annis.libgui.visualizers.AbstractIFrameVisualizer.java Source code

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Here is the source code for annis.libgui.visualizers.AbstractIFrameVisualizer.java

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/*
 * Copyright 2009-2011 Collaborative Research Centre SFB 632 
 *
 * 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 annis.libgui.visualizers;

import annis.gui.widgets.AutoHeightIFrame;
import annis.libgui.VisualizationToggle;
import com.vaadin.server.VaadinSession;
import com.vaadin.ui.Component;
import com.vaadin.ui.UI;
import java.io.ByteArrayOutputStream;
import java.io.OutputStream;
import java.net.URI;
import java.util.UUID;
import org.slf4j.LoggerFactory;

/**
 * Base class for all iframe visualizer plugins
 *
 * @author Thomas Krause <krauseto@hu-berlin.de>
 * @author Benjamin Weienfels <b.pixeldrama@gmail.com>
 */
public abstract class AbstractIFrameVisualizer extends AbstractVisualizer implements ResourcePlugin {
    private static final org.slf4j.Logger log = LoggerFactory.getLogger(AbstractIFrameVisualizer.class);

    /**
     * Returns the character encoding for this particular Visualizer output. For
     * more information see
     * {@link javax.servlet.ServletResponse#setCharacterEncoding(String)}. Must be
     * overridden to change default "utf-8".
     *
     * @return the CharacterEncoding
     */
    public String getCharacterEncoding() {
        return "utf-8";
    }

    public String getContentType() {
        return "text/html";
    }

    /**
     * Writes the final output to passed OutputStream. The stream should remain
     * open.
     *
     * @param input The input from which the visualization should be generated
     * from
     * @param outstream The OutputStream to be used
     */
    public abstract void writeOutput(VisualizerInput input, OutputStream outstream);

    @Override
    public Component createComponent(final VisualizerInput vis, VisualizationToggle visToggle) {

        VaadinSession session = VaadinSession.getCurrent();
        if (session.getAttribute(IFrameResourceMap.class) == null) {
            session.setAttribute(IFrameResourceMap.class, new IFrameResourceMap());
        }

        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        writeOutput(vis, outStream);

        IFrameResource res = new IFrameResource();
        res.setData(outStream.toByteArray());
        res.setMimeType(getContentType());

        UUID uuid = UUID.randomUUID();
        session.getAttribute(IFrameResourceMap.class).put(uuid, res);

        URI base = UI.getCurrent().getPage().getLocation();
        AutoHeightIFrame iframe = new AutoHeightIFrame(base.resolve("vis-iframe-res/" + uuid.toString()));
        return iframe;
    }
}