java - Swing 自定义组件虚拟鼠标监听器

Question

我刚刚开始组装一个供我自己使用的日志工具，该工具可以记录健身房/运行的统计数据，而我对 swing/awt 的唯一经验是对游戏进行主动渲染，您可以完全控制 Graphics2D 对象，并且不要依赖于使用覆盖的绘制来实现 swing 组件。

不管怎样，我希望创建一个虚拟的 JComponent，我可以将其添加到我的一个面板中(该面板将显示图形、统计信息等，具体取决于我从另一个不同的侧面板中选择的选项)，它除了监听之外什么也不做。 mouseevents 在前面提到的面板中，并在 mousedrags 上绘制一个选择矩形，以便在存在更高分辨率的情况下可以放大数据。我只是不知道如何，我已将组件添加到面板中，但它在面板内没有注册任何内容，相反，它似乎有一个仅限于面板/框架底部的本地空间。

这是组件

package gui;

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;

import javax.swing.JComponent;

@SuppressWarnings("serial")
public class MarkerRectangle extends JComponent implements MouseListener,
        MouseMotionListener {

private boolean draw;
private int startX, endX, startY, endY;
private Color color = new Color(0, 255, 0, 100);

public MarkerRectangle(int width, int height) {
    setPreferredSize(new Dimension(width, height));
    this.addMouseListener(this);
    this.addMouseMotionListener(this);
}

@Override
public void mouseClicked(MouseEvent e) {
    System.out.println("Mouse clicked@ " + e.getX() + "," + e.getY());
}

@Override
public void mouseEntered(MouseEvent e) {
    System.out.println("Mouse entered @ " + e.getX() + "," + e.getY());

}

@Override
public void mouseExited(MouseEvent e) {
    System.out.println("Mouse left @ " + e.getX() + "," + e.getY());
}

@Override
public void mousePressed(MouseEvent e) {
    System.out.println("Mouse pressed@ " + e.getX() + "," + e.getY());
}

@Override
public void mouseReleased(MouseEvent e) {
    System.out.println("Mouse was released @ " + e.getX() + "," + e.getY());
}

@Override
public void mouseDragged(MouseEvent e) {
    System.out.println("Mouse being dragged, currently@ " + e.getX() + ","
            + e.getY());

}

@Override
public void mouseMoved(MouseEvent e) {
    System.out.println("I registered a move@ " + e.getX() + "," + e.getY());
}

@Override
// Draw rectangle
protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    Graphics2D g2d = (Graphics2D) g.create();
    g2d.dispose();
}

}

面板

public class GraphPane extends JPanel {


public GraphPane(Graph graph) {
    this.add(graph);
    this.add(new MarkerRectangle(800, 600));
    this.setBackground(Color.gray);
    this.setPreferredSize(new Dimension(800, 600));
}


}

图表，保存随机数据 atm

public class Graph extends JComponent {
private GeneralPath data;
private Stroke stroke;

public Graph() {
    this.data = new GeneralPath();
    this.stroke = new BasicStroke(3f);
    this.setPreferredSize(new Dimension(750, 550));
    init();
}

private void init() {
    data.moveTo(0, 0);
    double cntr = 0;
    double[][] points = new double[10][1];
    for (double[] point : points) {
        cntr += 100;
        point[0] = Math.random() * 100;
        point[1] = Math.random() * 100;
        data.lineTo(cntr, point[1]);
    }
}

@Override
protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    Graphics2D g2d = (Graphics2D) g.create();
    g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
            RenderingHints.VALUE_ANTIALIAS_ON);
    g2d.setStroke(stroke);
    g2d.draw(data);
    g2d.dispose();
}
}

我想实现类似上面的东西，因为最终我想象 GUI 会变得相当复杂，而像绘制矩形来标记数据这样的简单事件不应该出现在主 Controller 中(以防止大量的 if 测试和代码困惑)。

我得到的截图:

我想要什么:

编辑虽然下面接受的答案是更好的解决方案，但如果有人可能想要使用它，我会将其发布。如果您将 prefferedSize 调整得更小，它将不起作用。

public class Test {

public static void main(String[] args) {
    GeneralJFrame frame = new GeneralJFrame(1200, 800);
    frame.addPanel(new GraphPane(new Graph()), BorderLayout.CENTER);
    frame.addPanel(new ButtonPane(), BorderLayout.SOUTH);
    frame.addPanel(new ButtonPane(), BorderLayout.SOUTH);
    frame.addPanel(new ButtonPane(), BorderLayout.WEST);
    frame.addPanel(new ButtonPane(), BorderLayout.EAST);
    frame.addPanel(new ButtonPane(), BorderLayout.NORTH);
    frame.start();
}
}

public class GraphPane extends JPanel {


public GraphPane(Graph graph) {
    GridBagConstraints c = new GridBagConstraints();
    c.gridwidth = GridBagConstraints.REMAINDER;
    c.gridheight = GridBagConstraints.REMAINDER;
    c.gridx = 0;
    c.gridy = 0;
    this.setLayout(new GridBagLayout());
    this.add(graph);
    this.add(new MarkerRectangle(), c);
    this.setBackground(new Color(205, 201, 201));
}



}

public class MarkerRectangle extends JComponent implements MouseListener,
    MouseMotionListener {

private boolean draw;
private int startX, endX, startY, endY;

public MarkerRectangle() {
    this.addMouseListener(this);
    this.addMouseMotionListener(this);
    setOpaque(false);
    setPreferredSize(new Dimension(800, 600));
}

@Override
public void mouseClicked(MouseEvent e) {

}

@Override
public void mouseEntered(MouseEvent e) {

}

@Override
public void mouseExited(MouseEvent e) {

}

@Override
public void mousePressed(MouseEvent e) {
    startX = e.getX();
    startY = e.getY();
    draw = true;
}

@Override
public void mouseReleased(MouseEvent e) {
    draw = false;
    repaint();
}

@Override
public void mouseDragged(MouseEvent e) {
    endX = e.getX();
    endY = e.getY();
    repaint();
}

@Override
public void mouseMoved(MouseEvent e) {

}

@Override
// Draw rectangle
protected void paintComponent(Graphics g) {
    System.out.println(getSize());
    if (!draw)
        return;
    int w = endX-startX;
    int h = endY - startY;
    Graphics2D g2d = (Graphics2D) g.create();
    g2d.setColor(new Color(255, 165, 0));
    g2d.fillRect(startX, startY, w, h);
    g2d.dispose();
}

}

public class ButtonPane extends JPanel {
public ButtonPane() {
    add(new JButton("HELLO"));
    setBackground(Color.gray);
    setBorder(BorderFactory.createEtchedBorder(Color.white,
            Color.gray.darker()));
}
}

public class GeneralJFrame {
private JFrame frame;

public GeneralJFrame(int width, int height) {
    this.frame = new JFrame("Le Muscles");
    this.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}

public void addPanel(JPanel panel, String location) {
    this.frame.add(panel, location);
}

public void start() {
    frame.pack();
    frame.setLocationRelativeTo(null);
    frame.setVisible(true);
}
}

输出:(用鼠标拖动橙色)

Answer 1

我还是不太明白你的问题。在我看来，你已经

• 创建了多个 JPanel
• 给定一个 JPanel、一个 MouseListener 和 MouseMotionListener
• 您已将该 JPanel 添加到另一个 JPanel 的底部。
• 位于底部的 JPanel 按照指示注册所有鼠标事件

• 因此，您的程序根据您的代码按预期运行。

• 我的问题是:它的行为为何不符合您的预期？

• 如果您期望添加附加了 MouseListeners 和 MouseMotionListeners 的 JPanel 将导致 GUI 的所有 JPanel 都被监听，那么当然这不会发生。要让更多的 GUI 注册鼠标事件，您必须将 MouseListeners 和 MouseMotionListeners 添加到这些组件。到目前为止，这就是我对你的问题的回答。如果我没有回答您当前面临的真实问题，请为我们澄清。

<小时/>

您声明:

What I want is an invisible (transparent) panel on top of the blue one in the above screenshot that is just as large as the blue one, not a subpanel that is sitting in the bottom. I want the blue one to contain this one (should not be a problem since it is just a jcomponent). What I hope to achieve is a sort over "invisible" overlay that registers mousevents so I don't have to implement these events in the blue panel.

为此考虑使用 JLayer。根据 JLayer API:

JLayer is a good solution if you only need to do custom painting over compound component or catch input events from its subcomponents.

<小时/>

好吧，我尝试了一下并想出了这样的结果:

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.Path2D;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.util.Random;

import javax.swing.*;
import javax.swing.plaf.LayerUI;

@SuppressWarnings("serial")
public class GraphPane2 extends JPanel {
   private static final int GRAPH_WIDTH = 1000;
   private static final int GRAPH_HEIGHT = 750;
   private Graph2 graph2 = new Graph2(GRAPH_WIDTH, GRAPH_HEIGHT);

   public GraphPane2() {
      LayerUI<Graph2> myLayerUI = new MyLayerUI<Graph2>();
      JLayer<Graph2> panelLayer = new JLayer<Graph2>(graph2, myLayerUI);
      setLayout(new BorderLayout());
      add(panelLayer);

      myLayerUI.addPropertyChangeListener(new PropertyChangeListener() {

         @Override
         public void propertyChange(PropertyChangeEvent evt) {
            if (MyLayerUI.MOUSE_RELEASED.equals(evt.getPropertyName())) {
               Rectangle rect = (Rectangle) evt.getNewValue();
               System.out.println(rect);
            }
         }
      });
   }

   private static void createAndShowGui() {
      GraphPane2 mainPanel = new GraphPane2();

      JFrame frame = new JFrame("Graph Pane2");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(mainPanel);
      frame.setResizable(false);
      frame.pack();
      frame.setLocationByPlatform(true);
      frame.setVisible(true);
   }

   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() {
         public void run() {
            createAndShowGui();
         }
      });
   }
}

@SuppressWarnings("serial")
class MyLayerUI<V extends JComponent> extends LayerUI<V> {
   private static final Color FILL_COLOR = new Color(0, 128, 0, 128);
   public static final String MOUSE_RELEASED = "mouse released";
   private Point pressedPt;
   private Point draggedPt;
   private Rectangle rect;

   @Override
   public void paint(Graphics g, JComponent c) {
      super.paint(g, c);
      if (rect != null) {
         Graphics2D g2 = (Graphics2D) g;
         g2.setColor(FILL_COLOR);
         g2.fill(rect);
      }
   }

   public void installUI(JComponent c) {
      super.installUI(c);
      ((JLayer) c).setLayerEventMask(AWTEvent.MOUSE_MOTION_EVENT_MASK | AWTEvent.MOUSE_EVENT_MASK);
   }

   public void uninstallUI(JComponent c) {
      super.uninstallUI(c);
      ((JLayer)c).setLayerEventMask(0);
   }

   @Override
   public void eventDispatched(AWTEvent e, JLayer<? extends V> l) {
      MouseEvent mEvt = (MouseEvent) e;
      int id = mEvt.getID();
      int btn = mEvt.getButton();
      if (id == MouseEvent.MOUSE_PRESSED && btn == MouseEvent.BUTTON1) {
         pressedPt = mEvt.getPoint();
         rect = new Rectangle(pressedPt.x, pressedPt.y, 0, 0);
      }
      if (id == MouseEvent.MOUSE_PRESSED && btn != MouseEvent.BUTTON1) {
         pressedPt = null;
      }
      if (id == MouseEvent.MOUSE_DRAGGED && pressedPt != null) {
         draggedPt = mEvt.getPoint();
         int x = Math.min(draggedPt.x, pressedPt.x);
         int y = Math.min(draggedPt.y, pressedPt.y);
         int width = Math.abs(draggedPt.x - pressedPt.x);
         int height = Math.abs(draggedPt.y - pressedPt.y);
         rect = new Rectangle(x, y, width, height);
      }
      if (id == MouseEvent.MOUSE_RELEASED && pressedPt != null) {
         draggedPt = mEvt.getPoint();
         int x = Math.min(draggedPt.x, pressedPt.x);
         int y = Math.min(draggedPt.y, pressedPt.y);
         int width = Math.abs(draggedPt.x - pressedPt.x);
         int height = Math.abs(draggedPt.y - pressedPt.y);
         rect = new Rectangle(x, y, width, height);
         firePropertyChange(MOUSE_RELEASED, null, rect);
      }      
      l.repaint();
   }
}

@SuppressWarnings("serial")
class Graph2 extends JPanel {
   private static final int MAX_DATA_POINTS = 100;
   private static final int STEP = 10;
   private static final Stroke STROKE = new BasicStroke(3f);
   private Path2D path2D;
   private int width;
   private int height;
   private int[] data = new int[MAX_DATA_POINTS + 1];
   private Random random = new Random();

   public Graph2(int width, int height) {
      this.width = width;
      this.height = height;
      init();

      addComponentListener(new ComponentAdapter() {
         @Override
         public void componentResized(ComponentEvent e) {
            path2D = new Path2D.Double();
            int w = getWidth();
            int h = getHeight();
            double x = 0;
            double y = ((double) MAX_DATA_POINTS - data[0]) * h
                  / MAX_DATA_POINTS;
            path2D.moveTo(x, y);
            for (int i = 1; i < data.length; i++) {
               x = (i * w) / (double) MAX_DATA_POINTS;
               y = ((double) MAX_DATA_POINTS - data[i]) * h
                     / (double) MAX_DATA_POINTS;
               path2D.lineTo(x, y);
            }
         }
      });
   }

   @Override
   public Dimension getPreferredSize() {
      return new Dimension(width, height);
   }

   protected void paintComponent(Graphics g) {
      super.paintComponent(g);
      if (path2D != null) {
         Graphics2D g2d = (Graphics2D) g;
         g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
               RenderingHints.VALUE_ANTIALIAS_ON);
         g2d.setStroke(STROKE);
         g2d.draw(path2D);
      }
   };

   private void init() {
      // create and fill random data
      data[0] = 0;
      boolean up = true;
      // max and min data values -- used for normalization
      int min = Integer.MAX_VALUE;
      int max = Integer.MIN_VALUE;
      for (int i = 1; i < data.length; i++) {
         up = random.nextInt(4) < 3 ? up : !up;
         if (up) {
            data[i] = data[i - 1] + random.nextInt(STEP);
         } else {
            data[i] = data[i - 1] - random.nextInt(STEP);
         }

         if (data[i] > max) {
            max = data[i];
         }
         if (data[i] < min) {
            min = data[i];
         }
      }

      // normalize the data
      for (int i = 0; i < data.length; i++) {
         int datum = (MAX_DATA_POINTS * (data[i] - min)) / (max - min);
         data[i] = datum;
      }

   }
}

这看起来像: