public class ActiveComponent extends Component
Component<TT>java.awt.Component</TT> with a channel interface.
All channels are optional. The configure channel is settable from a constructor. Event channels can be added to notify the occurrence of any type of Event 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 myMouseEvent = Channel.createOne2One (new OverWriteOldestBuffer (n)); final ActiveComponent myComponent = new ActiveComponent (); myComponent.addMouseEventChannel (myMouseEvent.out ());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 | ActiveComponent.Configure | Invoke the user-defined Configure.configure method on the component. |
Output Channels | ||
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 java.awt.event.*; import org.jcsp.util.*; import org.jcsp.lang.*; import org.jcsp.awt.*; public class ActiveComponentExample { public static void main (String argv[]) { final Frame root = new Frame ("ActiveComponent Example"); final One2OneChannel mouseEvent = Channel.createOne2One (new OverWriteOldestBuffer (10)); final ActiveComponent component = new ActiveComponent (); component.addMouseEventChannel (mouseEvent.out ()); root.add (component); root.setSize (400, 400); root.setVisible (true); new Parallel ( new CSProcess[] { component, new CSProcess () { public void run () { boolean running = true; while (running) { switch (((MouseEvent) mouseEvent.in ().read ()).getID ()) { case MouseEvent.MOUSE_ENTERED: System.out.println ("MOUSE_ENTERED"); break; case MouseEvent.MOUSE_EXITED: System.out.println ("MOUSE_EXITED"); break; case MouseEvent.MOUSE_PRESSED: System.out.println ("MOUSE_PRESSED"); break; case MouseEvent.MOUSE_RELEASED: System.out.println ("MOUSE_RELEASED"); break; case MouseEvent.MOUSE_CLICKED: System.out.println ("MOUSE_CLICKED ... goodbye!"); running = false; break; } } root.setVisible (false); System.exit (0); } } } ).run (); } }
Modifiers | Name | Description |
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static interface |
ActiveComponent.Configure |
This enables general configuration of this component. |
Fields inherited from class | Fields |
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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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ActiveComponent
() Constructs a new ActiveComponent with no configuration channel. |
ActiveComponent
(ChannelInput configure) Constructs a new ActiveComponent with a configuration channel. |
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 |
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 ActiveComponent. |
Constructs a new ActiveComponent with no configuration channel.
Constructs a new ActiveComponent with a configuration channel.
configure
- the channel for configuration events
-- can be null if no configuration is required.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 ComponentEvents will be sent.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 FocusEvents will be sent.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 KeyEvents will be sent.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 MouseEvents will be sent.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 MouseMotionEvents will be sent.The main body of this process.
Sets the configuration channel for this ActiveComponent. 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