Class ActiveComponent
- All Implemented Interfaces:
ImageObserver
,MenuContainer
,Serializable
,CSProcess
java.awt.Component
with a channel interface.
Process Diagram
Description
ActiveComponent is a process extension of java.awt.Component with channels for run-time configuration and event notification. The event channels should be connected to one or more application-specific server processes (instead of registering a passive object as a Listener to this component).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.one2one (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.
Channel Protocols
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 method. |
focusEvent | FocusEvent | See the addFocusEventChannel method. |
keyEvent | KeyEvent | See the addKeyEventChannel method. |
mouseEvent | MouseEvent | See the addMouseEventChannel method. |
mouseMotionEvent | MouseEvent | See the addMouseMotionEventChannel method. |
Example
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.one2one (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) { final MouseEvent event = (MouseEvent) mouseEvent.in ().read (); switch (event.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: if (event.getClickCount() > 1) { System.out.println ("MOUSE_DOUBLE_CLICKED ... goodbye!"); running = false; } else { System.out.println ("MOUSE_CLICKED ... *double* click to quit!"); } break; } } root.setVisible (false); System.exit (0); } } } ).run (); } }
- Author:
- P.D. Austin and P.H. Welch
- See Also:
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionstatic interface
This enables general configuration of this component.Nested classes/interfaces inherited from class java.awt.Component
Component.AccessibleAWTComponent, Component.BaselineResizeBehavior, Component.BltBufferStrategy, Component.FlipBufferStrategy
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Field Summary
Fields inherited from class java.awt.Component
accessibleContext, BOTTOM_ALIGNMENT, CENTER_ALIGNMENT, LEFT_ALIGNMENT, RIGHT_ALIGNMENT, TOP_ALIGNMENT
Fields inherited from interface java.awt.image.ImageObserver
ABORT, ALLBITS, ERROR, FRAMEBITS, HEIGHT, PROPERTIES, SOMEBITS, WIDTH
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Constructor Summary
ConstructorsConstructorDescriptionConstructs a new ActiveComponent with no configuration channel.ActiveComponent
(ChannelInput configure) Constructs a new ActiveComponent with a configuration channel. -
Method Summary
Modifier and TypeMethodDescriptionvoid
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.Methods inherited from class java.awt.Component
action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, addNotify, addPropertyChangeListener, addPropertyChangeListener, applyComponentOrientation, areFocusTraversalKeysSet, bounds, checkImage, checkImage, coalesceEvents, contains, contains, createImage, createImage, createVolatileImage, createVolatileImage, deliverEvent, disable, disableEvents, dispatchEvent, doLayout, enable, enable, enableEvents, enableInputMethods, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getAccessibleContext, getAlignmentX, getAlignmentY, getBackground, getBaseline, getBaselineResizeBehavior, getBounds, getBounds, getColorModel, getComponentAt, getComponentAt, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeys, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphics, getGraphicsConfiguration, getHeight, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getListeners, getLocale, getLocation, getLocation, getLocationOnScreen, getMaximumSize, getMinimumSize, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPreferredSize, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getSize, getToolkit, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, hide, imageUpdate, inside, invalidate, isBackgroundSet, isCursorSet, isDisplayable, isDoubleBuffered, isEnabled, isFocusable, isFocusCycleRoot, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isOpaque, isPreferredSizeSet, isShowing, isValid, isVisible, keyDown, keyUp, layout, list, list, list, list, list, locate, location, lostFocus, minimumSize, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paint, paintAll, paramString, postEvent, preferredSize, prepareImage, prepareImage, print, printAll, processComponentEvent, processEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processKeyEvent, processMouseEvent, processMouseMotionEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removeNotify, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, repaint, requestFocus, requestFocus, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, requestFocusInWindow, reshape, resize, resize, revalidate, setBackground, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setEnabled, setFocusable, setFocusTraversalKeys, setFocusTraversalKeysEnabled, setFont, setForeground, setIgnoreRepaint, setLocale, setLocation, setLocation, setMaximumSize, setMinimumSize, setMixingCutoutShape, setName, setPreferredSize, setSize, setSize, setVisible, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle, update, validate
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Constructor Details
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ActiveComponent
public ActiveComponent()Constructs a new ActiveComponent with no configuration channel. -
ActiveComponent
Constructs a new ActiveComponent with a configuration channel.- Parameters:
configure
- the channel for configuration events -- can be null if no configuration is required.
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Method Details
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setConfigureChannel
Sets the configuration channel for this ActiveComponent. This method overwrites any configuration channel set in the constructor.- Parameters:
configure
- the channel for configuration events -- can be null if no configuration is required.
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addComponentEventChannel
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.
- Parameters:
componentEvent
- the channel down which ComponentEvents will be sent.
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addFocusEventChannel
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.
- Parameters:
focusEvent
- the channel down which FocusEvents will be sent.
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addKeyEventChannel
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.
- Parameters:
keyEvent
- the channel down which KeyEvents will be sent.
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addMouseEventChannel
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.
- Parameters:
mouseEvent
- the channel down which MouseEvents will be sent.
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addMouseMotionEventChannel
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.
- Parameters:
mouseMotionEvent
- the channel down which MouseMotionEvents will be sent.
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run
public void run()The main body of this process.
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