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Defining a background color and a foreground icon for a JButton?

I'm working on a Fire Emblem mock up using Swing (which I'm just getting the hang of, I used to work mostly on console programs). To those who are not familiar with the game, it's a tile based strategy game where you move units on a grid (akin to chess).
I'm thinking about using JButtons for the grid, so that the player is able to click on the unit he wants to move, and click on his destination. As you can see on the picture, the tile color behind the unit can vary (red means the unit can attack the unit on that tile, blue means a tile where the selected unit can move). I don't want to have 15 different tile designs for each unit (UnitX with blue background, UnitX with red background, UnitX with green background, etc.) so is there a way to use "layers" with JButtons? Draw a blue tile and draw the correct character over it?

Draw a blue tile and draw the correct character over it?
Use the setBackground(...) method to set the background
color.
Use the setIcon(...) method to set the character.

The answer from camickr is correct (assuming that I've understood your question).
The following code demonstrates how you can use setBackground and setIcon on a JButton. It shows one button with a background color and an icon. The button changes its background color when it's clicked:
import javax.swing.*;
import java.awt.*;
import java.net.*;
import java.util.*;
import java.util.List;
public class ButtonBackgroundAndIcon {
private static final List<Color> BACKGROUND_COLORS = Arrays.asList(
new Color(229, 119, 120),
Color.BLUE,
Color.CYAN,
Color.GREEN,
Color.YELLOW,
Color.RED
);
private int backgroundIndex;
public static void main(String[] arguments) {
SwingUtilities.invokeLater(new ButtonBackgroundAndIcon()::run);
}
private void run() {
JFrame frame = new JFrame("Stack Overflow");
frame.setBounds(100, 100, 800, 600);
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
JButton tileButton = new JButton();
tileButton.setBackground(BACKGROUND_COLORS.get(0));
Icon icon = getRoyIcon();
if (icon != null) {
tileButton.setIcon(icon);
}
tileButton.addActionListener(actionEvent -> {
backgroundIndex = (backgroundIndex + 1) % BACKGROUND_COLORS.size();
tileButton.setBackground(BACKGROUND_COLORS.get(backgroundIndex));
});
frame.getContentPane().add(tileButton);
frame.setVisible(true);
}
private ImageIcon getRoyIcon() {
ImageIcon imageIcon;
try {
String iconLocation = "http://orig06.deviantart.net/fd0e/f/2008"
+ "/060/d/1/roy_sprite_by_chstuba007.gif";
imageIcon = new ImageIcon(new URL(iconLocation));
} catch (MalformedURLException e) {
imageIcon = null;
}
return imageIcon;
}
}

Assuming if you have a transparent image you can use this class to accomplish what you desire.
public class ColorBackgroundIcon implements Icon {
private ImageIcon image;
private Color background;
public ColorBackgroundIcon(ImageIcon image,
Color background) {
this.image = image;
this.background = background;
}
#Override
public void paintIcon(Component c, Graphics g, int x, int y) {
Graphics2D g2d = (Graphics2D) g;
g.setColor(background);
g.fillRect(x, y, getIconWidth(), getIconHeight());
g2d.drawImage(image.getImage(), x, y, null);
}
public void setColor(Color bgColor) {
this.background = bgColor;
}
#Override
public int getIconWidth() {
return image.getIconWidth();
}
#Override
public int getIconHeight() {
return image.getIconHeight();
}
}
Then just setIcon() using a instance created above. Works great for me since I have four states a certain icon can represent. Instead of creating four different icons I have one transparent icon and I change the background with the code provided.
Hope that helps for anyone,
DK

JFileChooser icons on 2K Displays

Any idea how to make the Java Swing file chooser
look better on 2K displays where the windows
font scaling is > 125%?
I am using ordinary code such as:
JFileChooser fc = new JFileChooser();
if (settings.currentdir != null)
fc.setCurrentDirectory(new File(settings.currentdir));
int returnVal = fc.showOpenDialog((Window) holder);
if (returnVal == JFileChooser.APPROVE_OPTION) {
But the file chooser is only displaying tiny
icons for the listed files and directories. I am using
JDK 8. What is going wrong?
P.S.: Scope of the question is only Windows, not
Unixes. On Windows, the two default L&F, they
scale the font. But they don't scale icons. The
application has to do that, since it might use
a different bitmap resources for higher scales.
It seems that JFileChooser is not coded this way.
But it might be that the JFileChooser can be
instructed to do so. I don't see that the
other question addresses icon size and the
JFileChooser on Windows: How to set the DPI of Java Swing apps on Windows/Linux? The
other question deals with font size, which is
not an issue for the JFileChooser on Windows with
one of the two Windows L&F.

Just a quick idea while i came across this thread. You can try to deliver your own iconset:
new JFileChooser().setFileView(new FileView() {
#Override
public Icon getIcon(File f) {
return fancy2kIconForExtension(StringUtils.substringAfterLast("."));
}
});
be careful to load your Icons from a Cache, as this method is called very often from inside JFileChooser, otherwise you end up reloading icon all the time.

I very recently ran into same problem. the only work around is not using java build in ImageIcon class but to write one yourself,
This one took the provided image, scale it to fit current component size and paint it. I tried to make is as simple as possible and as close to original class as able, but its not perfect and need improvement, especially in component-icon alignment
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.geom.AffineTransform;
import javax.swing.AbstractButton;
import javax.swing.ImageIcon;
/**
*
* #author Rastislav
*/
public class ScaleToFitAndAntialiasIcon extends ImageIcon{
private ImageIcon icon;
public ScaleToFitAndAntialiasIcon(ImageIcon icon)
{
this.icon = icon;
}
public int getIconWidth()
{
return icon.getIconWidth();
}
public int getIconHeight()
{
return icon.getIconHeight();
}
#Override
public void paintIcon(Component c, Graphics g, int x, int y)
{
Graphics2D g2d = (Graphics2D)g.create();
AffineTransform at = g2d.getTransform();
double scaleToFit = ((double)c.getHeight() / (double)icon.getIconHeight());
if((int)icon.getIconHeight()*scaleToFit == c.getHeight()){
scaleToFit = ((double)c.getHeight() / (double)icon.getIconHeight()) - 0.1;
}
AffineTransform scaled = AffineTransform.getScaleInstance(scaleToFit, scaleToFit);
at.concatenate( scaled );
g2d.setTransform( at );
//need improvement
/* int lineupMinus = (int)((double)icon.getIconWidth() *((double)c.getHeight() / (double)icon.getIconHeight()));
int lineup = (int)((double)icon.getIconWidth() * scaleToFit);
int ff = (int)(lineupMinus - lineup);
System.out.println(ff);
*/
g2d.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BICUBIC);
//improved code goes here
icon.paintIcon(c, g2d, x, 4);
if(c instanceof AbstractButton a){
a.setIconTextGap((int)(-icon.getIconWidth()/2));
}
g2d.dispose();
}
}

Setting multiple icons on JButton

I have a JButton which I have set a custom icon on. Now I want it to display another icon ontop of the one that is already displayed when I drag my mouse cursor over it but I can't figure out how to do it because if I use button.setIcon(icon); it will replace the icon that already is displayed. How would I do this in an as easy way as possible?

I have a JButton which I have set a custom icon on. Now I want it to
display another icon ontop of the one that is already displayed when I
drag my mouse cursor over it but I can't figure out how to do it
because if I use button.setIcon(icon); it will replace the icon that
already is displayed. How would I do this in an as easy way as
possible
I think thats about JButton.setRolloverIcon(myIcon);
JButton has implemented those methods in API
JButton.setIcon(myIcon);
JButton.setRolloverIcon(myIcon);
JButton.setPressedIcon(myIcon);
JButton.setDisabledIcon(myIcon);
for example

If your icons are already transparent you can easily implement your own Icon to combine the two -
public class CombineIcon implements Icon {
private Icon top;
private Icon bottom;
public CombineIcon(Icon top, Icon bottom) {
this.top = top;
this.bottom = bottom;
}
public int getIconHeight() {
return Math.max(top.getIconHeight(), bottom.getIconHeight());
}
public int getIconWidth() {
return Math.max(top.getIconWidth(), bottom.getIconWidth());
}
public void paintIcon(Component c, Graphics g, int x, int y) {
bottom.paintIcon(c, g, x, y);
top.paintIcon(c, g, x, y);
}
}
You use setRolloverIcon(icon) to specify the icon you want to show when the mouse is over the button.

Create a second version of that button icon which contains the overlay. On mouse over switch to the image with the overlay.
Another approach could be to combine the icon with its overlay to a new icon in memory and place it as an icon on the button. This might be a good approach if your icons are frequently changing. If that's not the case I would definitely use the first approach.

I find this pretty easy.
import java.awt.*;
import java.awt.image.BufferedImage;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.*;
class CombinedIconButton {
public static BufferedImage getCombinedImage(BufferedImage i1, BufferedImage i2) {
if (i1.getHeight() != i2.getHeight()
|| i1.getWidth() != i2.getWidth()) {
throw new IllegalArgumentException("Images are not the same size!");
}
BufferedImage bi = new BufferedImage(
i1.getHeight(),
i1.getWidth(),
BufferedImage.TYPE_INT_ARGB);
Graphics g = bi.getGraphics();
g.drawImage(i1,0,0,null);
g.drawImage(i2,0,0,null);
g.dispose();
return bi;
}
public static void main(String[] args) throws Exception {
URL url1 = new URL("http://i.stack.imgur.com/gJmeJ.png"); // blue circle
URL url2 = new URL("http://i.stack.imgur.com/5v2TX.png"); // red triangle
final BufferedImage bi1 = ImageIO.read(url1);
final BufferedImage bi2 = ImageIO.read(url2);
final BufferedImage biC = getCombinedImage(bi1,bi2);
Runnable r = new Runnable() {
#Override
public void run() {
JPanel gui = new JPanel(new BorderLayout());
JToggleButton b = new JToggleButton();
b.setIcon(new ImageIcon(bi1));
b.setRolloverIcon(new ImageIcon(biC));
b.setSelectedIcon(new ImageIcon(bi2));
gui.add(b);
JOptionPane.showMessageDialog(null, gui);
}
};
// Swing GUIs should be created and updated on the EDT
// http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html
SwingUtilities.invokeLater(r);
}
}
Images borrowed from this answer.

One way to do that is:
Create an icon which you want to see when the pointer is hovered on top of the button by some image editing tool. And set that image once mousehover event occurs.
p.s. use any pic editing tool and you can easily create a overlay image.
I also saw now that there is a concept of roll over icon in AbsractButton class. You can use that as well.

Creating custom JButton from images containing transparent pixels

Read edit 2 for what I'm actually missing to make it work
I'm currently trying to create some custom JButtons using images created in photoshop that have an alpha parameter.
So far, overriding the paint() method to draw the image has worked in the sense that the button is drawn showing the correct image. I'd like to improve it, though, by making its shape (clickable area) the same as the visible pixels on the image (right now if I draw the button's border, it's a square).
Is there an easy way to do that or do I have to parse the image and find the alpha pixels to make a custom border?
Which methods would I have to override to make it work the way I want?
Also, another question I'm going to have later: would it be better to use some kind of algorithm to change the images' colors to make it seem like it is being clicked when people click on it or am I better off creating a second image and drawing that one while the button is active?
Edit: I just read on some other question that I should redefine paintComponent() instead of paint(), I'd like to know why since redefining paint() works fine?
Edit 2: I changed everything to make sure my JButtons are created using the default constructor with an icon. What I'm trying to do is get the X and Y position of where the click was registered and grab the icon's pixel at that position and check its alpha channel to see if it is 0 (if it is, do nothing, else do the action it is supposed to do).
The thing is, the alpha channel always returns 255 (and blue, red and green are at 238 on transparent pixels). On other pixels, everything returns the value it should be returning.
Here's an example (try it with another image if you want) that recreates my problem:
public class TestAlphaPixels extends JFrame
{
private final File FILECLOSEBUTTON = new File("img\\boutonrondX.png"); //My round button with transparent corners
private JButton closeButton = new JButton(); //Creating it empty to be able to place it and resize the image after the button size is known
public TestAlphaPixels() throws IOException
{
setLayout(null);
setSize(150, 150);
closeButton.setSize(100, 100);
closeButton.setContentAreaFilled(false);
closeButton.setBorderPainted(false);
add(closeButton);
closeButton.addMouseListener(new MouseListener()
{
public void mouseClicked(MouseEvent e)
{
}
public void mousePressed(MouseEvent e)
{
}
public void mouseReleased(MouseEvent e)
{
System.out.println("Alpha value of pixel (" + e.getX() + ", " + e.getY() + ") is: " + clickAlphaValue(closeButton.getIcon(), e.getX(), e.getY()));
}
public void mouseEntered(MouseEvent e)
{
}
public void mouseExited(MouseEvent e)
{
}
});
Image imgCloseButton = ImageIO.read(FILECLOSEBUTTON);
//Resize the image to fit the button
Image newImg = imgCloseButton.getScaledInstance((int)closeButton.getSize().getWidth(), (int)closeButton.getSize().getHeight(), java.awt.Image.SCALE_SMOOTH);
closeButton.setIcon(new ImageIcon(newImg));
}
private int clickAlphaValue(Icon icon, int posX, int posY)
{
int width = icon.getIconWidth();
int height = icon.getIconHeight();
BufferedImage tempImage = (BufferedImage)createImage(width, height);
Graphics2D g = tempImage.createGraphics();
icon.paintIcon(null, g, 0, 0);
g.dispose();
int alpha = (tempImage.getRGB(posX, posY) >> 24) & 0x000000FF;
return alpha;
}
public static void main(String[] args)
{
try
{
TestAlphaPixels testAlphaPixels = new TestAlphaPixels();
testAlphaPixels.setVisible(true);
testAlphaPixels.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
catch(IOException ioe)
{
ioe.printStackTrace();
}
}
}
This is just a wild guess, but is it possible that when my image gets cast to an Icon, it loses its Alpha property and thus doesn't return the correct value? Anyway, I'd really appreciate it if someone could actually help me out and tell me what I should be changing to get the correct value.
I'm guessing that because when I try it with the original image, the alpha channel's value is fine, but I can't actually use that BufferedImage because I resize it, so I actually get the channel values of the image with the original size...

I think you are on the wrong way. You do not have to override neither paint() nor paintComponent() methods. JButton already "knows" to be shown with image only:
ImageIcon cup = new ImageIcon("images/cup.gif");
JButton button2 = new JButton(cup);
See the following tutorial for example: http://www.apl.jhu.edu/~hall/java/Swing-Tutorial/Swing-Tutorial-JButton.html
Moreover swing is fully customized. You can control opacity, border, color etc. You probably should override some mentioned methods to change functionality. But in most cases there is better and simpler solution.

Since there were good elements in multiple answers, but none of the answers were complete on their own, I'll answer my own question so other people that have the same problem can try something similar.
I created my buttons using a new class which extends JButton, with a new constructor that takes a BufferedImage as parameter instead of an icon. The reason for that is that when I did something like myButton.getIcon(), it would return an Icon, then I'd have to make various manipulations on it to make it a BufferedImage of the right size, and it ended up not working anyway because it seems like the first cast to Icon made it lose the alpha data in the pixels, so I couldn't check to see if the user was clicking on transparent pixels or not.
So I did something like this for the constructor:
public class MyButton extends JButton
{
private BufferedImage bufImg;
public MyButton(BufferedImage bufImg)
{
super(new ImageIcon(bufImg));
this.bufImg = bufImg;
}
}
Then I created an accessor for my bufImg that resized the image to fit the JButton using the getSize() method and then returned an image resized at the right size. I do the transformations in the getBufImg() accessor because the image size might change when the window gets resized. When you call the getBufImg(), it's usually because you clicked on the button and thus you're not currently resizing the window.
Something a little bit like this will return the image at the right size:
public BufferedImage getBufImg()
{
BufferedImage newImg = new BufferedImage(getSize().getWidth(), getSize().getHeight(), BufferedImage.TYPE_INT_ARGB); //Create a new buffered image the right size
Graphics2D g2d = newImg.createGraphics();
g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2d.drawImage(bufImg, 0, 0, getSize().getWidth(), getSize().getHeight(), null);
g2d.dispose();
return newImg;
}
With that buffered image, you can then code a method like this:
private int clickAlphaValue(BufferedImage bufImg, int posX, int posY)
{
int alpha;
alpha = (bufImg.getRGB(posX, posY) >>24) & 0x000000FF; //Gets the bit that contains alpha information
return alpha;
}
That you call on the button that implements a MouseListener, like this:
myButton.addMouseListener(new MouseListener()
{
public void mouseClicked(MouseEvent e)
{
}
public void mousePressed(MouseEvent e)
{
}
public void mouseReleased(MouseEvent e)
{
if(clickAlphaValue(((myButton)e.getSource()).getBufImg(), e.getX(), e.getY()) != 0) //If alpha is not set to 0
System.exit(0); //Or other things you want your button to do
}
public void mouseEntered(MouseEvent e)
{
}
public void mouseExited(MouseEvent e)
{
}
});
And voila! The button will only do the action if you clicked on non-transparent pixels.
Thanks for the help everyone, I couldn't have come up with this solutions on my own.

If you want to have shape-specific click points, you're better off using Shape and their contains method. If you want, you can create a shape when creating your custom button class as part of it, and implement a contains method by wrapping around the shape's contains method.
As for the custom JButton, create a class that extends JButton, like this:
import java.awt.*;
import javax.swing.*;
public class CustomButton extends JButton{
/** Filename of the image to be used as the button's icon. */
private String fileName;
/** The width of the button */
private int width;
/** The height of the button. */
private int height;
public CustomButton(String fileName, int width, int height){
this.fileName = fileName;
this.width = width;
this.height = height;
createButton();
}
/**
* Creates the button according to the fields set by the constructor.
*/
private void createButton(){
this.setIcon(getImageIcon(filename));
this.setPreferredSize(new Dimension(width, height));
this.setMaximumSize(new Dimension(width, height));
this.setFocusPainted(false);
this.setRolloverEnabled(false);
this.setOpaque(false);
this.setContentAreaFilled(false);
this.setBorderPainted(false);
this.setBorder(BorderFactory.createEmptyBorder(0,0,0,0));
}
}
Here's how you can load the ImageIcon, if you want to do it like this.
public ImageIcon getImageIcon(String fileName){
String imageDirectory = "images/"; //relative to classpath
URL imgURL = getClass().getResource(imageDirectory + fileName);
return new ImageIcon(imgURL);
}
This will give you a button that will at least look like your image.
I asked a similar question regarding Image-based events on click, and Shapes helped wonders.
I guess it comes down to how complex your button images are.
Here's reference anyway:
How can you detect a mouse-click event on an Image object in Java?
PS: Maybe look into generating shapes from images, that go around all the pixels that aren't transparent. No idea if this is possible, but it would mean that a button would only be "pressed" if the user clicks on the image part of it. Just a thought.

If you want your button layout to be that of the non-transparent pixels in your image, then you should redefine the paintComponent() method. It is the most correct way of doing it (overriding paint() worked in old times but is now discouraged).
However I think it is not exactly what you want: you want a click on the button to be detected only if it is on a non-transparent pixel, right? In that case you have to parse your image and when clicked compare mouse coordinates to the pixel alpha channel of your image as JButton does not have such a feature.

If you have a round button, this is exactly what you need:
public class RoundButton extends JButton {
public RoundButton() {
this(null, null);
}
public RoundButton(Icon icon) {
this(null, icon);
}
public RoundButton(String text) {
this(text, null);
}
public RoundButton(Action a) {
this();
setAction(a);
}
public RoundButton(String text, Icon icon) {
setModel(new DefaultButtonModel());
init(text, icon);
if(icon==null) return;
setBorder(BorderFactory.createEmptyBorder(0,0,0,0));
setContentAreaFilled(false);
setFocusPainted(false);
initShape();
}
protected Shape shape, base;
protected void initShape() {
if(!getBounds().equals(base)) {
Dimension s = getPreferredSize();
base = getBounds();
shape = new Ellipse2D.Float(0, 0, s.width, s.height);
}
}
#Override public Dimension getPreferredSize() {
Icon icon = getIcon();
Insets i = getInsets();
int iw = Math.max(icon.getIconWidth(), icon.getIconHeight());
return new Dimension(iw+i.right+i.left, iw+i.top+i.bottom);
}
#Override public boolean contains(int x, int y) {
initShape();
return shape.contains(x, y);
//or return super.contains(x, y) && ((image.getRGB(x, y) >> 24) & 0xff) > 0;
}
}
JButton has a contains() method. Override it and call it on mouseReleased();

paintComponent() instead of paint() depends if you paint() inside XxxButtonUI or just override paintComponent(), but there exists the option JButton#setIcon.

How do I crop an image in Java?

I want to crop an image manually using the mouse.
Suppose the image has some text, and I want to select some text from an image, then
for that purpose I want to crop that area by using the mouse.

The solution I found most useful for cropping a buffered image uses the getSubImage(x,y,w,h);
My cropping routine ended up looking like this:
private BufferedImage cropImage(BufferedImage src, Rectangle rect) {
BufferedImage dest = src.getSubimage(0, 0, rect.width, rect.height);
return dest;
}

There are two potentially major problem with the leading answer to this question. First, as per the docs:
public BufferedImage getSubimage(int x,
int y,
int w,
int h)
Returns a subimage defined by a specified rectangular region.
The returned BufferedImage shares the same data array as the original
image.
Essentially, what this means is that result from getSubimage acts as a pointer which points at a subsection of the original image.
Why is this important? Well, if you are planning to edit the subimage for any reason, the edits will also happen to the original image. For example, I ran into this problem when I was using the smaller image in a separate window to zoom in on the original image. (kind of like a magnifying glass). I made it possible to invert the colors to see certain details more easily, but the area that was "zoomed" also got inverted in the original image! So there was a small section of the original image that had inverted colors while the rest of it remained normal. In many cases, this won't matter, but if you want to edit the image, or if you just want a copy of the cropped section, you might want to consider a method.
Which brings us to the second problem. Fortunately, it is not as big a problem as the first. getSubImage shares the same data array as the original image. That means that the entire original image is still stored in memory. Assuming that by "crop" the image you actually want a smaller image, you will need to redraw it as a new image rather than just get the subimage.
Try this:
BufferedImage img = image.getSubimage(startX, startY, endX, endY); //fill in the corners of the desired crop location here
BufferedImage copyOfImage = new BufferedImage(img.getWidth(), img.getHeight(), BufferedImage.TYPE_INT_RGB);
Graphics g = copyOfImage.createGraphics();
g.drawImage(img, 0, 0, null);
return copyOfImage; //or use it however you want
This technique will give you the cropped image you are looking for by itself, without the link back to the original image. This will preserve the integrity of the original image as well as save you the memory overhead of storing the larger image. (If you do dump the original image later)

This is a method which will work:
import java.awt.image.BufferedImage;
import java.awt.Rectangle;
import java.awt.Color;
import java.awt.Graphics;
public BufferedImage crop(BufferedImage src, Rectangle rect)
{
BufferedImage dest = new BufferedImage(rect.getWidth(), rect.getHeight(), BufferedImage.TYPE_ARGB_PRE);
Graphics g = dest.getGraphics();
g.drawImage(src, 0, 0, rect.getWidth(), rect.getHeight(), rect.getX(), rect.getY(), rect.getX() + rect.getWidth(), rect.getY() + rect.getHeight(), null);
g.dispose();
return dest;
}
Of course you have to make your own JComponent:
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.image.BufferedImage;
import java.awt.Rectangle;
import java.awt.Graphics;
import javax.swing.JComponent;
public class JImageCropComponent extends JComponent implements MouseListener, MouseMotionListener
{
private BufferedImage img;
private int x1, y1, x2, y2;
public JImageCropComponent(BufferedImage img)
{
this.img = img;
this.addMouseListener(this);
this.addMouseMotionListener(this);
}
public void setImage(BufferedImage img)
{
this.img = img;
}
public BufferedImage getImage()
{
return this;
}
#Override
public void paintComponent(Graphics g)
{
g.drawImage(img, 0, 0, this);
if (cropping)
{
// Paint the area we are going to crop.
g.setColor(Color.RED);
g.drawRect(Math.min(x1, x2), Math.min(y1, y2), Math.max(x1, x2), Math.max(y1, y2));
}
}
#Override
public void mousePressed(MouseEvent evt)
{
this.x1 = evt.getX();
this.y1 = evt.getY();
}
#Override
public void mouseReleased(MouseEvent evt)
{
this.cropping = false;
// Now we crop the image;
// This is the method a wrote in the other snipped
BufferedImage cropped = crop(new Rectangle(Math.min(x1, x2), Math.min(y1, y2), Math.max(x1, x2), Math.max(y1, y2));
// Now you have the cropped image;
// You have to choose what you want to do with it
this.img = cropped;
}
#Override
public void mouseDragged(MouseEvent evt)
{
cropping = true;
this.x2 = evt.getX();
this.y2 = evt.getY();
}
//TODO: Implement the other unused methods from Mouse(Motion)Listener
}
I didn't test it. Maybe there are some mistakes (I'm not sure about all the imports).
You can put the crop(img, rect) method in this class.
Hope this helps.

File fileToWrite = new File(filePath, "url");
BufferedImage bufferedImage = cropImage(fileToWrite, x, y, w, h);
private BufferedImage cropImage(File filePath, int x, int y, int w, int h){
try {
BufferedImage originalImgage = ImageIO.read(filePath);
BufferedImage subImgage = originalImgage.getSubimage(x, y, w, h);
return subImgage;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}

This question has not enough information to answer. A general solution (depending on your GUI framework): add a mouse event handler that will catch clicks and mouse movements. This will give you your (x, y) coordinates. Next use these coordinates to crop your image.

You need to read about Java Image API and mouse-related API, maybe somewhere under the java.awt.event package.
For a start, you need to be able to load and display the image to the screen, maybe you'll use a JPanel.
Then from there, you will try implement a mouse motion listener interface and other related interfaces. Maybe you'll get tied on the mouseDragged method...
For a mousedragged action, you will get the coordinate of the rectangle form by the drag...
Then from these coordinates, you will get the subimage from the image you have and you sort of redraw it anew....
And then display the cropped image... I don't know if this will work, just a product of my imagination... just a thought!

I'm giving this example because this actually work for my use case.
I was trying to use the AWS Rekognition API.
The API returns a BoundingBox object:
BoundingBox boundingBox = faceDetail.getBoundingBox();
The code below uses it to crop the image:
import com.amazonaws.services.rekognition.model.BoundingBox;
private BufferedImage cropImage(BufferedImage image, BoundingBox box) {
Rectangle goal = new Rectangle(Math.round(box.getLeft()* image.getWidth()),Math.round(box.getTop()* image.getHeight()),Math.round(box.getWidth() * image.getWidth()), Math.round(box.getHeight() * image.getHeight()));
Rectangle clip = goal.intersection(new Rectangle(image.getWidth(), image.getHeight()));
BufferedImage clippedImg = image.getSubimage(clip.x, clip.y , clip.width, clip.height);
return clippedImg;
}