Uses a combination of a clear image and a background image to clip all except a desired portion of an underlying image.

Do not use this class - it is used for implementation only, and its methods may change in the future.

class ClippedImageImpl {

 String clearImage = DWT.getModuleBaseURL() + "resource/images/clear.gif";

 dart_html.Element createStructure(SafeUri url, int left, int top, int width, int height) {
   dart_html.ImageElement img = new dart_html.ImageElement();
   img.src = clearImage;
   //
   String style = "url(\"${url.asString()}\") no-repeat ${-left}px ${-top}px";
   img.style.background = style;
   img.style.width = "${width}px";
   img.style.height = "${height}px";
   img.onLoad.listen((dart_html.Event evt) {
     img.dataset[DomImpl.UNHANDLED_EVENT_ATTR] = BrowserEvents.LOAD;
   });
   //
   return img;
 }

 SafeHtml getSafeHtml(SafeUri url, int left, int top, int width, int height) {
   String style = "url(\"${url.asString()}\") no-repeat ${-left}px ${-top}px";
   String res = "<img onload='this.data-${DomImpl.UNHANDLED_EVENT_ATTR}=\"load\";' src='${clearImage}' style='background:${style}; width: ${width}px; height: ${height}px' border='0'>";
   return new SafeHtmlString(res);
 }

 dart_html.ImageElement getImgElement(Image image) {
   return image.getElement() as dart_html.ImageElement;
 }

 void adjust(dart_html.ImageElement img, SafeUri url, int left, int top, int width, int height) {
   String style = "url(\"${url.asString()}\") no-repeat -${left}px -${top}px";
   img.style.background = style;
   img.style.width = width.toString() + Unit.PX.value;
   img.style.height = height.toString() + Unit.PX.value;
 }
}