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自定义Java鼠标侦听器?

mouse-listeners swing java

Azmisov · 技术社区 · 16 年前

首先,我是作为一名网站程序员来到Java的。在JavaScript中,要添加mousemove、mouseover或click事件,只需调用addEventListener函数。根据我对Java的有限经验,您不能只从任何对象实现MouseListener接口。

基本上,到目前为止,我所拥有的是一个JPanel,它绘制一些具有x/y/width/height值的形状(带有绘制方法的CustomShape对象)。我想向shape对象添加某种类型的鼠标侦听器,这样我就可以为shape触发move/roll/click事件。仅仅实现CustomShape对象的MouseListener接口是行不通的(我认为这是显而易见的原因)。我已经查找了如何设计自定义事件侦听器,但似乎不可能创建自定义鼠标侦听器。

最后,我将鼠标侦听器添加到JPanel中,然后遍历所有的shape对象。如果shape对象附加了一个“listener”,并且鼠标坐标验证了鼠标事件的发生,则它会触发该方法。最初,它很好,但随着应用程序的进一步开发,它开始变得非常混乱。另外,如果不复制一堆代码,我将无法将形状对象/接口复制到另一个应用程序。

举个简单的例子:(实际代码相当大)

Interface CustomShape{
    int width, height, x, y;
    void paint(Graphics g);
}

public class StarShape implements CustomShape{
    int width, height, x, y;
    public StarShape(){
        width = 100;
        height = 100;
        x = 50;
        y = 50;
    }
    void paint(Graphics g){
        g.setColor(Color.black);
        g.draw(new Rectangle(x,y,width,height));
    }
}

public class Main extends JPanel{
    StarShape check = new StarShape();
    public Main(){  }
    @Override
    public void paintComponent(Graphics g){
        super.paintComponent(g);
        check.paint(g);
    }
}

所以,我想知道是否有一种干净的方法来实现某种类型的鼠标侦听器的“手绘”形状。

3 回复 | 直到 16 年前

Mike Clark 16 年前

我做你想做的事的方法。编译,运行,读取:-)

Example01.java . 编译并运行它。)

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

public class Example01 {
    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JFrame jf = new JFrame();
                MainPanel mainPanel = new MainPanel();
                jf.add(mainPanel);
                jf.setSize(640, 480);
                jf.setLocationRelativeTo(null);
                jf.setVisible(true);
            }
        });
    }
}

class MainPanel extends JPanel {
    StarShape check1 = new StarShape();
    StarShape check2 = new StarShape();

    public MainPanel() {
        check1.setName("check1");
        check2.setName("check2");
        check1.addMouseListener(new MyMouseListener(check1));
        check2.addMouseListener(new MyMouseListener(check2));
        this.add(check1);
        this.add(check2);
    }
}

class StarShape extends JComponent {
    public StarShape() {
        this.setPreferredSize(new Dimension(100, 100));
    }

    @Override
    protected void paintComponent(Graphics g) {
        g.setColor(Color.black);
        Graphics2D g2d = (Graphics2D) g;
        int x = 0;
        int y = 0;
        int width = this.getWidth() - 1;
        int height = this.getHeight() - 1;
        g2d.draw(new Rectangle(x, y, width, height));
    }
}

class MyMouseListener implements MouseListener {
    private final JComponent component;

    public MyMouseListener(JComponent component) {
        this.component = component;
    }

    public void mouseClicked(MouseEvent e) {
        System.out.println("mouseClicked: " + component.getName());
    }

    public void mouseEntered(MouseEvent e) {
        System.out.println("mouseEntered: " + component.getName());
        Dimension preferredSize = component.getPreferredSize();
        preferredSize.height += 20;
        preferredSize.width += 20;
        component.setPreferredSize(preferredSize);
        component.invalidate();
        SwingUtilities.getWindowAncestor(component).validate();
    }

    public void mouseExited(MouseEvent e) {
        System.out.println("mouseExited: " + component.getName());
        Dimension preferredSize = component.getPreferredSize();
        preferredSize.height -= 20;
        preferredSize.width -= 20;
        component.setPreferredSize(preferredSize);
        component.invalidate();
        SwingUtilities.getWindowAncestor(component).validate();
    }

    public void mousePressed(MouseEvent e) {
        System.out.println("mousePressed: " + component.getName());
    }

    public void mouseReleased(MouseEvent e) {
        System.out.println("mouseReleased: " + component.getName());
    }
}

vanza 16 年前

为了能够接收事件,“Shape”对象应该扩展java.awt.Component(或javax.swing.JComponent)。然后,您可以将它们作为一个孩子添加到JPanel中,它们将接收事件,您可以直接向它们添加侦听器。

Community Mohan Dere 9 年前

你能做的就是把它的形状拉长 JPanel .

public abstract class CustomShape extends JPanel {

    public CustomShape(){
        setOpaque(false);
    }

    public abstract void paintShape(Graphics g);

    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        paintShape(g);
    }

}

然后可以直接在形状上添加侦听器。

面板 ,并设置 LayoutManager 到 null

阅读有关手动布局组件的更多信息 here . 如果你不喜欢这种方法,看看我的答案 this