java - 拖放多个/不同的组件

Question

这是我的程序的代码。你能给一些技巧让其他矩形可以像第一个矩形一样移动

注意:第一个矩形是唯一可以拖放的

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

public class GraphicDragAndDrop extends JPanel {

        Rectangle and = new Rectangle(5,5,75,75);
        Rectangle or = new Rectangle(5,105,75,75);
        Rectangle xnor = new Rectangle(5,205,75,75);
        Rectangle nand = new Rectangle(5,305,75,75);
        Rectangle xor = new Rectangle(5,405,75,75);
        Rectangle inverter = new Rectangle(5,505,75,75);

    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D)g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        g2.setPaint(Color.blue);
        g2.draw(and);

         Graphics2D g3 = (Graphics2D)g;
        g3.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        g3.setPaint(Color.red);
        g3.draw(or);

        Graphics2D g4 = (Graphics2D)g;
        g4.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        g4.setPaint(Color.blue);
        g4.draw(xnor);

        Graphics2D g5 = (Graphics2D)g;
        g5.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        g5.setPaint(Color.red);
        g5.draw(nand);

        Graphics2D g6 = (Graphics2D)g;
        g6.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        g6.setPaint(Color.blue);
        g6.draw(xor);


        Graphics2D g7 = (Graphics2D)g;
        g7.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        g7.setPaint(Color.red);
        g7.draw(inverter);
    }

    public void setRect(int x, int y) {

       and.setLocation(x, y);
             repaint();

    }

    public static void main(String[] args) {
        GraphicDragAndDrop test = new GraphicDragAndDrop();
        new GraphicDragController(test);
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(test);
        f.setSize(400,400);
        f.setLocation(100,100);
        f.setVisible(true);
    }
}

class GraphicDragController extends MouseInputAdapter {
    GraphicDragAndDrop component;
    Point offset = new Point();
    boolean dragging = false;

    public GraphicDragController(GraphicDragAndDrop gdad) {
        component = gdad;
        component.addMouseListener(this);
        component.addMouseMotionListener(this);
    }

    public void mousePressed(MouseEvent e) {
        Point p = e.getPoint();
        Rectangle r = component.and;
        Rectangle a = component.or;
        if(r.contains(p)) {
            offset.x = p.x - r.x;
            offset.y = p.y - r.y;
            dragging = true;
    }
    }
    public void mouseReleased(MouseEvent e) {
        dragging = false;
    }

    public void mouseDragged(MouseEvent e) {
        if(dragging) {
            int x = e.getX() - offset.x;
            int y = e.getY() - offset.y;
            component.setRect(x, y);
        }


    }
}

各种帮助将不胜感激，谢谢:)

Answer 1

第一个矩形是唯一可以拖动的，因为您的类中具有始终引用第一个矩形的硬编码逻辑。

您需要更改类的整体设计:

1. 不要对矩形进行硬编码。您将需要一个 ArrayList 来跟踪所有矩形以及每个矩形的颜色

2. 在 MouseListener 代码中，您需要循环访问此列表，以使用 Rectangle 的 contains(...) 方法和 MouseEvent 中的鼠标点来找出您单击了哪个 Rectangle。

3. 找到被单击的矩形后，您将需要更改代码以在该矩形上进行拖动，而不是您现在使用的硬编码“和”变量。

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4. 需要更改 paintComponent() 逻辑，以迭代 ArrayList 来绘制每个矩形。在尝试解决拖动问题之前，您应该首先重构这部分代码。您可能想查看Playing With Shapes了解如何从 ArrayList 绘制 Shape 对象的一些想法。

可能还有其他问题，但希望这能让您朝着正确的方向开始。