CPGraphicsContext saveGraphicsState and restoreGraphicsState.

AppKit/CPGraphicsContext.j

@@ -25,7 +25,8 @@
 @import "CGContext.j"
 
 
-var CPGraphicsContextCurrent = nil;
+var CPGraphicsContextCurrent = nil,
+    CPGraphicsContextThreadStack = nil;
 
 /*!
     @ingroup appkit
@@ -52,6 +53,28 @@ var CPGraphicsContextCurrent = nil;
     CPGraphicsContextCurrent = aGraphicsContext;
 }
 
++ (void)saveGraphicsState
+{
+    if (!CPGraphicsContextCurrent)
+        return;
+
+    if (!CPGraphicsContextThreadStack)
+        CPGraphicsContextThreadStack = [CPMutableArray array];
+
+    [CPGraphicsContextThreadStack addObject:CPGraphicsContextCurrent];
+    [CPGraphicsContextCurrent saveGraphicsState];
+}
+
++ (void)restoreGraphicsState
+{
+    var lastContext = [CPGraphicsContextThreadStack lastObject];
+    if (lastContext)
+    {
+        [lastContext restoreGraphicsState];
+        [CPGraphicsContextThreadStack removeLastObject];
+    }
+}
+
 /*!
     Creates a graphics context with a provided port.
     @param aContext the context to initialize with
@@ -99,4 +122,14 @@ var CPGraphicsContextCurrent = nil;
     return YES;
 }
 
+- (void)saveGraphicsState
+{
+    CGContextSaveGState(_graphicsPort);
+}
+
+- (void)restoreGraphicsState
+{
+    CGContextRestoreGState(_graphicsPort);
+}
+
 @end