gate.gui.ControllerMetadataViewer.java Source code

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Here is the source code for gate.gui.ControllerMetadataViewer.java

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/*
 * ControllerMetadataViewer.java
 *
 * Copyright (c) 2012, The University of Sheffield. See the file COPYRIGHT.txt
 * in the software or at http://gate.ac.uk/gate/COPYRIGHT.txt
 *
 * This file is part of GATE (see http://gate.ac.uk/), and is free software,
 * licenced under the GNU Library General Public License, Version 2, June 1991
 * (in the distribution as file licence.html, and also available at
 * http://gate.ac.uk/gate/licence.html).
 *
 * Mark A. Greenwood, 08/11/2012
 */

package gate.gui;

import gate.Controller;
import gate.Gate;
import gate.GateConstants;
import gate.Resource;
import gate.creole.AbstractVisualResource;
import gate.creole.ResourceInstantiationException;
import gate.creole.metadata.CreoleResource;
import gate.creole.metadata.GuiType;

import java.awt.BorderLayout;
import java.awt.Font;
import java.io.StringReader;
import java.net.URL;
import java.util.Iterator;
import java.util.List;

import javax.swing.JScrollPane;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import org.apache.commons.io.IOUtils;
import org.apache.commons.lang.StringEscapeUtils;
import org.apache.xerces.parsers.DOMParser;
import org.cyberneko.html.HTMLConfiguration;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.xhtmlrenderer.simple.XHTMLPanel;
import org.xhtmlrenderer.swing.BasicPanel;
import org.xhtmlrenderer.swing.FSMouseListener;
import org.xhtmlrenderer.swing.LinkListener;
import org.xhtmlrenderer.util.Configuration;
import org.xml.sax.InputSource;

/**
 * This viewer displays metadata associated with a GATE Controller. The location
 * of the <code>metadata.xml</code> file is specified using the
 * <code>gate.app.MetadataURL</code> feature on the controller. Note that this
 * feature must be a URL object and not a String. Currently the only way to
 * specifiy a URL as a controler feature is to manually edit the saved xgapp
 * file.
 * 
 * @author Mark A. Greenwood
 */
@CreoleResource(name = "About...", guiType = GuiType.LARGE, resourceDisplayed = "gate.Controller")
public class ControllerMetadataViewer extends AbstractVisualResource {

    private static final long serialVersionUID = -1161421403987238291L;

    private XHTMLPanel display = new XHTMLPanel();

    private DocumentBuilderFactory builderFactory = DocumentBuilderFactory.newInstance();

    private DocumentBuilder builder = null;

    @SuppressWarnings("rawtypes")
    @Override
    public Resource init() throws ResourceInstantiationException {
        setLayout(new BorderLayout());
        add(new JScrollPane(display), BorderLayout.CENTER);

        try {
            builder = builderFactory.newDocumentBuilder();
        } catch (ParserConfigurationException e) {
            throw new ResourceInstantiationException("Unable to construct an XML parser", e);
        }

        if (Configuration.isTrue("xr.use.listeners", true)) {
            List l = display.getMouseTrackingListeners();
            for (Iterator i = l.iterator(); i.hasNext();) {
                FSMouseListener listener = (FSMouseListener) i.next();
                if (listener instanceof LinkListener) {
                    display.removeMouseTrackingListener(listener);
                }
            }
            display.addMouseTrackingListener(new LinkListener() {

                @Override
                public void linkClicked(BasicPanel panel, String uri) {
                    //open any links in an actual web browser
                    MainFrame.getInstance().showHelpFrame(uri, null);
                }
            });
        }

        return this;
    }

    @Override
    public void setTarget(Object target) {

        if (target == null)
            throw new NullPointerException("received a null target");

        if (!(target instanceof Controller))
            throw new IllegalArgumentException("not a controller");

        Controller controller = (Controller) target;

        if (!controller.getFeatures().containsKey("gate.app.MetadataURL"))
            throw new IllegalArgumentException("no gate.app.MetadataURL feature");

        try {
            URL metadata = (URL) controller.getFeatures().get("gate.app.MetadataURL");
            URL longDesc = new URL(metadata, "long-desc.html");
            URL iconDesc = new URL(metadata, "icon.png");

            Document document = builder.parse(metadata.openStream());

            Node text = document.getDocumentElement().getElementsByTagName("pipeline-name").item(0).getFirstChild();

            Font font = Gate.getUserConfig().getFont(GateConstants.TEXT_COMPONENTS_FONT);

            StringBuilder page = new StringBuilder();
            page.append("<!DOCTYPE html>");
            page.append("<html>");
            page.append("<head>");
            page.append("<style type='text/css'>body { font-family: ").append(font.getFamily())
                    .append("; font-size: ").append(font.getSize()).append("pt }</style>");
            page.append("</head>");
            page.append("<body>");
            page.append("<h1><img style='vertical-align: middle;' src='")
                    .append(StringEscapeUtils.escapeHtml(iconDesc.toString())).append("'/> ")
                    .append(StringEscapeUtils.escapeHtml(text.getTextContent())).append("</h1>");
            page.append(IOUtils.toString(longDesc, "UTF-8"));
            page.append("</body></html>");

            // parse using NekoHTML
            HTMLConfiguration config = new HTMLConfiguration();
            // Force element names to lower case to match XHTML requirements
            // as that is what Flying Saucer expects
            config.setProperty("http://cyberneko.org/html/properties/names/elems", "lower");
            DOMParser htmlParser = new DOMParser(config);
            htmlParser.parse(new InputSource(new StringReader(page.toString())));
            display.setDocument(htmlParser.getDocument(), longDesc.toString());

        } catch (Exception e) {
            throw new IllegalArgumentException(e);
        }
    }
}