-bool m_postRoutineRegistered = false;
-
-static CGColorSpaceRef qt_mac_displayColorSpace(const QWidget *widget);
-static CGColorSpaceRef qt_mac_genericColorSpace()
-{
-#if 0
-    if (!m_genericColorSpace) {
-        if (QSysInfo::MacintoshVersion >= QSysInfo::MV_10_4) {
-            m_genericColorSpace = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);
-        } else
-        {
-            m_genericColorSpace = CGColorSpaceCreateDeviceRGB();
-        }
-        if (!m_postRoutineRegistered) {
-            m_postRoutineRegistered = true;
-            qAddPostRoutine(QCoreGraphicsPaintEngine::cleanUpMacColorSpaces);
-        }
-    }
-    return m_genericColorSpace;
-#else
-    // Just return the main display colorspace for the moment.
-    return qt_mac_displayColorSpace(0);
-#endif
-}
-
-static void qt_mac_cleanUpMacColorSpaces()
-{
-    if (m_genericColorSpace) {
-        CFRelease(m_genericColorSpace);
-        m_genericColorSpace = 0;
-    }
-    QHash<CGDirectDisplayID, CGColorSpaceRef>::const_iterator it = m_displayColorSpaceHash.constBegin();
-    while (it != m_displayColorSpaceHash.constEnd()) {
-        if (it.value())
-            CFRelease(it.value());
-        ++it;
-    }
-    m_displayColorSpaceHash.clear();
-}
-
-/*
-    Ideally, we should pass the widget in here, and use CGGetDisplaysWithRect() etc.
-    to support multiple displays correctly.
-*/
-static CGColorSpaceRef qt_mac_displayColorSpace(const QWidget *widget)
-{
-    CGColorSpaceRef colorSpace;
-
-    CGDirectDisplayID displayID;
-    if (widget == 0) {
-        displayID = CGMainDisplayID();
-    } else {
-        displayID = CGMainDisplayID();
-        /*
-        ### get correct display
-        const QRect &qrect = widget->window()->geometry();
-        CGRect rect = CGRectMake(qrect.x(), qrect.y(), qrect.width(), qrect.height());
-        CGDisplayCount throwAway;
-        CGDisplayErr dErr = CGGetDisplaysWithRect(rect, 1, &displayID, &throwAway);
-        if (dErr != kCGErrorSuccess)
-            return macDisplayColorSpace(0); // fall back on main display
-        */
-    }
-    if ((colorSpace = m_displayColorSpaceHash.value(displayID)))
-        return colorSpace;
-
-    colorSpace = CGDisplayCopyColorSpace(displayID);
-    if (colorSpace == 0)
-        colorSpace = CGColorSpaceCreateDeviceRGB();
-
-    m_displayColorSpaceHash.insert(displayID, colorSpace);
-    if (!m_postRoutineRegistered) {
-        m_postRoutineRegistered = true;
-        qAddPostRoutine(qt_mac_cleanUpMacColorSpaces);
-    }
-    return colorSpace;
-}
-
 bool qt_macWindowIsTextured(const QWidget *window)
 {
     if (QWindow *w = window->windowHandle())
@@ -2283,7 +2162,7 @@ void qt_mac_fill_background(QPainter *painter, const QRegion &rgn, const QBrush
 
         painter->setClipRegion(rgn);
 
-        QCFType<CGContextRef> cg = qt_mac_cg_context(target);
+        QMacCGContext cg(target);
         CGContextSaveGState(cg);
         HIThemeSetFill(kThemeBrushDialogBackgroundActive, 0, cg, kHIThemeOrientationInverted);
 
@@ -2357,7 +2236,7 @@ void QMacStyle::polish(QWidget* w)
             mtinfo.menuType = kThemeMenuTypePopUp;
             // HIRect rect = CGRectMake(0, 0, px.width(), px.height());
             // ###
-            //HIThemeDrawMenuBackground(&rect, &mtinfo, QCFType<CGContextRef>(qt_mac_cg_context(&px)),
+            //HIThemeDrawMenuBackground(&rect, &mtinfo, QMacCGContext(&px)),
             //                          kHIThemeOrientationNormal);
             QPalette pal = w->palette();
             QBrush background(px);
@@ -7187,158 +7066,6 @@ int QMacStyle::layoutSpacing(QSizePolicy::ControlType control1,
     return_SIZE(10, 8, 6);  // guess
 }
 
-static void qt_mac_clip_cg(CGContextRef hd, const QRegion &rgn, CGAffineTransform *orig_xform)
-{
-    CGAffineTransform old_xform = CGAffineTransformIdentity;
-    if (orig_xform) { //setup xforms
-        old_xform = CGContextGetCTM(hd);
-        CGContextConcatCTM(hd, CGAffineTransformInvert(old_xform));
-        CGContextConcatCTM(hd, *orig_xform);
-    }
-
-    //do the clipping
-    CGContextBeginPath(hd);
-    if (rgn.isEmpty()) {
-        CGContextAddRect(hd, CGRectMake(0, 0, 0, 0));
-    } else {
-        QCFType<HIMutableShapeRef> shape = qt_mac_toHIMutableShape(rgn);
-        Q_ASSERT(!HIShapeIsEmpty(shape));
-        HIShapeReplacePathInCGContext(shape, hd);
-    }
-    CGContextClip(hd);
-
-    if (orig_xform) {//reset xforms
-        CGContextConcatCTM(hd, CGAffineTransformInvert(CGContextGetCTM(hd)));
-        CGContextConcatCTM(hd, old_xform);
-    }
-}
-
-// move to QRegion?
-void qt_mac_scale_region(QRegion *region, qreal scaleFactor)
-{
-    if (!region || !region->rectCount())
-        return;
-
-    QVector<QRect> scaledRects;
-    scaledRects.reserve(region->rectCount());
-
-    for (const QRect &rect : *region)
-        scaledRects.append(QRect(rect.topLeft() * scaleFactor, rect.size() * scaleFactor));
-
-    region->setRects(&scaledRects[0], scaledRects.count());
-}
-
-static CGColorSpaceRef qt_mac_colorSpaceForDeviceType(const QPaintDevice *paintDevice);
-
-namespace {
-QMacCGContext::QMacCGContext(QPainter *p)
-{
-    QPaintEngine *pe = p->paintEngine();
-    pe->syncState();
-    context = 0;
-
-    int devType = p->device()->devType();
-    if (pe->type() == QPaintEngine::Raster
-            && (devType == QInternal::Widget ||
-                devType == QInternal::Pixmap ||
-                devType == QInternal::Image)) {
-
-        CGColorSpaceRef colorspace = qt_mac_colorSpaceForDeviceType(pe->paintDevice());
-        uint flags = kCGImageAlphaPremultipliedFirst;
-        flags |= kCGBitmapByteOrder32Host;
-
-        const QImage *image = (const QImage *) pe->paintDevice();
-
-        context = CGBitmapContextCreate((void *) image->bits(), image->width(), image->height(),
-                                        8, image->bytesPerLine(), colorspace, flags);
-
-        // Invert y axis.
-        CGContextTranslateCTM(context, 0, image->height());
-        CGContextScaleCTM(context, 1, -1);
-
-        const qreal devicePixelRatio = image->devicePixelRatio();
-
-        if (devType == QInternal::Widget) {
-            // Set the clip rect which is an intersection of the system clip
-            // and the painter clip. To make matters more interesting these
-            // are in device pixels and device-independent pixels, respectively.
-            QRegion clip = p->paintEngine()->systemClip(); // get system clip in device pixels
-            QTransform native = p->deviceTransform();      // get device transform. dx/dy is in device pixels
-
-            if (p->hasClipping()) {
-                QRegion r = p->clipRegion();               // get painter clip, which is in device-independent pixels
-                qt_mac_scale_region(&r, devicePixelRatio); // scale painter clip to device pixels
-                r.translate(native.dx(), native.dy());
-                if (clip.isEmpty())
-                    clip = r;
-                else
-                    clip &= r;
-            }
-            qt_mac_clip_cg(context, clip, 0); // clip in device pixels
-
-            // Scale the context so that painting happens in device-independet pixels.
-            CGContextScaleCTM(context, devicePixelRatio, devicePixelRatio);
-            CGContextTranslateCTM(context, native.dx() / devicePixelRatio, native.dy() / devicePixelRatio);
-        } else {
-            // Scale to paint in device-independent pixels.
-            CGContextScaleCTM(context, devicePixelRatio, devicePixelRatio);
-        }
-    } else {
-        qDebug() << "QMacCGContext:: Unsupported painter devtype type" << devType;
-    }
-}
-
-} // anonymous namespace
-
-static CGColorSpaceRef qt_mac_colorSpaceForDeviceType(const QPaintDevice *paintDevice)
-{
-    bool isWidget = (paintDevice->devType() == QInternal::Widget);
-    return qt_mac_displayColorSpace(isWidget ? static_cast<const QWidget *>(paintDevice) : 0);
-}
-
-/*! \internal
-
-    Returns the CoreGraphics CGContextRef of the paint device. 0 is
-    returned if it can't be obtained. It is the caller's responsibility to
-    CGContextRelease the context when finished using it.
-
-    \warning This function is only available on \macos.
-    \warning This function is duplicated in the Cocoa platform plugin.
-*/
-
-CGContextRef qt_mac_cg_context(const QPaintDevice *pdev)
-{
-    if (pdev->devType() == QInternal::Pixmap) {
-        const QPixmap *pm = static_cast<const QPixmap*>(pdev);
-        CGColorSpaceRef colorspace = qt_mac_colorSpaceForDeviceType(pdev);
-        uint flags = kCGImageAlphaPremultipliedFirst;
-        flags |= kCGBitmapByteOrder32Host;
-        CGContextRef ret = 0;
-
-        QPlatformPixmap *data = const_cast<QPixmap *>(pm)->data_ptr().data();
-        if (data->classId() == QPlatformPixmap::RasterClass) {
-            QImage *image = data->buffer();
-            ret = CGBitmapContextCreate(image->bits(), image->width(), image->height(),
-                                        8, image->bytesPerLine(), colorspace, flags);
-        } else {
-            qDebug("qt_mac_cg_context: Unsupported pixmap class");
-        }
-
-        CGContextTranslateCTM(ret, 0, pm->height());
-        qreal devicePixelRatio = pdev->devicePixelRatioF();
-        CGContextScaleCTM(ret, devicePixelRatio, devicePixelRatio);
-        CGContextScaleCTM(ret, 1, -1);
-        return ret;
-    } else if (pdev->devType() == QInternal::Widget) {
-        //CGContextRef ret = static_cast<CGContextRef>(static_cast<const QWidget *>(pdev)->macCGHandle());
-        ///CGContextRetain(ret);
-        //return ret;
-        qDebug("qt_mac_cg_context: not implemented: Widget class");
-        return 0;
-    }
-    return 0;
-}
-
 /*
 FontHash::FontHash()
 {