com.google.gwt.examples.ImageExample.java Source code

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Here is the source code for com.google.gwt.examples.ImageExample.java

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/*
 * Copyright 2007 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.examples;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.ErrorEvent;
import com.google.gwt.event.dom.client.ErrorHandler;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.Image;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.VerticalPanel;

public class ImageExample implements EntryPoint {

    private Label lbl = new Label();
    private Button btn = new Button("Clip this image");
    private Button btn2 = new Button("Restore image");

    public void onModuleLoad() {
        // Create an image, not yet referencing a URL. We make it final so that we
        // can manipulate the image object within the ClickHandlers for the buttons.
        final Image image = new Image();

        // Hook up an error handler, so that we can be informed if the image fails
        // to load.
        image.addErrorHandler(new ErrorHandler() {
            public void onError(ErrorEvent event) {
                lbl.setText("An error occurred while loading.");
            }
        });

        // Point the image at a real URL.
        image.setUrl("http://www.google.com/images/logo.gif");

        // When the user clicks this button, we want to clip the image.
        btn.addClickHandler(new ClickHandler() {
            public void onClick(ClickEvent event) {
                image.setVisibleRect(70, 0, 47, 110);
            }
        });
        btn.setWidth("120px");

        // When the user clicks this button, we want to restore the image to its
        // unclipped state.
        btn2.addClickHandler(new ClickHandler() {
            public void onClick(ClickEvent event) {
                image.setUrl("http://www.google.com/images/logo.gif");
            }
        });
        btn2.setWidth("120px");

        // Add the image, label, and clip/restore buttons to the root panel.
        VerticalPanel panel = new VerticalPanel();
        panel.add(lbl);
        panel.add(image);

        HorizontalPanel buttonPanel = new HorizontalPanel();
        buttonPanel.add(btn);
        buttonPanel.add(btn2);

        panel.add(buttonPanel);

        RootPanel.get().add(panel);
    }
}