macOS: Share code for resolving CGImage bitmapInfor for a QImage

Removes assumptions about QImage format in a few places.

Change-Id: I515701be53190429a48956c31986fa0804806406
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>

2 files changed, 35 insertions, 15 deletions

diff --git a/src/gui/painting/qcoregraphics.mm b/src/gui/painting/qcoregraphics.mm
index d45da14767..53066687d3 100644
--- a/src/gui/painting/qcoregraphics.mm
+++ b/src/gui/painting/qcoregraphics.mm
@@ -51,6 +51,33 @@ QT_BEGIN_NAMESPACE
 
 // ---------------------- Images ----------------------
 
+CGBitmapInfo qt_mac_bitmapInfoForImage(const QImage &image)
+{
+    CGBitmapInfo bitmapInfo = kCGImageAlphaNone;
+    switch (image.format()) {
+    case QImage::Format_ARGB32:
+        bitmapInfo = kCGImageAlphaFirst | kCGBitmapByteOrder32Host;
+        break;
+    case QImage::Format_RGB32:
+        bitmapInfo = kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Host;
+        break;
+    case QImage::Format_RGBA8888_Premultiplied:
+        bitmapInfo = kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big;
+        break;
+    case QImage::Format_RGBA8888:
+        bitmapInfo = kCGImageAlphaLast | kCGBitmapByteOrder32Big;
+        break;
+    case QImage::Format_RGBX8888:
+        bitmapInfo = kCGImageAlphaNoneSkipLast | kCGBitmapByteOrder32Big;
+        break;
+    case QImage::Format_ARGB32_Premultiplied:
+        bitmapInfo = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Host;
+        break;
+    default: break;
+    }
+    return bitmapInfo;
+}
+
 CGImageRef qt_mac_toCGImage(const QImage &inImage)
 {
     CGImageRef cgImage = inImage.toCGImage();
@@ -362,13 +389,10 @@ QMacCGContext::QMacCGContext(QPaintDevice *paintDevice) : context(0)
     if (!image)
         return; // Context type not supported.
 
-    CGColorSpaceRef colorSpace = CGColorSpaceCreateWithName(kCGColorSpaceSRGB);
-    uint flags = kCGImageAlphaPremultipliedFirst;
-    flags |= kCGBitmapByteOrder32Host;
+    QCFType<CGColorSpaceRef> colorSpace = CGColorSpaceCreateWithName(kCGColorSpaceSRGB);
+    context = CGBitmapContextCreate(image->bits(), image->width(), image->height(), 8,
+                                image->bytesPerLine(), colorSpace, qt_mac_bitmapInfoForImage(*image));
 
-    context = CGBitmapContextCreate(image->bits(), image->width(), image->height(),
-                                8, image->bytesPerLine(), colorSpace, flags);
-    CFRelease(colorSpace);
     CGContextTranslateCTM(context, 0, image->height());
     const qreal devicePixelRatio = paintDevice->devicePixelRatioF();
     CGContextScaleCTM(context, devicePixelRatio, devicePixelRatio);
@@ -396,16 +420,10 @@ QMacCGContext::QMacCGContext(QPainter *painter) : context(0)
                 devType == QInternal::Pixmap ||
                 devType == QInternal::Image)) {
 
-        CGColorSpaceRef colorSpace = CGColorSpaceCreateWithName(kCGColorSpaceSRGB);
-        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);
-        CFRelease(colorSpace);
+        QCFType<CGColorSpaceRef> colorSpace = CGColorSpaceCreateWithName(kCGColorSpaceSRGB);
+        context = CGBitmapContextCreate((void *)image->bits(), image->width(), image->height(), 8,
+                                        image->bytesPerLine(), colorSpace, qt_mac_bitmapInfoForImage(*image));
 
         // Invert y axis
         CGContextTranslateCTM(context, 0, image->height());
diff --git a/src/gui/painting/qcoregraphics_p.h b/src/gui/painting/qcoregraphics_p.h
index de721c94aa..868c2b08b5 100644
--- a/src/gui/painting/qcoregraphics_p.h
+++ b/src/gui/painting/qcoregraphics_p.h
@@ -64,6 +64,8 @@
 
 QT_BEGIN_NAMESPACE
 
+Q_GUI_EXPORT CGBitmapInfo qt_mac_bitmapInfoForImage(const QImage &image);
+
 #ifdef HAVE_APPKIT
 Q_GUI_EXPORT NSImage *qt_mac_create_nsimage(const QPixmap &pm);
 Q_GUI_EXPORT NSImage *qt_mac_create_nsimage(const QIcon &icon, int defaultSize = 0);