java - JLabel重叠

Question

我已经创建了一个标签，覆盖了它的 paintComponent(用不同的弧形格式绘制它)并将它们放在面板上。一切正常，但位于同一位置的标签(通过 .setlocation)产生了问题。

假设我在同一位置有 3 个不同形状的标签。 A-B-C首先创建 A，然后创建 B，最后创建 c。当我点击 A 时，我的函数绘制 A 并显示“你点击了 A”

但是当我点击 B 或 C 时，它就像我点击了 A 一样。

(我在滚动 Pane 中堆叠的面板中添加标签)

这是我制作标签的代码

for(int i=0;i<rowcount;i++){
        arcstart = Rawazimuth(azimuth[i]);
                    //custom JLabel to paint it like an arc
        MyLabel FLabel = new MyLabel(100, 50, (int)arcstart,cellid[i],lon[i],lat[i]);
        FLabel.setOpaque(true);
        Dimension LabelSize = new Dimension( 100,50);
        FLabel.setSize(LabelSize);
                    //locate the JLabel to labels location. it might be same or not
        FLabel.setLocation(lon[i], lat[i]);

        MyPanel.add(FLabel);    
}

这是我自定义的 jlabel 类

public MyLabel(int W, int H, int start,int outcellid,int lonn, int latt) {
    addMouseListener(this);
    arcsizeW = W;
    arcsizeH = H;
    arcstart = start;
    cellid = outcellid;
    clicked = false;
    lon = lonn;
    lat = latt;
}

@Override
public void paintComponent(Graphics g){
    // true if button is clicked, so paint acordingly
    if(clicked ==true){
       g.setColor(dummyg.getColor());  
   }else{
       g.setColor(Color.blue);
   }
  // draw the arc
   g.fillArc(0, 0,arcsizeW , arcsizeH, arcstart, 60);
}

 //if cell is clicked, change its color to red and print its cellid
@Override
public void mouseClicked(MouseEvent e) {

    System.out.println(cellid);

     dummyg = this.getGraphics();
     dummyg.setColor(Color.red);
    this.paintComponent(dummyg);
    clicked = true;
}// other listener stuff}

那么我该如何防止呢？我想我可以使用 jlayerpane，但我至少需要 4 层(不知道是否可以)。

Answer 1

确保您正在调用 super.paintComponent。这对于确保组件进行绘画校正很重要。

鼠标事件如雨。它们将击中第一个注册接收鼠标事件的组件并停止(就像雨打雨伞一样)。

如果您有重叠的组件，在它们重叠的地方，鼠标事件会转到注册处理它们的第一个组件(在本例中为 A)。

这里有一个简单的例子来说明我的意思......

当你将鼠标悬停在每个圆圈上时，它会突出显示，尝试将鼠标悬停在中间......

public class OverlappingMouseTest {

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

    public OverlappingMouseTest() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException ex) {
                } catch (InstantiationException ex) {
                } catch (IllegalAccessException ex) {
                } catch (UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame();
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new BackgroundPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }            
        });
    }

    protected class BackgroundPane extends JLayeredPane {

        private CirclePane redPane;
        private CirclePane greenPane;
        private CirclePane bluePane;

        public BackgroundPane() {            
            redPane = new CirclePane(Color.RED);
            greenPane = new CirclePane(Color.GREEN);
            bluePane = new CirclePane(Color.BLUE);

            add(redPane);
            add(greenPane);
            add(bluePane);            
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(200, 200);
        }

        @Override
        public void doLayout() {            
            Dimension size = new Dimension(100, 100);
            int width = getWidth() - 1;
            int height = getHeight() - 1;

            Point p = new Point();
            p.x = (width / 2) - 50;
            p.y = (height / 2) - 75;            
            redPane.setBounds(new Rectangle(p, size));

            p.x = (width / 2) - 75;
            p.y = (height / 2) - 25;
            bluePane.setBounds(new Rectangle(p, size));

            p.x = (width / 2) - 25;
            p.y = (height / 2) - 25;
            greenPane.setBounds(new Rectangle(p, size));            
        }        
    }

    protected class CirclePane extends JPanel {

        private boolean mouseHover = false;

        public CirclePane(Color background) {
            setOpaque(false);
            setBackground(background);
            addMouseListener(new MouseAdapter() {
                @Override
                public void mouseExited(MouseEvent me) {
                    mouseHover = false;
                    repaint();
                }

                @Override
                public void mouseEntered(MouseEvent me) {
                    mouseHover = true;
                    repaint();
                }                
            });
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(100, 100);
        }

        @Override
        protected void paintComponent(Graphics grphcs) {            
            super.paintComponent(grphcs);

            Graphics2D g2d = (Graphics2D) grphcs.create();
            if (!mouseHover) {
                g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.5f));
            }
            g2d.setColor(getBackground());
            g2d.fill(new Ellipse2D.Float(0, 0, getWidth() - 1, getHeight() - 1));
            g2d.dispose();            
        }        
    }    
}