helpviewer.java

Java写的文本编辑器

/*
 * HelpViewer.java - HTML Help viewer
 * Copyright (C) 1999, 2000, 2001 Slava Pestov
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

package org.gjt.sp.jedit.gui;

import com.microstar.xml.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.event.*;
import javax.swing.text.html.*;
import javax.swing.text.Document;
import javax.swing.tree.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import java.net.*;
import java.util.*;
import org.gjt.sp.jedit.msg.PropertiesChanged;
import org.gjt.sp.jedit.*;
import org.gjt.sp.util.Log;

/**
 * jEdit's HTML viewer. It uses a Swing JEditorPane to display the HTML,
 * and implements a URL history.
 * @author Slava Pestov
 * @version $Id: HelpViewer.java,v 1.2 2001/09/03 05:58:06 spestov Exp $
 */
public class HelpViewer extends JFrame implements EBComponent
{
	/**
	 * @deprecated Create a new HelpViewer instance instead
	 */
	public static void gotoURL(URL url)
	{
		new HelpViewer(url.toString());
	}

	/**
	 * @deprecated Pass a String instead of a URL
	 */
	public HelpViewer(URL url)
	{
		// XXX
		this(url.toString());
	}

	/**
	 * Creates a new help viewer for the specified URL.
	 * @param url The URL
	 */
	public HelpViewer(String url)
	{
		super(jEdit.getProperty("helpviewer.title"));

		setIconImage(GUIUtilities.getEditorIcon());

		history = new String[25];
		nodes = new Hashtable();

		ActionHandler actionListener = new ActionHandler();

		JToolBar toolBar = new JToolBar();
		toolBar.setFloatable(false);
		toolBar.putClientProperty("JToolBar.isRollover",Boolean.TRUE);

		JLabel label = new JLabel(jEdit.getProperty("helpviewer.url"));
		label.setBorder(new EmptyBorder(0,12,0,12));
		toolBar.add(label);
		Box box = new Box(BoxLayout.Y_AXIS);
		box.add(Box.createGlue());
		urlField = new JTextField();
		urlField.addKeyListener(new KeyHandler());
		Dimension dim = urlField.getPreferredSize();
		dim.width = Integer.MAX_VALUE;
		urlField.setMaximumSize(dim);
		box.add(urlField);
		box.add(Box.createGlue());
		toolBar.add(box);

		toolBar.add(Box.createHorizontalStrut(6));

		JPanel buttons = new JPanel();
		buttons.setLayout(new BoxLayout(buttons,BoxLayout.X_AXIS));
		buttons.setBorder(new EmptyBorder(0,12,0,0));
		back = new JButton(GUIUtilities.loadIcon("Back24.gif"));
		back.setToolTipText(jEdit.getProperty("helpviewer.back"));
		back.addActionListener(actionListener);
		back.setRequestFocusEnabled(false);
		toolBar.add(back);
		forward = new JButton(GUIUtilities.loadIcon("Forward24.gif"));
		forward.addActionListener(actionListener);
		forward.setToolTipText(jEdit.getProperty("helpviewer.forward"));
		forward.setRequestFocusEnabled(false);
		toolBar.add(forward);
		back.setPreferredSize(forward.getPreferredSize());

		getContentPane().add(BorderLayout.NORTH,toolBar);

		createTOC();

		toc = new TOCTree(tocModel);
		toc.putClientProperty("JTree.lineStyle", "Angled");
		toc.setCellRenderer(new TOCCellRenderer());
		toc.setEditable(false);
		toc.setRootVisible(false);
		toc.setShowsRootHandles(true);

		viewer = new JEditorPane();
		viewer.setEditable(false);
		viewer.addHyperlinkListener(new LinkHandler());
		viewer.setFont(new Font("Monospaced",Font.PLAIN,12));

		JSplitPane splitter = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,
			new JScrollPane(toc),new JScrollPane(viewer));
		splitter.setBorder(null);


		getContentPane().add(BorderLayout.CENTER,splitter);

		gotoURL(url,true);

		setDefaultCloseOperation(DISPOSE_ON_CLOSE);

		setSize(800,400);
		GUIUtilities.loadGeometry(this,"helpviewer");

		EditBus.addToBus(this);

		show();
	}

	/**
	 * Displays the specified URL in the HTML component.
	 * @param url The URL
	 * @param addToHistory Should the URL be added to the back/forward
	 * history?
	 */
	public void gotoURL(String url, boolean addToHistory)
	{
		// reset default cursor so that the hand cursor doesn't
		// stick around
		viewer.setCursor(Cursor.getDefaultCursor());

		int index = url.indexOf('#');

		URL _url = null;
		try
		{
			_url = new URL(url);

			urlField.setText(_url.toString());
			viewer.setPage(_url);
			if(addToHistory)
			{
				history[historyPos] = url;
				if(historyPos + 1 == history.length)
				{
					System.arraycopy(history,1,history,
						0,history.length - 1);
					history[historyPos] = null;
				}
				else
					historyPos++;
			}
		}
		catch(MalformedURLException mf)
		{
			Log.log(Log.ERROR,this,mf);
			String[] args = { url, mf.getMessage() };
			GUIUtilities.error(this,"badurl",args);
			return;
		}
		catch(IOException io)
		{
			Log.log(Log.ERROR,this,io);
			String[] args = { url, io.toString() };
			GUIUtilities.error(this,"read-error",args);
			return;
		}

		// select the appropriate tree node.
		index = url.lastIndexOf("/doc/");
		if(index != -1)
			url = url.substring(index + 5);

		DefaultMutableTreeNode node = (DefaultMutableTreeNode)nodes.get(url);

		if(node == null)
			return;

		TreePath path = new TreePath(tocModel.getPathToRoot(node));
		toc.expandPath(path);
		toc.setSelectionPath(path);
		toc.scrollPathToVisible(path);
	}

	public void dispose()
	{
		EditBus.removeFromBus(this);
		GUIUtilities.saveGeometry(this,"helpviewer");
		super.dispose();
	}

	public void handleMessage(EBMessage msg)
	{
		if(msg instanceof PropertiesChanged)
			SwingUtilities.updateComponentTreeUI(getRootPane());
	}

	// private members
	private JButton back;
	private JButton forward;
	private DefaultTreeModel tocModel;
	private JTree toc;
	// this makes gotoURL()'s tree updating simpler
	private Hashtable nodes;
	private JEditorPane viewer;
	private JTextField urlField;
	private String[] history;
	private int historyPos;

	private void createTOC()
	{
		DefaultMutableTreeNode root = new DefaultMutableTreeNode();

		root.add(createNode("jeditresource:/doc/welcome.html",
			jEdit.getProperty("helpviewer.toc.welcome")));

		root.add(createNode("jeditresource:/doc/README.txt",
			jEdit.getProperty("helpviewer.toc.readme")));
		root.add(createNode("jeditresource:/doc/NEWS.txt",
			jEdit.getProperty("helpviewer.toc.news")));
		root.add(createNode("jeditresource:/doc/TODO.txt",
			jEdit.getProperty("helpviewer.toc.todo")));
		root.add(createNode("jeditresource:/doc/CHANGES.txt",
			jEdit.getProperty("helpviewer.toc.changes")));
		root.add(createNode("jeditresource:/doc/COPYING.txt",
			jEdit.getProperty("helpviewer.toc.copying")));
		root.add(createNode("jeditresource:/doc/COPYING.DOC.txt",
			jEdit.getProperty("helpviewer.toc.copying-doc")));

		loadUserGuideTOC(root);

		DefaultMutableTreeNode pluginDocs = new DefaultMutableTreeNode(
			jEdit.getProperty("helpviewer.toc.plugins"),true);

		EditPlugin[] plugins = jEdit.getPlugins();
		for(int i = 0; i < plugins.length; i++)
		{
			EditPlugin plugin = plugins[i];
			EditPlugin.JAR jar = plugin.getJAR();
			if(jar == null)
				continue;

			String name = plugin.getClassName();

			String docs = jEdit.getProperty("plugin." + name + ".docs");
			String label = jEdit.getProperty("plugin." + name + ".name");
			if(docs != null)
			{
				if(label != null && docs != null)
				{
					URL url = jar.getClassLoader()
						.getResource(docs);
					if(url != null)
					{
						pluginDocs.add(createNode(
							url.toString(),label));
					}
				}
			}
		}

		root.add(pluginDocs);

		tocModel = new DefaultTreeModel(root);
	}

	private void loadUserGuideTOC(DefaultMutableTreeNode root)
	{
		URL resource = getClass().getResource("/doc/users-guide/toc.xml");
		if(resource == null)
			return;

		TOCHandler h = new TOCHandler(root);
		XmlParser parser = new XmlParser();
		parser.setHandler(h);

		try
		{
			// use a URL here because with Web Start version,
			// toc.xml is not a local file
			parser.parse(null, null, new InputStreamReader(
				resource.openStream()));
		}
		catch(XmlException xe)
		{
			int line = xe.getLine();
			String message = xe.getMessage();
			Log.log(Log.ERROR,this,"toc.xml:" + line
				+ ": " + message);
		}
		catch(Exception e)
		{
			Log.log(Log.ERROR,this,e);
		}
	}

	private DefaultMutableTreeNode createNode(String href, String title)
	{
		DefaultMutableTreeNode node = new DefaultMutableTreeNode(
			new HelpNode(href,title),true);
		nodes.put(href,node);
		return node;
	}

	static class HelpNode
	{
		String href, title;

		HelpNode(String href, String title)
		{
			this.href = href;
			this.title = title;
		}

		public String toString()
		{
			return title;
		}
	}

	class TOCHandler extends HandlerBase
	{
		TOCHandler(DefaultMutableTreeNode root)
		{
			nodes = new Stack();
			node = root;
		}

		public void attribute(String aname, String value, boolean isSpecified)
		{
			if(aname.equals("HREF"))
				href = value;
		}

		public void charData(char[] c, int off, int len)
		{
			if(tag.equals("TITLE"))
				title = new String(c, off, len);
		}

		public void startElement(String name)
		{
			tag = name;
		}

		public void endElement(String name)
		{
			if(name == null)
				return;

			if(name.equals("TITLE"))
			{
				DefaultMutableTreeNode newNode = createNode(
					"jeditresource:/doc/users-guide/"
					+ href,title);
				node.add(newNode);
				nodes.push(node);
				node = newNode;
			}
			else if(name.equals("ENTRY"))
				node = (DefaultMutableTreeNode)nodes.pop();
		}
		// end HandlerBase implementation

		// private members
		private String tag;
		private String title;
		private String href;
		private DefaultMutableTreeNode node;
		private Stack nodes;
	}

	class TOCTree extends JTree
	{
		TOCTree(TreeModel model)
		{
			super(model);
			ToolTipManager.sharedInstance().registerComponent(this);
		}

		public final String getToolTipText(MouseEvent evt)
		{
			TreePath path = getPathForLocation(evt.getX(), evt.getY());
			if(path != null)
			{
				Rectangle cellRect = getPathBounds(path);
				if(cellRect != null && !cellRectIsVisible(cellRect))
					return path.getLastPathComponent().toString();
			}
			return null;
		}

		public final Point getToolTipLocation(MouseEvent evt)
		{
			TreePath path = getPathForLocation(evt.getX(), evt.getY());
			if(path != null)
			{
				Rectangle cellRect = getPathBounds(path);
				if(cellRect != null && !cellRectIsVisible(cellRect))
				{
					return new Point(cellRect.x, cellRect.y - 1);
				}
			}
			return null;
		}

		protected void processMouseEvent(MouseEvent evt)
		{
			ToolTipManager ttm = ToolTipManager.sharedInstance();

			switch(evt.getID())
			{
			case MouseEvent.MOUSE_ENTERED:
				toolTipInitialDelay = ttm.getInitialDelay();
				toolTipReshowDelay = ttm.getReshowDelay();
				ttm.setInitialDelay(200);
				ttm.setReshowDelay(0);
				super.processMouseEvent(evt);
				break;
			case MouseEvent.MOUSE_EXITED:
				ttm.setInitialDelay(toolTipInitialDelay);
				ttm.setReshowDelay(toolTipReshowDelay);
				super.processMouseEvent(evt);
				break;
			case MouseEvent.MOUSE_CLICKED:
				TreePath path = getPathForLocation(evt.getX(),evt.getY());
				if(path != null)
				{
					if(!isPathSelected(path))
						setSelectionPath(path);

					Object obj = ((DefaultMutableTreeNode)
						path.getLastPathComponent())
						.getUserObject();
					if(!(obj instanceof HelpNode))
					{
						toc.expandPath(path);
						return;
					}

					HelpNode node = (HelpNode)obj;

					gotoURL(node.href,true);
				}

				super.processMouseEvent(evt);
				break;
			default:
				super.processMouseEvent(evt);
				break;
			}
		}

		// private members
		private int toolTipInitialDelay = -1;
		private int toolTipReshowDelay = -1;

		private boolean cellRectIsVisible(Rectangle cellRect)
		{
			Rectangle vr = TOCTree.this.getVisibleRect();
			return vr.contains(cellRect.x,cellRect.y) &&
				vr.contains(cellRect.x + cellRect.width,
				cellRect.y + cellRect.height);
		}
	}

	class TOCCellRenderer extends DefaultTreeCellRenderer
	{
		EmptyBorder border = new EmptyBorder(1,0,1,1);

		public Component getTreeCellRendererComponent(JTree tree,
			Object value, boolean sel, boolean expanded,
			boolean leaf, int row, boolean focus)
		{
			super.getTreeCellRendererComponent(tree,value,sel,
				expanded,leaf,row,focus);
			setIcon(null);
			setBorder(border);

			return this;
		}
	}

	class ActionHandler implements ActionListener
	{
		public void actionPerformed(ActionEvent evt)
		{
			Object source = evt.getSource();
			if(source == back)
			{
				if(historyPos <= 1)
					getToolkit().beep();
				else
				{
					String url = history[--historyPos - 1];
					gotoURL(url,false);
				}
			}
			else if(source == forward)
			{
				if(history.length - historyPos <= 1)
					getToolkit().beep();
				else
				{
					String url = history[historyPos];
					if(url == null)
						getToolkit().beep();
					else
					{
						historyPos++;
						gotoURL(url,false);
					}
				}
			}
		}
	}

	class LinkHandler implements HyperlinkListener
	{
		public void hyperlinkUpdate(HyperlinkEvent evt)
		{
			if(evt.getEventType() == HyperlinkEvent.EventType.ACTIVATED)
			{
				if(evt instanceof HTMLFrameHyperlinkEvent)
				{
					((HTMLDocument)viewer.getDocument())
						.processHTMLFrameHyperlinkEvent(
						(HTMLFrameHyperlinkEvent)evt);
				}
				else
				{
					URL url = evt.getURL();
					if(url != null)
						gotoURL(url.toString(),true);
				}
			}
			else if (evt.getEventType() == HyperlinkEvent.EventType.ENTERED) {
				viewer.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
			}
			else if (evt.getEventType() == HyperlinkEvent.EventType.EXITED) {
				viewer.setCursor(Cursor.getDefaultCursor());
			}
		}
	}

	class KeyHandler extends KeyAdapter
	{
		public void keyPressed(KeyEvent evt)
		{
			if(evt.getKeyCode() == KeyEvent.VK_ENTER)
			{
				gotoURL(urlField.getText(),true);
			}
		}
	}
}