Get an attribute from a GWT object via jsni?

[markww]

Hi,

I'm using Canvas, I need to get a property from the context:

    context.webkitBackingStorePixelRatio;

I'm not sure how to make a jsni function to do this (this property does not seem to have a wrapper already in the gwt Context2d class):

    // How do we define this function and pass in our GWT Context2d instance?

    public static native double getBackingStoreRatio(Context2d context) /*-{

        return context.webkitBackingStorePixelRatio || 1;

    }-*/;

    Canvas canvas = Canvas.createIfSupported();

    Context2d context = canvas.getContext2d();

    double isThatRight = getBackingStoreRation(context);

Yeah I'm not sure what the sytax is for this, the Context2d variable is a GWT object already,

Thanks

(trying to get the variables from this article for hdpi screen support)

http://www.html5rocks.com/en/tutorials/canvas/hidpi/

[Sebastián Gurin]

that should work... What is the result ?

[Andrea Boscolo]

Try with

return context.@com.google.gwt.canvas.dom.client.Context2d::webkitBackingStorePixelRatio;

but I don't think it will ever work.

[Sebastián Gurin]

no,

com.google.gwt.canvas.dom.client.Context2d is a JavaScriptObject so just treat it as a javascript object not as a java object in jsni code. .