WebAppInterface wai = new WebAppInterface(this, this);
myWebView.addJavascriptInterface(wai, "Android");
myWebView.loadUrl("http://192.168.2.246/abhishek/test/");

class WebAppInterface {
    Context mContext;
    MainActivity parent;

    /** Instantiate the interface and set the context */
    WebAppInterface(Context c, MainActivity parent) {
        mContext = c;
        this.parent = parent;
    }

    @JavascriptInterface
    public void setHeading(String heading) {
        Toast.makeText(mContext, "Setting heading to " + heading, Toast.LENGTH_SHORT).show();
    }
}

function setHeading(heading) {
    console.log("setting heading...");
    // Android callback
    if(typeof Android !== 'undefined'){
        Android.setHeading(heading);
    }
    if(typeof Android == 'undefined') {
        console.log("undefined!!");
    }
}

public static final native void setAppHeading(String heading) /*-{
    $wnd.setHeading(heading);
}-*/;