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Class jcsp.awt.ActiveWindow

java.lang.Object
   |
   +----java.awt.Component
           |
           +----java.awt.Container
                   |
                   +----java.awt.Window
                           |
                           +----jcsp.awt.ActiveWindow

public class ActiveWindow
extends Window
implements CSProcess

Process Diagram

External View

             ________________
  configure |                | event
 ----->-----|  ActiveWindow  |--->---
            |________________|

Internal View

             __________________________________________
            |  ____________      ____________________  |
  configure | |            |    |                    | | event
 ----->-------|  Configure |    | WindowEventHandler |----->---
            | |____________|    |____________________| |
            |                                          |
            |                             ActiveWindow |
            |__________________________________________|

Description

An ActiveWindow is a sub class of Window which uses Channels for event notification and configuration.

If the event Channel is not a null reference an new WindowEventHandler is created with the Channel and is registered as WindowListener with the ActiveWindow and has its windowOpened(), windowClosed(), windowClosing(), windowIconified(), windowDeiconified(), windowActivated() or windowDeactivated() methods invoked when WindowEvents are generated. Any events generated when the WindowEventHandler is blocked writing to the event Channel are ignored so that the main Java Event Thread is not blocked. The output from the WindowEventHanlder is connected to the event Channel causing an Object to be sent down the Channel when the WindowEvents occur.

It is also possible to register Channels to be used to notify the occurrence of other types of Event that the Window generates. This can be done by calling one of the addXXXXEventChannel() methods.

To configure the Window messages can be sent down the configure channel. If the configure Channel is not a null reference a new Configure is created. The configure process sits in an infinite loop which reads from the configure Channel and configures the component based on the Object received (see table below for details).

Channel Protocols

Input Channels
configure	Boolean	If the Boolean Object refers to the Boolean.TRUE instance the button is made active If the Boolean Object refers to the Boolean.FALSE instance the button is made inactive If the Boolean Object refers to any other Boolean instance the message is discarded
Output Channels
event	WindowEvent	The WindowEvent Object generated by the component

Example

 import java.awt.*;
 import jcsp.lang.*;
 import jcsp.awt.*;
 public class WindowExample extends Frame {
   public WindowExample() {
     super("Window Example");
     final Channel event = new One2OneChannel();
     final Channel id = new One2OneChannel();
     ActiveWindow w = new ActiveWindow(null, event, this);
     setVisible(true);
     w.setVisible(true);
     new Parallel(new CSProcess[] {
       w,
       new EventIDFilter(event, id),
       new CSProcess() {
         public void run() {
           Integer i = (Integer)id.read();
           if (i.intValue() == WindowEvent.WINDOW_OPENED) {
             setVisible(false);
             w.setVisible(false);
             System.exit(0);
           }
         }
       }
     }).run();
   }
   public static void main(String argv[]) {
     new WindowExample();
   }
 }

Author:: P.D.Austin

par: The Parallel construct containing the processes to be executed by this CSProcess.

ActiveWindow(ChannelInput, ChannelOutput, Frame): Constructs a new ActiveWindow.
ActiveWindow(Frame): Constructs a new ActiveWindow.

addComponentEventChannel(ChannelOutput): Add a new Channel to the Component which will be used to notify that a ComponentEvent has occurred on the component.
addContainerEventChannel(ChannelOutput): Add a new Channel to the Container which will be used to notify that a ContainerEvent has occurred on the Container.
addFocusEventChannel(ChannelOutput): Add a new Channel to the Component which will be used to notify that a FocusEvent has occurred on the component.
addKeyEventChannel(ChannelOutput): Add a new Channel to the Component which will be used to notify that a KeyEvent has occurred on the component.
addMouseEventChannel(ChannelOutput): Add a new Channel to the Component which will be used to notify that a MouseEvent has occurred on the component.
addMouseMotionEventChannel(ChannelOutput): Add a new Channel to the Component which will be used to notify that a MouseMotionEvent has occurred on the component.
run(): The main body of this process.

par

 protected Parallel par

The Parallel construct containing the processes to be executed by this CSProcess.

ActiveWindow

 public ActiveWindow(Frame f)

Constructs a new ActiveWindow.

Parameters:: f - The parent frame for the window

ActiveWindow

 public ActiveWindow(ChannelInput configure,
                     ChannelOutput event,
                     Frame f)

Constructs a new ActiveWindow.

Parameters:: configure - The Channel configuration events should be sent down. Can be null if no configuration is required.; event - The Channel events will be notified down when the button is pressed. Can be null if events are going to be ignored.; f - The parent frame for the window

addContainerEventChannel

 public void addContainerEventChannel(ChannelOutput containerEvent)

Add a new Channel to the Container which will be used to notify that a ContainerEvent has occurred on the Container. This should be used instead of registering a ContainerListener with the Container. It is possible to add more than one Channel by calling this method multiple times If the reference passed is null no action will be taken. Otherwise a new ContainerEventHanlder will be generated for the Channel so that each Channel operates independently of the others.