vaadin-framework/client/src/main/java/com/vaadin/client/ui/ImageIcon.java

/*
 * Copyright 2000-2018 Vaadin Ltd.
 *
 * 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.vaadin.client.ui;

import com.google.gwt.core.client.Scheduler;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Event;
import com.vaadin.client.BrowserInfo;

/**
 * A image based implementation of {@link Icon}.
 * <p>
 * The image is loaded from the given URL ( {@link #setUri(String)}) and
 * displayed in full.
 * </p>
 *
 * @author Vaadin Ltd
 */
public class ImageIcon extends Icon {
    public static final String CLASSNAME = "v-icon";

    public ImageIcon() {
        setElement(DOM.createImg());
        setStyleName(CLASSNAME);
    }

    @Override
    public void setUri(final String imageUrl) {
        /*
         * Start sinking onload events, widgets responsibility to react. We must
         * do this BEFORE we set src as IE fires the event immediately if the
         * image is found in cache (#2592).
         */
        sinkEvents(Event.ONLOAD);

        if (BrowserInfo.get().isIE()) {
            // apply src later for IE, to ensure onload is fired
            Scheduler.get().scheduleDeferred(() -> DOM
                    .setElementProperty(getElement(), "src", imageUrl));
        }

        DOM.setElementProperty(getElement(), "src", imageUrl);

    }

    @Override
    public void setAlternateText(String alternateText) {
        getElement().setAttribute("alt",
                alternateText == null ? "" : alternateText);
    }

    @Override
    public String getUri() {
        return DOM.getElementProperty(getElement(), "src");
    }

}