Rice University - Comp 212 - Intermediate Programming

Fall 2002

Lecture #20 -  Simple Java Drawing


<Under construction>

1.  Simple Hangman Drawing

Click here to run simple hangman drawing applet.

 

HangmanGame.java
Created with JBuilder
package model;

import java.awt.*;

import model.bodyPart.*;

/**
 * This simplified version of the model has no adapters to play the game.
 * There is no game to play here.  Just a few ABodyPart to display via the
 * paint() method.
 * The IPaintAdapter installed by the controller will call the HangmanGame to
 * paint(...).
 */
public class HangmanGame {
    /**
     * A few ABodyPart to be drawn.
     */
    private ABodyPart _noose = new NoosePart(null, null);
    private ABodyPart _rightArm = new RArmPart(null);
    private ABodyPart _torso = new TorsoPart(null);

    /**
     * Paints the visible body parts on the supplied Graphics context.
     * @param g The Graphics context to draw on.
     */
    public void paint(Graphics g) {
        // FOR ILLUSTRATION ONLY:
        System.out.println("HangmanGame.paint()...");

        _noose.draw(g);
        _rightArm.draw(g);
        _torso.draw(g);
    }
}


HangmanGUI.java
Created with JBuilder
package view;

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

/**
 * Contains a JPanel where the body parts are painted.
 * To paint something in Java, we need to paint on a JPanel and override
 * its paintComponent(...) method.
 * Everytime the JPanel needs repainting, it will call paintComponent(...).
 * For example, when the JFrame that contains the JPanel is resized, it will
 * try to update all of its contents, in particular it will call its JPanel to
 * update, which in turns will schedule a call to repaint(...), which in turn
 * will call paintComponent(...)!
 */
public class HangmanGUI {

    /**
     * The GUI component that holds all other GUI components.
     */
    private JApplet _applet;

    /**
     * The adapter used to communicate with the model to tell it to paint the
     * body parts.
     */
    private IPaintAdapter _paintAdapter = new IPaintAdapter() {
        // Null-Object Pattern: avoid comparison to null.
        public void paint(Graphics g) {
            // do nothing
        }
    };

    /**
     * A panel derived from a JPanel where the body parts are drawn.
     * The JPanel's paint() method is overriden so that the gallows is
     * automatically drawn when the panel is repainted.
     */
    private JPanel _displayPanel = new JPanel() {
        public void paintComponent(Graphics g) { // called whenever the panel is repainted.


            super.paintComponent(g);   // do whatever usually is done, e.g. clear the panel.
            g.setColor(Color.black);  // set the drawing color
            g.fillRect(0,220,200,5);  // base of scaffold
            g.fillRect(0,0,70,5);     // top of scaffold
            g.fillRect(0,0,5,220);    // side of scaffold

            // FOR ILLUSTRATION ONLY:
            System.out.println("HangmanGUI._displayPanel.paintComponent() calling _paintAdapter.paint()...");

            _paintAdapter.paint(g);   //  Delegate to the adapter to get the body parts drawn.
        }
    };


    /**
     * Initializes the GUI components.
     * @param a the applet that holds all GUI components.
     * @param gc The IGameControlAdapter object used to for guessing and
     * resetting.
     * @param pa The IPaintAdapter object used for requesting that the model
     * paint the body parts.
     */
    public HangmanGUI(JApplet a, IPaintAdapter pa) {
        // FOR ILLUSTRATION ONLY:
        System.out.println("HangmanGUI.constructor initializing _displayPanel and _applet...");

        _applet = a;
        _paintAdapter = pa;
        jbInit();
    }

    /**Component initialization*/
    private void jbInit() {
        _displayPanel.setBackground(Color.white);
        _applet.setSize(400, 350);
        Container contentPane = _applet.getContentPane();
        contentPane.setLayout(new BorderLayout());
        contentPane.add(_displayPanel, BorderLayout.CENTER);
    }
}

HangmanController.java
Created with JBuilder
package controller;

import model.*;
import view.*;
import javax.swing.*;
import java.awt.*;

/**
 * The controller that instantiates and connects the HangmanGame (the model)
 * and the HangmanGUI (the view) via adapters.
 * The controller also instantiates the adapters.
 * The adapters are implemented as anonymous inner classes.
 * @stereotype controller
 */
public class HangmanController extends JApplet{

    private HangmanGUI _gui;
    private HangmanGame _hangman;

    /**
     * Instantiates the HangmanGame, HangmanFrame, and connects them together
     * using anonymous inner class defined adapters.
     * In this simplified version, there is no game playing, so there is no
     * need for loose and/or win adapters.
     */
    public void init() {
        _hangman = new HangmanGame();
        _gui = new HangmanGUI(this, new IPaintAdapter()  {
            public void paint(Graphics g) {
                // FOR ILLUSTRATION ONLY:
                System.out.println("anonymous IPaintAdapter.paint() calling _hangman.paint()...");

                _hangman.paint(g);
            }
        });
    }

    public static void main(String[] args) {
        JFrame frame = new AFrame("Simple Hangman Drawing") {
            protected void initialize() {
                HangmanController controller = new HangmanController();
                controller.init();
                getContentPane().add(controller, "Center");
                setSize(400, 400);
                setVisible(true);
            }
        };
    }

}




dxnguyen@cs.rice.edu
Copyright 2002, Dung X. Nguyen - All rights reserved.