org.jgroups.demos.wb

## Class Whiteboard

- java.lang.Object
- - java.awt.Component
  - - java.awt.Container
    - - java.awt.Panel
      - - java.applet.Applet
        - - org.jgroups.demos.wb.Whiteboard

All Implemented Interfaces:
  java.awt.event.ActionListener, java.awt.event.ComponentListener, java.awt.event.FocusListener, java.awt.image.ImageObserver, java.awt.MenuContainer, java.io.Serializable, java.util.EventListener, javax.accessibility.Accessible, MembershipListener, MessageListener

    public class Whiteboard
    extends java.applet.Applet
    implements java.awt.event.ActionListener, MessageListener, MembershipListener, java.awt.event.ComponentListener, java.awt.event.FocusListener

Shared whiteboard: members are represented by rectangles that contain their names and the OS/arch of the machine they are working on. The boxes can be moved by anyone and by clicking on them, messages can be sent to specific or all members. Whiteboard is both an application and an applet.

Author:
  Bela Ban
See Also:
  Serialized Form

### Nested Class Summary

### Nested classes/interfaces inherited from class java.applet.Applet

`java.applet.Applet.AccessibleApplet`

### 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
`RpcDispatcher` `disp`
`static java.lang.String` `groupname`

### Fields inherited from class java.awt.Component

`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 and Description
`Whiteboard()`
`Whiteboard(java.lang.String properties)`

### Method Summary

Methods
`void` `actionPerformed(java.awt.event.ActionEvent e)`
`void` `addNode(java.lang.String lbl, Address addr, int xloc, int yloc)`
`void` `block()` Called (usually by the FLUSH protocol), as an indication that the member should stop sending messages.
`void` `componentHidden(java.awt.event.ComponentEvent e)`
`void` `componentMoved(java.awt.event.ComponentEvent e)`
`void` `componentResized(java.awt.event.ComponentEvent e)`
`void` `componentShown(java.awt.event.ComponentEvent e)`
`void` `destroy()`
`void` `displayMessage(java.lang.String sender, java.lang.String msg)`
`void` `focusGained(java.awt.event.FocusEvent e)`
`void` `focusLost(java.awt.event.FocusEvent e)`
`byte[]` `getState()` Answers the group state; e.g., when joining.
`void` `init()`
`static void` `main(java.lang.String[] args)`
`void` `moveNode(Node n)`
`void` `receive(Message m)` Called when a message is received.
`void` `removeNode(java.lang.Object addr)`
`void` `repaint()`
`void` `setState(byte[] new_state)` Sets the group state; e.g., when joining.
`void` `suspect(Address obj)` Called whenever a member is suspected of having crashed, but has not yet been excluded.
`void` `viewAccepted(View v)` Called when a change in membership has occurred.

### Methods inherited from class java.applet.Applet

`getAccessibleContext, getAppletContext, getAppletInfo, getAudioClip, getAudioClip, getCodeBase, getDocumentBase, getImage, getImage, getLocale, getParameter, getParameterInfo, isActive, newAudioClip, play, play, resize, resize, setStub, showStatus, start, stop`

### Methods inherited from class java.awt.Panel

`addNotify`

### 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, 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, 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, requestFocus, requestFocus, requestFocusInWindow, requestFocusInWindow, reshape, 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

#### disp

    public RpcDispatcher disp

#### groupname

    public static final java.lang.String groupname

See Also:
  Constant Field Values

### Constructor Detail

#### Whiteboard

    public Whiteboard()

#### Whiteboard

    public Whiteboard(java.lang.String properties)

### Method Detail

#### receive

    public void receive(Message m)

Description copied from interface: `MessageListener`
Called when a message is received.

Specified by:
  `receive` in interface `MessageListener`

#### getState

    public byte[] getState()

Description copied from interface: `MessageListener`
Answers the group state; e.g., when joining.

Specified by:
  `getState` in interface `MessageListener`
Returns:
  byte[]

#### setState

    public void setState(byte[] new_state)

Description copied from interface: `MessageListener`
Sets the group state; e.g., when joining.

Specified by:
  `setState` in interface `MessageListener`

#### init

    public void init()

Overrides:
  `init` in class `java.applet.Applet`

#### destroy

    public void destroy()

Overrides:
  `destroy` in class `java.applet.Applet`

#### repaint

    public void repaint()

Overrides:
  `repaint` in class `java.awt.Component`

#### actionPerformed

    public void actionPerformed(java.awt.event.ActionEvent e)

Specified by:
  `actionPerformed` in interface `java.awt.event.ActionListener`

#### viewAccepted

    public void viewAccepted(View v)

Description copied from interface: `MembershipListener`
Called when a change in membership has occurred. No long running actions or sending of messages should be done in this callback. If some long running action needs to be performed, it should be done in a separate thread.

Note that on reception of the first view (a new member just joined), the channel will not yet be in the connected state. This only happens when `Channel.connect(String)` returns.

Specified by:
  `viewAccepted` in interface `MembershipListener`

#### suspect

    public void suspect(Address obj)

Description copied from interface: `MembershipListener`
Called whenever a member is suspected of having crashed, but has not yet been excluded.

Specified by:
  `suspect` in interface `MembershipListener`

#### block

    public void block()

Description copied from interface: `MembershipListener`
Called (usually by the FLUSH protocol), as an indication that the member should stop sending messages. Any messages sent after returning from this callback might get blocked by the FLUSH protocol. When the FLUSH protocol is done, and messages can be sent again, the FLUSH protocol will simply unblock all pending messages. If a callback for unblocking is desired, implement `ExtendedMembershipListener.unblock()`. Note that block() is the equivalent of reception of a BlockEvent in the pull mode.

Specified by:
  `block` in interface `MembershipListener`

#### moveNode

    public void moveNode(Node n)

#### addNode

    public void addNode(java.lang.String lbl,
               Address addr,
               int xloc,
               int yloc)

#### removeNode

    public void removeNode(java.lang.Object addr)

#### displayMessage

    public void displayMessage(java.lang.String sender,
                      java.lang.String msg)

#### componentResized

    public void componentResized(java.awt.event.ComponentEvent e)

Specified by:
  `componentResized` in interface `java.awt.event.ComponentListener`

#### componentMoved

    public void componentMoved(java.awt.event.ComponentEvent e)

Specified by:
  `componentMoved` in interface `java.awt.event.ComponentListener`

#### componentShown

    public void componentShown(java.awt.event.ComponentEvent e)

Specified by:
  `componentShown` in interface `java.awt.event.ComponentListener`

#### componentHidden

    public void componentHidden(java.awt.event.ComponentEvent e)

Specified by:
  `componentHidden` in interface `java.awt.event.ComponentListener`

#### focusGained

    public void focusGained(java.awt.event.FocusEvent e)

Specified by:
  `focusGained` in interface `java.awt.event.FocusListener`

#### focusLost

    public void focusLost(java.awt.event.FocusEvent e)

Specified by:
  `focusLost` in interface `java.awt.event.FocusListener`

#### main

    public static void main(java.lang.String[] args)