/*
* Copyright 2008 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.gwt.user.client.ui.impl;
import com.google.gwt.core.client.GWT;
import com.google.gwt.dom.client.Document;
import com.google.gwt.dom.client.Element;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.safecss.shared.SafeStyles;
import com.google.gwt.safecss.shared.SafeStylesBuilder;
import com.google.gwt.safecss.shared.SafeStylesUtils;
import com.google.gwt.safehtml.client.SafeHtmlTemplates;
import com.google.gwt.safehtml.shared.SafeHtml;
import com.google.gwt.safehtml.shared.SafeUri;
import com.google.gwt.safehtml.shared.UriUtils;
import com.google.gwt.user.client.ui.Image;
/**
* 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.
*/
public class ClippedImageImpl {
interface Template extends SafeHtmlTemplates {
@SafeHtmlTemplates.Template("<img onload='this.__gwtLastUnhandledEvent=\"load\";' src='{0}' "
+ "style='{1}' border='0'>")
SafeHtml image(SafeUri clearImage, SafeStyles style);
}
protected static final SafeUri clearImage =
UriUtils.fromTrustedString(GWT.getModuleBaseURL() + "clear.cache.gif");
private static Template template;
public void adjust(Element img, SafeUri url, int left, int top, int width, int height) {
String style = "url(\"" + url.asString() + "\") no-repeat " + (-left + "px ") + (-top + "px");
img.getStyle().setProperty("background", style);
img.getStyle().setPropertyPx("width", width);
img.getStyle().setPropertyPx("height", height);
}
public Element createStructure(SafeUri url, int left, int top, int width, int height) {
Element tmp = Document.get().createSpanElement();
tmp.setInnerHTML(getSafeHtml(url, left, top, width, height).asString());
return tmp.getFirstChildElement();
}
public Element getImgElement(Image image) {
return image.getElement();
}
public SafeHtml getSafeHtml(SafeUri url, int left, int top, int width, int height) {
SafeStylesBuilder builder = new SafeStylesBuilder();
builder.width(width, Unit.PX).height(height, Unit.PX).trustedNameAndValue("background",
"url(" + url.asString() + ") " + "no-repeat " + (-left + "px ") + (-top + "px"));
return getTemplate().image(clearImage,
SafeStylesUtils.fromTrustedString(builder.toSafeStyles().asString()));
}
private Template getTemplate() {
// no need to synchronize, JavaScript in the browser is single-threaded
if (template == null) {
template = GWT.create(Template.class);
}
return template;
}
}