如何正确使用MouseMotionListener按JButtons？

Question

我制作了一个小型的Conway Game of Life计划。我完成了大约80％。我使用JButtons的网格作为单元格。现在我在每个按钮上都有一个ButtonListener，所以你必须通过点击各个按钮逐个绘制你想要的模式。我希望能够单击并拖动鼠标并快速选择按钮。我使用了MotionListener类，实现了MouseMotionListener并将mouseDragged方法编码为与actionPerformed类中的ButtonListener方法相同的方式。

我认为逻辑应该是一样的，但我肯定错过了一些东西。我玩了一下，认为它只是比我能说的更快地选择和取消选择。我添加了一个检查，以确保它没有尝试连续更改相同的按钮，但这没有帮助。这是我的MotionListener课程：

    class MotionListener implements MouseMotionListener {

    @Override
    public void mouseDragged(MouseEvent e) {
        for (int i = 0; i < size; i++) {
            for (int j = 0; j < size; j++) {
                if (e.getSource() == squares[i][j]) {
                    if (litSquares[i][j] == false) {
                        squares[i][j].setBackground(selected);
                        litSquares[i][j] = true;
                    } else {
                        squares[i][j].setBackground(backGround);
                        litSquares[i][j] = false;
                    }
                }
            }
        }
    }

    @Override
    public void mouseMoved(MouseEvent e) {
        // TODO Auto-generated method stub

    }

}

我的JButton数组是squares[][]，而litSquares[][]是当前所选内容的布尔图，我在计算下一步时会使用它。

有关如何纠正MotionListener的任何想法？我不了解如何正确实现这个类。我发现的所有简单示例都涉及绘图，但它们似乎都跟踪拖动光标的Points并随后更新像素。这是我用按钮以某种方式做的事情吗？

*****这是MCVE，或者至少可以缩小它。 *****

package extraCredit;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;

import javax.swing.*;
import javax.swing.border.Border;

public class MCVE extends JPanel {

    private static final long serialVersionUID = -8031881678612431401L;

    static JFrame frame;
    static JPanel grid;
    static JButton[][] squares;
    static boolean[][] litSquares, boardCopy;
    static int size, boardSize, tick = 1, goal = 100, rateIncrease = 10;
    ButtonListener listener = new ButtonListener();
    MotionListener mListerner = new MotionListener();
    Border noBorder = BorderFactory.createEmptyBorder();
    Color backGround = Color.BLUE;
    Color selected = Color.PINK;

    public MCVE(int size) {
        MCVE.size = size;
        squares = new JButton[size][size];
        litSquares = new boolean[size][size];
        grid = new JPanel(new GridLayout(size, size));
        for (int i = 0; i < size; i++) {
            for (int j = 0; j < size; j++) {
                squares[i][j] = new JButton();
                squares[i][j].addActionListener(listener);
                // squares[i][j].addMouseMotionListener(mListerner);
                squares[i][j].setBackground(backGround);
                squares[i][j].setBorder(noBorder);
                grid.add(squares[i][j]);
            }
        }

        frame = new JFrame();
        frame.setLayout(new BorderLayout());
        frame.add(grid, BorderLayout.CENTER);
        frame.setTitle("Life");
        if (25 * size < 525) {
            boardSize = 525;
        } else {
            boardSize = 25 * size;
        }
        frame.setSize(boardSize, boardSize);
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }

    class ButtonListener implements ActionListener {

        @Override
        public void actionPerformed(ActionEvent e) {
            for (int i = 0; i < size; i++) {
                for (int j = 0; j < size; j++) {
                    if (e.getSource() == squares[i][j]) {
                        if (litSquares[i][j] == false) {
                            squares[i][j].setBackground(selected);
                            litSquares[i][j] = true;
                        } else {
                            squares[i][j].setBackground(backGround);
                            litSquares[i][j] = false;
                        }
                    }
                }
            }
        }
    }

    class MotionListener implements MouseMotionListener {

        @Override
        public void mouseDragged(MouseEvent e) {
            for (int i = 0; i < size; i++) {
                for (int j = 0; j < size; j++) {
                    if (e.getSource() == squares[i][j]) {
                        if (litSquares[i][j] == false) {
                            squares[i][j].setBackground(selected);
                            litSquares[i][j] = true;
                        } else {
                            squares[i][j].setBackground(backGround);
                            litSquares[i][j] = false;
                        }
                    }
                }
            }
        }

        @Override
        public void mouseMoved(MouseEvent e) {
            // TODO Auto-generated method stub
        }
    }

    public static void main(String args[]) {
        new MCVE(20);
    }
}

解决方案，感谢@MadProgrammer和@ durron597。 Mad回答了我的另一个question，这让我对这个问题感到不满。

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.GridLayout;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.util.HashSet;
import java.util.Set;

import javax.swing.*;

public class ChangesAttempt extends JPanel {
private static final long serialVersionUID = -8031881678612431401L;

static JFrame frame;
static JPanel grid;
static JLabel[][] squares;
static boolean[][] litSquares;
static int size, boardSize;
static boolean startDrag, origin;
static Set<Component> compList = new HashSet<Component>();
MouseEvent listener = new MouseEvent();
MotionListener mListerner = new MotionListener();
Color backGround = Color.BLUE;
Color selected = Color.PINK;

public ChangesAttempt(int size) {
    ChangesAttempt.size = size;
    squares = new JLabel[size][size];
    litSquares = new boolean[size][size];
    grid = new JPanel(new GridLayout(size, size));
    grid.addMouseMotionListener(mListerner);
    grid.addMouseListener(listener);
    setBoard();

    frame = new JFrame();
    frame.setLayout(new BorderLayout());
    frame.add(grid, BorderLayout.CENTER);
    frame.setTitle("ChangedLife");
    if (25 * size < 525)
        boardSize = 525;
    else
        boardSize = 25 * size;
    frame.setSize(boardSize, boardSize);
    frame.setLocationRelativeTo(null);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
}

class MouseEvent implements MouseListener {

    @Override
    public void mousePressed(java.awt.event.MouseEvent e) {
        startDrag = true;
    }

    @Override
    public void mouseClicked(java.awt.event.MouseEvent e) {
        Component source = e.getComponent().getComponentAt(e.getPoint());
        System.out.println("X = " +source.getX() + ", Y = " + source.getY());
        for (int i = 0; i < size; i++) {
            for (int j = 0; j < size; j++) {
                if (source == squares[i][j]) {
                    if (litSquares[i][j] == false) {
                        squares[i][j].setBackground(selected);
                        litSquares[i][j] = true;
                    } else {
                        squares[i][j].setBackground(backGround);
                        litSquares[i][j] = false;
                    }
                }
            }
        }
    }

    @Override
    public void mouseEntered(java.awt.event.MouseEvent e) {
    }

    @Override
    public void mouseExited(java.awt.event.MouseEvent e) {
    }

    @Override
    public void mouseReleased(java.awt.event.MouseEvent e) {
        compList.clear();
    }
}

class MotionListener implements MouseMotionListener {
    @Override
    public void mouseDragged(java.awt.event.MouseEvent e) {
        compList.add(e.getComponent().getComponentAt(e.getPoint()));
        updateBoard();
    }

    @Override
    public void mouseMoved(java.awt.event.MouseEvent e) {

    }
}

public void setBoard() {
    for (int i = 0; i < size; i++) {
        for (int j = 0; j < size; j++) {
            squares[i][j] = new JLabel();
            squares[i][j].setOpaque(true);
            squares[i][j].setBackground(backGround);
            grid.add(squares[i][j]);
        }
    }
}

public void updateBoard(){
    for (int i = 0; i < size; i++) {
        for (int j = 0; j < size; j++) {
            if (compList.contains(squares[i][j])) {
                if(startDrag){
                    startDrag = false;
                    origin = litSquares[i][j];
                }
                if (litSquares[i][j] == origin) {
                    if(origin)
                        squares[i][j].setBackground(backGround);
                    else
                        squares[i][j].setBackground(selected);
                    litSquares[i][j] = !litSquares[i][j];
                }
            }
        }
    }
}

class MyLabel extends JLabel {
    private static final long serialVersionUID = -1414933339546989142L;

}

public static void main(String args[]) {
    new ChangesAttempt(20);
}
}

Answer 1

我认为你遇到的问题是你正在尝试使用JButton来做一些它不打算做的事情。我会使用更简单的控件，例如JLabel，这样您就不会拥有JButton所具有的所有额外功能。

其次，您的litSquares数组显然是Data Clump。您绝对应该创建自己的自定义控件（可以是extend JComponent或extend JLabel），具体取决于JLabel是否符合您的需求，其中包含应与控件配对的其他信息本身。

第三，您可能不希望按钮的状态为boolean，您可能希望它是enum ...喜欢

public enum State {
    UNLIT, LIT, CURRENTLY_SELECTED;
}

这样您就可以看到哪些组件正在进行新颜色翻转。

最后，正如评论中提到的那样，使用public Component getComponentAt(int x, int y)来确定MouseMotionListener被拖过的内容，并使用它来更改颜色。