repaint（）方法不适用于色彩图像

Question

Full project here https://github.com/jafetrd/easyImageEditor

I'm trying to apply a color to an image using the paintComponent(), this is the class I use

public class Metodos extends JPanel{
...............................
........more code..........
................

public void setColor(Color color) {
    this.color = color;
    System.out.println("entrecolor");
    repaint();
}
@Override
protected void paintComponent(Graphics g) {
        if(imagen != null){
        super.paintComponent(g);
          Graphics2D g2d = (Graphics2D) g.create();
              g2d.setXORMode(color); //this is the filter i want to repaint
                if(detectar==false){
                     g2d.drawImage(imagen, getWidth()/2 - nuevoTamaño.width/2, getHeight()/2 - nuevoTamaño.height/2, nuevoTamaño.width, nuevoTamaño.height, this);
                }else{
                     g2d.drawImage(imagen, posX-nuevoTamaño.width/2, posY-nuevoTamaño.height/2, nuevoTamaño.width, nuevoTamaño.height,this);
                }
           g2d.dispose();
        }
}

I call to setColor() from another class to send the color object and repaint the image with the XOR inside the paint component, but it's not working. The class from where I send the color looks like this:

 public final class Colores extends JFrame{
  JColorChooser jc;
  private Metodos m;
public Colores(){
        componentes();
        inicio();    
   m = new Metodos();
}

public final void componentes(){
    setLayout(new BorderLayout());
   // Metodos a = new Metodos();
    jc = new JColorChooser();
    jc.setPreviewPanel(new JPanel());
    jc.getSelectionModel().addChangeListener((ChangeEvent arg0) -> {
        m.setColor(jc.getColor());
        super.repaint();
    });

    add(jc);
    pack();
}
.........................
.........more code.........
...................................

Here I take the color from the JColorChooser and send to the method setColor() and repaint the image, but it does not work at all.

Answer 1

Your problem is a basic example of a bad and misguided design.

In your Colores you create a new instance of Metodos ...

public final class Colores extends JFrame{

    JColorChooser jc;
    private Metodos m;
    public Colores(){
       componentes();
       inicio();    
       m = new Metodos();
    }

In what way does this have anything to do with the instance which you created earlier and put on the screen?

You need to pass a reference of Metodos to Colores

Have a look at Passing Information to a Method or a Constructor for more details

public final class Colores extends JFrame {

    JColorChooser jc;
    private Metodos m;

    public Colores(Metodos m) {
        componentes();
        inicio();
        this.m = m;
    }

And update Metodos

case Colores:
    new Colores(this).setVisible(true);
    break;

Things don't magically bind together, you actually need to provide the valid information to you program before it can work.

I would, however, encourage you to use a different mechanism.

JColorChooser actually has it's dialog support built in...

case Colores:
    Color newColor = JColorChooser.showDialog(this, "Colors", color);
    if (newColor != null){
        color = newColor;
        repaint();
    }
    break;

This allows the user to cancel the dialog if they don't want to select a color

Answer 2

Here is an example of a program that works. You need a png file to see the results.

import javax.swing.*;
import java.awt.image.*;
import javax.imageio.*;
import java.awt.*;
import java.io.*;
import java.awt.event.*;
public class TintPicture{

    static Color[] colors = {Color.BLUE, Color.RED, Color.GREEN, Color.YELLOW};

    public static void main(String[] args) throws Exception{
        JFrame frame = new JFrame("tinted");
        BufferedImage img = ImageIO.read(new File("sample.png"));
        int[] index = {0};
        JPanel pane = new JPanel(){
            @Override
            public void paintComponent(Graphics g){
                Graphics2D g2d = (Graphics2D)g;
                g2d.setXORMode(colors[index[0]]);
                g2d.drawImage(img, 0, 0, this);
            }
        };

        pane.addMouseListener(new MouseAdapter(){
            @Override
            public void mouseClicked(MouseEvent evt){
                index[0] = (index[0] + 1)%colors.length;
                pane.repaint();
            }
        });

        frame.setContentPane(pane);

        frame.setSize(700, 500);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }

}

It includes using the xor, and changing/updating the display.