com.vaadin.ui.renderers.ImageRenderer.java Source code

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Here is the source code for com.vaadin.ui.renderers.ImageRenderer.java

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/*
 * 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.ui.renderers;

import com.vaadin.server.ExternalResource;
import com.vaadin.server.Resource;
import com.vaadin.server.ResourceReference;
import com.vaadin.server.ThemeResource;
import com.vaadin.shared.communication.URLReference;
import com.vaadin.shared.ui.grid.renderers.ImageRendererState;

import elemental.json.JsonValue;

/**
 * A renderer for presenting images.
 * <p>
 * The image for each rendered cell is read from a Resource-typed property in
 * the data source. Only {@link ExternalResource}s and {@link ThemeResource}s
 * are currently supported.
 *
 * @param <T>
 *            the type of the grid this renderer can be attached to
 *
 * @since 7.4
 * @author Vaadin Ltd
 */
public class ImageRenderer<T> extends ClickableRenderer<T, Resource> {

    /**
     * Creates a new image renderer.
     */
    public ImageRenderer() {
        super(Resource.class, null);
    }

    /**
     * Creates a new image renderer and adds the given click listener to it.
     *
     * @param listener
     *            the click listener to register
     */
    public ImageRenderer(RendererClickListener<T> listener) {
        this();
        addClickListener(listener);
    }

    @Override
    public JsonValue encode(Resource resource) {
        if (!(resource == null || resource instanceof ExternalResource || resource instanceof ThemeResource)) {
            throw new IllegalArgumentException("ImageRenderer only supports ExternalResource and ThemeResource ("
                    + resource.getClass().getSimpleName() + " given)");
        }

        return encode(ResourceReference.create(resource, this, null), URLReference.class);
    }

    @Override
    protected ImageRendererState getState() {
        return (ImageRendererState) super.getState();
    }

    @Override
    protected ImageRendererState getState(boolean markAsDirty) {
        return (ImageRendererState) super.getState(markAsDirty);
    }
}