public class ActiveMenuItem extends MenuItem
MenuItem<TT>java.awt.MenuItem</TT> with a channel interface.
The configure and event channels are settable from a constructor. The event channel delivers the current label on the ActiveMenuItem whenever it is selected. Messages can be sent down the configure channel at any time to configure the component. See the table below for details.
All channels are managed by independent internal handler processes. It is, therefore, safe for a serial application process both to service the event channel and configure the component -- no deadlock can occur.
IMPORTANT: it is essential that a (non-null) event channel from this process is always serviced -- otherwise the Java Event Thread will be blocked and the GUI will stop responding. A simple way to guarantee this is to use channels configured with overwriting buffers. For example:
final One2OneChannel myMenuItemEvent = Channel.createOne2One (new OverWriteOldestBuffer (n)); final ActiveMenuItem myMenuItem = new ActiveMenuItem (null, myMenuItemEvent.out (), "Choose Me");This will ensure that the Java Event Thread will never be blocked. Slow or inattentive readers may miss rapidly generated events, but the n most recent events will always be available.
Input Channels | ||
---|---|---|
configure | String | Change the label on the ActiveMenuItem to the value of the String |
java.awt.MenuShortcut | Sets the MenuShortcut for the ActiveMenuItem | |
Boolean |
|
|
ActiveMenuItem.Configure | Invoke the user-defined Configure.configure method on the menuItem. | |
Output Channels | ||
event | String | The label on the ActiveMenuItem (when the item is selected) |
import java.awt.*; import org.jcsp.lang.*; import org.jcsp.util.*; import org.jcsp.awt.*; public class ActiveMenuItemExample { public static void main (String argv[]) { final ActiveClosingFrame activeClosingFrame = new ActiveClosingFrame ("ActiveMenuItem Example"); final ActiveFrame frame = activeClosingFrame.getActiveFrame (); final MenuBar menuBar = new MenuBar (); frame.setMenuBar (menuBar); final Menu fileMenu = new Menu ("File"); final Menu langMenu = new Menu ("Language"); menuBar.add (fileMenu); menuBar.add (langMenu); final String[] fileOptions = {"Hello World", "Rocket Science", "CSP", "Monitors", "Ignore Me", "Goodbye World"}; final String[] langOptions = {"occam", "Java", "Smalltalk", "Algol-60", "Pascal", "Haskell", "SML", "Lisp"}; final Any2OneChannel event[] = Channel.createAny2One (2, new OverWriteOldestBuffer (10)); final ActiveMenuItem[] fileMenuItem = new ActiveMenuItem[fileOptions.length]; for (int i = 0; i < fileOptions.length; i++) { fileMenuItem[i] = new ActiveMenuItem (null, event[0].out (), fileOptions[i]); fileMenu.add (fileMenuItem[i]); } final ActiveMenuItem[] langMenuItem = new ActiveMenuItem[langOptions.length]; for (int i = 0; i < langOptions.length; i++) { langMenuItem[i] = new ActiveMenuItem (null, event[1].out (), langOptions[i]); langMenu.add (langMenuItem[i]); } frame.setSize (300, 200); frame.setBackground (Color.green); frame.setVisible (true); new Parallel ( new CSProcess[] { activeClosingFrame, new Parallel (fileMenuItem), new Parallel (langMenuItem), new CSProcess () { public void run () { boolean running = true; while (running) { final String s = (String) event[0].in ().read (); System.out.println ("File ==> `" + s + "' selected ..."); running = (s != fileOptions[fileOptions.length - 1]); } frame.setVisible (false); System.exit (0); } }, new CSProcess () { public void run () { while (true) { final String s = (String) event[1].in ().read (); System.out.println ("Language ==> `" + s + "' selected ..."); } } } } ).run (); } }
Modifiers | Name | Description |
---|---|---|
static interface |
ActiveMenuItem.Configure |
This enables general configuration of this component. |
Constructor and description |
---|
ActiveMenuItem
() Constructs a new ActiveMenuItem with no label and no shortcut and no configuration or event channels. |
ActiveMenuItem
(String s) Constructs a new ActiveMenuItem with no shortcut and no configuration or event channels. |
ActiveMenuItem
(String s, MenuShortcut ms) Constructs a new ActiveMenuItem with no configuration or event channels. |
ActiveMenuItem
(ChannelInput configure, ChannelOutput event) Constructs a new ActiveMenuItem with no label and no shortcut. |
ActiveMenuItem
(ChannelInput configure, ChannelOutput event, String s) Constructs a new ActiveMenuItem with no shortcut. |
ActiveMenuItem
(ChannelInput configure, ChannelOutput event, String s, MenuShortcut ms) Constructs a new ActiveMenuItem. |
Type | Name and description |
---|---|
void |
run() The main body of this process. |
void |
setConfigureChannel(ChannelInput configure) Sets the configuration channel for this ActiveMenuItem. |
Methods inherited from class | Name |
---|---|
class MenuItem |
paramString, disable, enable, enable, deleteShortcut, getShortcut, setShortcut, isEnabled, getLabel, setLabel, addActionListener, getAccessibleContext, getActionCommand, getActionListeners, getListeners, removeActionListener, setActionCommand, setEnabled, addNotify, toString, getName, getParent, setName, getFont, getPeer, removeNotify, setFont, dispatchEvent, postEvent, wait, wait, wait, equals, hashCode, getClass, notify, notifyAll |
class MenuComponent |
toString, getName, getParent, setName, getFont, getPeer, removeNotify, setFont, dispatchEvent, postEvent, getAccessibleContext, wait, wait, wait, equals, hashCode, getClass, notify, notifyAll |
Constructs a new ActiveMenuItem with no label and no shortcut and no configuration or event channels.
Constructs a new ActiveMenuItem with no shortcut and no configuration or event channels.
s
- the initial label displayed on the menuItem.Constructs a new ActiveMenuItem with no configuration or event channels.
s
- the initial label displayed on the menuItem.ms
- the MenuShortcut for the menuItem.Constructs a new ActiveMenuItem with no label and no shortcut.
configure
- the channel for configuration events
-- can be null if no configuration is required.event
- the current label will be output when the menuItem is selected
-- can be null if no notification is required.Constructs a new ActiveMenuItem with no shortcut.
configure
- the channel for configuration events
-- can be null if no configuration is required.event
- the current label will be output when the menuItem is selected
-- can be null if no notification is required.s
- the initial label displayed on the menuItem.Constructs a new ActiveMenuItem.
configure
- the channel for configuration events
-- can be null if no configuration is required.event
- the current label will be output when the menuItem is selected
-- can be null if no notification is required.s
- the initial label displayed on the menuItem.ms
- the MenuShortcut for the menuItem.The main body of this process.
Sets the configuration channel for this ActiveMenuItem. This method overwrites any configuration channel set in the constructor.
configure
- the channel for configuration events
-- can be null if no configuration is required.JCSP for Java 1.8 generated 14-10-2016 by Jon Kerridge, Edinburgh Napier University - j dot kerridge at napier dot ac dot uk