Index: applications/editors/josm/plugins/tageditor/src/org/openstreetmap/josm/plugins/tageditor/LaunchAction.java
===================================================================
--- applications/editors/josm/plugins/tageditor/src/org/openstreetmap/josm/plugins/tageditor/LaunchAction.java	(revision 14322)
+++ applications/editors/josm/plugins/tageditor/src/org/openstreetmap/josm/plugins/tageditor/LaunchAction.java	(revision 14322)
@@ -0,0 +1,170 @@
+package org.openstreetmap.josm.plugins.tageditor;
+
+import static org.openstreetmap.josm.tools.I18n.tr;
+
+import java.awt.Component;
+import java.awt.Dimension;
+import java.awt.GraphicsConfiguration;
+import java.awt.Point;
+import java.awt.Rectangle;
+import java.awt.Window;
+import java.awt.event.ActionEvent;
+import java.awt.event.KeyEvent;
+import java.util.Collection;
+
+import javax.swing.JMenu;
+import javax.swing.JMenuBar;
+import javax.swing.JMenuItem;
+import javax.swing.KeyStroke;
+
+import org.openstreetmap.josm.Main;
+import org.openstreetmap.josm.actions.JosmAction;
+import org.openstreetmap.josm.data.SelectionChangedListener;
+import org.openstreetmap.josm.data.osm.DataSet;
+import org.openstreetmap.josm.data.osm.OsmPrimitive;
+import org.openstreetmap.josm.tools.Shortcut;
+
+@SuppressWarnings("serial")
+public class LaunchAction extends JosmAction implements SelectionChangedListener {
+	 
+	protected void registerAsMenuItem() {
+        JMenuBar menu = Main.main.menu;
+        JMenu edit = null;
+        JMenuItem item = new JMenuItem(this);
+
+        for (int i = 0; i < menu.getMenuCount(); ++i) {
+            if (menu.getMenu(i) != null
+                    && tr("Edit").equals(menu.getMenu(i).getText())) {
+                edit = menu.getMenu(i);
+                break;
+            }
+        }
+
+        if (edit != null) {
+        	edit.insertSeparator(edit.getItemCount());
+        	JMenuItem mitem = edit.insert(this, edit.getItemCount());
+        	mitem.setAccelerator(KeyStroke.getKeyStroke('T'));
+        } else if (menu.getMenuCount() > 0) {
+            edit = menu.getMenu(0);
+            JMenuItem mitem = edit.insert(this, 0);
+        	mitem.setAccelerator(KeyStroke.getKeyStroke('T'));
+
+        }
+
+        item.setVisible(true);
+	}
+	
+
+
+	public LaunchAction()  {
+		super(
+			tr("Edit tags"),
+			null, //TODO: set "tag-editor" and add /images/tag-editor.png to distrib
+			tr("Launches the tag editor dialog"),
+			Shortcut.registerShortcut(
+					"edit:launchtageditor", 
+					tr("Launches the tag editor dialog"),
+					KeyEvent.VK_T,
+					Shortcut.GROUP_EDIT),						
+			false // don't register, plugin will add the action to the menu
+		);
+		
+		
+		// register as dataset selection listener
+		//
+		DataSet.selListeners.add(this);
+		
+		// insert a menu item
+		//
+		registerAsMenuItem();
+		
+		// initially not enabled; becomes enabled when the selection becomes non-empty
+		//
+		setEnabled(false);
+		
+	}
+	
+	/**
+	 *  
+	 * @return  the top window of the JOSM GUI; can be null
+	 */
+	protected Window getTopWindow() {
+		if (Main.contentPane == null) {
+			return null;
+		}
+		Component c = Main.contentPane;
+		while(c.getParent() != null) {
+			c = c.getParent();
+		}
+		if (c instanceof Window) {
+			return (Window)c;
+		} else {
+			return null;
+		}
+	}
+	
+	/**
+	 * tries to center the tag editor dialog on the top window or, alternatively, 
+	 * on the screen
+	 * 
+	 * @param dialog the dialog to be placed on the screen 
+	 */
+	protected void placeDialogOnScreen(TagEditorDialog dialog) {
+		Window w = getTopWindow();
+		if (w == null) {
+			// don't center 
+			return;
+		}
+		
+		GraphicsConfiguration gc = w.getGraphicsConfiguration();
+		Rectangle screenBounds = null;
+		if (gc != null) {
+			screenBounds = gc.getBounds();
+		}
+		Rectangle winBounds = w.getBounds();
+		Dimension d = dialog.getPreferredSize();
+
+		Point p = new Point();
+		if (d.width <= winBounds.width && d.height <= winBounds.height) {
+			p.x = winBounds.x + ((winBounds.width - d.width)/2 );
+			p.y = winBounds.y + ((winBounds.height - d.height)/2 );
+		} else  {
+			p.x = screenBounds.x + ((screenBounds.width - d.width)/2 );
+			p.y = screenBounds.y + ((screenBounds.height - d.height)/2 );
+		}
+
+		dialog.setLocation(p);
+		
+	}
+	
+	/**
+	 * launch the editor 
+	 */
+	protected void launchEditor() {
+		if (!isEnabled()) {
+			return;
+		}
+		TagEditorDialog dialog = TagEditorDialog.getInstance();
+		placeDialogOnScreen(dialog);
+		dialog.startEditSession();		
+		dialog.setVisible(true);		
+	}
+	
+	
+	
+	
+	@Override
+	public void actionPerformed(ActionEvent e) {
+		launchEditor();
+	}
+
+	
+	@Override
+	public void selectionChanged(Collection<? extends OsmPrimitive> newSelection) {
+		setEnabled(newSelection != null && newSelection.size() >0);
+	}
+
+	
+	
+
+}