org.jcsp.awt
Class ActiveFileDialog

java.lang.Object
  java.awt.Component
      java.awt.Container
          java.awt.Window
              java.awt.Dialog
                  java.awt.FileDialog
                      org.jcsp.awt.ActiveFileDialog

All Implemented Interfaces:

ImageObserver, MenuContainer, Serializable, Accessible, CSProcess

public class ActiveFileDialog
extends FileDialog
implements CSProcess

java.awt.FileDialog with a channel interface.

Process Diagram

Description

ActiveFileDialog is a process extension of java.awt.FileDialog 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. The event channel delivers directory and file names (see next paragraph). 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.

The ActiveFileDialog is made visible by sending a Boolean.TRUE down its configure channel. A modal dialogue takes place to select a file and the selected directory and file names are output down its event channel.

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 myFileDialogConfigure = Channel.one2one ();
   final One2OneChannel myFileDialogEvent = Channel.one2one (new OverWriteOldestBuffer (n));
 
   final ActiveFileDialog myFileDialog =
     new ActiveFileDialog (myFileDialogConfigure.in (), myFileDialogEvent.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	The start directory for the fileDialog
	Boolean	If this is the Boolean.TRUE object, the fileDialog is made visible If this is the Boolean.FALSE object, the fileDialog is made invisible Other Boolean objects are ignored
	ActiveFileDialog.Configure	Invoke the user-defined Configure.configure method on the activeFileDialog.
Output Channels
event	String, String	The directory and file names generated by the fileDialog – these may be null
windowEvent	WindowEvent	See the addWindowEventChannel method.
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 org.jcsp.lang.*;
 import org.jcsp.util.*;
 import org.jcsp.awt.*;
 
 public class ActiveFileDialogExample {
 
   public static void main (String argv[]) {
 
     final Frame root = new Frame ();
 
     final One2OneChannel configure = Channel.one2one ();
 
     final One2OneChannel event = Channel.one2one (new OverWriteOldestBuffer (10));
 
     final ActiveFileDialog fileDialog =
       new ActiveFileDialog (configure.in (), event.out (), root, "ActiveFileDialog Example");
 
     new Parallel (
       new CSProcess[] {
         fileDialog,
         new CSProcess () {
           public void run () {
             String dir = ".";           // start directory for the file dialogue
             String file = "";
             while (file != null) {
               configure.out ().write (dir);
               configure.out ().write (Boolean.TRUE);
               dir = (String) event.in ().read ();
               file = (String) event.in ().read ();
               if (file != null)
                 System.out.println ("Chosen file = `" + dir + file + "'");
             }
           System.exit (0);
           }
         }
       }
     ).run ();
   }
 
 }
 

Author:

P.D. Austin and P.H. Welch

See Also:

FileDialog, WindowEvent, ContainerEvent, ComponentEvent, FocusEvent, KeyEvent, MouseEvent, OverWriteOldestBuffer, Serialized Form

Nested Class Summary

static interface

ActiveFileDialog.Configure This enables general configuration of this component.

Nested classes/interfaces inherited from class java.awt.Dialog

Dialog.AccessibleAWTDialog

Nested classes/interfaces inherited from class java.awt.Window

Window.AccessibleAWTWindow

Nested classes/interfaces inherited from class java.awt.Container

Container.AccessibleAWTContainer

Nested classes/interfaces inherited from class java.awt.Component

Component.AccessibleAWTComponent, Component.BltBufferStrategy, Component.FlipBufferStrategy

Field Summary

Fields inherited from class java.awt.FileDialog

LOAD, SAVE

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

ActiveFileDialog(ChannelInput configure, ChannelOutput event, Frame parent)
Constructs a new ActiveFileDialog with a blank title for loading a file.

ActiveFileDialog(ChannelInput configure, ChannelOutput event, Frame parent, int mode)
Constructs a new ActiveFileDialog with a blank title.

ActiveFileDialog(ChannelInput configure, ChannelOutput event, Frame parent, String title)
Constructs a new ActiveFileDialog for loading a file.

ActiveFileDialog(ChannelInput configure, ChannelOutput event, Frame parent, String title, int mode)
Constructs a new ActiveFileDialog.

ActiveFileDialog(Frame parent)
Constructs a new ActiveDialog with a blank title for loading a file and with no configuration or event channels.

ActiveFileDialog(Frame parent, int mode)
Constructs a new ActiveFileDialog with a blank title and no configuration or event channels.

ActiveFileDialog(Frame parent, String title)
Constructs a new ActiveFileDialog for loading a file and no configuration or event channels.

ActiveFileDialog(Frame parent, String title, int mode)
Constructs a new ActiveFileDialog with no configuration or event channels.

Method Summary

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	addWindowEventChannel(ChannelOutput windowEvent) Add a new channel to this component that will be used to notify that a WindowEvent has occurred.
void	run() The main body of this process.
void	setConfigureChannel(ChannelInput configure) Sets the configuration channel for this ActiveFileDialog.

Methods inherited from class java.awt.FileDialog

addNotify, getDirectory, getFile, getFilenameFilter, getMode, paramString, setDirectory, setFile, setFilenameFilter, setMode

Methods inherited from class java.awt.Dialog

getAccessibleContext, getTitle, hide, isModal, isResizable, isUndecorated, setModal, setResizable, setTitle, setUndecorated, show

Methods inherited from class java.awt.Window

addPropertyChangeListener, addPropertyChangeListener, addWindowFocusListener, addWindowListener, addWindowStateListener, applyResourceBundle, applyResourceBundle, createBufferStrategy, createBufferStrategy, dispose, finalize, getBufferStrategy, getFocusableWindowState, getFocusCycleRootAncestor, getFocusOwner, getFocusTraversalKeys, getGraphicsConfiguration, getInputContext, getListeners, getLocale, getMostRecentFocusOwner, getOwnedWindows, getOwner, getToolkit, getWarningString, getWindowFocusListeners, getWindowListeners, getWindowStateListeners, isActive, isAlwaysOnTop, isFocusableWindow, isFocusCycleRoot, isFocused, isLocationByPlatform, isShowing, pack, postEvent, processEvent, processWindowEvent, processWindowFocusEvent, processWindowStateEvent, removeWindowFocusListener, removeWindowListener, removeWindowStateListener, setAlwaysOnTop, setBounds, setCursor, setFocusableWindowState, setFocusCycleRoot, setLocationByPlatform, setLocationRelativeTo, toBack, toFront

Methods inherited from class java.awt.Container

add, add, add, add, add, addContainerListener, addImpl, applyComponentOrientation, areFocusTraversalKeysSet, countComponents, deliverEvent, doLayout, findComponentAt, findComponentAt, getAlignmentX, getAlignmentY, getComponent, getComponentAt, getComponentAt, getComponentCount, getComponents, getComponentZOrder, getContainerListeners, getFocusTraversalPolicy, getInsets, getLayout, getMaximumSize, getMinimumSize, getMousePosition, getPreferredSize, insets, invalidate, isAncestorOf, isFocusCycleRoot, isFocusTraversalPolicyProvider, isFocusTraversalPolicySet, layout, list, list, locate, minimumSize, paint, paintComponents, preferredSize, print, printComponents, processContainerEvent, remove, remove, removeAll, removeContainerListener, removeNotify, setComponentZOrder, setFocusTraversalKeys, setFocusTraversalPolicy, setFocusTraversalPolicyProvider, setFont, setLayout, transferFocusBackward, 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, getBounds, getBounds, getColorModel, getComponentListeners, getComponentOrientation, getCursor, getDropTarget, getFocusListeners, getFocusTraversalKeysEnabled, getFont, getFontMetrics, getForeground, getGraphics, getHeight, getHierarchyBoundsListeners, getHierarchyListeners, getIgnoreRepaint, getInputMethodListeners, getInputMethodRequests, getKeyListeners, getLocation, getLocation, getLocationOnScreen, getMouseListeners, getMouseMotionListeners, getMousePosition, getMouseWheelListeners, getName, getParent, getPeer, getPropertyChangeListeners, getPropertyChangeListeners, getSize, getSize, getTreeLock, getWidth, getX, getY, gotFocus, handleEvent, hasFocus, imageUpdate, inside, isBackgroundSet, isCursorSet, isDisplayable, isDoubleBuffered, isEnabled, isFocusable, isFocusOwner, isFocusTraversable, isFontSet, isForegroundSet, isLightweight, isMaximumSizeSet, isMinimumSizeSet, isOpaque, isPreferredSizeSet, isValid, isVisible, keyDown, keyUp, list, list, list, location, lostFocus, mouseDown, mouseDrag, mouseEnter, mouseExit, mouseMove, mouseUp, move, nextFocus, paintAll, 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, setBackground, setBounds, setComponentOrientation, setDropTarget, setEnabled, setFocusable, setFocusTraversalKeysEnabled, setForeground, setIgnoreRepaint, setLocale, setLocation, setLocation, setMaximumSize, setMinimumSize, setName, setPreferredSize, setSize, setSize, setVisible, show, size, toString, transferFocus, transferFocusUpCycle

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

ActiveFileDialog

public ActiveFileDialog(Frame parent)

Constructs a new ActiveDialog with a blank title for loading a file and with no configuration or event channels. Constructs a new ActiveFileDialog.

Parameters:

parent - the parent frame for the fileDialog.

ActiveFileDialog

public ActiveFileDialog(Frame parent,
                        int mode)

Constructs a new ActiveFileDialog with a blank title and no configuration or event channels.

Parameters:

parent - the parent frame for the fileDialog.

mode - java.awt.FileDialog.LOAD or java.awt.FileDialog.SAVE.

ActiveFileDialog

public ActiveFileDialog(Frame parent,
                        String title)

Constructs a new ActiveFileDialog for loading a file and no configuration or event channels.

Parameters:

parent - the parent frame for the fileDialog.

title - the title of the fileDialog.

ActiveFileDialog

public ActiveFileDialog(Frame parent,
                        String title,
                        int mode)

Constructs a new ActiveFileDialog with no configuration or event channels.

Parameters:

parent - the parent frame for the fileDialog.

title - the title of the fileDialog.

mode - java.awt.FileDialog.LOAD or java.awt.FileDialog.SAVE.

ActiveFileDialog

public ActiveFileDialog(ChannelInput configure,
                        ChannelOutput event,
                        Frame parent)

Constructs a new ActiveFileDialog with a blank title for loading a file.

Parameters:

configure - the channel for configuration events – can be null if no configuration is required.

event - the directory and file names will be output whenever selected – can be null if no notification is required.

parent - the parent frame for the fileDialog.

ActiveFileDialog

public ActiveFileDialog(ChannelInput configure,
                        ChannelOutput event,
                        Frame parent,
                        int mode)

Constructs a new ActiveFileDialog with a blank title.

Parameters:

configure - the channel for configuration events – can be null if no configuration is required.

event - the directory and file names will be output whenever selected – can be null if no notification is required.

parent - the parent frame for the fileDialog.

mode - java.awt.FileDialog.LOAD or java.awt.FileDialog.SAVE.

ActiveFileDialog

public ActiveFileDialog(ChannelInput configure,
                        ChannelOutput event,
                        Frame parent,
                        String title)

Constructs a new ActiveFileDialog for loading a file.

Parameters:

configure - the channel for configuration events – can be null if no configuration is required.

event - the directory and file names will be output whenever selected – can be null if no notification is required.

parent - the parent frame for the fileDialog.

title - the title of the fileDialog.

ActiveFileDialog

public ActiveFileDialog(ChannelInput configure,
                        ChannelOutput event,
                        Frame parent,
                        String title,
                        int mode)

Constructs a new ActiveFileDialog.

Parameters:

configure - the channel for configuration events – can be null if no configuration is required.

event - the directory and file names will be output whenever selected – can be null if no notification is required.

parent - the parent frame for the fileDialog.

title - the title of the fileDialog.

mode - java.awt.FileDialog.LOAD or java.awt.FileDialog.SAVE.

Method Detail

setConfigureChannel

public void setConfigureChannel(ChannelInput configure)

Sets the configuration channel for this ActiveFileDialog. 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.

addWindowEventChannel

public void addWindowEventChannel(ChannelOutput windowEvent)

Add a new channel to this component that will be used to notify that a WindowEvent has occurred. This should be used instead of registering a WindowListener 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:

windowEvent - the channel down which to send ContainerEvents.

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