java - 递归和/或 getBackground() 未按预期工作

Question

我正在使用递归方法为 Boggle 板上由用户输入的 JButton 着色。例如，如果使用单词“CAT”作为单词参数，则该方法将搜索 Buttons[][] 数组以查找旁边有“A”和“T”的“C”，并将相应的按钮着色为橙色并返回 true。但是，我的代码存在一个问题，即像 CATATATAT 这样的单词也会返回 true，因为我的代码无意中允许重复使用按钮。

问题是我无法检查 JButton 是否已被使用(已为橙色)。当我在递归方法中使用 getBackground() 时，我发现 JButton 仍然是默认的白色，即使它们在视觉上是橙色的。关于如何检测 JButton 已被使用(已呈橙色)有什么想法吗？

JButton[][] buttons = new JButton[4][4];
Color orange = new Color(245, 130, 32);

假设 JButton 数组中充满了新按钮，每个按钮上有一个随机字母

public boolean findWord(String word) {
    clearButtons();
    for (int row = 0; row < length; row++) {
        for (int col = 0; col < length; col++) {
            if (findWord(word, row, col)) {
                System.out.println("");
                return true;
            }
        }
    }
    return false;
}

private boolean findWord(String word, int row, int col) {

    if(word.equals("")) {
        return true;
    }


    if (row < 0 || row >= length || 
             col < 0 || col >= length || 
             !(buttons[row][col].getText().equals(word.substring(0,1))) ||
             buttons[row][col].getBackground().equals(orange) // <- always is false
                ) {
        return false;
    }


        String rest = word.substring(1, word.length());

        boolean letter =
               findWord(rest, row-1, col-1) ||
               findWord(rest, row-1,   col) ||
               findWord(rest, row-1, col+1) ||
               findWord(rest, row, col-1) ||
               findWord(rest, row, col+1) ||
               findWord(rest, row+1, col-1) ||
               findWord(rest, row+1,   col) ||
               findWord(rest, row+1, col+1);

        if(letter) {
            buttons[row][col].setBackground(orange); // <- despite this
        }
        return letter;
}

我已经尝试尽可能地减少程序以使其可以运行。只需在文本区域中键入重复单词的一部分的内容即可。这是一个完整的可运行版本:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.UIManager.LookAndFeelInfo;
import javax.swing.text.JTextComponent;

public class BoggleGame extends JFrame implements ActionListener, KeyListener {
private static final long serialVersionUID = -3125864417227564060L;
String[] wordArray = new String[0];
static String username;
int length = 4;
public JTextArea searchTextArea = new JTextArea(0,12);
DefaultListModel wordListModel= new DefaultListModel();
JButton[][] buttons = new JButton[length][length];
JList wordList = new JList(wordListModel);
JScrollPane wordScrollPane = new JScrollPane(wordList);
JPanel northPanel = new JPanel();
JPanel timePanel = new JPanel();
JPanel usernamePanel = new JPanel();
JPanel southPanel = new JPanel();
JPanel centerPanel = new JPanel();
JPanel eastPanel = new JPanel();
ImageIcon logo = new ImageIcon(getClass().getResource("logo.png"));
Color white = new Color(255,255,255);
Color blue = new Color(0,150 ,240);
Color orange = new Color(245, 130, 32);
Color dark_orange = new Color(180, 117 , 70);

public static void main(String[] arguments){        
    new BoggleGame();
}


public BoggleGame(){
    // Set Title
    super("");

    // Set up Frame
    setResizable(false);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

    // Set Layout
    getContentPane().setLayout(new BorderLayout());
    nimbusLookAndFeel();

    // North Panel
    northPanel.setLayout(new GridLayout(1,3));
    northPanel.setPreferredSize(new Dimension(550,100));
    northPanel.setBackground(blue);
    // Username Panel
    usernamePanel.setLayout(new FlowLayout(FlowLayout.LEFT));
    usernamePanel.setBackground(blue);
    JLabel usernameLabel = new JLabel("Username:");
    usernamePanel.add(usernameLabel);
    JTextArea usernameTextArea = new JTextArea();
    usernameTextArea.setText(Login.username);
    usernamePanel.add(usernameTextArea);
    northPanel.add(usernamePanel);
    usernameTextArea.setEditable(false);
    add(northPanel, BorderLayout.NORTH);
    northPanel.add(usernamePanel);
    // Logo
    northPanel.add(new JLabel(logo));
    // Time Panel
    timePanel.setLayout(new FlowLayout(FlowLayout.RIGHT));
    timePanel.setBackground(blue);
    JLabel timeLabel = new JLabel("Time:");
    timePanel.add(timeLabel);
    JTextArea timeTextArea = new JTextArea();
    timeTextArea.setText("0");
    timePanel.add(timeTextArea);
    northPanel.add(timePanel);
    timeTextArea.setEditable(false);
    add(northPanel, BorderLayout.NORTH);

    // South Panel
    southPanel.setPreferredSize(new Dimension(550,50));
    southPanel.setBackground(blue);
    searchTextArea.setLineWrap(true);
    southPanel.add(searchTextArea);
    searchTextArea.setBorder(BorderFactory.createLineBorder(Color.BLACK));
    searchTextArea.setFont(new Font("Geniva", Font.PLAIN, 30));
    searchTextArea.addKeyListener((KeyListener) this);
    JButton submitButton = new JButton("Submit");
    submitButton.addActionListener(this);
    southPanel.add(submitButton);
    JButton quitButton = new JButton("Quit");
    quitButton.addActionListener(this);
    southPanel.add(quitButton);
    getContentPane().add(southPanel, BorderLayout.SOUTH);

    // Center Panel
    centerPanel.setPreferredSize(new Dimension(400,400));
    centerPanel.setBackground(blue);
    centerPanel.setLayout(new GridLayout(length, length));
        //generate buttons
    for(int i=0; i<length; i++) {
        for(int j=0; j<length; j++) {
        buttons[i][j]=new JButton(Character.toString(((char)(int)(Math.random() * 25 + 65))));
        buttons[i][j].setBackground(white);
        //buttons[i][j].setForeground(white);
        buttons[i][j].setFont(new Font("Geniva", Font.BOLD, 200/length));
        buttons[i][j].addActionListener(this);
        centerPanel.add(buttons[i][j]);
        }
    }
    getContentPane().add(centerPanel, BorderLayout.CENTER);

    // East Panel
    eastPanel.add(wordScrollPane);
    wordScrollPane.setPreferredSize(new Dimension(150,400));
    eastPanel.setBackground(blue);
    getContentPane().add(eastPanel, BorderLayout.EAST);


    // Finalize
    pack();
    searchTextArea.requestFocusInWindow();
    setLocationRelativeTo(null);
    setVisible(true);
}
public void nimbusLookAndFeel() {
    try {
        for (LookAndFeelInfo info : UIManager.getInstalledLookAndFeels()) {
            if ("Nimbus".equals(info.getName())) {
                UIManager.setLookAndFeel(info.getClassName());
                break;
            }
        }
    } catch (Exception e) {
    }
}

public void clearButtons() {
    for(int i= 0; i<buttons.length; i++) {
        for(int j=0; j<buttons[0].length; j++) {
            buttons[i][j].setBackground(white);
        }
    }
}
public void submitWord() {
    if(findWord(searchTextArea.getText()) && !(searchTextArea.getText().equals(""))){

        wordListModel.addElement(searchTextArea.getText().toUpperCase());
        } else {
            wordListModel.addElement("Not a word!");
        }
        searchTextArea.getDocument().putProperty("filterNewlines", Boolean.TRUE);
        wordList.ensureIndexIsVisible(wordListModel.size()-1);
        searchTextArea.setText("");
}
@Override
public void actionPerformed(ActionEvent e) {
    // Check if source is the Submit Button
    if(((JButton) e.getSource()).getText().equals("Submit")){
        submitWord();
    // Check if source is the Quit Button
    } else if(((JButton) e.getSource()).getText().equals("Quit")){
        dispose();
    // Source must be a Letter Button
    } else if(!((JButton) e.getSource()).getBackground().equals(orange)){
        searchTextArea.append(((JButton) e.getSource()).getText());
        ((JButton) e.getSource()).setBackground(orange);
    }
    searchTextArea.requestFocusInWindow();
}

@Override
public void keyPressed(KeyEvent e) {

    searchTextArea.setText(searchTextArea.getText().toUpperCase());
    if (e.getKeyCode()==KeyEvent.VK_ENTER){
        submitWord();
    }       
}

@Override
public void keyReleased(KeyEvent e) {

    searchTextArea.setText(searchTextArea.getText().toUpperCase());
    if(!findWord(searchTextArea.getText())) {
        clearButtons();
    }
    if (e.getKeyCode()==KeyEvent.VK_ENTER){
        searchTextArea.setText("");
    }
}

@Override
public void keyTyped(KeyEvent e) {
}

// here is the method that does not work!
public boolean findWord(String word) {
    clearButtons();
    for (int row = 0; row < length; row++) {
        for (int col = 0; col < length; col++) {
            if (findWord(word, row, col)) {
                System.out.println("");
                return true;
            }
        }
    }
    return false;
}

private boolean findWord(String word, int row, int col) {

    if(word.equals("")) {
        return true;
    }


    if (row < 0 || row >= length || 
             col < 0 || col >= length || 
             !(buttons[row][col].getText().equals(word.substring(0,1))) ||
             buttons[row][col].getBackground().equals(orange) //<-doesn't work
                ) {
        return false;
    }
        System.out.println(buttons[row][col].getBackground());

        String rest = word.substring(1, word.length());

        boolean letter =
               findWord(rest, row-1, col-1) ||
               findWord(rest, row-1,   col) ||
               findWord(rest, row-1, col+1) ||
               findWord(rest, row, col-1) ||
               findWord(rest, row, col+1) ||
               findWord(rest, row+1, col-1) ||
               findWord(rest, row+1,   col) ||
               findWord(rest, row+1, col+1);
        if(letter) {
            buttons[row][col].setBackground(orange);
        }
        return letter;
}

}

Answer 1

如 Java Docs 中所述

public Color getBackground()

Gets the background color of this component.

Returns: this component's background color; if this component does not have a background color, the background color of its parent is returned

此方法返回 Color 的实例，因此您需要比较 Color.orange 或 Color.ORANGE