org.jcsp.plugNplay
Class FramedButtonGrid

java.lang.Object
  org.jcsp.plugNplay.FramedButtonGrid

All Implemented Interfaces:

CSProcess

public final class FramedButtonGrid
extends Object
implements CSProcess

A free-standing grid of button processes in their own frame, with configure and event channels.

Process Diagram

Please check out the process diagram for a framed single button in FramedButton. Imagine here a 2D grid of these, each with individual configure and event channels.

Description

This process provides a free-standing grid of button processes in their own frame. They are just ActiveButtons wrapped in an ActiveClosingFrame, but save us the trouble of constructing them.

Wire them to application processes with configure channels (for setting labels, enabling/disabling and all other configuration options) and event channels (on which the current label on any button is sent when that button is clicked). Note that all the events may be streamed to the same channel, provided an Any2*Channel is used (as in the example below).

Initially, all button labels are empty java.lang.Strings. To set a button label, send a java.lang.String down the appropriate configure channel.

Initially, all buttons are enabled. To disable a button, send java.lang.Boolean.FALSE down the appropriate configure channel. To enable, send java.lang.Boolean.TRUE.

For other configuration options, send objects implementing the ActiveButton.Configure interface.

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 myButtonEvent =
     Channel.one2one (new OverWriteOldestBuffer (n));
 

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.

Example

This runs a framed button grid in parallel with a simple application process (in-lined in the Parallel below). All event channels from the buttons are mulitplexed through an Any2OneChannel to the application process. The application configures the buttons with their labels, then reports each time any of them is pressed. The application ends when the button labelled `Goodbye World' is pressed.

 import org.jcsp.lang.*;
 import org.jcsp.util.*;
 import org.jcsp.plugNplay.*;
 
 public class FramedButtonGridExample {
 
   public static void main (String argv[]) {
   
     // labels for the grid of buttons
 
     final String[][] label = {
       new String[] {"Java", "occam-pi", "Handel-C"},
       new String[] {"C", "C++", "C#"},
       new String[] {"Haskell", "Modula", "Goodbye World"}
     };
 
     final int nDown = label.length;
     final int nAcross = label[0].length;
 
     // initial pixel sizes for the frame for the grid of buttons
 
     final int pixDown = 20 + (nDown*100);
     final int pixAcross = nAcross*120;
   
     // all button events are wired (for this example) to the same channel ...
 
     final Any2OneChannel allEvents =
       Channel.any2one (new OverWriteOldestBuffer (10));
 
     final Any2OneChannel[][] event = new Any2OneChannel[nDown][nAcross];
     
     for (int i = 0; i < nDown; i++) {
       for (int j = 0; j < nAcross; j++) {
         event[i][j] = allEvents;
       }
     }
 
     // make the grid of buttons (each one separately configured) ...
 
     final One2OneChannel[][] configure = new One2OneChannel[nDown][nAcross];
     
     for (int i = 0; i < nDown; i++) {
       configure[i] = Channel.one2oneArray (nAcross);
     }
 
     final ChannelInput[][] configureIn = new ChannelInput[nDown][nAcross];
     final ChannelOutput[][] eventOut = new ChannelOutput[nDown][nAcross];
     
     for (int i = 0; i < nDown; i++) {
       configureIn[i] = Channel.getInputArray (configure[i]);
       eventOut[i] = Channel.getOutputArray (event[i]);
     }
 
     final FramedButtonGrid grid =
       new FramedButtonGrid (
         "FramedButtonGrid Demo", nDown, nAcross,
         pixDown, pixAcross, configureIn, eventOut
       );
 
     // testrig ...
 
     new Parallel (
     
       new CSProcess[] {
       
         grid,
         
         new CSProcess () {
         
           public void run () {
     
             for (int i = 0; i < nDown; i++) {
               for (int j = 0; j < nAcross; j++) {
                 configure[i][j].out ().write (label[i][j]);
               }
             }
             
             boolean running = true;
             while (running) {
               final String s = (String) allEvents.in ().read ();
               System.out.println ("Button `" + s + "' pressed ...");
               running = (s != label[nDown - 1][nAcross - 1]);
             }
             
             System.exit (0);
             
           }
           
         }
         
       }
     ).run ();
 
   }
 
 }
 

Author:

P.H. Welch

See Also:

ActiveButton, FramedButton, FramedButtonArray, FramedScrollbar

Constructor Summary

FramedButtonGrid(String title, int nDown, int nAcross, int pixDown, int pixAcross, ChannelInput[][] configure, ChannelOutput[][] event)
Construct a framed button grid process.

Method Summary

void	run() This defines the actions of the process.

Methods inherited from class java.lang.Object

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

Constructor Detail

FramedButtonGrid

public FramedButtonGrid(String title,
                        int nDown,
                        int nAcross,
                        int pixDown,
                        int pixAcross,
                        ChannelInput[][] configure,
                        ChannelOutput[][] event)

Construct a framed button grid process.

Parameters:

title - the title for the frame (must not be null)

nDown - the number of buttons down in the grid (must be at least 1)

nAcross - the number of buttons across in the grid (must be at least 1)

pixDown - the pixel hieght of the frame (must be at least 100)

pixAcross - the pixel width of the frame (must be at least 100)

configure - the matrix of configure channels for the buttons (must not be null)

event - the matrix of event channels from the buttons (must not be null)

Method Detail

run

public void run()

Description copied from interface: CSProcess

This defines the actions of the process.

Specified by:

run in interface CSProcess