edu.mit.ai.psg.ui.outliner
Class OutlineCommand

java.lang.Object
  |
  +--edu.mit.ai.psg.ui.outliner.OutlineCommand

public abstract class OutlineCommand

extends Object

implements ActionListener, Runnable

Used for popup menu commands. Provides an ActionListener with methods that run the command in a separate thread so the AWT thread can continue to update the screen. Sets the cursor to the wait cursor while it is running. Derived classes must implement runCommand() to perform the command in the new thread, and queue work for the AWT thread to update the UI by calling SwingUtilities.invokeLater(java.lang.Runnable) or SwingUtilities.invokeAndWait(java.lang.Runnable) For example:

. void addPopupMenuTitle(final PopupMenu menu, final OutlineNode node,
.                        final TreePath treePath, final JTree jTree);
.   OutlineCommand.installCommand
.     (menu, "Compute",
.      new OutlineCommand(jTree, "MyProgram-Compute") {
.        protected void runCommand() throws InterruptedException {
.          compute...
.          SwingUtilities.invokeAndWait(new Runnable() { 
.            public void run() { update display... }); }});

See Also:

OutlineRenderer.addPopupMenuItems(java.awt.PopupMenu, edu.mit.ai.psg.ui.outliner.OutlineNode, javax.swing.tree.TreePath, javax.swing.JTree)

Field Summary

protected JTree	myJTree
protected String	myThreadName
static Cursor	waitCursor

Constructor Summary

OutlineCommand(JTree jTree, String threadName)
Initializes command; if this command is invoked, jTree is the JTree whose cursor becomes the wait cursor while this command runs in another thread named threadName.

Method Summary

void	actionPerformed(ActionEvent event) creates and starts a new thread that calls run()
static void	installCommand(Menu menu, String menuItemString, ActionListener outlineCommand) convenience procedure to install a MenuItem displayed with menuItemString that performs outlineCommand when invoked
static void	installDisabledCommand(Menu menu, String menuItemString)
protected void	invokeSwingAndWait(Runnable doUpdate) try { SwingUtilities.invokeAndWait(doUpate); } catch (InterruptedException e) {} catch (InvocationException e) { e.printStackTrace(); }
void	run() saves old JTree cursor and calls runCommand() and then restores old JTree cursor upon exit.
protected abstract void	runCommand() implement this method to perform command when invoked.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

myJTree

protected final JTree myJTree

myThreadName

protected final String myThreadName

waitCursor

public static Cursor waitCursor

Constructor Detail

OutlineCommand

public OutlineCommand(JTree jTree,
                      String threadName)

Initializes command; if this command is invoked, jTree is the JTree whose cursor becomes the wait cursor while this command runs in another thread named threadName.

Method Detail

installCommand

public static void installCommand(Menu menu,
                                  String menuItemString,
                                  ActionListener outlineCommand)

convenience procedure to install a MenuItem displayed with menuItemString that performs outlineCommand when invoked

installDisabledCommand

public static void installDisabledCommand(Menu menu,
                                          String menuItemString)

actionPerformed

public void actionPerformed(ActionEvent event)

creates and starts a new thread that calls run()

Specified by:

actionPerformed in interface ActionListener

run

public void run()

saves old JTree cursor and calls runCommand() and then restores old JTree cursor upon exit.

Specified by:

run in interface Runnable

runCommand

protected abstract void runCommand()

implement this method to perform command when invoked. It is run in its own thread, so accessing any (mutable) part of UI objects, including OutlineNodes, should be queued for the AWT thread through SwingUtilities.invokeLater(java.lang.Runnable) or SwingUtilities.invokeAndWait(java.lang.Runnable).

invokeSwingAndWait

protected void invokeSwingAndWait(Runnable doUpdate)

try { SwingUtilities.invokeAndWait(doUpate); } catch (InterruptedException e) {} catch (InvocationException e) { e.printStackTrace(); }