Package org.jcsp.awt

Class ActiveList

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

    public class ActiveList
    extends java.awt.List
    implements CSProcess
    java.awt.List with a channel interface.

    Process Diagram

    Description

    ActiveList is a process extension of java.awt.List 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 and event channels are settable from a constructor. When an item in the ActiveList is double-clicked, its label is written down the event channel. 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 myListEvent = Channel.one2one (new OverWriteOldestBuffer (n));
       final One2OneChannel myListItemEvent = Channel.one2one (new OverWriteOldestBuffer (n));
     
       final ActiveList myList = new ActiveList (null, myListEvent.out ());
       myList.addItemEventChannel (myListItemEvent.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 String Empty strings are ignored. If the string is "-*", all items in the list are removed. Otherwise, if the first character is '-', the item corresponding to the tail of the string is removed from the list. Otherwise, the string is added to the end of the list.
    Integer Sets the selected item in this ActiveList list to be the item at the specified position.
    Boolean
    1. If this is the Boolean.TRUE object, the list is made active
    2. If this is the Boolean.FALSE object, the list is made inactive
    3. Other Boolean objects are ignored
    ActiveList.Configure Invoke the user-defined Configure.configure method on the list.
    Output Channels
    event String When an item in the ActiveList is double-clicked, its label is written down this channel.
    itemEvent ItemEvent See the addItemEventChannel 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.lang.*;
     import org.jcsp.util.*;
     import org.jcsp.awt.*;
     
     public class ActiveListExample {
     
       public static void main (String argv[]) {
     
         final Frame root = new Frame ("ActiveList Example");
     
         final One2OneChannel configure = Channel.one2one ();
     
         final One2OneChannel event = Channel.one2one (new OverWriteOldestBuffer (10));
         final One2OneChannel itemEvent = Channel.one2one (new OverWriteOldestBuffer (10));
     
         final ActiveList list = new ActiveList (configure.in (), event.out (), 0, true);
         list.addItemEventChannel (itemEvent.out ());
     
         final String[] menu = {"Hello World", "Rocket Science", "CSP",
                               "Monitors", "Ignore Me", "Goodbye World"};
     
         for (int i = 0; i < menu.length; i++) {
           list.add (menu[i]);
         }
     
         root.setSize (300, 105);
         root.add (list);
         root.setVisible (true);
     
         new Parallel (
           new CSProcess[] {           // respond to the event channel
             list,
             new CSProcess () {
               public void run () {
                 boolean running = true;
                 while (running) {
                   final String s = (String) event.in ().read ();
                   System.out.println ("                         Action ==> `" + s + "'");
                   running = (s != menu[menu.length - 1]);
                 }
                 root.setVisible (false);
                 System.exit (0);
               }
             },
             new CSProcess () {        // respond to the itemEvent channel
               public void run () {
                 while (true) {
                   final ItemEvent e = (ItemEvent) itemEvent.in ().read ();
                   final Integer item = (Integer) e.getItem ();
                   if (e.getStateChange () == ItemEvent.SELECTED) {
                     System.out.println ("Selected item " + item);
                   } else {
                     System.out.println ("Unselected item " + item);
                   }
                 }
               }
             },
             new CSProcess () {        // dynamically reconfigure the list
               public void run () {
                 CSTimer tim = new CSTimer ();
                 long timeout = tim.read ();
                 while (true) {
                   timeout += 10000;
                   tim.after (timeout);
                   System.out.println ("*** Removing last three items ...");
                   for (int i = 3; i < menu.length; i++) {
                     configure.out ().write ("-" + menu[i]);
                   }
                   timeout += 10000;
                   tim.after (timeout);
                   System.out.println ("*** Restoring last three items ...");
                   for (int i = 3; i < menu.length; i++) {
                     configure.out ().write (menu[i]);
                   }
                 }
               }
             }
           }
         ).run ();
     
       }
     
     }
     
    See Also:
    List, ItemEvent, ComponentEvent, FocusEvent, KeyEvent, MouseEvent, OverWriteOldestBuffer, Serialized Form
    • Nested Class Summary

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

        java.awt.List.AccessibleAWTList
      • 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
      ActiveList()
      Constructs an ActiveList with no visible lines, no configuration or event channels and only one item selectable.
      ActiveList​(int rows)
      Constructs an ActiveList with the specified number of visible lines, but with no configuration or event channels and only one item selectable.
      ActiveList​(int rows, boolean multipleMode)
      Constructs an ActiveList with the specified number of visible lines and a multiple selection option, but with no configuration or event channels.
      ActiveList​(ChannelInput configure, ChannelOutput event)
      Constructs an ActiveList with configuration and event channels, but no visible items and only one item selectable.
      ActiveList​(ChannelInput configure, ChannelOutput event, int rows)
      Constructs an ActiveList with configuration and event channels, the specified number of visible lines and only one item selectable.
      ActiveList​(ChannelInput configure, ChannelOutput event, int rows, boolean multipleMode)
      Constructs an ActiveList with configuration and event channels, the specified number of visible lines and a multiple selection option.
    • 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 addFocusEventChannel​(ChannelOutput focusEvent)
      Add a new channel to this component that will be used to notify that a FocusEvent has occurred.
      void addItemEventChannel​(ChannelOutput itemEvent)
      Add a new channel to this component that will be used to notify that an ItemEvent 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 ActiveList.
      • Methods inherited from class java.awt.List

        add, add, addActionListener, addItem, addItem, addItemListener, addNotify, allowsMultipleSelections, clear, countItems, delItem, delItems, deselect, getAccessibleContext, getActionListeners, getItem, getItemCount, getItemListeners, getItems, getListeners, getMinimumSize, getMinimumSize, getPreferredSize, getPreferredSize, getRows, getSelectedIndex, getSelectedIndexes, getSelectedItem, getSelectedItems, getSelectedObjects, getVisibleIndex, isIndexSelected, isMultipleMode, isSelected, makeVisible, minimumSize, minimumSize, paramString, preferredSize, preferredSize, processActionEvent, processEvent, processItemEvent, remove, remove, removeActionListener, removeAll, removeItemListener, removeNotify, replaceItem, select, setMultipleMode, setMultipleSelections
      • Methods inherited from class java.awt.Component

        action, add, addComponentListener, addFocusListener, addHierarchyBoundsListener, addHierarchyListener, addInputMethodListener, addKeyListener, addMouseListener, addMouseMotionListener, addMouseWheelListener, 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, 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, getLocale, getLocation, getLocation, getLocationOnScreen, getMaximumSize, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPeer, 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, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paint, paintAll, postEvent, prepareImage, prepareImage, print, 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, setFocusTraversalKeys, setFocusTraversalKeysEnabled, setFont, setForeground, setIgnoreRepaint, setLocale, setLocation, setLocation, setMaximumSize, setMinimumSize, setName, setPreferredSize, setSize, setSize, setVisible, show, show, size, toString, transferFocus, transferFocusBackward, transferFocusUpCycle, update, validate
      • 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

      • ActiveList

        public ActiveList()
        Constructs an ActiveList with no visible lines, no configuration or event channels and only one item selectable.
      • ActiveList

        public ActiveList​(int rows)
        Constructs an ActiveList with the specified number of visible lines, but with no configuration or event channels and only one item selectable.
        Parameters:
        rows - the number of visible lines.
      • ActiveList

        public ActiveList​(int rows,
                          boolean multipleMode)
        Constructs an ActiveList with the specified number of visible lines and a multiple selection option, but with no configuration or event channels.
        Parameters:
        rows - the number of visible lines.
        multipleMode - the multiple selection option.
      • ActiveList

        public ActiveList​(ChannelInput configure,
                          ChannelOutput event)
        Constructs an ActiveList with configuration and event channels, but no visible items and only one item selectable.
        Parameters:
        configure - the channel for configuration events -- can be null if no configuration is required.
        event - the String label from a list item will be output when it is double-clicked -- can be null if no notification is required.
      • ActiveList

        public ActiveList​(ChannelInput configure,
                          ChannelOutput event,
                          int rows)
        Constructs an ActiveList with configuration and event channels, the specified number of visible lines and only one item selectable.
        Parameters:
        configure - the channel for configuration events -- can be null if no configuration is required.
        event - the String label from a list item will be output when it is double-clicked -- can be null if no notification is required.
        rows - the number of visible lines.
      • ActiveList

        public ActiveList​(ChannelInput configure,
                          ChannelOutput event,
                          int rows,
                          boolean multipleMode)
        Constructs an ActiveList with configuration and event channels, the specified number of visible lines and a multiple selection option.
        Parameters:
        configure - the channel for configuration events -- can be null if no configuration is required.
        event - the String label from a list item will be output when it is double-clicked -- can be null if no notification is required.
        rows - the number of visible lines.
        multipleMode - the multiple selection option.
    • Method Detail

      • setConfigureChannel

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

        public void addItemEventChannel​(ChannelOutput itemEvent)
        Add a new channel to this component that will be used to notify that an ItemEvent has occurred. This should be used instead of registering a ItemListener 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:
        itemEvent - the channel down which to send ItemEvents.
      • 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