Chapter 8: The Styles of Generated Programs

package com.craigc.progen;
import java.awt.*;
import java.awt.event.*;

public class JackAndJillPlay1 extends Frame {
    
    /** base class for all button props */
    class ButtonProp extends Button {
        ButtonProp(String label, ActionListener script) {
            super(label);
            addActionListener(script);
        }
    }
    
    /* The Props for JackAndJillPlay ******************/
    
    ButtonProp upProp = new ButtonProp("Go up the hill",
        new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                fetchProp.setLabel("Fetch a pail of water");
                enterNewScene(topScene);
            }
        });
    ButtonProp fetchProp = new ButtonProp("Fetch a pail of water",
        new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                fetchProp.setLabel("Fetch another pail");
            }
        });
    ButtonProp fallProp = new ButtonProp("Fall down, break crown",
        new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                fallProp.setLabel("Break crown");
                tumbleProp.setLabel("Tumble after");
                enterNewScene(bottomScene);
            }
        });
    ButtonProp tumbleProp = new ButtonProp("Tumble down",
        new ActionListener() {
            public void actionPerformed(ActionEvent evt) {
                enterNewScene(bottomScene);
            }
        });
    
    /* The Scenes for JackAndJillPlay ******************/
    
    /** base class for all scenes */
    class Scene extends Panel {
        void setup() {};    // used to setup a scene on entry
    };
    
    class BottomScene extends Scene {
        void setup() {
            removeAll();    // remove any old props
            setLayout(new FlowLayout());
            add(upProp);
            add(fallProp);
            setBackground(Color.decode("#8888aa"));
        }
    }
            
    class TopScene extends Scene {
        void setup() {
            removeAll();    // remove any old props
            setLayout(new FlowLayout());
            add(fetchProp);
            add(fallProp);
            add(tumbleProp);
            setBackground(Color.decode("#dddddd"));
        }
    }
            
    BottomScene bottomScene = new BottomScene();
    TopScene topScene = new TopScene();
        
    /* Creating and starting up the JackAndJillPlay **/
    
    Scene currentScene;
    
    public JackAndJillPlay1() {
        super("Jack and Jill #1");
        setSize(300, 120);
        
        // start scene
        enterNewScene(bottomScene);
    }
    
    public void enterNewScene(Scene scene) {
        removeAll();  // remove previous scene if any
        currentScene = scene;
        scene.setup();
        add(scene);
        show();
    }
    
    public static void main(String[] args) {
        new JackAndJillPlay1();
    }
}

package com.craigc.progen;
import java.awt.*;
import java.awt.event.*;

class JackAndJillPlay2 extends Frame {
    
    /* The Props for JackAndJill ****************/
    
    Button upProp = new Button("Go up the hill");
    Button fetchProp = new Button("Fetch a pail of water");
    Button fallProp = new Button("Fall down, break crown");
    Button tumbleProp = new Button("Tumble down");

    /* The Events in the JackAndJill ***************/

    class PropEvent implements ActionListener {
        public void actionPerformed(ActionEvent evt) {
            Object prop = evt.getSource();
            if (prop==upProp) {
                fetchProp.setLabel("Fetch a pail of water");
                enterNewScene("top");
            } else if (prop==fetchProp) {
                fetchProp.setLabel("Fetch another pail");
            } else if (prop==fallProp) {
                fallProp.setLabel("Break crown");
                tumbleProp.setLabel("Tumble after");
                enterNewScene("bottom");
            } else if (prop==tumbleProp) {
                enterNewScene("bottom");
            } else {
                System.out.println("Invalid prop");
            }
        }
    }
    
    /* Creating and starting up the JackAndJill ****/
    
    String currentScene;
    
    public JackAndJillPlay2() {
        super("Jack and Jill");
        setSize(200, 120);
        setLayout(new FlowLayout());
        
        // initialize props
        PropEvent a = new PropEvent();
        upProp.addActionListener(a);
        fetchProp.addActionListener(a);
        fallProp.addActionListener(a);
        tumbleProp.addActionListener(a);

        // start scene
        enterNewScene("bottom");
    }

    public void enterNewScene(String scene) {
        removeAll();  // remove previous scene
        currentScene = scene;
        if (scene.equals("bottom")) {
            add(upProp);
            add(fallProp);
            setBackground(Color.decode("#8888aa"));
        } else if (scene.equals("top")) {
            add(fetchProp);
            add(fallProp);
            add(tumbleProp);
            setBackground(Color.decode("#dddddd"));
        } else {
            System.out.println("Invalid scene: "+scene);
        }
        show();
    }

    public static void main(String[] args) {
        new JackAndJillPlay2();
    }

}

package com.craigc.progen;
import java.awt.*;
import java.awt.event.*;

class JackAndJillPlay3 extends Frame {
    
    /* The Prop and Scene tables *******************/
    
    final static String title = "Jack and Jill #3";
    final int width = 300;
    final int height = 120;
    final int startScene = 0; // bottom
    
    // String[] propNames = { "up", "fetch", "fall", "down" };
    
    // initial labels
    final String[] propLabels = {
        "Go up the hill",
        "Fetch a pail of water",
        "Fall down, break crown",
        "Tumble down",
    };
    
    // map props to actions after each prop's action event
    final int[][][] propActions = {
        { { 1, 0 } },  // fetch "Fetch a pail of water"
        { { 1, 1 } },  // fetch "Fetch another pail"
        { { 2, 2 },    // fall "Break crown"
          { 3, 3 }, }, // tumble "Tumble after"
        {},
    };
    
    // map props to next scene
    final int[] nextScene = {
        1,  // top
        -1, // none
        0,  // bottom
        0,  // bottom
    };
    
    // String[] sceneNames = { "bottom", "top" };
    
    // map scenes to list of props to add for that scene
    final int[][] sceneProps = {
        { 0, 2 },    // up fall
        { 1, 2, 3 }, // fetch fall tumble
    };
    
    final String[] sceneColors = {
        "#8888aa",
        null,
    };

    final String[] traitValues = {
        "Fetch a pail of water",
        "Fetch another pail",
        "Break crown",
        "Tumble after",
    };
    
    /* The Events in the JackAndJillPlay *******************/
    
    class PropEvent implements ActionListener {
        int propnum;    // what prop this listener listens for
        
        public PropEvent(int j) {
            propnum = j;
        }
        
        public void actionPerformed(ActionEvent evt) {
            for (int j=0; j<propActions[propnum].length; ++j) {
                props[propActions[propnum][j][0]].setLabel(
                    traitValues[propActions[propnum][j][1]]);
            }
            
            if (nextScene[propnum] >= 0) {
                enterNewScene(nextScene[propnum]);
            }
        }
    }
    
    /* Creating and starting up the JackAndJillPlay *********/
    
    int currentScene;
    Button[] props; // the props
    
    public JackAndJillPlay3() {
        super(title);
        setSize(width, height);
        setLayout(new FlowLayout());
        
        // initialize props
        props = new Button[propLabels.length];
        for (int j=0; j<propLabels.length; ++j) {
            props[j] = new Button();
            props[j].setLabel(propLabels[j]);
            props[j].addActionListener(new PropEvent(j));
        }
  
        // start scene
        enterNewScene(startScene);
    }
    
    public void enterNewScene(int scene) {
        removeAll();  // remove previous scene if any
        currentScene = scene;
        for (int j=0; j<sceneProps[scene].length; ++j) {
            add(props[sceneProps[scene][j]]);
        }
        String bg = sceneColors[scene];
        setBackground(Color.decode(bg==null?"#dddddd":bg));
        show();
    }
    
    public static void main(String[] args) {
        new JackAndJillPlay3();
    }
}