JavaMe MIDlet and Canvas

Question

I'm trying to make a program that uses midlet for the menu. When certain command accessed from the menu,it will access the canvas (like in a popup button a selection of fillrectangle and fillarc). If I select the fillrectangle it will access the canvas that draws the fill rectangle.
The problem is when I access the fillarc nothing happens, but on the fillrectangle it does.

Another problem is that I don't know how to apply the X and Y coordinates in the menu to the fillrectangle for the user to control the position of the selected object. '

Here is my code:

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

/**
 * @author Nico
 */
public class emp extends MIDlet implements CommandListener {
    Display display;
    Form frm = new Form ("Main");
    ChoiceGroup Cg1;
    ChoiceGroup Cg2;
    TextField tfX = new TextField ("X Axis"," ",40,TextField.ANY);
    TextField tfY = new TextField ("Y Axis"," ",40,TextField.ANY);
    Command OK;

    public emp () {
        OK = new Command ("OK",Command.OK,1);
        Cg2 = new ChoiceGroup("Color", Choice.POPUP);
        Cg1 = new ChoiceGroup("Type", Choice.POPUP);
        Cg1.append("Rectangle", null);
        Cg1.append("Arc", null);
        Cg1.append("Line", null);
        Cg2.append("Red", null);
        Cg2.append("Blue", null);
        Cg2.append("Green", null);

        frm.append(Cg1);
        frm.append(tfX);
        frm.append(tfY);
        frm.append(Cg2);
        frm.addCommand(OK);

        frm.setCommandListener(this);
    }



      public void startApp () {
            display = Display.getDisplay(this);
            display.setCurrent(frm);
  }

  public void pauseApp () {}

  public void destroyApp (boolean forced) {}




class DrawingRect extends Canvas implements CommandListener {
    Command Bk;


    public DrawingRect (){
        this.addCommand(Bk= new Command("Back", Command.BACK, 0 ) );
        this.setCommandListener(this);
    }
  public void paint (Graphics g) {
    int x1=100,y1=100;

    g.setColor (0, 0, 0);
    g.fillRect(0, 0, getWidth(), getHeight());
    g.setColor (0, 0, 255);
    g.fillRect(x1,y1, 50, 50);
    g.drawString("aaaaaa", getWidth()/2, getHeight()/2, Graphics.TOP|Graphics.HCENTER);



  }

        public void commandAction(Command c, Displayable d) {
            if (c==Bk){
                display.setCurrent(frm);
            }
        }
    }

public class DrawingArc extends Canvas implements CommandListener {
    Command Bk;



    public DrawingArc (){
        this.addCommand(Bk= new Command("Back", Command.BACK, 0 ) );
        this.setCommandListener(this);
    }
  public void paint (Graphics g) {


    g.setColor (0, 0, 0);
    g.fillRect(0, 0, getWidth(), getHeight());
        g.setGrayScale(13*16);
        g.fillArc(0,0,getWidth(),getHeight(),90,360);



  }

        public void commandAction(Command c, Displayable d) {
            if (c==Bk){
                display.setCurrent(frm);
            }
        }
    }
    public void commandAction(Command c, Displayable d) {

        if (c==OK) {
        int select = Cg1.getSelectedIndex();
            if (select==0){
            display.setCurrent (new DrawingRect ());
            }
        }
        else if (c==OK){
        int select = Cg1.getSelectedIndex();
            if (select==1){
            display.setCurrent (new DrawingArc ());
        }
        }
        else {

        }
}
}

Answer 1

Have a look to this piece of code... (comments and indents by me)

public void commandAction(Command c, Displayable d) {
  if (c==OK) {
    int select = Cg1.getSelectedIndex();
    if (select==0){
      display.setCurrent (new DrawingRect ());
    }
  }else if (c==OK){
    // It will never ever ever reach this block
    int select = Cg1.getSelectedIndex();
    if (select==1){
      display.setCurrent (new DrawingArc ());
    }
  }else {
    // WTF?
  }
}

I don't mean to be rude, but this code is not very understable... you should clarify your java me concepts or try to clarify you code... I believe if you change to the code below, you could solve the first problem:

public void commandAction(Command c, Displayable d) {
  if (c==OK) {
    int select = Cg1.getSelectedIndex();
    if (select==0){
      display.setCurrent (new DrawingRect ());
    }else if (select==1){
      display.setCurrent (new DrawingArc ());
    }
  }
}

For the second problem, I would probably add some sort of Move to... button to the form. If you press it, you can create the canvas with given X and Y, or... Some hint below:

class DrawingRect extends Canvas implements CommandListener {
  Command Bk;
  int x1, y1;

  public DrawingRect (int newX, int newY){
    this.addCommand(Bk= new Command("Back", Command.BACK, 0 ) );
    this.setCommandListener(this);
    x1 = newX;
    y1 = newY;
  }


  public void paint (Graphics g) {
    g.setColor (0, 0, 0);
    g.fillRect(0, 0, getWidth(), getHeight());
    g.setColor (0, 0, 255);
    g.fillRect(x1,y1, 50, 50);
    g.drawString("aaaaaa", getWidth()/2, getHeight()/2, Graphics.TOP|Graphics.HCENTER);
  }

  public void commandAction(Command c, Displayable d) {
    if (c==Bk){
      display.setCurrent(frm);
    }
  }
}

And obviously, calling it like this:

display.setCurrent (new DrawingRect(tfX.getString(),tfY.getString()));

But, all of these are very basic Java concepts, I think you should improve them before going any further... Just a suggestion.