public class ActiveButton extends Button
Button<TT>java.awt.Button</TT> with a channel interface.
All channels are optional. The configure and event channels are settable from a constructor. The event channel delivers the current button label whenever the ActiveButton is pressed. 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 myButtonEvent = Channel.createOne2One (new OverWriteOldestBuffer (n)); final ActiveButton myButton = new ActiveButton (null, myButtonEvent.out (), "Press 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 ActiveButton to the value of the String. |
Boolean |
|
|
ActiveButton.Configure | Invoke the user-defined Configure.configure method on the button. | |
Output Channels | ||
event | String | The label on the ActiveButton (when the button is pressed and released). |
componentEvent | ComponentEvent | See the addComponentEventChannel<TT>addComponentEventChannel</TT> method. |
focusEvent | FocusEvent | See the addFocusEventChannel<TT>addFocusEventChannel</TT> method. |
keyEvent | KeyEvent | See the addKeyEventChannel<TT>addKeyEventChannel</TT> method. |
mouseEvent | MouseEvent | See the addMouseEventChannel<TT>addMouseEventChannel</TT> method. |
mouseMotionEvent | MouseEvent | See the addMouseMotionEventChannel<TT>addMouseMotionEventChannel</TT> method. |
import java.awt.*; import org.jcsp.lang.*; import org.jcsp.util.*; import org.jcsp.awt.*; public class ActiveButtonExample { public static void main (String argv[]) { final Frame root = new Frame ("ActiveButton Example"); final String[] label = {"Hello World", "Rocket Science", "CSP", "Monitors", "Ignore Me", "Goodbye World"}; final Any2OneChannel event = Channel.createAny2One (new OverWriteOldestBuffer (10)); final ActiveButton[] button = new ActiveButton[label.length]; for (int i = 0; i < label.length; i++) { button[i] = new ActiveButton (null, event.out (), label[i]); } root.setSize (300, 200); root.setLayout (new GridLayout (label.length/2, 2)); for (int i = 0; i < label.length; i++) { root.add (button[i]); } root.setVisible (true); new Parallel ( new CSProcess[] { new Parallel (button), new CSProcess () { public void run () { boolean running = true; while (running) { final String s = (String) event.in ().read (); System.out.println ("Button `" + s + "' pressed ..."); running = (s != label[label.length - 1]); } root.setVisible (false); System.exit (0); } } } ).run (); } }
Modifiers | Name | Description |
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static interface |
ActiveButton.Configure |
This enables general configuration of this component. |
Fields inherited from class | Fields |
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class Button |
TOP_ALIGNMENT, CENTER_ALIGNMENT, BOTTOM_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, WIDTH, HEIGHT, PROPERTIES, SOMEBITS, FRAMEBITS, ALLBITS, ERROR, ABORT |
class Component |
TOP_ALIGNMENT, CENTER_ALIGNMENT, BOTTOM_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, WIDTH, HEIGHT, PROPERTIES, SOMEBITS, FRAMEBITS, ALLBITS, ERROR, ABORT |
Constructor and description |
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ActiveButton
() Constructs a new ActiveButton with no label, configuration or event channels. |
ActiveButton
(String s) Constructs a new ActiveButton with no configuration or event channels. |
ActiveButton
(ChannelInput configure, ChannelOutput event) Constructs a new ActiveButton with no initial label. |
ActiveButton
(ChannelInput configure, ChannelOutput event, String s) Constructs a new ActiveButton. |
Type | Name and description |
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void |
addComponentEventChannel(ChannelOutput componentEvent) Add a new channel to this component that will be used to notify that a ComponentEvent has occurred. |
void |
addEventChannel(ChannelOutput event) Add a new channel to this component that will be used to notify that the button has been pressed. |
void |
addFocusEventChannel(ChannelOutput focusEvent) Add a new channel to this component that will be used to notify that a FocusEvent has occurred. |
void |
addKeyEventChannel(ChannelOutput keyEvent) Add a new channel to this component that will be used to notify that a KeyEvent has occurred. |
void |
addMouseEventChannel(ChannelOutput mouseEvent) Add a new channel to this component that will be used to notify that a MouseEvent has occurred. |
void |
addMouseMotionEventChannel(ChannelOutput mouseMotionEvent) Add a new channel to this component that will be used to notify that a MouseMotionEvent has occurred. |
void |
run() The main body of this process. |
void |
setConfigureChannel(ChannelInput configure) Sets the configuration channel for this ActiveButton. |
Constructs a new ActiveButton with no label, configuration or event channels.
Constructs a new ActiveButton with no configuration or event channels.
s
- the initial label displayed on the button.Constructs a new ActiveButton 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 button is pressed
-- can be null if no notification is required.Constructs a new ActiveButton.
configure
- the channel for configuration events
-- can be null if no configuration is required.event
- the current label will be output when the button is pressed
-- can be null if no notification is required.s
- the initial label displayed on the button.Add a new channel to this component that will be used to notify that a ComponentEvent has occurred. This should be used instead of registering a ComponentListener 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.
componentEvent
- the channel down which to send ComponentEvents.Add a new channel to this component that will be used to notify that the button has been pressed. This should be used instead of registering an 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. This method is an alternative to setting such a channel in the constructor.
NOTE: This method must be called before this process is run.
event
- the channel down which to send the current label
when the button is pressed.Add a new channel to this component that will be used to notify that a FocusEvent has occurred. This should be used instead of registering a FocusListener 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.
focusEvent
- the channel down which to send FocusEvents.Add a new channel to this component that will be used to notify that a KeyEvent has occurred. This should be used instead of registering a KeyListener 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.
keyEvent
- the channel down which to send KeyEvents.Add a new channel to this component that will be used to notify that a MouseEvent has occurred. This should be used instead of registering a MouseListener 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.
mouseEvent
- the channel down which to send MouseEvents.Add a new channel to this component that will be used to notify that a MouseMotionEvent has occurred. This should be used instead of registering a MouseMotionListener 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.
mouseMotionEvent
- the channel down which to send MouseMotionEvents.The main body of this process.
Sets the configuration channel for this ActiveButton. 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