java - 鼠标监听器不监听

我有一个固定的学校作业。

我的目标是实现MVC，但现在我只是在视图中进行所有操作（暂时简化一下）。

所以-我有一个框架，它有一个面板。

面板上有一个形状列表。每当用户按下addLine / addRect按钮时，就会引发一个事件并将行/矩形添加到此列表中。

paintComponent函数绘制列表中的所有形状（所有形状都知道如何绘制自己）。

到目前为止，一切都很好-它有效！

此分配的唯一其他要求是，只要用户单击绘图区域中的一个点，就会删除所有包含该点的形状。
每个形状都有其自己的Contains（p）函数。
因此，我决定将MouseListener添加到面板中，该面板将获取点击的X，Y坐标，并将从形状列表中删除相关的形状。

我不知道这是否是个好主意，但目前这不是我的问题。

我的问题是MouseListener无法响应单击-我知道这是因为在mouseClicked实现的内部有一个断点，而调试器从未到达该断点。

我的问题是为什么？

这是我的代码：还有更多我需要解决的问题，但现在他们不关心我

//MyFrame.java

public class MyFrame extends JFrame {
    private MyJPanel panel ;

    public MyFrame() throws MyShape.IllegalArgumentException {
        initUI();
    }

    private void initUI() throws IllegalArgumentException {
        setLayout(new FlowLayout());
        panel = new MyJPanel();
        add(panel);
        setTitle("Shapes Editor");
        setSize(600, 600);
        setLocationRelativeTo(null);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.pack();
        setVisible(true);
    }
}

//MyPanel.java

public class MyJPanel extends JPanel {

    ArrayList<MyShapeAbstract> pic;
    DrawingArea drawingArea;
    ButtonsPanel buttonsPanel;

    public ButtonsPanel getButtonsPanel() {
        return buttonsPanel;
    }
    public void setButtonsPanel(ButtonsPanel buttonsPanel) {
        this.buttonsPanel = buttonsPanel;
    }

    public ArrayList<MyShapeAbstract> getPic() {
        return pic;
    }
    public void setPic(ArrayList<MyShapeAbstract> pic) {
        this.pic = pic;
    }

    public MyJPanel() throws MyShape.IllegalArgumentException {
        initUI();
    }

    private void initUI() throws MyShape.IllegalArgumentException {
        setLayout(new FlowLayout());
        pic = new ArrayList<MyShapeAbstract>();
        add(buttonsPanel = new ButtonsPanel(this));
        add(drawingArea = new DrawingArea(this));
        drawingArea.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                super.mouseClicked(e);
                Point p = null;
                try {
                    p = new Point(e.getX(), e.getY());
                } catch (IllegalArgumentException e1) {
                    e1.printStackTrace();
                }
                Iterator<MyShapeAbstract> iter = pic.iterator();
                while (iter.hasNext()){
                    MyShapeAbstract shape = iter.next();
                    if(shape.contains(p))
                    {
                        iter.remove();
                    }
                }
                drawingArea.repaint();
                pic.clear();
                repaint();
            }
        });

        JButton addLineButton = buttonsPanel.getAddLineButton();
        addLineButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    addLine();
                    drawingArea.repaint();
                    repaint();
                } catch (IllegalArgumentException e1) {
                    e1.printStackTrace();
                }
            }
        });
        add(addLineButton);

        JButton addRectButton = buttonsPanel.getAddRectButton();
        addRectButton.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                try {
                    addRect();
                } catch (IllegalArgumentException e1) {
                    e1.printStackTrace();
                }
                drawingArea.repaint();
                repaint();
            }
        });
        add(addRectButton);
    }

    @Override
    public void repaint() {
        Graphics g = getGraphics();
        if(g!=null && pic != null)
            for(MyShapeAbstract shape : pic){
                shape.draw(g);
            }
    }

    private void addRect() throws IllegalArgumentException {
        Random r = new Random();
        pic.add(new MyRectangle(new Point(r.nextInt(200), r.nextInt(200)), new Point(r.nextInt(200),r.nextInt(200))));
    }
    private void addLine() throws IllegalArgumentException {
        Random r = new Random();
        pic.add(new MyLine(new Point(r.nextInt(200), r.nextInt(200)), new Point(r.nextInt(200),r.nextInt(200))));
    }
}

class DrawingArea extends JPanel{
    public DrawingArea(MyJPanel parent) {
        this.parent = parent;
        setLayout(new FlowLayout());
    }

    @Override
    public void repaint() {
        Graphics g = getGraphics();
        if(g!=null && parent.getPic() != null)
            for(MyShapeAbstract shape : parent.getPic()){
                shape.draw(g);
            }
    }

    MyJPanel parent;
}

class ButtonsPanel extends JPanel{
    //ArrayList<JButton> buttons = new ArrayList<JButton>();

    MyJPanel parent;
    private JButton addLineButton  = new JButton("addLineButton");
    private JButton addRectButton = new JButton("addRectButton");


    ButtonsPanel(final MyJPanel parent){
        this.parent = parent;
        setLayout(new FlowLayout());
        add(addLineButton);
        add(addRectButton);
        addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                super.mouseClicked(e);
                Point p = null;
                try {
                    p = new Point(e.getX(), e.getY());
                } catch (IllegalArgumentException e1) {
                    e1.printStackTrace();
                }
                Iterator<MyShapeAbstract> iter = parent.getPic().iterator();
                while (iter.hasNext()){
                    MyShapeAbstract shape = iter.next();
                    if(shape.contains(p))
                    {
                        iter.remove();
                    }
                }
                repaint();
            }
        });
    }

    @Override
    public void repaint() {
        Graphics g = getGraphics();
        if(g!=null && parent.getPic() != null)
            for(MyShapeAbstract shape : parent.getPic()){
                shape.draw(g);
            }
    }

    public JButton getAddLineButton() {
        return addLineButton;
    }

    public void setAddLineButton(JButton addLineButton) {
        this.addLineButton = addLineButton;
    }

    public JButton getAddRectButton() {
        return addRectButton;
    }

    public void setAddRectButton(JButton addRectButton) {
        this.addRectButton = addRectButton;
    }
}

最佳答案

我在您的“按钮面板”中添加了以下内容：

 ButtonsPanel(final MyJPanel parent){
    this.parent = parent;
    setLayout(new FlowLayout());
    add(addLineButton);
    add(addRectButton);
    //show me the Panel size :)
    this.setBackground(Color.RED);

红色小矩形是鼠标侦听器工作的区域。所以也许您的意思是parent.addMouseListener或drawingArea..addMouseListener（但是您的drawingArea也很小）？只需将技巧与背景结合使用，然后检查您的区域并调整大小或您真正想拥有监听器的面板即可。也许还添加MyShapeAbstract，MyLine，MyRectangle，以便可以测试完整的代码。