According to http://www.w3.org/html/wg/drafts/2dcontext/html5_canvas/#dom-context-2d-globalcompositeoperation the setGlobalCompositeOperation needs String parameter
1.1 --- a/javaquery/api/src/main/java/org/apidesign/bck2brwsr/htmlpage/api/GraphicsContext.java Thu Feb 14 12:05:43 2013 +0100
1.2 +++ b/javaquery/api/src/main/java/org/apidesign/bck2brwsr/htmlpage/api/GraphicsContext.java Thu Feb 14 12:06:16 2013 +0100
1.3 @@ -307,10 +307,10 @@
1.4 public native double getGlobalAlpha();
1.5
1.6 @JavaScriptBody(args = {"operation"}, body = "this._context().globalCompositeOperation=operation;")
1.7 - public native void setGlobalCompositeOperation(double alpha);
1.8 + public native void setGlobalCompositeOperation(String operation);
1.9
1.10 @JavaScriptBody(args = {}, body = "return this._context().globalCompositeOperation;")
1.11 - public native double getGlobalCompositeOperation();
1.12 + public native String getGlobalCompositeOperation();
1.13
1.14 public LinearGradient createLinearGradient(double x0, double y0, double x1, double y1) {
1.15 return new LinearGradient(createLinearGradientImpl(context, x0, y0, x1, y1));