Add utility functions for using Core Graphics contexts.

These snippets are often used while managing
Core Graphics contexts. Putting them in inlined
functions makes code easier to read.

Reviewed-by: Richard Moe Gustavsen

1 files changed, 28 insertions, 0 deletions

diff --git a/src/gui/kernel/qt_cocoa_helpers_mac_p.h b/src/gui/kernel/qt_cocoa_helpers_mac_p.h
index 25dcdc3..b177210 100644
--- a/src/gui/kernel/qt_cocoa_helpers_mac_p.h
+++ b/src/gui/kernel/qt_cocoa_helpers_mac_p.h
@@ -232,6 +232,34 @@ void qt_mac_display(QWidget *widget);
 void qt_mac_setneedsdisplay(QWidget *widget);
 #endif // QT_MAC_USE_COCOA
 
+
+// Utility functions to ease the use of Core Graphics contexts.
+
+inline void qt_mac_retain_graphics_context(CGContextRef context)
+{
+    CGContextRetain(context);
+    CGContextSaveGState(context);
+}
+
+inline void qt_mac_release_graphics_context(CGContextRef context)
+{
+    CGContextRestoreGState(context);
+    CGContextRelease(context);
+}
+
+inline void qt_mac_draw_image(CGContextRef context, CGContextRef imageContext, CGRect area, CGRect drawingArea)
+{
+    CGImageRef image = CGBitmapContextCreateImage(imageContext);
+    CGImageRef subImage = CGImageCreateWithImageInRect(image, area);
+
+    CGContextTranslateCTM (context, 0, drawingArea.origin.y + CGRectGetMaxY(drawingArea));
+    CGContextScaleCTM(context, 1, -1);
+    CGContextDrawImage(context, drawingArea, subImage);
+
+    CGImageRelease(subImage);
+    CGImageRelease(image);
+}
+
 QT_END_NAMESPACE
 
 #endif // QT_COCOA_HELPERS_MAC_P_H