Java Swing - 空布局 - 如何设置组件的 Z 索引？

Question

我正在尝试创建一个空当接龙游戏，但我尚未实现逻辑，因为我在布局方面遇到问题。

我无法解决的主要问题是 JFrame 按照卡片绘制的顺序对卡片 Z 索引值进行排序，使得第一张绘制的卡片具有最高的 Z 索引。

我正在尝试使 z 索引可变。

我使用的是空布局 - 教授的指示说不要使用任何管理器或外部布局帮助。 (呃)

尝试的解决方案:

我尝试使用 JLayeredPane，方法是实例化一个 Pane ，将其边界设置为完全适合 JFrame，将所有卡片添加到分层 Pane ，然后将 Pane 添加到 JFrame - 但这不起作用。

我尝试使用“setComponentZOrder(comp, index)”，但这也没有改变轴。

下面是我的代码。有没有办法在空布局上执行此操作？

如果您尝试运行该程序，此 oneDrive 链接包含卡片图像。

Images Download

主要:

import java.awt.*;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.io.File;
import java.util.*;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;

@SuppressWarnings("serial")
public class FreeCellGame extends JFrame implements MouseListener, MouseMotionListener
{
    public ArrayList<String> randomizedKeys = new ArrayList<String>();
    public HashMap<String, CardImagePanel> allCards;

    public static void main(String[] args)
    {
        FreeCellGame projectBoard = new FreeCellGame();
        projectBoard.allCards = new HashMap<String, CardImagePanel>();
        projectBoard.setSize(1218,800);
        projectBoard.setLayout(null);
        projectBoard.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        
        projectBoard.allCards = projectBoard.loadCardObjects(projectBoard.allCards);
        projectBoard = projectBoard.placeCardsOnBoard(projectBoard);
        projectBoard = addshapes(projectBoard);
        projectBoard.repaint();
        projectBoard.revalidate();
        projectBoard.setVisible(true);

    }

    private static FreeCellGame addshapes(FreeCellGame projectBoard) {

        int xPos = 0;
        int yPos = 50;

        JLabel foundations = new JLabel("Foundations");
        foundations.setBounds(790, 50, 300, 50);
        foundations.setFont(new Font("Courier New", Font.BOLD, 30));
        projectBoard.add(foundations);
        JLabel freeCells = new JLabel("Free Cells");
        freeCells.setBounds(210, 200, 300, 50);
        freeCells.setFont(new Font("Courier New", Font.BOLD, 30));
        projectBoard.add(freeCells);

        for(int i = 0;  i < 8; i++)
        {
            JPanel rect = new JPanel();
            rect.setBorder(BorderFactory.createLineBorder(Color.black));
            rect.setBounds(xPos, yPos, 150, 150);
            projectBoard.add(rect);
            xPos+=150;
            if(i == 3)
            {
                yPos = 100;
            }
        }
        return projectBoard;
    }

    private HashMap<String, CardImagePanel> loadCardObjects(HashMap<String, CardImagePanel> allCards)
    {
      File folder = new File("C:/Users/chris/Documents/GitHub/EclipseProjects/C585-FreeCell/src/images");
      File[] listOfFiles = folder.listFiles();
      allCards = new HashMap<String, CardImagePanel>();

      for (File file : listOfFiles) {
        if (file.isFile()) {
          String hashKey = file.getName();
          randomizedKeys.add(hashKey);
          CardImagePanel currentImage = new CardImagePanel(file);
          currentImage.setPreferredSize(new Dimension(157, 157));//5px on both sides as margin
          allCards.put(hashKey, currentImage);
          allCards.get(hashKey).addMouseListener(allCards.get(hashKey));
          allCards.get(hashKey).addMouseMotionListener(allCards.get(hashKey));
        }
      }
      Collections.shuffle(randomizedKeys);
      return allCards;
    }

    private FreeCellGame placeCardsOnBoard(FreeCellGame projectBoard)
    {
        int x = 0;
        int y = 540;
        int count = 0;
        for(String newRandomKey : randomizedKeys)
        {
            System.out.println(newRandomKey);
            if(count == 7 || count == 14 || count == 21)
            {
                x+=150;
                y=540;
            }
            else if( count == 28 || count == 34 || count == 40 || count == 46)
            {
                x+=150;
                y=500;
            }
            else if (count != 0)
            {
                y-=40;
            }
            allCards.get(newRandomKey).setBounds(x, y, 150, 150);
            projectBoard.add(allCards.get(newRandomKey));
            count++;
        }
        return projectBoard;
    }
    @Override
    public void mouseDragged(MouseEvent e) {
        // TODO Auto-generated method stub
    }
    @Override
    public void mouseMoved(MouseEvent e) {
        // TODO Auto-generated method stub
    }
    @Override
    public void mouseClicked(MouseEvent e) {
//      ((CardImagePanel) e.getSource()).setComponentZOrder(projectBoard, 5000);
    }
    @Override
    public void mouseEntered(MouseEvent arg0) {
        // TODO Auto-generated method stub
    }
    @Override
    public void mouseExited(MouseEvent arg0) {
        // TODO Auto-generated method stub
    }
    @Override
    public void mousePressed(MouseEvent arg0) {
        // TODO Auto-generated method stub
    }
    @Override
    public void mouseReleased(MouseEvent arg0) {
        // TODO Auto-generated method stub
    }
 }

JPanel 类:

import java.awt.Graphics;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JPanel;

@SuppressWarnings("serial")
public class CardImagePanel extends JPanel implements MouseListener, MouseMotionListener
{
    private BufferedImage picture;  
    private char cardType;
    private int cardNum;

    public CardImagePanel(File newImageFile)
    {
        try {
            picture = ImageIO.read(newImageFile);

        } catch (IOException e){
            e.printStackTrace();
        }
        cardType = newImageFile.getName().charAt(0);
        String tempString = newImageFile.getName();
        cardNum = Integer.parseInt(tempString.substring(1,tempString.lastIndexOf('.')));
    }

    public void paintComponent(Graphics g) {
      super.paintComponent(g);
      g.drawImage(picture, 0, 0, 150, 150, this);
    }

    public BufferedImage getPicture() {
        return picture;
    }
    public char getCardType() {
        return cardType;
    }
    public int getCardNum() {
        return cardNum;
    }

    @Override
    public void mouseDragged(MouseEvent e) {
        this.setBounds(e.getX() + this.getX()-75, e.getY() + this.getY()-75, 150, 150);
    }
    @Override
    public void mouseMoved(MouseEvent arg0) {
        // TODO Auto-generated method stub
    }
    @Override
    public void mouseClicked(MouseEvent e) {
    }
    @Override
    public void mouseEntered(MouseEvent e) {
        // TODO Auto-generated method stub
    }
    @Override
    public void mouseExited(MouseEvent e) {
        // TODO Auto-generated method stub
    }
    @Override
    public void mousePressed(MouseEvent e) {
        // TODO Auto-generated method stub
    }
    @Override
    public void mouseReleased(MouseEvent e) {
        // TODO Auto-generated method stub
    }
}

Answer 1

I am using a null layout - the professors instructions said to not utilize any managers or external layout help. (ugh)

所以基本上你需要编写自己的布局管理器。

Below is my code. Is there no way to do this on null layouts?

空布局不会影响 Z 排序的工作方式。 Z 顺序将自动为您完成。关键在于将组件添加到面板的顺序，以便获得所需的 Z 顺序。

I am trying to make the z index changeable.

向面板添加组件会影响 Z 顺序。

查看Overlap Layout这是专门为此设计的布局管理器。我知道您无法使用布局管理器，但更好地理解 Z-Order 的工作原理将使您能够简单地编写代码。

例如，查看下面的简单代码。只需使用将卡片添加到面板的 add(...) 方法，您就可以控制 Z 顺序以发挥您的优势:

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

public class SSCCE extends JPanel
{
    ArrayList<JLabel> cards = new ArrayList<JLabel>();

    public SSCCE()
    {
        setLayout( null );

        cards.add( createCard("1", Color.RED) );
        cards.add( createCard("2", Color.GREEN) );
        cards.add( createCard("3", Color.BLUE) );
        cards.add( createCard("4", Color.YELLOW) );

        //  This would be your first natural attempt (but it doesn't work)

        for (int i = 0; i < cards.size(); i++)
            add( cards.get(i) );

        //  This affects the Z-Order to do what you want

//      for (int i = 0; i < cards.size(); i++)
//          add(cards.get(i), 0);
    }

    public JLabel createCard(String text, Color background)
    {
        JLabel label = new JLabel(text);
        label.setOpaque( true );
        label.setBackground( background );
        label.setSize(30, 70);
        label.setLocation((cards.size() + 1) * 20 , 20);

        return label;
    }



    private static void createAndShowGUI()
    {
        JFrame frame = new JFrame("SSCCE");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(new SSCCE());
        frame.setLocationByPlatform( true );
        frame.setSize(200, 200);
        frame.setVisible( true );
    }

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