Package org.jcsp.awt

Class ActivePanel

  • All Implemented Interfaces:
    java.awt.image.ImageObserver, java.awt.MenuContainer, java.io.Serializable, javax.accessibility.Accessible, CSProcess

    public class ActivePanel
    extends java.awt.Panel
    implements CSProcess
    java.awt.Panel with a channel interface.

    Process Diagram

    Description

    ActivePanel is a process extension of java.awt.Panel 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 ActivePanel myPanel = new ActivePanel ();
       myPanel.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
    configure ActivePanel.Configure Invoke the user-defined Configure.configure method on the panel.
    Output Channels
    containerEvent ContainerEvent See the addContainerEventChannel method.
    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 ActivePanelExample {
     
       public static void main (String argv[]) {
     
         final Frame root = new Frame ("ActivePanel Example");
     
         final One2OneChannel mouseEvent = Channel.one2one (new OverWriteOldestBuffer (10));
     
         final ActivePanel panel = new ActivePanel ();
         panel.addMouseEventChannel (mouseEvent.out ());
     
         root.add (panel);
         root.setSize (400, 400);
         root.setVisible (true);
     
         new Parallel (
           new CSProcess[] {
             panel,
             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 ();
       }
     
     }
     
    See Also:
    Panel, ContainerEvent, ComponentEvent, FocusEvent, KeyEvent, MouseEvent, OverWriteOldestBuffer, Serialized Form
    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static interface  ActivePanel.Configure
      This enables general configuration of this component.
      • Nested classes/interfaces inherited from class java.awt.Panel

        java.awt.Panel.AccessibleAWTPanel
      • Nested classes/interfaces inherited from class java.awt.Container

        java.awt.Container.AccessibleAWTContainer
      • Nested classes/interfaces inherited from class java.awt.Component

        java.awt.Component.AccessibleAWTComponent, java.awt.Component.BaselineResizeBehavior, java.awt.Component.BltBufferStrategy, java.awt.Component.FlipBufferStrategy
    • Field Summary

      Fields 
      Modifier and Type Field Description
      private ChannelInput configure
      The channel from which configuration messages arrive.
      private java.util.Vector vec
      The Vector construct containing the handlers.
      • 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
    • Constructor Summary

      Constructors 
      Constructor Description
      ActivePanel()
      Constructs a new ActivePanel with no configuration channel.
      ActivePanel​(ChannelInput configure)
      Constructs a new ActivePanel with a configuration channel.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void addComponentEventChannel​(ChannelOutput componentEvent)
      Add a new channel to this component that will be used to notify that a ComponentEvent has occurred.
      void addContainerEventChannel​(ChannelOutput containerEvent)
      Add a new channel to this component that will be used to notify that a ContainerEvent 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 ActivePanel.
      • Methods inherited from class java.awt.Panel

        addNotify, getAccessibleContext
      • Methods inherited from class java.awt.Container

        add, add, add, add, add, addContainerListener, addImpl, addPropertyChangeListener, addPropertyChangeListener, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getAlignmentX, getAlignmentY, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getComponentZOrder, getContainerListeners, getFocusTraversalKeys, getFocusTraversalPolicy, getInsets, getLayout, getListeners, getMaximumSize, getMinimumSize, getMousePosition, getPreferredSize, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusCycleRoot, isFocusTraversalPolicyProvider, isFocusTraversalPolicySet, isValidateRoot, layout, list, list, locate, minimumSize, paint, paintComponents, paramString, preferredSize, print, printComponents, processContainerEvent, processEvent, remove, remove, removeAll, removeContainerListener, removeNotify, setComponentZOrder, setFocusCycleRoot, setFocusTraversalKeys, setFocusTraversalPolicy, setFocusTraversalPolicyProvider, setFont, setLayout, transferFocusDownCycle, update, validate, validateTree
      • Methods inherited from class java.awt.Component

        action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, bounds, checkImage, checkImage, coalesceEvents, contains, contains, createImage, createImage, createVolatileImage, createVolatileImage, disable, disableEvents, dispatchEvent, enable, enable, enableEvents, enableInputMethods, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, firePropertyChange, getBackground, getBaseline, getBaselineResizeBehavior, getBounds, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusCycleRootAncestor, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphics, getGraphicsConfiguration, getHeight, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputContext, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocale, getLocation, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPeer, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getSize, getToolkit, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, hide, imageUpdate, inside, isBackgroundSet, isCursorSet, isDisplayable, isDoubleBuffered, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isOpaque, isPreferredSizeSet, isShowing, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, postEvent, prepareImage, prepareImage, printAll, processComponentEvent, processFocusEvent, processHierarchyBoundsEvent, processHierarchyEvent, processInputMethodEvent, processKeyEvent, processMouseEvent, processMouseMotionEvent, processMouseWheelEvent, remove, removeComponentListener, removeFocusListener, removeHierarchyBoundsListener, removeHierarchyListener, removeInputMethodListener, removeKeyListener, removeMouseListener, removeMouseMotionListener, removeMouseWheelListener, removePropertyChangeListener, removePropertyChangeListener, repaint, repaint, repaint, repaint, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, reshape, resize, resize, revalidate, setBackground, setBounds, setBounds, setComponentOrientation, setCursor, setDropTarget, setEnabled, setFocusable, setFocusTraversalKeysEnabled, setForeground, setIgnoreRepaint, setLocale, setLocation, setLocation, setMaximumSize, setMinimumSize, setName, setPreferredSize, setSize, setSize, setVisible, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
    • Field Detail

      • vec

        private java.util.Vector vec
        The Vector construct containing the handlers.
      • configure

        private ChannelInput configure
        The channel from which configuration messages arrive.
    • Constructor Detail

      • ActivePanel

        public ActivePanel()
        Constructs a new ActivePanel with no configuration channel.
      • ActivePanel

        public ActivePanel​(ChannelInput configure)
        Constructs a new ActivePanel with a configuration channel.
        Parameters:
        configure - the channel for configuration events -- can be null if no configuration is required.
    • Method Detail

      • setConfigureChannel

        public void setConfigureChannel​(ChannelInput configure)
        Sets the configuration channel for this ActivePanel. 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.
      • addContainerEventChannel

        public void addContainerEventChannel​(ChannelOutput containerEvent)
        Add a new channel to this component that will be used to notify that a ContainerEvent has occurred. This should be used instead of registering a ContainerListener 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:
        containerEvent - the channel down which to send ContainerEvents.
      • addComponentEventChannel

        public void addComponentEventChannel​(ChannelOutput componentEvent)
        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 to send ComponentEvents.
      • addFocusEventChannel

        public void addFocusEventChannel​(ChannelOutput focusEvent)
        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 to send FocusEvents.
      • addKeyEventChannel

        public void addKeyEventChannel​(ChannelOutput keyEvent)
        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 to send KeyEvents.
      • addMouseEventChannel

        public void addMouseEventChannel​(ChannelOutput mouseEvent)
        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 to send MouseEvents.
      • addMouseMotionEventChannel

        public void addMouseMotionEventChannel​(ChannelOutput mouseMotionEvent)
        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 to send MouseMotionEvents.
      • run

        public void run()
        The main body of this process.
        Specified by:
        run in interface CSProcess