从组件更改JLabel ICON

Question

So I have a grid of JLabels that are randomly assigned background colours and ICONs to match (Bubbles for a Bubble Breaker game), the issue comes when I'm using findComponentAt(getX(), getY()) to get the component im clicking.... this is because I then want to find out which label I am clicked and change its ICON to a different ICON, however the component API doesn't seem to have a setIcon() method, any suggestions on how I could change the ICON?

My code for the one file is given below, a but messy since I'm still developing obviously, so sorry.

code is pasting weird..:

import javax.swing.*;
import javax.swing.border.*;
import java.awt.*;
import java.util.Random;
import java.awt.Color.*;
import java.awt.Cursor.*;
import javax.swing.border.*;
import java.awt.event.*;

public class GridForGame extends JPanel {
JTextField myNumberArray[] = new JTextField[16];
MouseHandling handler = new MouseHandling();

JLabel statusbar = new JLabel("default");
JLabel tempLabel = new JLabel();

JPanel squareContainer = new JPanel();
Boolean handlerOn = false;
boolean colourChanged = false;

ImageIcon redBubble;
ImageIcon blueBubble;
ImageIcon yellowBubble;
ImageIcon orangeBubble;
ImageIcon greenBubble;
ImageIcon pinkBubble;
ImageIcon purpleBubble;


public void smallIcons(){
    redBubble = new ImageIcon("images/redSmall.jpg");
    blueBubble = new ImageIcon("images/blueSmall.jpg");
    yellowBubble = new ImageIcon("images/yellowSmall.jpg");
    orangeBubble = new ImageIcon("images/orangeSmall.jpg");
    greenBubble = new ImageIcon("images/greenSmall.jpg");
    pinkBubble = new ImageIcon("images/pinkSmall.jpg");
    purpleBubble = new ImageIcon("images/purpleSmall.jpg");
}

public void mediumIcons(){
    redBubble = new ImageIcon("images/redMedium.jpg");
    blueBubble = new ImageIcon("images/blueMedium.jpg");
    yellowBubble = new ImageIcon("images/yellowMedium.jpg");
    orangeBubble = new ImageIcon("images/orangeMedium.jpg");
    greenBubble = new ImageIcon("images/greenMedium.jpg");
    pinkBubble = new ImageIcon("images/pinkMedium.jpg");
}

public void largeIcons(){
    redBubble = new ImageIcon("images/redLarge.jpg");
    blueBubble = new ImageIcon("images/blueLarge.jpg");
    yellowBubble = new ImageIcon("images/yellowLarge.jpg");
    orangeBubble = new ImageIcon("images/orangeLarge.jpg");
    greenBubble = new ImageIcon("images/greenLarge.jpg");
    pinkBubble = new ImageIcon("images/pinkLarge.jpg");
}

public GridForGame(){
    setLayout(new BorderLayout());
    setBackground(Color.gray);  
    setBorder(new EtchedBorder(4, Color.blue, Color.blue));
    setPreferredSize(new Dimension(600,600));
}

public void small(){

    smallIcons();
    /*
     * Below empties the main game view so that
     * more can be 'painted' on it.
     */
    squareContainer.removeAll();
    revalidate();

    // Set the grid for 8 x 8
    squareContainer.setLayout(new GridLayout(8,8));
    squareContainer.setPreferredSize(new Dimension(500,500));
    squareContainer.setMaximumSize(new Dimension(500,500));

    /*
     * Checks if a Mouse handler has already been
     * assigned to game view, if not, Add one!
     */
    if(!handlerOn){
        squareContainer.addMouseListener(handler);
        handlerOn = true;
    }

    statusbar.setText("default");
    add(statusbar, BorderLayout.NORTH);

    for(int i=0; i<8; i++){

        for(int j=0; j<8; j++){
            JLabel number = new JLabel();

            number.setEnabled(true);
            number.setOpaque(true);
            number.setBorder(new MatteBorder(1, 1, 1, 1, Color.black));

            for(int k=0; k<8; k++){
                int n = new Random().nextInt(7);
                    switch(n){
                        case 0: number.setBackground(Color.red);
                                number.setIcon(redBubble); break;
                        case 1: number.setBackground(Color.cyan);
                                number.setIcon(orangeBubble); break;
                        case 2: number.setBackground(Color.blue);
                                number.setIcon(blueBubble); break;
                        case 3: number.setBackground(Color.green);
                                number.setIcon(greenBubble); break;
                        case 4: number.setBackground(Color.yellow);
                                number.setIcon(yellowBubble); break;
                        case 5: number.setBackground(Color.magenta);
                                number.setIcon(pinkBubble); break;
                        default:
                    }   
                }

                 squareContainer.add(number);
            }

            //squareContainer.add(squares);
        }
    add(squareContainer);
    revalidate();
}

public void medium(){

    mediumIcons();

    /*
     * Below empties the main game view so that
     * more can be 'painted' on it.
     */
    squareContainer.removeAll();
    revalidate();

    // Set the grid for 12 x 12
    squareContainer.setLayout(new GridLayout(12,12));
    squareContainer.setPreferredSize(new Dimension(500,500));
    squareContainer.setMaximumSize(new Dimension(500,500));

    /*
     * Checks if a Mouse handler has already been
     * assigned to game view, if not, Add one!
     */
    if(!handlerOn){
        squareContainer.addMouseListener(handler);
        handlerOn = true;
    }

    statusbar.setText("default");
    add(statusbar, BorderLayout.NORTH);

    for(int i=0; i<12; i++){
        JPanel squares = new JPanel();
        squares.setLayout(new GridLayout(1,1));
        for(int j=0; j<12; j++){
            JLabel number = new JLabel();
            number.setEnabled(true);
            number.setOpaque(true);
            number.setBorder(new MatteBorder(1, 1, 1, 1, Color.black));

            squares.add(number);
            for(int k=0; k<12; k++){
                int n = new Random().nextInt(7);
                    switch(n){
                        case 0: number.setBackground(Color.red);
                                number.setIcon(redBubble); break;
                        case 1: number.setBackground(Color.cyan);
                                number.setIcon(orangeBubble); break;
                        case 2: number.setBackground(Color.blue);
                                number.setIcon(blueBubble); break;
                        case 3: number.setBackground(Color.green);
                                number.setIcon(greenBubble); break;
                        case 4: number.setBackground(Color.yellow);
                                number.setIcon(yellowBubble); break;
                        case 5: number.setBackground(Color.magenta);
                                number.setIcon(pinkBubble); break;
                        default:
                    }   
                }
            }

            squareContainer.add(squares);
        }
    add(squareContainer);
    revalidate();
}

public void large(){

    largeIcons();

    /*
     * Below empties the main game view so that
     * more can be 'painted' on it.
     */
    squareContainer.removeAll();
    revalidate();

    // Set the grid for 16 x 16
    squareContainer.setLayout(new GridLayout(16,16));
    squareContainer.setPreferredSize(new Dimension(500,500));
    squareContainer.setMaximumSize(new Dimension(500,500));

    /*
     * Checks if a Mouse handler has already been
     * assigned to game view, if not, Add one!
     */
    if(!handlerOn){
        squareContainer.addMouseListener(handler);
        handlerOn = true;
    }

    statusbar.setText("default");
    add(statusbar, BorderLayout.NORTH);

    for(int i=0; i<16; i++){
        JPanel squares = new JPanel();
        squares.setLayout(new GridLayout(1,1));
        for(int j=0; j<16; j++){
            JLabel number = new JLabel();
            number.setEnabled(true);
            number.setOpaque(true);
            number.setBorder(new MatteBorder(1, 1, 1, 1, Color.black));

            squares.add(number);
            for(int k=0; k<16; k++){
                int n = new Random().nextInt(7);
                    switch(n){
                        case 0: number.setBackground(Color.red);
                                number.setIcon(redBubble); break;
                        case 1: number.setBackground(Color.cyan);
                                number.setIcon(orangeBubble); break;
                        case 2: number.setBackground(Color.blue);
                                number.setIcon(blueBubble); break;
                        case 3: number.setBackground(Color.green);
                                number.setIcon(greenBubble); break;
                        case 4: number.setBackground(Color.yellow);
                                number.setIcon(yellowBubble); break;
                        case 5: number.setBackground(Color.magenta);
                                number.setIcon(pinkBubble); break;
                        default:
                    }   
                }
            }

            squareContainer.add(squares);
        }
    add(squareContainer);
    revalidate();
}

private class MouseHandling implements MouseListener{
    public void mouseClicked(MouseEvent event){
        statusbar.setText(String.format("Clicked at %d,%d", event.getX(), event.getY()));
        System.out.println(String.format("Component clicked was " + findComponentAt(event.getX(), event.getY()).getBackground()));

        /*JLabel temp = new JLabel();

        temp = findComponentAt(event.getX(), event.getY());*/

        if(colourChanged == true){
            findComponentAt(event.getX(), event.getY()).setBackground(Color.white);
            System.out.println("selected label now set to white");
        }

        if(colourChanged == false){
            findComponentAt(event.getX(), event.getY()).setBackground(Color.black);
            System.out.println("selected label now set to black");
            colourChanged = true;
        }
    }   

    public void mousePressed(MouseEvent event){
        statusbar.setText("anything");
    }

    public void mouseReleased(MouseEvent event){
        statusbar.setText(String.format("Released at %d,%d", event.getX(), event.getY()));
    }

    public void mouseEntered(MouseEvent event){
        statusbar.setText("Entered");
    }

    public void mouseExited(MouseEvent event){
        statusbar.setText("Exited");
    }
}

}

Answer 1

Check if the component is a JLabel via the instanceof operator, and then if false, exit out of the mouse listener method, and else if true, cast to JLabel and set its icon. For example:

public void mouseClicked(MouseEvent event){
    statusbar.setText(String.format("Clicked at %d,%d", event.getX(), event.getY()));
    System.out.println(String.format("Component clicked was " + findComponentAt(event.getX(), event.getY()).getBackground()));

    Component comp =  findComponentAt(event.getX(), event.getY());
    if (!(comp instanceof JLabel)) {
       return;   // if it's not a JLabel get out of this method
    }

    // it is a JLabel so cast it.

    JLabel temp = (JLabel) comp;

    // now you can use the JLabel

Answer 2

You should use the event.getSource() method for finding your label and then you can cast it to a JLabel and change the Icon

    public void mouseClicked(MouseEvent e) {
        Object o;
        if((o = e.getSource()) instanceof JLabel){
            JLabel source = (JLabel) o;
            source.setIcon(icon);
            //Now you can use your JLabel
        }
    }