Java 重写到 MVC 后 GUI 不工作

GUI not working after rewriting to MVC

提问by trevor_nise

I'm practicing MVC style programming. I have a Mastermind game in a single file, working fine (maybe apart of the fact that "Check" button is invisible at start).

我正在练习 MVC 风格的编程。我在单个文件中有一个 Mastermind 游戏，运行良好（也许除了“检查”按钮在开始时不可见的事实）。

http://paste.pocoo.org/show/226726/

http://paste.pocoo.org/show/226726/

But when I've rewritten it to model, view, controller files - and when I click on empty Pin (that should be updated, and repainted with new color) - noting happens. Can anybody see any problems here ? I've tried placing repaint() in different places, but it simply does not work at all :/

但是，当我将它重写为模型、视图、控制器文件时——当我点击空 Pin（应该更新，并用新颜色重新绘制）时——注意发生了。任何人都可以在这里看到任何问题吗？我试过将 repaint() 放在不同的地方，但它根本不起作用：/

Main :

主要的 ：

public class Main { 
    public static void main(String[] args){
        Model model = new Model();
        View view = new View("Mastermind", 400, 590, model);
        Controller controller = new Controller(model, view); 
        view.setVisible(true);
    }
}

Model :

模型 ：

import java.util.Random;

public class Model{
    static final int
    LINE = 5,
    SCORE = 10, OPTIONS = 20;
    Pin pins[][] = new Pin[21][LINE];
    int combination[] = new int[LINE];
    int curPin = 0;
    int turn = 1;
    Random generator = new Random();
    int repaintPin;
    boolean pinsRepaint=false;
    int pinsToRepaint;
    boolean isUpdate = true, isPlaying = true, isRowFull = false;
    static final int HIT_X[] = {270,290,310,290,310}, HIT_Y[] = {506,496,496,516,516};

    public Model(){

        for ( int i=0; i < SCORE; i++ ){
            for ( int j = 0; j < LINE; j++ ){
                pins[i][j] = new Pin(20,0);
                pins[i][j].setPosition(j*50+30,510-i*50);
                pins[i+SCORE][j] = new Pin(8,0);
                pins[i+SCORE][j].setPosition(HIT_X[j],HIT_Y[j]-i*50);
            }
        }
        for ( int i=0; i < LINE; i++ ){
            pins[OPTIONS][i] = new Pin( 20, i+2 );
            pins[OPTIONS][i].setPosition( 370,i * 50 + 56);
        }

    }

    void fillHole(int color) {
        pins[turn-1][curPin].setColor(color+1);
        pinsRepaint = true;
        pinsToRepaint = turn;
        curPin = (curPin+1) % LINE;
        if (curPin == 0){
            isRowFull = true;
        }
        pinsRepaint = false;
        pinsToRepaint = 0;
    }

    void check() {
        int junkPins[] = new int[LINE], junkCode[] = new int[LINE];
        int pinCount = 0, pico = 0;

        for ( int i = 0; i < LINE; i++ ) {
            junkPins[i] = pins[turn-1][i].getColor();
            junkCode[i] = combination[i];
        }
        for ( int i = 0; i < LINE; i++ ){
            if (junkPins[i]==junkCode[i]) {
                pins[turn+SCORE][pinCount].setColor(1);
                pinCount++;
                pico++;
                junkPins[i] = 98;
                junkCode[i] = 99;
            }
        }
        for ( int i = 0; i < LINE; i++ ){
            for ( int j = 0; j < LINE; j++ )
                if (junkPins[i]==junkCode[j]) {
                    pins[turn+SCORE][pinCount].setColor(2);
                    pinCount++;
                    junkPins[i] = 98;
                    junkCode[j] = 99;
                    j = LINE;
            }
        }
        pinsRepaint = true;
        pinsToRepaint = turn + SCORE;
        pinsRepaint = false;
        pinsToRepaint=0;

        if ( pico == LINE ){
            isPlaying = false;
        }
        else if ( turn >= 10 ){
                isPlaying = false;
        }
        else{
            curPin = 0;
            isRowFull = false;
            turn++;
        }
    }

    void combination() {
        for ( int i = 0; i < LINE; i++ ){
          combination[i] = generator.nextInt(6) + 1;
        }
    }
}

class Pin{
    private int color, X, Y, radius;

    public Pin(){
        X = 0; Y = 0; radius = 0; color = 0;
    }

    public Pin( int r,int c ){
        X = 0; Y = 0; radius = r; color = c;
    }

    public int getX(){
        return X;
    }

    public int getY(){
        return Y;
    }

    public int getRadius(){
        return radius;
    }

    public void setRadius(int r){
        radius = r;
    }

    public void setPosition( int x,int y ){
        this.X = x ;
        this.Y = y ;
    }
    public void setColor( int c ){
        color = c;
    }
    public int getColor() {
        return color;
    }
}

View:

看法：

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

public class View extends Frame{  
    Model model;
    JButton checkAnswer;
    private JPanel button;
    private static final Color COLORS[] = {Color.black, Color.white, Color.red, Color.yellow, Color.green, Color.blue, new Color(7, 254, 250)};

    public View(String name, int w, int h, Model m){
        model = m;
        setTitle( name );
        setSize( w,h );
        setResizable( false );
        this.setLayout(new BorderLayout());

        button = new JPanel();
        button.setSize( new Dimension(400, 100));
        button.setVisible(true);
        checkAnswer = new JButton("Check");
        checkAnswer.setSize( new Dimension(200, 30));
        button.add( checkAnswer );
        this.add( button, BorderLayout.SOUTH);
        button.setVisible(true);
    }

    @Override
    public void paint( Graphics g ) {
        g.setColor( new Color(238, 238, 238));
        g.fillRect( 0,0,400,590);

        for ( int i=0; i < model.pins.length; i++ ) {
            paintPins(model.pins[i][0],g);
            paintPins(model.pins[i][1],g);
            paintPins(model.pins[i][2],g);
            paintPins(model.pins[i][3],g);
            paintPins(model.pins[i][4],g);
        }
    }

    @Override
    public void update( Graphics g ) {
        if ( model.isUpdate ) {
            paint(g);
        }
        else {
            model.isUpdate = true;
            paintPins(model.pins[model.repaintPin-1][0],g);
            paintPins(model.pins[model.repaintPin-1][1],g);
            paintPins(model.pins[model.repaintPin-1][2],g);
            paintPins(model.pins[model.repaintPin-1][3],g);
            paintPins(model.pins[model.repaintPin-1][4],g);
        }
    }

    void repaintPins( int pin ) {
        model.repaintPin = pin;
        model.isUpdate = false;
        repaint();
    }

    public void paintPins(Pin p, Graphics g ){
        int X = p.getX();
        int Y = p.getY();
        int color = p.getColor();
        int radius = p.getRadius();
        int x = X-radius;
        int y = Y-radius;

        if (color > 0){
            g.setColor( COLORS[color]);
            g.fillOval( x,y,2*radius,2*radius );
        }
        else{
            g.setColor( new Color(238, 238, 238) );
            g.drawOval( x,y,2*radius-1,2*radius-1 );
        }
        g.setColor( Color.black );
        g.drawOval( x,y,2*radius,2*radius );
    }
}

Controller:

控制器：

import java.awt.*;
import java.awt.event.*;

public class Controller implements MouseListener, ActionListener { 
    private Model model;
    private View view;

    public Controller(Model m, View v){ 
        model = m;
        view = v;

        view.addWindowListener( new WindowAdapter(){
            public void windowClosing(WindowEvent e){
            System.exit(0);
        } });
        view.addMouseListener(this);
        view.checkAnswer.addActionListener(this);
        model.combination();
    }

    public void actionPerformed( ActionEvent e ) {
        if(e.getSource() == view.checkAnswer){
            if(model.isRowFull){
                model.check();
            }
        }
    }

    public void mousePressed(MouseEvent e) {
        Point mouse = new Point();

        mouse = e.getPoint();
        if (model.isPlaying){
            if (mouse.x > 350) {
                int button = 1 + (int)((mouse.y - 32) / 50);
                if ((button >= 1) && (button <= 5)){
                    model.fillHole(button);
                    if(model.pinsRepaint){
                        view.repaintPins( model.pinsToRepaint );
                    }
                }
            }
        }
    }

    public void mouseClicked(MouseEvent e) {}
    public void mouseReleased(MouseEvent e){}
    public void mouseEntered(MouseEvent e) {}
    public void mouseExited(MouseEvent e)  {}
}

回答by trashgod

As you've discovered, the Model–View–Controllerpattern is no panacea, but it offers some advantages. Rooted in MVC, the Swing separable model architecture is discussed in A Swing Architecture Overview. Based on this outline, the following example shows an MVCimplementation of a much simpler game that illustrates similar principles. Note that the Modelmanages a single Piece, chosen at random. In response to a user's selection, the Viewinvokes the check()method, while listening for a response from the Modelvia update(). The Viewthen updates itself using information obtained from the Model. Similarly, the Controllermay reset()the Model. In particular, there is no drawing in the Modeland no game logic in the View. This somewhat more complex gamewas designed to illustrate the same concepts.

正如您所发现的，模型-视图-控制器模式不是灵丹妙药，但它提供了一些优势。根植于MVC，Swing 可分离模型体系结构在Swing 体系结构概述中进行了讨论。基于这个大纲，下面的例子展示了一个更简单的游戏的MVC实现，它说明了类似的原理。请注意，Model管理单个Piece，随机选择。响应用户的选择，View调用该check()方法，同时侦听来自Modelvia的响应update()。在View随后利用所获得的信息来更新自身Model。类似地，Controller可以reset()在Model. 特别地，在无拉丝Model并在没有游戏逻辑View。这个稍微复杂的游戏旨在说明相同的概念。

Addendum: I've modified the original example to show how MVCallows one to enhance the Viewwithout changing the nature of the Model.

附录：我修改了原始示例以展示MVC如何允许在View不改变Model.

Addendum: As @akf observes, MVChinges on the observer pattern. Your Modelneeds a way to notify the Viewof changes. Several approaches are widely used:

附录：正如@a​​kf 所观察到的，MVC取决于观察者模式。您Model需要一种通知View更改的方法。几种方法被广泛使用：

• In the example below, Modelextends Observablefor simplicity.

• A more common approach uses an EventListenerList, as shown in the Converterapplication and suggested by the large number of EventListenersubinterfaces and implementing classes.

• A third option is to use a PropertyChangeListener, as shown hereand here.

• 在下面的示例中，为简单起见进行了Model扩展Observable。

• 更常见的方法是使用EventListenerList，如Converter应用程序中所示并由大量EventListener子接口和实现类建议。

• 第三种选择是使用 a PropertyChangeListener，如此处和此处所示。

Addendum: Some common questions about Swing controllers are addressed hereand here.

附录：此处和此处解决了有关 Swing 控制器的一些常见问题。

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Observable;
import java.util.Observer;
import java.util.Random;
import javax.swing.Icon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

/**
 * @see https://stackoverflow.com/q/3066590/230513
 * 15-Mar-2011 r8 https://stackoverflow.com/questions/5274962
 * 26-Mar-2013 r17 per comment
 */
public class MVCGame implements Runnable {

    public static void main(String[] args) {
        EventQueue.invokeLater(new MVCGame());
    }

    @Override
    public void run() {
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(new MainPanel());
        f.pack();
        f.setLocationRelativeTo(null);
        f.setVisible(true);
    }
}

class MainPanel extends JPanel {

    public MainPanel() {
        super(new BorderLayout());
        Model model = new Model();
        View view = new View(model);
        Control control = new Control(model, view);
        JLabel label = new JLabel("Guess what color!", JLabel.CENTER);
        this.add(label, BorderLayout.NORTH);
        this.add(view, BorderLayout.CENTER);
        this.add(control, BorderLayout.SOUTH);
    }
}

/**
 * Control panel
 */
class Control extends JPanel {

    private Model model;
    private View view;
    private JButton reset = new JButton("Reset");

    public Control(Model model, View view) {
        this.model = model;
        this.view = view;
        this.add(reset);
        reset.addActionListener(new ButtonHandler());
    }

    private class ButtonHandler implements ActionListener {

        @Override
        public void actionPerformed(ActionEvent e) {
            String cmd = e.getActionCommand();
            if ("Reset".equals(cmd)) {
                model.reset();
            }
        }
    }
}

/**
 * View
 */
class View extends JPanel {

    private static final String s = "Click a button.";
    private Model model;
    private ColorIcon icon = new ColorIcon(80, Color.gray);
    private JLabel label = new JLabel(s, icon, JLabel.CENTER);

    public View(Model model) {
        super(new BorderLayout());
        this.model = model;
        label.setVerticalTextPosition(JLabel.BOTTOM);
        label.setHorizontalTextPosition(JLabel.CENTER);
        this.add(label, BorderLayout.CENTER);
        this.add(genButtonPanel(), BorderLayout.SOUTH);
        model.addObserver(new ModelObserver());
    }

    private JPanel genButtonPanel() {
        JPanel panel = new JPanel();
        for (Piece p : Piece.values()) {
            PieceButton pb = new PieceButton(p);
            pb.addActionListener(new ButtonHandler());
            panel.add(pb);
        }
        return panel;
    }

    private class ModelObserver implements Observer {

        @Override
        public void update(Observable o, Object arg) {
            if (arg == null) {
                label.setText(s);
                icon.color = Color.gray;
            } else {
                if ((Boolean) arg) {
                    label.setText("Win!");
                } else {
                    label.setText("Keep trying.");
                }
            }
        }
    }

    private class ButtonHandler implements ActionListener {

        @Override
        public void actionPerformed(ActionEvent e) {
            PieceButton pb = (PieceButton) e.getSource();
            icon.color = pb.piece.color;
            label.repaint();
            model.check(pb.piece);
        }
    }

    private static class PieceButton extends JButton {

        Piece piece;

        public PieceButton(Piece piece) {
            this.piece = piece;
            this.setIcon(new ColorIcon(16, piece.color));
        }
    }

    private static class ColorIcon implements Icon {

        private int size;
        private Color color;

        public ColorIcon(int size, Color color) {
            this.size = size;
            this.color = color;
        }

        @Override
        public void paintIcon(Component c, Graphics g, int x, int y) {
            Graphics2D g2d = (Graphics2D) g;
            g2d.setRenderingHint(
                RenderingHints.KEY_ANTIALIASING,
                RenderingHints.VALUE_ANTIALIAS_ON);
            g2d.setColor(color);
            g2d.fillOval(x, y, size, size);
        }

        @Override
        public int getIconWidth() {
            return size;
        }

        @Override
        public int getIconHeight() {
            return size;
        }
    }
}

/**
 * Model
 */
class Model extends Observable {

    private static final Random rnd = new Random();
    private static final Piece[] pieces = Piece.values();
    private Piece hidden = init();

    private Piece init() {
        return pieces[rnd.nextInt(pieces.length)];
    }

    public void reset() {
        hidden = init();
        setChanged();
        notifyObservers();
    }

    public void check(Piece guess) {
        setChanged();
        notifyObservers(guess.equals(hidden));
    }
}

enum Piece {

    Red(Color.red), Green(Color.green), Blue(Color.blue);
    public Color color;

    private Piece(Color color) {
        this.color = color;
    }
}

回答by akf

When looking through Swing, one way that the designers consistently employ updating of View components in its MVC implementation is through Observer/Observable callbacks. An example can be seen in the AbstractTableModel, which has a variety of fireTable*Changed/Updated/etcmethods that will alert all of its TableModelListenerobservers of mods to the model.

在查看 Swing 时，设计人员在其 MVC 实现中始终采用更新 View 组件的一种方法是通过 Observer/Observable 回调。在 中可以看到一个例子AbstractTableModel，它有多种fireTable*Changed/Updated/etc方法可以提醒所有TableModelListener模型观察者注意模型。

One option you have is to add a listener type to your Modelclass, and then notify your registered observers of any mods to the state of your model. Your Viewshould be a listener, and it should repaint itself upon receipt of an update.

您拥有的一种选择是向您的Model类添加一个侦听器类型，然后将任何 mod 通知您注册的观察者到您的模型状态。你View应该是一个监听器，它应该在收到更新后重新绘制自己。

EDIT: +1 to trashgod. consider this an alternate wording to his explanation.

编辑：+1 给垃圾神。认为这是他解释的替代措辞。