001// License: GPL. For details, see LICENSE file. 002package org.openstreetmap.josm.actions; 003 004import static org.openstreetmap.josm.tools.I18n.tr; 005 006import java.awt.Component; 007import java.awt.Point; 008import java.awt.event.ActionEvent; 009 010import javax.swing.AbstractAction; 011import javax.swing.SwingUtilities; 012 013import org.openstreetmap.josm.Main; 014import org.openstreetmap.josm.gui.help.HelpBrowser; 015import org.openstreetmap.josm.gui.help.HelpUtil; 016import org.openstreetmap.josm.io.OnlineResource; 017import org.openstreetmap.josm.tools.ImageProvider; 018 019/** 020 * Open a help browser and displays lightweight online help. 021 * @since 155 022 */ 023public class HelpAction extends AbstractAction { 024 025 /** 026 * Constructs a new {@code HelpAction}. 027 */ 028 public HelpAction() { 029 super(tr("Help"), ImageProvider.get("help")); 030 putValue("toolbar", "help"); 031 setEnabled(!Main.isOffline(OnlineResource.JOSM_WEBSITE)); 032 } 033 034 @Override 035 public void actionPerformed(ActionEvent e) { 036 if (e.getActionCommand() == null) { 037 String topic; 038 if (e.getSource() instanceof Component) { 039 Component c = SwingUtilities.getRoot((Component)e.getSource()); 040 Point mouse = c.getMousePosition(); 041 if (mouse != null) { 042 c = SwingUtilities.getDeepestComponentAt(c, mouse.x, mouse.y); 043 topic = HelpUtil.getContextSpecificHelpTopic(c); 044 } else { 045 topic = null; 046 } 047 } else { 048 Point mouse = Main.parent.getMousePosition(); 049 topic = HelpUtil.getContextSpecificHelpTopic(SwingUtilities.getDeepestComponentAt(Main.parent, mouse.x, mouse.y)); 050 } 051 if (topic == null) { 052 HelpBrowser.setUrlForHelpTopic("/"); 053 } else { 054 HelpBrowser.setUrlForHelpTopic(topic); 055 } 056 } else { 057 HelpBrowser.setUrlForHelpTopic("/"); 058 } 059 } 060}