记住鼠标点击的位置？的ArrayList？哈希码？

Question

对不起,伙计们,我删除了我的APPLES和CATS示例:)这是我的问题的更新版本!

我在这里失去理智.我需要能够启发我的人.我曾尝试过几次在这里解释我的问题.希望这次,我的问题会更容易理解.

基本上我有这个框架,并显示一个图像.右侧有一个JList,底部有另一个JLabel面板.这是我框架的屏幕截图.

当我点击图像时,会弹出一个JOptionPane,就像这样.我输入了我的输入.我的JList是一个ArrayList,所以我输入的所有内容都被添加到JList和底部的JPanel.

现在,当我将鼠标悬停在我点击的部分时,你注意到方形消失了).它仅在我单击图像时出现,并且当我将标签悬停在底部时.我的标签,截至目前是LOLZ NOSE和INPUT HERE.

我想要做的是当我将鼠标悬停在标签上时,例如INPUT HERE,它再次显示正方形,其中包含我点击的部分.我现在的问题是,当我点击NOSE时,它应该在鼻子部分显示一个正方形,并且名字NOSE有黑色bg,它不显示.此外,仅显示最后一个标签的正方形,而忽略其他标签的位置点击.

如何获得标签以记住我所做的点击的位置？人们说我应该使用ArrayLists或HashCodes但是我不知道如何实现它们.感谢任何能提供帮助的人.

编辑:我已经完成了矩形,顺便说一句.它仅显示输入的最后一个标签.以下是一些要求的代码片段!

我如何在JLabel上设置文本并更新JList:

public void updateLabel(){

        StringBuilder text = new StringBuilder(); //creates empty builder, capacity 16

        for(Object s: tagModel.toArray()) //returns an array containing the elements of the tagModel
            text.append(" " + s);

        repaint();      
        hoverLabel.setText(text.toString()); //returns a String
        hoverLabel.addMouseMotionListener(this);
        hoverPanel.add(hoverLabel);

    }

点击后我的mouseListener:

@Override
    public void mouseClicked(MouseEvent event) {
        // TODO Auto-generated method stub

        x = event.getX();
        y = event.getY();

        isRectPresent = true;
        repaint();

        input = JOptionPane.showInputDialog("Enter tag name:");

        if((input != null) && !input.isEmpty()){
            tagModel.addElement(input);
        }
    }

我的mouseMotionListener在悬停时:

@Override
    public void mouseMoved(MouseEvent e) {
        // TODO Auto-generated method stub

        xpos = e.getX(); //gets where the mouse moved
        ypos = e.getY(); 

        //checks if the mouse is inside the bounds of the rectangle
        if (xpos > x && xpos < x + 100 && ypos > y && ypos < y + 100)
            isRectPresent = false;

        if(e.getSource() == hoverLabel){
            isRectPresent = true;
            repaint();
        }

        repaint();
    }

我是怎么画的:

    public void paintComponent(Graphics g){ 
            Graphics2D g2 = (Graphics2D) g;

            g2.drawImage(image, 0, 0, null);

            if(image != null && isRectPresent){                 
                            Stroke stroke = g2.getStroke();
                g2.setStroke(new BasicStroke(4));
                g2.setColor(Color.WHITE);
                g2.drawRect(x-50, y-50, 100, 100);
                g2.setStroke(stroke);
            }else{
                if(xpos > x && xpos < x + 100 && ypos > y && ypos < y + 100){
                    g.setColor(Color.BLACK);
                    g.fillRect(x-50, y-50, 100, 25);
                    g.setColor(Color.WHITE);
                    g.setFont(new Font("Tahoma", Font.BOLD, 12));
                    g.drawString(input, x-30, y-30);
                }
            }
        }

如果你想让我添加更多片段,请告诉我!:)

Answer 1

你应该创建一个 HashMap，如下所示：

映射 linkSet = new HashMap();

每当您单击绘图并创建标签时，请使用 put 方法将 JLabel 和图像上的点添加到集合中，其中 JLabel 为键，Point 为值。然后在 JLabel 的 MouseMotionListener 中，使用标签作为键，并使用地图的get(...)方法从集合中获取相应的点。

编辑：
根据 alicedimarco 的评论进行更正。再次感谢！

编辑2
我想你想再次使用地图。如果您有一个 Map，则可以让它从 JLabel 或 JList 的字符串中检索感兴趣的点，然后将此 Point 传递给正在绘制图像的类，并让它使用该 Point 来绘制矩形。例如，您可以为图像绘制类提供一个名为 displayPoint 的 Point 字段和一个名为 setDisplayPoint(Point p) 的方法。它可以像这样简单：

public void setDisplayPoint(Point p) {
  this.displayPoint  = p;
  repaint();
}

并假设感兴趣的对象位于该点的中心，请在paintComponent方法中使用displayPoint：

protected void paintComponent(Graphics g) {
  super.paintComponent(g);
  // draw image
  if (img != null) {
     g.drawImage(img, X_SHIFT, Y_SHIFT, null);
  }

  // if displayPoint not null, draw the surrounding rectangle
  if (displayPoint != null) {
     g.setColor(RECT_COLOR);
     int x = displayPoint.x - RECT_WIDTH / 2;
     int y = displayPoint.y - RECT_WIDTH / 2;
     int width = RECT_WIDTH;
     int height = RECT_WIDTH;
     g.drawRect(x, y, width, height);
  }
}

编辑3：
要获得鼠标点击，非常简单，只需将 MouseListener 添加到保存图像的组件即可：

     // !! added
     imgRect.addMouseListener(new MouseAdapter() {
        public void mousePressed(MouseEvent e) {
           imgMousePressed(e);
        }
     }); 

在从此鼠标侦听器调用的代码中，使用 JOptionPane 获取用户选择的标签名称，并将生成的 String 添加到 listDataModel 中，以便在 JList 中以及 stringPointMap 中与 Point 一起看到它从 MouseEvent 获取，以便您可以将 String 映射到 Point 并能够检索它：

// !! added
private void imgMousePressed(MouseEvent e) {
  String result = JOptionPane.showInputDialog(this,
        "Please enter name for this point on image:");
  if (result != null) {
     stringPointMap.put(result, e.getPoint());
     listDataModel.addElement(result);
  }
}

就是这样。

然后把它们放在一起：

import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import javax.imageio.ImageIO;
import javax.swing.*;

@SuppressWarnings("serial")
public class ImageRectMain extends JPanel {
   private ImageRect imgRect;
   private DefaultListModel listDataModel = new DefaultListModel();
   private JList list = new JList(listDataModel);
   private Map<String, Point> stringPointMap = new HashMap<String, Point>();

   public ImageRectMain() {
      String nose = "Nose";
      String ear = "Ear";
      String rightEye = "Right Eye";
      String leftEye = "Left Eye";
      listDataModel.addElement(ear);
      listDataModel.addElement(nose);
      listDataModel.addElement(rightEye);
      listDataModel.addElement(leftEye);
      stringPointMap.put(nose, new Point(480, 500));
      stringPointMap.put(ear, new Point(270, 230));
      stringPointMap.put(rightEye, new Point(380, 390));
      stringPointMap.put(leftEye, new Point(662, 440));

      MouseAdapter listMouseAdapter = new MouseAdapter() {
         @Override
         public void mouseMoved(MouseEvent e) {
            listMouseMoved(e);
         }

         @Override
         public void mouseExited(MouseEvent e) {
            listMouseExited(e);
         }

      };
      list.addMouseMotionListener(listMouseAdapter);
      list.addMouseListener(listMouseAdapter);

      try {
         imgRect = new ImageRect();

         // !! added
         imgRect.addMouseListener(new MouseAdapter() {
            public void mousePressed(MouseEvent e) {
               imgMousePressed(e);
            }
         }); 

         JPanel eastPanel = new JPanel();
         eastPanel.setLayout(new BoxLayout(eastPanel, BoxLayout.PAGE_AXIS));
         eastPanel.add(new JLabel("You have tagged the following:"));
         eastPanel.add(new JScrollPane(list));
         eastPanel.add(Box.createVerticalGlue());
         eastPanel.add(Box.createVerticalGlue());
         eastPanel.add(Box.createVerticalGlue());
         eastPanel.add(Box.createVerticalGlue());
         setLayout(new BorderLayout());
         add(imgRect, BorderLayout.CENTER);
         add(eastPanel, BorderLayout.EAST);
      } catch (MalformedURLException e) {
         e.printStackTrace();
      } catch (IOException e) {
         e.printStackTrace();
      }
   }

   // !! added
   private void imgMousePressed(MouseEvent e) {
      String result = JOptionPane.showInputDialog(this,
            "Please enter name for this point on image:");
      if (result != null) {
         stringPointMap.put(result, e.getPoint());
         listDataModel.addElement(result);
      }
   }

   private void listMouseExited(MouseEvent e) {
      imgRect.setDisplayPoint(null);
   }

   private void listMouseMoved(MouseEvent e) {
      int index = list.locationToIndex(e.getPoint());
      Object value = listDataModel.get(index);
      if (value != null) {
         Point point = stringPointMap.get(value.toString());
         if (point != null) {
            imgRect.setDisplayPoint(point);
         }
      }
   }

   private static void createAndShowGui() {
      JFrame frame = new JFrame("ImageRectMain");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(new ImageRectMain());
      frame.pack();
      frame.setLocationRelativeTo(null);
      frame.setVisible(true);
   }

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

@SuppressWarnings("serial")
class ImageRect extends JPanel {
   public static final String IMAGE_PATH = "https://i.stack.imgur.com/7oNzg.jpg";
   private static final int DEFAULT_W = 687;
   private static final int DEFAULT_H = 636;
   private static final int X_SHIFT = -6;
   private static final int Y_SHIFT = -26;
   private static final Color RECT_COLOR = Color.pink;
   private static final int RECT_WIDTH = 40;
   private BufferedImage img;
   private Point displayPoint = null;

   public ImageRect() throws MalformedURLException, IOException {
      img = ImageIO.read(new URL(IMAGE_PATH));
   }

   public void setDisplayPoint(Point p) {
      this.displayPoint = p;
      repaint();
   }

   @Override
   protected void paintComponent(Graphics g) {
      super.paintComponent(g);
      if (img != null) {
         g.drawImage(img, X_SHIFT, Y_SHIFT, null);
      }
      if (displayPoint != null) {
         g.setColor(RECT_COLOR);
         int x = displayPoint.x - RECT_WIDTH / 2;
         int y = displayPoint.y - RECT_WIDTH / 2;
         int width = RECT_WIDTH;
         int height = RECT_WIDTH;
         g.drawRect(x, y, width, height);
      }
   }

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