iOS: add helper to convert UIImage to QImage

Going through the UIImage.CGImage flattens the image to monochrome.

Change-Id: If74c33badb4e94253b3bf21b6d69bb9f521d6bff
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

2 files changed, 30 insertions, 3 deletions

diff --git a/src/gui/painting/qcoregraphics.mm b/src/gui/painting/qcoregraphics.mm
index c05ba06146..e8904dff06 100644
--- a/src/gui/painting/qcoregraphics.mm
+++ b/src/gui/painting/qcoregraphics.mm
@@ -182,6 +182,24 @@ QPixmap qt_mac_toQPixmap(const NSImage *image, const QSizeF &size)
 
 #endif // Q_OS_MACOS
 
+#ifdef Q_OS_IOS
+
+QImage qt_mac_toQImage(const UIImage *image, QSizeF size)
+{
+    QImage ret(size.width(), size.height(), QImage::Format_ARGB32_Premultiplied);
+    ret.fill(Qt::transparent);
+    QMacCGContext ctx(&ret);
+    if (!ctx)
+        return QImage();
+    UIGraphicsPushContext(ctx);
+    const CGRect rect = CGRectMake(0, 0, size.width(), size.height());
+    [image drawInRect:rect];
+    UIGraphicsPopContext();
+    return ret;
+}
+
+#endif // Q_OS_IOS
+
 // ---------------------- Colors and Brushes ----------------------
 
 QColor qt_mac_toQColor(CGColorRef color)
diff --git a/src/gui/painting/qcoregraphics_p.h b/src/gui/painting/qcoregraphics_p.h
index f0640ba500..f2c2ba1db1 100644
--- a/src/gui/painting/qcoregraphics_p.h
+++ b/src/gui/painting/qcoregraphics_p.h
@@ -23,15 +23,24 @@
 
 #include <CoreGraphics/CoreGraphics.h>
 
-#if defined(__OBJC__) && defined(Q_OS_MACOS)
-#include <AppKit/AppKit.h>
-#define HAVE_APPKIT
+#if defined(__OBJC__)
+# if defined(Q_OS_MACOS)
+#  include <AppKit/AppKit.h>
+#  define HAVE_APPKIT
+# elif defined(Q_OS_IOS)
+#  include <UIKit/UIKit.h>
+#  define HAVE_UIKIT
+# endif
 #endif
 
 QT_BEGIN_NAMESPACE
 
 Q_GUI_EXPORT CGBitmapInfo qt_mac_bitmapInfoForImage(const QImage &image);
 
+#ifdef HAVE_UIKIT
+Q_GUI_EXPORT QImage qt_mac_toQImage(const UIImage *image, QSizeF size);
+#endif
+
 #ifdef HAVE_APPKIT
 Q_GUI_EXPORT QPixmap qt_mac_toQPixmap(const NSImage *image, const QSizeF &size);