• click 0 : within the window
• clickOnCanvas <coord> : click within the drawing canvas (with where click occured)
• clickRecenterButton 0 : click on the recenter "R" button
• clickRecenterPane 0 : click within the recenter pane
• clickRecenterTextBox 0 : click within the text box in the recenter pane
• clickTriChooseButton 0 : click on the triangle choice "T" button
• clickTriTypeChoice <type> : type is one of E, R or O
• documentReady 0 : this occurs when the document is first loaded
• mouseDownVertex <name>:<coord> : mouse down on one of the vertices. <name> is one of vertexA, vertexB, vertexC, <coord> is mouse position
• mouseLeaveCanvas 0 : occurs when mouse exits the canvas area
• mouseMove <coord> : each mouse movement generates this, <coord> is new position
• mouseUpCanvas <coord> : a mouse up within the canvas, <coord> is where the mouse is
• recenterTextChange <text> : user hit enter in text box, <text> is what's there
• recenterTextFail 0 : a checkCT action resulted in failure, i.e. not a valid point
• recenterTextSucc <coord> : a checkCT action resulted in success, <coord> is the result

• noop <data> : does nothing
• showTP <data> : shows the "triangle pane", i.e. the box with triangle choices
• hideTP <data> : hides the triangle pane
• resetT <data> : resets the triangle to one of the types <data> = E, R or O
• showCP <data> : shows the "centering pane", i.e. the box with center coords
• hideCP <data> : hides the "centering pane"
• checkCT <data> : checks the centering pane text box
• errorCT <data> : sets centering pane text box color to red (error!) and grabs focus
• moveC <data> : moves triangle to new center, <data> = coordinate of new center
• selectV <data> : sets vertex as selected, <data> = <name>:<coord> where <name> is one of vertexA, vertexB and vertexC, and <coord> is an ordered pair
• moveV <data> : moves the selected vertex, <data> is mouse coord for the movement
• resetV <data> : resets position of selected vertex back to where it was when selected

1. receive the documentReady 0 event-message
2. send the noop 0 action-message, since we have nothing to do
3. receive the clickTriChooseButton 0 event-message
4. send the showTP 0 message to show the pop-up
5. receive the clickTriTypeChoice R event-message
6. send the resetT R action-message, which resets the triangle to a right triangle, and send the hideTP 0 action-message to hide the triangle choice pop-up.

g++ -o doNothing doNothing.cpp idmsg.cpp

javac DoNothing.java

#include "idmsg.h"
#include <iostream>
#include <fstream>
#include <string>
using namespace std;

int main()
{
  // open pipes to/from GUI
  ifstream fin("fromGUI");
  ofstream fout("toGUI");

  // loop: read msg, respond with command
  int count = 0;
  string msg, data;
  while(1)
  {
    // Read message from GUI
    fin >> msg;        //- read message
    fin.get();         //- read space
    getline(fin,data); //- read data  Note: data *won't* have spaces, but ...
    if (!fin) { break; }
    cerr << "Read(" << (++count) << "): " << msg << " " << data << endl;

    // Choose command and command data
    // Here is a silly example: if you click on a vertex, the "Recentering Pane"
    // will appear, and when you leave the "canvas", it disappears.  See why?
    string response;
    switch(id(msg))
    {
    case mouseDownVertex : response = "showCP " + data; break;
    case mouseLeaveCanvas: response = "hideCP " + data; break;
    default: response = "noop 0"; break;
    }

    // Respond to GUI
    fout << response << endl;
    cerr << "Sent(" << count << "): " << response << endl;
  }
  
  return 0;
}

import java.util.*;
import java.io.*;

public class DoNothing
{
  public static void main(String[] args)
  {
    // open pipes to/from GUI
    Scanner fin = null;
    PrintStream fout = null;
    try {
      fin = new Scanner(new InputStreamReader(new FileInputStream("fromGUI")));
      fout = new PrintStream("toGUI");
    } catch(Throwable t) { System.exit(1); }
    
    // loop: read msg, respond with command
    int count = 0;
    String msg, data;
    while(true)
    {
      // Read message from GUI
      msg = fin.next();  //- read message
      data = fin.nextLine().trim(); //- read data  Note: data *won't* have spaces!
      if (msg == null || data == null) { break; }
      System.err.println("Read(" + (++count) + "): " + msg + " " + data);

      // Choose command and command data
      // Here is a silly example: if you click on a vertex, the "Recentering Pane"
      // will appear, and when you leave the "canvas", it disappears.  See why?
      String response;
      switch(Id.id(msg))
      {
      case Id.mouseDownVertex : response = "showCP " + data; break;
      case Id.mouseLeaveCanvas: response = "hideCP " + data; break;
      default: response = "noop 0"; break;
      }

      // Respond to GUI
      fout.println(response);
      System.err.println("Sent(" + count + "): " + response);
    }
  }
}