public class ActiveCheckboxMenuItem extends CheckboxMenuItem
CheckboxMenuItem<TT>java.awt.CheckboxMenuItem</TT> with a channel interface.
All channels are optional. The configure and event channels are settable from a constructor. The event channel delivers the generated java.awt.ItemEvent whenever the ActiveCheckboxMenuItem is selected. Other event channels can be added to notify the occurrence of any other events the component generates (by calling the appropriate addXXXEventChannel method before the process is run). 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 an event channel and configure the component -- no deadlock can occur.
IMPORTANT: it is essential that event channels from this process are 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 myCheckboxMenuItemEvent = Channel.createOne2One (new OverWriteOldestBuffer (n)); final ActiveCheckboxMenuItem myCheckboxMenuItem = new ActiveCheckboxMenuItem (null, myCheckboxMenuItemEvent.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 | ||
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configure | String | Change the label on the ActiveCheckboxMenuItem to the value of the String |
java.awt.MenuShortcut | Sets the MenuShortcut for the ActiveCheckboxMenuItem | |
Boolean |
|
|
ActiveCheckboxMenuItem.Configure | Invoke the user-defined Configure.configure method on the checkboxMenuItem. | |
Output Channels | ||
event | java.awt.ItemEvent | The generated java.awt.ItemEvent is written down this channel (when the checkboxMenuItem is selected or deslected) |
actionEvent | ActionEvent | See the addActionEventChannel<TT>addActionEventChannel</TT> method. |
import java.awt.*; import java.awt.event.*; import org.jcsp.lang.*; import org.jcsp.util.*; import org.jcsp.awt.*; public class ActiveCheckboxMenuItemExample { public static void main (String argv[]) { final ActiveClosingFrame activeClosingFrame = new ActiveClosingFrame ("ActiveCheckboxMenuItem 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 ActiveCheckboxMenuItem[] langCheckboxMenuItem = new ActiveCheckboxMenuItem[langOptions.length]; for (int i = 0; i < langOptions.length; i++) { langCheckboxMenuItem[i] = new ActiveCheckboxMenuItem (null, event[1].out (), langOptions[i]); langMenu.add (langCheckboxMenuItem[i]); } frame.setSize (300, 200); frame.setBackground (Color.green); frame.setVisible (true); new Parallel ( new CSProcess[] { activeClosingFrame, new Parallel (fileMenuItem), new Parallel (langCheckboxMenuItem), 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 ItemEvent e = (ItemEvent) event[1].in ().read (); final String item = (String) e.getItem (); System.out.print ("Language ==> `" + item); if (e.getStateChange () == ItemEvent.SELECTED) { System.out.println ("' selected ..."); } else { System.out.println ("' deselected ..."); } } } } } ).run (); } }
Modifiers | Name | Description |
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static interface |
ActiveCheckboxMenuItem.Configure |
This enables general configuration of this component. |
Constructor and description |
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ActiveCheckboxMenuItem
() Constructs a new unchecked ActiveCheckboxMenuItem with no initial label and no configuration or event channels. |
ActiveCheckboxMenuItem
(String s) Constructs a new unchecked ActiveCheckboxMenuItem with no configuration or event channels. |
ActiveCheckboxMenuItem
(String s, boolean state) Constructs a new ActiveCheckboxMenuItem with no configuration or event channels. |
ActiveCheckboxMenuItem
(ChannelInput configure, ChannelOutput event) Constructs a new unchecked ActiveCheckboxMenuItem with no initial label. |
ActiveCheckboxMenuItem
(ChannelInput configure, ChannelOutput event, String s) Constructs a new unchecked ActiveCheckboxMenuItem. |
ActiveCheckboxMenuItem
(ChannelInput configure, ChannelOutput event, String s, boolean state) Constructs a new ActiveCheckboxMenuItem. |
Type | Name and description |
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void |
addActionEventChannel(ChannelOutput actionEvent) Add a new channel to this component that will be used to notify that an ActionEvent has occurred. |
void |
run() The main body of this process. |
void |
setConfigureChannel(ChannelInput configure) Sets the configuration channel for this ActiveCheckboxMenuItem. |
Constructs a new unchecked ActiveCheckboxMenuItem with no initial label and no configuration or event channels.
Constructs a new unchecked ActiveCheckboxMenuItem with no configuration or event channels.
s
- the initial label displayed on the checkboxMenuItem.Constructs a new ActiveCheckboxMenuItem with no configuration or event channels.
s
- the initial label displayed on the checkboxMenuItem.state
- the initial state of the checkboxMenuItem.Constructs a new unchecked ActiveCheckboxMenuItem with no initial label.
configure
- the channel for configuration events
-- can be null if no configuration is required.event
- the current label will be output when the checkboxMenuItem is selected
-- can be null if no notification is required.Constructs a new unchecked ActiveCheckboxMenuItem.
configure
- the channel for configuration events
-- can be null if no configuration is required.event
- the current label will be output when the checkboxMenuItem is selected
-- can be null if no notification is required.s
- the initial label displayed on the checkboxMenuItem.Constructs a new ActiveCheckboxMenuItem.
configure
- the channel for configuration events
-- can be null if no configuration is required.event
- the current label will be output when the checkboxMenuItem is selected
-- can be null if no notification is required.s
- the initial label displayed on the checkboxMenuItem.state
- the initial state of the checkboxMenuItem.Add a new channel to this component that will be used to notify that an ActionEvent has occurred. This should be used instead of registering a ActionListener with the component. It is possible to add more than one channel by calling this method multiple times If the channel passed is null, no action will be taken.
NOTE: This method must be called before this process is run.
actionEvent
- the channel down which to send ActionEvents.The main body of this process.
Sets the configuration channel for this ActiveCheckboxMenuItem. 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