Java – rotate the image in the override paintcomponent (…) method

I just want to know how to use the paintcomponent () method of jlabel component to rotate the rectangular image and set its new width and height correctly?

I try to rotate (see the attached figure) and the image scale becomes larger, but the reason why the jlabel scale remains the same makes the image beyond the jlabel limit or s: so my question is how to dynamically set the new width and height of the image to a more optimized way of components?

Solution

1 comments and links to madprogrammers

Use the method in link (slightly edit to omit the use of graphicsconfiguration, drawrenderimage (..) And changed variable names):

//https://stackoverflow.com/questions/4156518/rotate-an-image-in-java
public static BufferedImage createTransformedImage(BufferedImage image,double angle) {
    double sin = Math.abs(Math.sin(angle));
    double cos = Math.abs(Math.cos(angle));
    int originalWidth = image.getWidth();
    int originalHeight = image.getHeight();
    int newWidth = (int) Math.floor(originalWidth * cos + originalHeight * sin);
    int newHeight = (int) Math.floor(originalHeight * cos + originalWidth * sin);
    BufferedImage rotatedBI = new BufferedImage(newWidth,newHeight,BufferedImage.TRANSLUCENT);
    Graphics2D g2d = rotatedBI.createGraphics();
    g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
    g2d.translate((newWidth - originalWidth) / 2,(newHeight - originalHeight) / 2);
    g2d.rotate(angle,originalWidth / 2,originalHeight / 2);
    g2d.drawImage(image,null);
    g2d.dispose();
    return rotatedBI;
}

Here is an example:

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class RotateImage {

    public static void main(String[] args) {
        SwingUtilities.invokelater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame();
                frame.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE);
                frame.add(new MyRotatableImage(createImage(),-45));
                frame.pack();
                frame.setVisible(true);
            }
        });
    }

    public static BufferedImage createImage() {
        BufferedImage img = new BufferedImage(100,50,BufferedImage.TRANSLUCENT);
        Graphics2D g2d = img.createGraphics();
        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
        g2d.setColor(Color.WHITE);
        g2d.fillRect(0,img.getWidth(),img.getHeight());
        g2d.setColor(Color.BLACK);
        g2d.setFont(new Font("Calibri",Font.BOLD,20));
        FontMetrics fm = g2d.getFontMetrics();
        String text = "Hello world";
        int textWidth = fm.stringWidth(text);
        g2d.drawString(text,(img.getWidth() / 2) - textWidth / 2,img.getHeight() / 2);
        g2d.dispose();
        return img;
    }
}

class MyRotatableImage extends JPanel {

    private BufferedImage transformedImage;

    public MyRotatableImage(BufferedImage img,int angle) {
        transformedImage = createTransformedImage(img,angle);
    }

    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2d = (Graphics2D) g;
        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
        g2d.drawImage(transformedImage,null);
    }

    @Override
    public Dimension getPreferredSize() {
        return new Dimension(transformedImage.getWidth(),transformedImage.getHeight());
    }

    //https://stackoverflow.com/questions/4156518/rotate-an-image-in-java
    public static BufferedImage createTransformedImage(BufferedImage image,double angle) {
        double sin = Math.abs(Math.sin(angle));
        double cos = Math.abs(Math.cos(angle));
        int originalWidth = image.getWidth();
        int originalHeight = image.getHeight();
        int newWidth = (int) Math.floor(originalWidth * cos + originalHeight * sin);
        int newHeight = (int) Math.floor(originalHeight * cos + originalWidth * sin);
        BufferedImage rotatedBI = new BufferedImage(newWidth,BufferedImage.TRANSLUCENT);
        Graphics2D g2d = rotatedBI.createGraphics();
        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
        g2d.translate((newWidth - originalWidth) / 2,(newHeight - originalHeight) / 2);
        g2d.rotate(angle,originalHeight / 2);
        g2d.drawImage(image,null);
        g2d.dispose();
        return rotatedBI;
    }
}

reference resources:

> Rotate an image in java