Java tutorial
/* Copyright (C) 2003 Nizar N. Batada, Morten O. Alver All programs in this directory and subdirectories are published under the GNU General Public License as described below. 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 (at your option) 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 Further information about the GNU GPL is available at: http://www.gnu.org/copyleft/gpl.ja.html */ package net.sf.jabref; import java.awt.Point; import java.awt.event.ActionEvent; import java.io.File; import java.io.IOException; import java.net.URL; import java.util.Stack; import javax.swing.*; import javax.swing.event.HyperlinkEvent; import javax.swing.event.HyperlinkListener; import javax.swing.text.DefaultEditorKit; import javax.swing.text.JTextComponent; import javax.swing.text.TextAction; import javax.swing.text.html.HTMLEditorKit; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; public class HelpContent extends JTextPane { static Log log = LogFactory.getLog(HelpContent.class); JScrollPane pane; private Stack<URL> history, forw; JabRefPreferences prefs; public HelpContent(JabRefPreferences prefs_) { super(); pane = new JScrollPane(this, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_NEVER); pane.setDoubleBuffered(true); prefs = prefs_; history = new Stack<URL>(); forw = new Stack<URL>(); setEditorKitForContentType("text/html", new MyEditorKit()); setContentType("text/html"); setText(""); setEditable(false); // Handles Anchors final HyperlinkListener hyperLinkListener = new HyperlinkListener() { public void hyperlinkUpdate(final HyperlinkEvent e) { if (e.getDescription().startsWith("#")) { scrollToReference(e.getDescription().substring(1)); } } }; addHyperlinkListener(hyperLinkListener); } public boolean back() { if (!history.empty()) { URL prev = (history.pop()); forw.push(getPage()); setPageOnly(prev); } return !history.empty(); } public boolean forward() { if (!forw.empty()) { URL next = (forw.pop()); history.push(getPage()); setPageOnly(next); } return !forw.empty(); } public void reset() { forw.removeAllElements(); history.removeAllElements(); } public void setPage(String filename, Class resourceOwner) { // Check for anchor int indexOf = filename.indexOf('#'); String file; String reference; if (indexOf != -1) { file = filename.substring(0, indexOf); reference = filename.substring(indexOf + 1); } else { file = filename; reference = ""; } String middle = prefs.get("language") + "/"; if (middle.equals("en/")) middle = ""; // english in base help dir. URL old = getPage(); try { // First check in specified language URL resource = resourceOwner.getResource(GUIGlobals.helpPre + middle + file); // If not available fallback to english if (resource == null) { resource = resourceOwner.getResource(GUIGlobals.helpPre + file); } // If still not available print a warning if (resource == null) { // TODO show warning to user log.error("Could not find html-help for file '" + file + "'."); return; } setPageOnly(new URL(resource.toString() + "#" + reference)); } catch (IOException ex) { ex.printStackTrace(); } forw.removeAllElements(); if (old != null) history.push(old); } /** * Convenience method for setPage(String) */ public void setPage(URL url) { File f = new File(url.getPath()); setPage(f.getName(), JabRef.class); } private void setPageOnly(URL url) { try { super.setPage(url); } catch (IOException ex) { if (url == null) { System.out.println("Error: Help file not set"); } else { System.out.println("Error: Help file not found '" + url.getFile() + "'"); } } } public JComponent getPane() { return pane; } /*public void paintComponent(Graphics g) { Graphics2D g2 = (Graphics2D) g; g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); g2.setRenderingHint(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY); super.paintComponent(g2); }*/ public class MyNextVisualPositionAction extends TextAction { private Action textActn; private int direction; private MyNextVisualPositionAction(Action textActn, int direction) { super((String) textActn.getValue(Action.NAME)); this.textActn = textActn; this.direction = direction; } public void actionPerformed(ActionEvent e) { JTextComponent c = getTextComponent(e); if (c.getParent() instanceof JViewport) { JViewport viewport = (JViewport) c.getParent(); Point p = viewport.getViewPosition(); if (this.direction == SwingConstants.NORTH) { c.setCaretPosition(c.viewToModel(p)); } else { p.y += viewport.getExtentSize().height; c.setCaretPosition(c.viewToModel(p)); } } textActn.actionPerformed(e); } } public class MyEditorKit extends HTMLEditorKit { private Action[] myActions; public Action[] getActions() { if (myActions == null) { Action[] actions = super.getActions(); Action[] newActions = new Action[2]; for (int i = 0; i < actions.length; i++) { Action actn = actions[i]; String name = (String) actn.getValue(Action.NAME); if (name.equals(DefaultEditorKit.upAction)) { newActions[0] = new MyNextVisualPositionAction(actions[i], SwingConstants.NORTH); } else if (name.equals(DefaultEditorKit.downAction)) { newActions[1] = new MyNextVisualPositionAction(actions[i], SwingConstants.SOUTH); } } myActions = TextAction.augmentList(actions, newActions); } return myActions; } } }