Create a clickable area around round JLabel image - java

I am trying to create a JLabel with a oval shaped image, like this.
My code is the following:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Image;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
public final class RoundedButtonDemo {
private static Image bi;
public static void main(String[] args) {
try {
loadImage();
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
createAndShowGUI();
}
});
} catch (IOException e) {
// handle exception
}
}
private static void loadImage() throws IOException {
int newWidth = 80;
int newHeight = 40;
bi = ImageIO.read(RoundedButtonDemo.class.getResource("/resources/login.png"));
bi = bi.getScaledInstance(newWidth, newHeight, Image.SCALE_DEFAULT);
}
private static void createAndShowGUI() {
final JFrame frame = new JFrame();
frame.setSize(400, 400);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final JLabel label = new JLabel();
label.setSize(new Dimension(5, 5));
label.setIcon(new ImageIcon(bi));
label.setText("Hello World");
label.setHorizontalTextPosition(JLabel.CENTER);
// label.setBorder(BorderFactory.createLineBorder(Color.BLACK));
label.addMouseListener(new MouseListener() {
private int count = 0;
#Override
public void mouseClicked(MouseEvent e) {
if (e.getSource() == label) {
if (count % 2 == 0) {
label.setText("Bye");
} else {
label.setText("Hello World");
}
count++;
}
}
#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
}
});
frame.add(label);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
This code creates a JLabel containing the above image. The text of the JLabel should alternate every time the button is clicked, based on a MouseListener added to the JLabel.
The problem I'm facing is that even when I click outside the image (also outside the JLabel), the MouseListener is triggered, and the text alternates.
The big picture of what I want to achieve is :
A rounded button which responds to a MouseListener, whenever it is clicked anywhere on its surface.

I tried your code. You are getting this behavior because your JLabel is actually filling the entire frame. You need to set a layout for your frame; something like this:
// ...
frame.setSize(400, 400);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new FlowLayout()); // <-- you need this
final JLabel label = new JLabel();
label.setPreferredSize(new Dimension(80, 40)); // <-- also this
label.setIcon(new ImageIcon(bi));
label.setText("Hello World");
// ...
FlowLayout is one of the simplest layout managers, of which there are many. You can read about them here: https://docs.oracle.com/javase/tutorial/uiswing/layout/visual.html
Hope this helps.
PS: you had a good idea trying to debug this problem, adding a border like this:
// label.setBorder(BorderFactory.createLineBorder(Color.BLACK));
Not sure why you commented it out. Maybe you didn't notice that there was a black border around the whole frame area. Try setting to color to Color.RED or something more noticeable.

As yoshi pointed out, the JLabel fills the entire content pane, so clicking anywhere in the content pane results in mouse events for the label.
Some words:
1) You could also use GridBagLayout, instead of FlowLayout, in case you want the JLabel centered in its parent component (both vertically and horizontally). This solution is here.
Like so:
final JPanel singleCenteredComponentJPanel = new JPanel(new GridBagLayout());
singleCenteredComponentJPanel.add(label);
frame.add(singleCenteredComponentJPanel);
2) If, furthermore, you want to ignore mouse clicks on any transparent pixels of the label icon (if any) you can do the following:
Use the BufferedImage.getRGB(int x, int y), BufferedImage.getColorModel() and ColorModel.getAlpha(int pixel) methods to determine the alpha value of the clicked pixel for each mouse event. If the alpha value is equal to 0, then the pixel is completely transparent, otherwise the alpha value is between 1 and 255 (both inclusive) which in turn means the pixel is not completely transparent. Example code follows below.
And instead of Image.getScaledInstance(...) to scale the image (which returns Image, but we need BufferedImage), use the solution provided here.
Like so:
private static void loadImage() throws IOException {
int newWidth = 80;
int newHeight = 40;
bi = ImageIO.read(RoundedButtonDemo.class.getResource("/resources/login.png"));
bi = getScaledBufferedImage(bi, newWidth, newHeight);
}
public static BufferedImage getScaledBufferedImage(final Image img,
final int newWidth,
final int newHeight) {
final GraphicsEnvironment genv = GraphicsEnvironment.getLocalGraphicsEnvironment();
final GraphicsDevice gdev = genv.getDefaultScreenDevice();
final GraphicsConfiguration gcnf = gdev.getDefaultConfiguration();
final BufferedImage simg = gcnf.createCompatibleImage(newWidth, newHeight, Transparency.TRANSLUCENT);
//Painting input image to output image:
final Graphics2D g2d = simg.createGraphics();
g2d.drawImage(img, 0, 0, newWidth, newHeight, null); //#Docs "...is scaled if necessary.".
g2d.dispose();
return simg;
}
Also change the reference bi from Image to BufferedImage.
And then the MouseListener of the label:
private int count = 0;
#Override
public void mouseClicked(MouseEvent e) {
if (e.getSource() == label) {
//Get the mouse click position (in pixels),
//relative to the top-left corner of label:
final Point relativeClickPoint = e.getPoint();
//Obtain alpha value from the TYPE_INT_ARGB pixel:
final int pixel = bi.getRGB(relativeClickPoint.x, relativeClickPoint.y);
final int alpha = bi.getColorModel().getAlpha(pixel);
if (alpha > 0) { //Check if the pixel is not transparent.
if (count % 2 == 0) {
label.setText("Bye");
} else {
label.setText("Hello World");
}
count++;
}
}
}
Be aware for the above implementation: All transparent pixels of the image will be ignored (including transparent pixels "inside" the shape, if any). Which means the user could click in the center of the image and nothing would happen if the clicked pixel was completely transparent. So I made the assumption that this is not the case with your image here.
3) For the scaling of the Image, you can determine the new size with the method collapseInside(...):
/**
* #param resultDim Output dimension (same aspect ratio as the original dimension, and inside containerDim).
* #param originalDim Original dimension.
* #param containerDim Dimension with the maximum width and maximum height.
*/
public static void collapseInside(final Dimension resultDim,
final Dimension originalDim,
final Dimension containerDim) {
resultDim.setSize(originalDim);
if (resultDim.width > containerDim.width) {
//Adjusting height for max width:
resultDim.height = ( resultDim.height * containerDim.width ) / resultDim.width;
resultDim.width = containerDim.width;
}
if (resultDim.height > containerDim.height) {
//Adjusting width for max height:
resultDim.width = ( resultDim.width * containerDim.height ) / resultDim.height;
resultDim.height = containerDim.height;
}
}
With this method:
a) Scaled Image's width will be less than or equal to container's size width (resultDim.width <= containerDim.width).
b) Same for height (resultDim.height <= containerDim.height).
c) Aspect ratio of the original Image size will be preserved in the new Image size (resultDim.width / resultDim.height == originalDim.width / originalDim.height).
With Image.getScaledInstance(...) and the previous getScaledBufferedImage(...) the aspect ratio of the Image could change.
So I edit the getScaledBufferedImage(...) to use collapseInside(...):
public static BufferedImage getScaledBufferedImage(final Image img,
final int newWidth,
final int newHeight) {
final Dimension originalDim = new Dimension(img.getWidth(null), img.getHeight(null)),
containerDim = new Dimension(newWidth, newHeight),
resultDim = new Dimension();
collapseInside(resultDim, originalDim, containerDim);
final GraphicsEnvironment genv = GraphicsEnvironment.getLocalGraphicsEnvironment();
final GraphicsDevice gdev = genv.getDefaultScreenDevice();
final GraphicsConfiguration gcnf = gdev.getDefaultConfiguration();
final BufferedImage simg = gcnf.createCompatibleImage(resultDim.width, resultDim.height, Transparency.TRANSLUCENT);
//Painting input image to output image:
final Graphics2D g2d = simg.createGraphics();
g2d.drawImage(img, 0, 0, resultDim.width, resultDim.height, null); //#Docs "...is scaled if necessary.".
g2d.dispose();
return simg;
}
Complete code for all three above:
import java.awt.Dimension;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.GridBagLayout;
import java.awt.Image;
import java.awt.Point;
import java.awt.Transparency;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public final class RoundedButtonDemo {
private static BufferedImage bi;
public static void main(String[] args) {
try {
loadImage();
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
createAndShowGUI();
}
});
} catch (IOException e) {
// handle exception
}
}
private static void loadImage() throws IOException {
int newWidth = 80;
int newHeight = 40;
bi = ImageIO.read(RoundedButtonDemo.class.getResource("/resources/login.png"));
bi = getScaledBufferedImage(bi, newWidth, newHeight);
}
public static BufferedImage getScaledBufferedImage(final Image img,
final int newWidth,
final int newHeight) {
final Dimension originalDim = new Dimension(img.getWidth(null), img.getHeight(null)),
containerDim = new Dimension(newWidth, newHeight),
resultDim = new Dimension();
collapseInside(resultDim, originalDim, containerDim);
final GraphicsEnvironment genv = GraphicsEnvironment.getLocalGraphicsEnvironment();
final GraphicsDevice gdev = genv.getDefaultScreenDevice();
final GraphicsConfiguration gcnf = gdev.getDefaultConfiguration();
final BufferedImage simg = gcnf.createCompatibleImage(resultDim.width, resultDim.height, Transparency.TRANSLUCENT);
//Painting input image to output image:
final Graphics2D g2d = simg.createGraphics();
g2d.drawImage(img, 0, 0, resultDim.width, resultDim.height, null); //#Docs "...is scaled if necessary.".
g2d.dispose();
return simg;
}
/**
* #param resultDim Output dimension (same aspect ratio as the original dimension, and inside containerDim).
* #param originalDim Original dimension.
* #param containerDim Dimension with the maximum width and maximum height.
*/
public static void collapseInside(final Dimension resultDim,
final Dimension originalDim,
final Dimension containerDim) {
resultDim.setSize(originalDim);
if (resultDim.width > containerDim.width) {
//Adjusting height for max width:
resultDim.height = ( resultDim.height * containerDim.width ) / resultDim.width;
resultDim.width = containerDim.width;
}
if (resultDim.height > containerDim.height) {
//Adjusting width for max height:
resultDim.width = ( resultDim.width * containerDim.height ) / resultDim.height;
resultDim.height = containerDim.height;
}
}
private static void createAndShowGUI() {
final JFrame frame = new JFrame();
frame.setSize(400, 400);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final JLabel label = new JLabel();
label.setSize(new Dimension(5, 5));
label.setIcon(new ImageIcon(bi));
label.setText("Hello World");
label.setHorizontalTextPosition(JLabel.CENTER);
// label.setBorder(BorderFactory.createLineBorder(Color.BLACK));
label.addMouseListener(new MouseListener() {
private int count = 0;
#Override
public void mouseClicked(MouseEvent e) {
if (e.getSource() == label) {
//Get the mouse click position (in pixels),
//relative to the top-left corner of label:
final Point relativeClickPoint = e.getPoint();
//Obtain alpha value from the TYPE_INT_ARGB pixel:
final int pixel = bi.getRGB(relativeClickPoint.x, relativeClickPoint.y);
final int alpha = bi.getColorModel().getAlpha(pixel);
if (alpha > 0) { //Check if the pixel is not transparent.
if (count % 2 == 0) {
label.setText("Bye");
} else {
label.setText("Hello World");
}
count++;
}
}
}
#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
}
});
final JPanel singleCenteredComponentJPanel = new JPanel(new GridBagLayout());
singleCenteredComponentJPanel.add(label);
frame.add(singleCenteredComponentJPanel);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
Alternatively, you may also override the paintComponent(...) of JPanel and use Graphics.drawImage(...) to paint the Image bi to the JPanel like so:
#Override
protected void paintComponent(final Graphics g) {
super.paintComponent(g);
//Drawing the image:
g.drawImage(img, 0, 0, null);
//Drawing the text:
//For centering the text, I used code from:
//https://stackoverflow.com/questions/27706197/how-can-i-center-graphics-drawstring-in-java
final FontMetrics metrics = g.getFontMetrics(g.getFont());
final int x = (img.getWidth(null) - metrics.stringWidth(text)) / 2;
final int y = (img.getHeight(null) - metrics.getHeight()) / 2 + metrics.getAscent();
g.drawString(text, x, y);
}
Where img is bi and text is the text of the button (i.e. "Hello World" and "Bye").
Then add the MouseListener to the JPanel as is.
Complete code for this (as "RoundedButtonDemo1" class, in the same package):
import java.awt.Dimension;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GraphicsConfiguration;
import java.awt.GraphicsDevice;
import java.awt.GraphicsEnvironment;
import java.awt.GridBagLayout;
import java.awt.Image;
import java.awt.Point;
import java.awt.Transparency;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public final class RoundedButtonDemo1 {
private static BufferedImage bi;
public static void main(String[] args) {
try {
loadImage();
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
createAndShowGUI();
}
});
} catch (IOException e) {
// handle exception
}
}
private static void loadImage() throws IOException {
int newWidth = 80;
int newHeight = 40;
bi = ImageIO.read(RoundedButtonDemo1.class.getResource("/resources/login.png"));
bi = getScaledBufferedImage(bi, newWidth, newHeight);
}
public static BufferedImage getScaledBufferedImage(final Image img,
final int newWidth,
final int newHeight) {
final Dimension originalDim = new Dimension(img.getWidth(null), img.getHeight(null)),
containerDim = new Dimension(newWidth, newHeight),
resultDim = new Dimension();
collapseInside(resultDim, originalDim, containerDim);
final GraphicsEnvironment genv = GraphicsEnvironment.getLocalGraphicsEnvironment();
final GraphicsDevice gdev = genv.getDefaultScreenDevice();
final GraphicsConfiguration gcnf = gdev.getDefaultConfiguration();
final BufferedImage simg = gcnf.createCompatibleImage(resultDim.width, resultDim.height, Transparency.TRANSLUCENT);
//Painting input image to output image:
final Graphics2D g2d = simg.createGraphics();
g2d.drawImage(img, 0, 0, resultDim.width, resultDim.height, null); //#Docs "...is scaled if necessary.".
g2d.dispose();
return simg;
}
/**
* #param resultDim Output dimension (same aspect ratio as the original dimension, and inside containerDim).
* #param originalDim Original dimension.
* #param containerDim Dimension with the maximum width and maximum height.
*/
public static void collapseInside(final Dimension resultDim,
final Dimension originalDim,
final Dimension containerDim) {
resultDim.setSize(originalDim);
if (resultDim.width > containerDim.width) {
//Adjusting height for max width:
resultDim.height = ( resultDim.height * containerDim.width ) / resultDim.width;
resultDim.width = containerDim.width;
}
if (resultDim.height > containerDim.height) {
//Adjusting width for max height:
resultDim.width = ( resultDim.width * containerDim.height ) / resultDim.height;
resultDim.height = containerDim.height;
}
}
private static class CustomButton extends JPanel {
private Image img;
private String text;
public void setImage(final Image img) {
this.img = img;
final Dimension imgDim = new Dimension(img.getWidth(null), img.getHeight(null));
setMinimumSize(imgDim);
setPreferredSize(imgDim);
repaint();
}
public Image getImage() {
return img;
}
public void setText(final String text) {
this.text = text;
repaint();
}
public String getText() {
return text;
}
#Override
protected void paintComponent(final Graphics g) {
super.paintComponent(g);
//Drawing the image:
g.drawImage(img, 0, 0, null);
//Drawing the text:
//For centering the text, I used code from:
//https://stackoverflow.com/questions/27706197/how-can-i-center-graphics-drawstring-in-java
final FontMetrics metrics = g.getFontMetrics(g.getFont());
final int x = (img.getWidth(null) - metrics.stringWidth(text)) / 2;
final int y = (img.getHeight(null) - metrics.getHeight()) / 2 + metrics.getAscent();
g.drawString(text, x, y);
}
}
private static void createAndShowGUI() {
final JFrame frame = new JFrame();
frame.setSize(400, 400);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final CustomButton button = new CustomButton();
button.setSize(new Dimension(5, 5));
button.setImage(bi);
button.setText("Hello World");
//button.setHorizontalTextPosition(SwingConstants.CENTER);
//button.setOpaque(false);
//button.setBorder(BorderFactory.createLineBorder(Color.BLACK));
button.addMouseListener(new MouseListener() {
private int count = 0;
#Override
public void mouseClicked(MouseEvent e) {
if (e.getSource() == button) {
//Get the mouse click position (in pixels),
//relative to the top-left corner of label:
final Point relativeClickPoint = e.getPoint();
//Obtain alpha value from the TYPE_INT_ARGB pixel:
final int pixel = bi.getRGB(relativeClickPoint.x, relativeClickPoint.y);
final int alpha = bi.getColorModel().getAlpha(pixel);
if (alpha > 0) { //Check if the pixel is not transparent.
if (count % 2 == 0) {
button.setText("Bye");
} else {
button.setText("Hello World");
}
count++;
}
}
}
#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
}
});
final JPanel singleCenteredComponentJPanel = new JPanel(new GridBagLayout());
singleCenteredComponentJPanel.add(button);
frame.add(singleCenteredComponentJPanel);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
}
Alternatively, if you want normal buttons, istead of labels, it seems here you can reshape buttons as well !
Other than that, I have also tried the following:
1) Using JLayeredPanes. There is a tutorial explaining them, and I guessed they could probably have a method to obtain the order of the visible pane for a given Point, or something like that, but they don't.
2) Using Container.getComponentAt(Point) and Container.findComponentAt(Point) in the MouseListener, but (as I found out after testing) these methods don't "see through" non-opaque (+transparent) pixels.
3) Searching for reshaping or translucency in JPanels (inspired by How to Create Translucent and Shaped Windows), but nothing found.
4) How to Decorate Components with the JLayer Class with first line saying:
... enables you to draw on components and respond to component events without modifying the underlying component directly.
seems promising, but I'm done here.
That's it for me for now. Goodbye.

Related

Need help to adjust a Zoom system in Graphics2D - Java

This is my 1st question here. I'm trying to build a White Page adjustable by zoom. It's inside a JScrollPane, so the size of the JScrollPane's ScrollBars are adjustable in the Dimension of that JPanel.
I want to adjust the size of those ScrollBars as the Size of the page (variables width and height in the code) + 2 borderSize, so the full size is equal the Page + margin of a borderSize around it. It works if zoom = 1.0.
If zoom < 1.0, the scroll bar is smaller than the Page and cut a piece of it. If zoom > 1 the Dimension size is way bigger than the page, leaving a huger border on its right and down corners, bigger than the borderSize.
How do I do this?
PS: I'm started learning java by myself, in the Quarantine last year, never had a teacher, just the internet, so any critics or suggestions, please, tell me.
Here's the JPanel's code:
package test;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.AdjustmentEvent;
import java.awt.event.AdjustmentListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseWheelEvent;
import java.awt.event.MouseWheelListener;
import java.awt.event.WindowEvent;
import java.awt.event.WindowStateListener;
import java.awt.geom.AffineTransform;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SpringLayout;
import javax.swing.JSlider;
import javax.swing.JScrollPane;
import javax.swing.JLabel;
public class Main2 {
private MyPanel mp = new MyPanel();
private JFrame frame;
private JSlider zoomSlider = new JSlider();
private JLabel zoomLabel = new JLabel("Zoom: XXX");
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
Main2 window = new Main2();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
public Main2() {
initialize();
}
private void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, 619, 403);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
SpringLayout springLayout = new SpringLayout();
frame.getContentPane().setLayout(springLayout);
springLayout.putConstraint(SpringLayout.SOUTH, zoomSlider, 40, SpringLayout.NORTH, frame.getContentPane());
springLayout.putConstraint(SpringLayout.EAST, zoomSlider, -115, SpringLayout.EAST, frame.getContentPane());
zoomSlider.setValue(100);
zoomSlider.setSnapToTicks(true);
zoomSlider.setPaintTicks(true);
zoomSlider.setMaximum(200);
zoomSlider.setMinorTickSpacing(5);
zoomSlider.setMinimum(5);
springLayout.putConstraint(SpringLayout.NORTH, zoomSlider, 0, SpringLayout.NORTH, frame.getContentPane());
springLayout.putConstraint(SpringLayout.WEST, zoomSlider, 0, SpringLayout.WEST, frame.getContentPane());
frame.getContentPane().add(zoomSlider);
JScrollPane scrollPane = new JScrollPane(mp);
springLayout.putConstraint(SpringLayout.NORTH, scrollPane, 10, SpringLayout.SOUTH, zoomSlider);
springLayout.putConstraint(SpringLayout.WEST, scrollPane, 10, SpringLayout.WEST, frame.getContentPane());
springLayout.putConstraint(SpringLayout.SOUTH, scrollPane, -10, SpringLayout.SOUTH, frame.getContentPane());
springLayout.putConstraint(SpringLayout.EAST, scrollPane, -10, SpringLayout.EAST, frame.getContentPane());
frame.getContentPane().add(scrollPane);
springLayout.putConstraint(SpringLayout.NORTH, zoomLabel, 10, SpringLayout.NORTH, frame.getContentPane());
springLayout.putConstraint(SpringLayout.WEST, zoomLabel, 6, SpringLayout.EAST, zoomSlider);
frame.getContentPane().add(zoomLabel);
frame.addWindowStateListener(new WindowStateListener() {
#Override
public void windowStateChanged(WindowEvent arg0) {
// TODO Auto-generated method stub
mp.draw();
}
});
zoomSlider.addMouseListener(new MouseListener() {
#Override
public void mouseClicked(MouseEvent arg0) {
// TODO Auto-generated method stub
int temp = (zoomSlider.getValue())-zoomSlider.getValue()%5;
setZoom(temp);
mp.draw();
}
#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) {
int temp = (zoomSlider.getValue())-zoomSlider.getValue()%5;
setZoom(temp);
mp.draw();
}
});
mp.addMouseWheelListener(new MouseWheelListener() {
#Override
public void mouseWheelMoved(MouseWheelEvent e) {
if (e.getPreciseWheelRotation() < 0) {
setZoom(zoomSlider.getValue()- 5);
} else {
setZoom(zoomSlider.getValue()+ 5);
}
// zoom += e.getPreciseWheelRotation();
if (mp.getZoom()*100 < 10) {
setZoom(10);
}
mp.draw();
}
});
AdjustmentListener adj = new AdjustmentListener() {
#Override
public void adjustmentValueChanged(AdjustmentEvent e) {
setZoom(zoomSlider.getValue());
mp.draw();
}
};
scrollPane.getVerticalScrollBar().addAdjustmentListener(adj);
scrollPane.getHorizontalScrollBar().addAdjustmentListener(adj);
}
public void setZoom(int n) {
mp.setZoom(n);
zoomSlider.setValue(n);
zoomLabel.setText("Zoom: "+mp.getZoom()+"x");
}
}
class MyPanel extends JPanel{
private static final long serialVersionUID = -716735372803790424L;
int borderSize=28;
int zoom=100;
int height = 3565;
int width = 2537;
int widthz, heightz;
public MyPanel() {
setBackground(Color.DARK_GRAY);
}
#Override
public Dimension getPreferredSize() {
int a, b;
String temp;
Float x, y;
x=(getZoom()*width); //Size of the page adjusted by zoom
y=(getZoom()*height);
temp = x.toString();
String temp1[] = temp.split("\\."); // converted to string to convert it to int
a = Integer.valueOf(temp1[0])+2*borderSize; //that value + 2 BorderSize
temp = y.toString();
String temp2[] = temp.split("\\.");
b = Integer.valueOf(temp2[0])+2*borderSize;
return new Dimension (a,b);
}
#Override
public void paintComponent (Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d = putZoom(g2d);
g2d.setColor(Color.WHITE);
g2d.fillRect(this.getX(),this.getY(), width, height);
g2d.setColor(Color.BLACK);
g2d.drawRect(this.getX()+borderSize,this.getY()+borderSize,width-2*borderSize,height-2*borderSize);
g2d.dispose();
}
public Graphics2D putZoom(Graphics2D g) {
AffineTransform at = new AffineTransform();
at.translate(borderSize,borderSize); // put the page a borderSize from the upper-left corner
at.scale(getZoom(),getZoom()); //adjust the page as zoom
Graphics2D g2d = g;
g2d.setTransform(at);
return g2d;
}
public void draw() { //this method is to update the draw from the main
repaint();
}
public Float getZoom() {
return Float.valueOf(zoom)/100;
}
public void setZoom(int zom) { //this method is to update Zoom from the main
zoom=zom;
String zoomheight []= (String.valueOf(getZoom()*height)).split("\\.");
heightz = Integer.valueOf(zoomheight[0]);
String zoomwidth []= (String.valueOf(getZoom()*width)).split("\\.");
widthz = Integer.valueOf(zoomwidth[0]);
}
public int getZoomInt() {
return this.zoom;
}
}
Zoom(values from 0.1 to 2.0).
How can i improve this? Also, i have no idea how to update the JScrollPane's scrollbars together with the zoom.Thanks for the help.
UPDATE: i've created a minimal reproducible exemple.
Introduction
I started working on this before you updated your question. I used a zoom percentage rather than a zoom factor.
I created the following GUI and set the initial state to 30 percent.
I made the inner JPanel a checkerboard so you can more easily see the zoom. I modified your initial values so the inner JPanel would represent an 8 1/2 x 11 piece of paper at 50 pixels per inch.
Here's the same GUI at 100 percent.
Here's the same GUI at 10 percent.
Explanation
I created a JFrame and a control JPanel to hold the JSlider. I used a GridLayout to create the control JPanel.
I created an inner JPanel to hold the drawing and a display JPanel that holds the JScrollPane. I made the display JPanel proportionate to the size of the inner JPanel so I wouldn't have any stretching issues.
Getting the GUI to revalidate / repaint turned out to be the biggest challenge. I wound up having to invalidate the JScrollPane, both JScrollBars, and the display JPanel. I also had to reset the JScrollBars to zero each time I changed the zoom percentage.
Code
Here's the complete runnable code. I made all of the classes inner classes so I could post this as one code block.
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import javax.swing.BorderFactory;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollBar;
import javax.swing.JScrollPane;
import javax.swing.JSlider;
import javax.swing.SwingUtilities;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class ZoomJPanelGUI implements Runnable {
public static void main(String[] args) {
SwingUtilities.invokeLater(new ZoomJPanelGUI());
}
private int zoomPercentage = 30;
private DisplayPanel displayPanel;
private JFrame frame;
#Override
public void run() {
frame = new JFrame("Zoom JPanel");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(createControlPanel(), BorderLayout.BEFORE_FIRST_LINE);
this.displayPanel = new DisplayPanel(zoomPercentage);
frame.add(displayPanel.getPanel(), BorderLayout.AFTER_LAST_LINE);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
private JPanel createControlPanel() {
JPanel panel = new JPanel(new GridLayout(0, 1));
panel.setBorder(BorderFactory.createEmptyBorder(5, 15, 5, 15));
JLabel label = new JLabel("Zoom Percentage");
label.setFont(panel.getFont().deriveFont(Font.BOLD, 24f));
panel.add(label);
JSlider slider = new JSlider(
JSlider.HORIZONTAL, 10, 100, zoomPercentage);
slider.setFont(panel.getFont().deriveFont(16f));
slider.setMajorTickSpacing(30);
slider.setMinorTickSpacing(5);
slider.setPaintTicks(true);
slider.setPaintLabels(true);
slider.addChangeListener(new ChangeListener() {
#Override
public void stateChanged(ChangeEvent event) {
JSlider slider = (JSlider) event.getSource();
if (!slider.getValueIsAdjusting()) {
zoomPercentage = (int) slider.getValue();
displayPanel.setZoomPercentage(zoomPercentage);
displayPanel.repaint();
frame.pack();
}
}
});
panel.add(slider);
return panel;
}
public class DisplayPanel {
private InnerPanel innerPanel;
private final JPanel panel;
private JScrollPane scrollPane;
private int zoomPercentage;
public DisplayPanel(int zoomPercentage) {
this.zoomPercentage = zoomPercentage;
this.panel = createDisplayPanel();
}
private JPanel createDisplayPanel() {
JPanel panel = new JPanel(new BorderLayout());
panel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
this.innerPanel = new InnerPanel(zoomPercentage);
scrollPane = new JScrollPane(innerPanel);
scrollPane.setPreferredSize(new Dimension(475, 600));
panel.add(scrollPane, BorderLayout.CENTER);
return panel;
}
public void setZoomPercentage(int zoomPercentage) {
this.zoomPercentage = zoomPercentage;
innerPanel.setZoomPercentage(zoomPercentage);
}
public JPanel getPanel() {
return panel;
}
public void repaint() {
innerPanel.repaint();
scrollPane.invalidate();
JScrollBar hScrollBar = scrollPane.getHorizontalScrollBar();
JScrollBar vScrollBar = scrollPane.getVerticalScrollBar();
hScrollBar.setValue(0);
vScrollBar.setValue(0);
hScrollBar.invalidate();
vScrollBar.invalidate();
panel.invalidate();
}
}
public class InnerPanel extends JPanel {
private static final long serialVersionUID = 1L;
private int maximumBorderSize = 25;
private int maximumCellSize = 50;
private int maximumHeight = 5500;
private int maximumWidth = 4250;
private int zoomPercentage;
public InnerPanel(int zoomPercentage) {
this.zoomPercentage = zoomPercentage;
}
public void setZoomPercentage(int zoomPercentage) {
this.zoomPercentage = zoomPercentage;
}
#Override
public Dimension getPreferredSize() {
int width = maximumWidth * zoomPercentage / 100;
int height = maximumHeight * zoomPercentage / 100;
return new Dimension(width, height);
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
int borderSize = maximumBorderSize * zoomPercentage / 100;
paintBackground(g2d);
paintBorder(g2d, borderSize);
paintCheckerboard(g2d, borderSize);
}
private void paintBackground(Graphics2D g2d) {
g2d.setColor(Color.WHITE);
g2d.fillRect(0, 0, getWidth(), getHeight());
}
private void paintBorder(Graphics2D g2d, int borderSize) {
g2d.setColor(Color.BLACK);
g2d.setStroke(new BasicStroke(3f));
g2d.drawRect(borderSize, borderSize, getWidth() - 2 * borderSize,
getHeight() - 2 * borderSize);
}
private void paintCheckerboard(Graphics2D g2d, int borderSize) {
int cellSize = maximumCellSize * zoomPercentage / 100;
int width = maximumWidth - maximumBorderSize * 2 - 2;
int height = maximumHeight - maximumBorderSize * 2 - 2;
int cellWidth = width / maximumCellSize;
int cellHeight = height / maximumCellSize;
boolean isBlue = true;
int x = borderSize;
int y = borderSize;
int heightRemainder = height - cellHeight * cellSize;
for (int i = 0; i < cellHeight; i++) {
int widthRemainder = width - cellWidth * cellSize;
for (int j = 0; j < cellWidth; j++) {
if (isBlue) {
g2d.setColor(Color.BLUE);
} else {
g2d.setColor(Color.YELLOW);
}
isBlue = !isBlue;
g2d.fillRect(x, y, cellSize, cellSize);
x += cellSize;
if (widthRemainder > 0) {
x++;
widthRemainder--;
}
}
// isBlue = !isBlue;
x = borderSize;
y += cellSize;
if (heightRemainder > 0) {
y++;
heightRemainder--;
}
}
}
}
}
I've finally did it. Started by not using transformation for scaling it, but making a new draw with the size zoomed, adapting all sizes in the method setSizes(), and adjusting the Dimension by those sizes.
(Just changed this class)
class MyPanel extends JPanel{
private static final long serialVersionUID = -716735372803790424L;
int borderSize=28;
int zoom=100;
int height = 3565;
int width = 2537;
int widthz, heightz;
int maxHeight, maxWidth; //max size of draw
int maxAreaHeight, maxAreaWidth; //max size of area
public MyPanel() {
setBackground(Color.DARK_GRAY);
}
#Override
public Dimension getPreferredSize() {
setSizes();
return new Dimension (maxAreaWidth,maxAreaHeight);
}
#Override
public void paintComponent (Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d= createBase(g2d);
}
public void draw() { //this method is to update the draw from the main
repaint();
}
public Float getZoom() {return Float.valueOf(zoom)/100;}
public void setZoom(int zom) {zoom=zom;}
public int getZoomInt() {return this.zoom;}
public void setSizes () {
widthz= width*getZoomInt()/100;
heightz=height*getZoomInt()/100;
maxHeight = heightz+2*borderSize;
maxWidth = widthz +2*borderSize;
maxAreaHeight = this.getY()+maxHeight;
maxAreaWidth = this.getX()+maxWidth;
if (this.getSize() != new Dimension(maxAreaWidth, maxAreaHeight)) {
this.setSize(maxAreaWidth, maxAreaHeight);
}
}
public Graphics2D createBase(Graphics2D g2d) {
Graphics2D g = g2d;
setSizes();
g.setColor(Color.WHITE);
g.fillRect(this.getX()+borderSize,this.getY()+borderSize, widthz, heightz);
g.setColor(Color.BLACK);
g.drawRect(this.getX()+borderSize+borderSize*zoom/100,this.getY()+borderSize+borderSize*zoom/100,widthz-2*borderSize*zoom/100,heightz-2*borderSize*zoom/100);
return g;
}
}
Thanks for all the help.

Java Array Loop Graphics page not functioning

edit 2: I decided that it would be easier to understand if I just put the entire code up, so that you can test it.
edit: I realize that what I said was unclear, so I will explain this as best as I can. Basically, I am drawing rectangles on a Graphics page using the fillRect method. The problem is that when I change the size of one, they all change, as they are all being redrawn everytime a new one is drawn. To correct this, I added an array that stores all of the sizes which are input via the scrollwheel in another part of the problem. Anyways, I know that the problem is isolated to the loop that supposedly draws them all a certain size, so I added a loop that in theory should give me a temporary variable each time to use that redraws all of the rectangle's sizes starting at 0 each time the main loop is run. The problem is that this does not in fact redraw the rectangles to their individual sizes, and instead draws them to the current size. I have updated the code part as well.
I am having trouble with a project in Java. What it is supposed to do is change the size of each individual rectangle object by storing it in an array, and then recreating the rectangles based off the length from the array. I (at least I think) do this by creating a variable that should be equal to the SIZE that is changed in another part of the program, and then set that equal to the particular element in the array at i. Anyhow, when I do this, I change all of the lengths to whatever the current length is when I draw a rectangle. I know that the problem is by me using i in the size part, but what would I use? Thanks in advance for any help!
Here is the code:
public class Dots
{
public static void main(String[] args)
{
JFrame frame = new JFrame("Array Rectangles");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
DotsPanel dotsPanel = new DotsPanel();
frame.getContentPane().add(dotsPanel);
//buttons
JButton btnNewButton = new JButton("RED");
btnNewButton.setHorizontalAlignment(SwingConstants.LEFT);
btnNewButton.setVerticalAlignment(SwingConstants.BOTTOM);
btnNewButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
}
});
btnNewButton.setForeground(Color.RED);
dotsPanel.add(btnNewButton);
JButton btnNewButton_1 = new JButton("GREEN");
btnNewButton_1.setForeground(Color.GREEN);
btnNewButton_1.setVerticalAlignment(SwingConstants.BOTTOM);
dotsPanel.add(btnNewButton_1);
JButton btnNewButton_2 = new JButton("BLUE");
btnNewButton_2.setForeground(Color.BLUE);
dotsPanel.add(btnNewButton_2);
JButton btnNewButton_3 = new JButton("BLACK");
btnNewButton_3.setForeground(new Color(0, 0, 0));
dotsPanel.add(btnNewButton_3);
frame.pack();
frame.setVisible(true);
}
}
import java.util.ArrayList;
import java.util.Random;
import javax.swing.JPanel;
import java.awt.*;
import java.awt.event.*;
public class DotsPanel extends JPanel
{
// radius of each dot
private int SIZE = 25;
private int SIZEAccess;
private static final Random generator = new Random();
//used to count amount of dots
private ArrayList<Point> pointList;
int[] sizes = new int [10000];
//Sets up this std. sized panel to listen for mouse events.
public DotsPanel()
{
pointList = new ArrayList<Point>();
addMouseListener (new DotsListener());
addMouseMotionListener(new DotsListener());
addMouseWheelListener(new DotsListener());
setBackground(Color.white);
setPreferredSize(new Dimension(1024, 768));
}
//used to generate a random color
public static Color randomColor() {
return new Color(generator.nextInt(256), generator.nextInt(256), generator.nextInt(256));
}
// Draws all of the dots stored in the list.
public void paintComponent(Graphics page)
{
super.paintComponent(page);
//draws a centered dot of random color
int i = 0;
for (Point spot : pointList)
{
sizes[i] = SIZE;
//SIZEAccess = SIZE;
//sizes[i] = SIZEAccess;
//page.fillRect(spot.x-SIZE, spot.y-SIZE, SIZE*2, SIZE*2);
for (int temp = 0; temp <= i; temp++)
page.fillRect(spot.x-sizes[temp], spot.y-sizes[temp], sizes[temp]*2, sizes[temp]*2);
//page.fillRect(spot.x-SIZE, spot.y-SIZE, SIZE*2, SIZE*2);
//page.setColor(randomColor());
//page.setColor(c)
i++;
}
//displays the amount of rectangles drawn at the top left of screen
page.drawString("Count: " + pointList.size(), 5, 15);
page.drawString("To change the size of the squares, use mouse scroll wheel.", 350, 15);
page.drawString("Size: " + SIZE, 950, 15);
}
// Represents the listener for mouse events.
private class DotsListener implements MouseListener, MouseMotionListener, MouseWheelListener
{
// Adds the current point to the list of points and redraws
// the panel whenever the mouse button is pressed.
public void mousePressed(MouseEvent event)
{
pointList.add(event.getPoint());
repaint();
}
// Provide empty definitions for unused event methods.
public void mouseClicked(MouseEvent event) {
}
public void mouseReleased(MouseEvent event) {
}
public void mouseEntered(MouseEvent event) {
}
public void mouseExited(MouseEvent event) {}
// Adds the current point to the list of points and redraws
// the panel whenever the mouse button is dragged.
public void mouseDragged(MouseEvent event) {
pointList.add(event.getPoint());
repaint();
}
public void mouseMoved(MouseEvent event) {
}
public void mouseWheelMoved(MouseWheelEvent event)
{
int notches = 0;
notches = event.getWheelRotation();
//int
if (notches > 0)
{
SIZE = SIZE + notches;
notches = 0;
}
else if (notches < 0)
{
int tempSIZE = SIZE;
tempSIZE = tempSIZE + notches;
//prevents the program from having dots that increase due to multiplying negatives by negatives
//by making anything less than 1 equal 1
if(tempSIZE < 1)
tempSIZE = 1;
SIZE = tempSIZE;
notches = 0;
}
}
}
//SIZE = SIZE + notches;
}
You appear to have ArrayList's interacting with arrays in a confusing mix that makes it hard for us to follow your logic. This suggests that your logic may be too complex for your own good and that your code might benefit from simplification. Why not instead create a List<Rectangle> such as an ArrayList<Rectangle>, and then simply loop through this list in your paintComponent method, and draw each Rectangle using the Graphics2D object's draw(...) or fill(...) method:
private List<Rectangle> rectangleList = new ArrayList<>();
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
for (Rectangle rectangle : rectangleList) {
g2.fill(rectangle);
}
}
For example:
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Stroke;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.List;
import javax.swing.*;
#SuppressWarnings("serial")
public class Foo extends JPanel {
private static final int PREF_W = 600;
private static final int PREF_H = PREF_W;
private static final Color BACKGROUND = Color.black;
private static final Color FILL_COLOR = Color.pink;
private static final Color DRAW_COLOR = Color.red;
private static final Stroke STROKE = new BasicStroke(3);
private List<Rectangle> rectangleList = new ArrayList<>();
private Point pressPoint = null;
private Point dragPoint = null;
public Foo() {
setBackground(BACKGROUND);
MyMouseAdapter myMouseAdapter = new MyMouseAdapter();
addMouseListener(myMouseAdapter);
addMouseMotionListener(myMouseAdapter);
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
Stroke oldStroke = g2.getStroke();
g2.setStroke(STROKE);
for (Rectangle rectangle : rectangleList) {
g2.setColor(FILL_COLOR);
g2.fill(rectangle);
g2.setColor(DRAW_COLOR);
g2.draw(rectangle);
}
g2.setStroke(oldStroke);
if (pressPoint != null && dragPoint != null) {
g2.setColor(FILL_COLOR.darker());
int x = Math.min(pressPoint.x, dragPoint.x);
int y = Math.min(pressPoint.y, dragPoint.y);
int width = Math.abs(pressPoint.x - dragPoint.x);
int height = Math.abs(pressPoint.y - dragPoint.y);
g2.drawRect(x, y, width, height);
}
}
private class MyMouseAdapter extends MouseAdapter {
#Override
public void mousePressed(MouseEvent e) {
pressPoint = e.getPoint();
repaint();
}
#Override
public void mouseDragged(MouseEvent e) {
dragPoint = e.getPoint();
repaint();
}
#Override
public void mouseReleased(MouseEvent e) {
dragPoint = e.getPoint();
int x = Math.min(pressPoint.x, dragPoint.x);
int y = Math.min(pressPoint.y, dragPoint.y);
int width = Math.abs(pressPoint.x - dragPoint.x);
int height = Math.abs(pressPoint.y - dragPoint.y);
Rectangle rect = new Rectangle(x, y, width, height);
rectangleList.add(rect);
pressPoint = null;
dragPoint = null;
repaint();
}
}
private static void createAndShowGui() {
JFrame frame = new JFrame("Foo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new Foo());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}

Select, Copy and Paste Images

What I want my app to do:
1 - Select an area of Image and get the coordinates. This code below should do this:
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import javax.swing.*;
public class ScreenCaptureRectangle {
Rectangle captureRect;
ScreenCaptureRectangle(final BufferedImage screen) {
final BufferedImage screenCopy = new BufferedImage(
screen.getWidth(),
screen.getHeight(),
screen.getType());
final JLabel screenLabel = new JLabel(new ImageIcon(screenCopy));
JScrollPane screenScroll = new JScrollPane(screenLabel);
screenScroll.setPreferredSize(new Dimension(
(int)(screen.getWidth()/3),
(int)(screen.getHeight()/3)));
JPanel panel = new JPanel(new BorderLayout());
panel.add(screenScroll, BorderLayout.CENTER);
final JLabel selectionLabel = new JLabel(
"Drag a rectangle in the screen shot!");
panel.add(selectionLabel, BorderLayout.SOUTH);
repaint(screen, screenCopy);
screenLabel.repaint();
screenLabel.addMouseMotionListener(new MouseMotionAdapter() {
Point start = new Point();
#Override
public void mouseMoved(MouseEvent me) {
start = me.getPoint();
repaint(screen, screenCopy);
selectionLabel.setText("Start Point: " + start);
screenLabel.repaint();
}
#Override
public void mouseDragged(MouseEvent me) {
Point end = me.getPoint();
captureRect = new Rectangle(start,
new Dimension(end.x-start.x, end.y-start.y));
repaint(screen, screenCopy);
screenLabel.repaint();
selectionLabel.setText("Rectangle: " + captureRect);
}
});
JOptionPane.showMessageDialog(null, panel);
System.out.println("Rectangle of interest: " + captureRect);
}
public void repaint(BufferedImage orig, BufferedImage copy) {
Graphics2D g = copy.createGraphics();
g.drawImage(orig,0,0, null);
if (captureRect!=null) {
g.setColor(Color.RED);
g.draw(captureRect);
g.setColor(new Color(255,255,255,150));
g.fill(captureRect);
}
g.dispose();
}
public static void main(String[] args) throws Exception {
Robot robot = new Robot();
final Dimension screenSize = Toolkit.getDefaultToolkit().
getScreenSize();
final BufferedImage screen = robot.createScreenCapture(
new Rectangle(screenSize));
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new ScreenCaptureRectangle(screen);
}
});
}
}
2 - get the coordinates and use it on getSubimage method.
double w = captureRect.getWidth();
double h = captureRect.getHeight();
double x = captureRect.getX();
double y = captureRect.getY();
int W = (int) w;
int H = (int) h;
int X = (int) x;
int Y = (int) y;
BufferedImage selectImg = screen.getSubimage(x, y, w, h);
3 - this code create a new image file and copy the imageselected.
BufferedImage img = new BufferedImage ( 5000, 5000, BufferedImage.TYPE_INT_RGB );
img.createGraphics().drawImage(selectImg, 0, 0, null);
File final_image = new File("C:/Final.jpg");
ImageIO.write(img, "jpeg", final_image);
The idea of app is:
- Select an area of the image.
- Copy that image and paste in other file. ( when I pressed any button )
- The program will continue run until I press another button.
- Every image that I copy the program will paste it beside the last one.
I think I am near to the solution. Can any one help me to "connect the parts" ?
Start by taking a look at:
How to Write a Mouse Listener
How to Use Buttons, Check Boxes, and Radio Buttons
How to Write an Action Listeners
Performing Custom Painting
Writing/Saving an Image
You need to take the concepts you have and rework them into a coherent workable solution. That is, provide functionality between the areas you need (selecting a region and saving the file) so that they work cleanly together...
The following example takes a screenshot, allows you to select an area, click save and the file will be saved. The example checks to see how many files are already in the current directory and increments the count by 1 so you are not overwriting the existing files...
import java.awt.AWTException;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileFilter;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class ScreenImage {
public static void main(String[] args) {
new ScreenImage();
}
public ScreenImage() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
try {
Robot robot = new Robot();
final Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
final BufferedImage screen = robot.createScreenCapture(new Rectangle(screenSize));
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane(screen));
frame.setSize(400, 400);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
} catch (AWTException exp) {
exp.printStackTrace();
}
}
});
}
public class TestPane extends JPanel {
private BufferedImage master;
public TestPane(BufferedImage image) {
this.master = image;
setLayout(new BorderLayout());
final ImagePane imagePane = new ImagePane(image);
add(new JScrollPane(imagePane));
JButton btnSave = new JButton("Save");
add(btnSave, BorderLayout.SOUTH);
btnSave.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
try {
BufferedImage img = imagePane.getSubImage();
master = append(master, img);
File save = new File("Capture.png");
ImageIO.write(master, "png", save);
imagePane.clearSelection();
JOptionPane.showMessageDialog(TestPane.this, save.getName() + " was saved", "Saved", JOptionPane.INFORMATION_MESSAGE);
} catch (IOException ex) {
ex.printStackTrace();
JOptionPane.showMessageDialog(TestPane.this, "Failed to save capture", "Error", JOptionPane.ERROR_MESSAGE);
}
}
public BufferedImage append(BufferedImage master, BufferedImage sub) {
// Create a new image which can hold both background and the
// new image...
BufferedImage newImage = new BufferedImage(
master.getWidth() + sub.getWidth(),
Math.max(master.getHeight(), sub.getHeight()),
BufferedImage.TYPE_INT_ARGB);
// Get new image's Graphics context
Graphics2D g2d = newImage.createGraphics();
// Draw the old background
g2d.drawImage(master, 0, 0, null);
// Position and paint the new sub image...
int y = (newImage.getHeight() - sub.getHeight()) / 2;
g2d.drawImage(sub, master.getWidth(), y, null);
g2d.dispose();
return newImage;
}
});
}
}
public class ImagePane extends JPanel {
private BufferedImage background;
private Rectangle selection;
public ImagePane(BufferedImage img) {
background = img;
MouseAdapter ma = new MouseAdapter() {
private Point clickPoint;
#Override
public void mousePressed(MouseEvent e) {
clickPoint = e.getPoint();
}
#Override
public void mouseDragged(MouseEvent e) {
Point dragPoint = e.getPoint();
int x = Math.min(clickPoint.x, dragPoint.x);
int y = Math.min(clickPoint.y, dragPoint.y);
int width = Math.abs(clickPoint.x - dragPoint.x);
int height = Math.abs(clickPoint.y - dragPoint.y);
selection = new Rectangle(x, y, width, height);
repaint();
}
};
addMouseListener(ma);
addMouseMotionListener(ma);
}
public void clearSelection() {
selection = null;
repaint();
}
public BufferedImage getSubImage() {
BufferedImage img = null;
if (selection != null) {
img = background.getSubimage(selection.x, selection.y, selection.width, selection.height);
}
return img;
}
#Override
public Dimension getPreferredSize() {
return new Dimension(background.getWidth(), background.getHeight());
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
int x = (getWidth() - background.getWidth()) / 2;
int y = (getHeight() - background.getHeight()) / 2;
g2d.drawImage(background, x, y, this);
if (selection != null) {
Color stroke = UIManager.getColor("List.selectionBackground");
Color fill = new Color(stroke.getRed(), stroke.getGreen(), stroke.getBlue(), 128);
g2d.setColor(fill);
g2d.fill(selection);
g2d.setColor(stroke);
g2d.draw(selection);
}
g2d.dispose();
}
}
}
So apart from rendering the selection the hardest part would be generating the resulting image...
Basically, this done by creating a new BufferedImage and painting the old image and the new, sub, image together.
public BufferedImage append(BufferedImage master, BufferedImage sub) {
// Create a new image which can hold both background and the
// new image...
BufferedImage newImage = new BufferedImage(
master.getWidth() + sub.getWidth(),
Math.max(master.getHeight(), sub.getHeight()),
BufferedImage.TYPE_INT_ARGB);
// Get new image's Graphics context
Graphics2D g2d = newImage.createGraphics();
// Draw the old background
g2d.drawImage(master, 0, 0, null);
// Position and paint the new sub image...
int y = (newImage.getHeight() - sub.getHeight()) / 2;
g2d.drawImage(sub, master.getWidth(), y, null);
g2d.dispose();
return newImage;
}
The example replaces the previous (master) image with the one created here, so it will constantly be appending new images to the end of it...
You need more listeners for button pressed and released.. some lines in the mouseMoved also better placed in mousePressed.
You would want to update your captureRect when you release the mouse (in mouseReleased method).
Then you just write it to the file. You may adjust other things according to your needs.
And for clarity maybe it's better to add a save button into your UI.
public class ScreenCaptureRectangle {
Rectangle captureRect;
Point start = new Point();
SimpleDateFormat sdf;
ScreenCaptureRectangle(final BufferedImage screen) {
sdf = new SimpleDateFormat("yyyy-MM-dd HH-mm-ss");
final BufferedImage screenCopy = new BufferedImage(
screen.getWidth(),
screen.getHeight(),
screen.getType());
final JLabel screenLabel = new JLabel(new ImageIcon(screenCopy));
JScrollPane screenScroll = new JScrollPane(screenLabel);
screenScroll.setPreferredSize(new Dimension(
(int) (screen.getWidth() / 3),
(int) (screen.getHeight() / 3)));
JPanel panel = new JPanel(new BorderLayout());
panel.add(screenScroll, BorderLayout.CENTER);
JButton btnSave = new JButton("SAVE");
btnSave.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent ae) {
double w = captureRect.getWidth();
double h = captureRect.getHeight();
double x = captureRect.getX();
double y = captureRect.getY();
int W = (int) w;
int H = (int) h;
int X = (int) x;
int Y = (int) y;
BufferedImage selectImg = screen.getSubimage(X, Y, W, H);
try {
String fName = generateFileName();
if (fName != null) {
File f = new File(fName);
if (f.createNewFile()) {
ImageIO.write(selectImg, "jpg", f);
}
}
} catch (IOException ex) {
Logger.getLogger(ScreenCaptureRectangle.class.getName()).log(Level.SEVERE, null, ex);
}
}
});
panel.add(btnSave, BorderLayout.AFTER_LAST_LINE);
final JLabel selectionLabel = new JLabel(
"Drag a rectangle in the screen shot!");
panel.add(selectionLabel, BorderLayout.SOUTH);
repaint(screen, screenCopy);
screenLabel.repaint();
screenLabel.addMouseMotionListener(new MouseMotionAdapter() {
#Override
public void mouseDragged(MouseEvent me) {
Point end = me.getPoint();
captureRect = new Rectangle(start,
new Dimension(end.x - start.x, end.y - start.y));
repaint(screen, screenCopy);
screenLabel.repaint();
selectionLabel.setText("Rectangle: " + captureRect);
}
});
screenLabel.addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(MouseEvent me) {
start = me.getPoint();
repaint(screen, screenCopy);
selectionLabel.setText("Start Point: " + start);
screenLabel.repaint();
}
#Override
public void mouseReleased(MouseEvent me) {
int endX = me.getX();
int endY = me.getY();
if (endX > start.x && endY > start.y) {
captureRect = new Rectangle(start.x, start.y, endX-start.x, endY-start.y);
System.out.println("Rectangle of interest: " + captureRect);
}
}
});
JOptionPane.showMessageDialog(null, panel);
}
private String generateFileName() {
return new StringBuilder("screencrop_").append(sdf.format(new Date())).append(".jpg").toString();
}
public void repaint(BufferedImage orig, BufferedImage copy) {
Graphics2D g = copy.createGraphics();
g.drawImage(orig, 0, 0, null);
if (captureRect != null) {
g.setColor(Color.RED);
g.draw(captureRect);
g.setColor(new Color(255, 255, 255, 150));
g.fill(captureRect);
}
g.dispose();
}
public static void main(String[] args) throws Exception {
Robot robot = new Robot();
final Dimension screenSize = Toolkit.getDefaultToolkit().
getScreenSize();
final BufferedImage screen = robot.createScreenCapture(
new Rectangle(screenSize));
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new ScreenCaptureRectangle(screen);
}
});
}
}

Drawn image inside panel seems to have wrong x,y offset

So, I have a JFrame with a menu, a toolbar and panel. I load images inside the panel but for some strange reason (to me at least) they are not correctly displayed in the panel. Sometimes they start under the toolbar, sometimes above. Furthermore the image is cut on bottom. The code is a cleaned example from the full one that can be compiled and tested. Thanks in advance.
Class of containing frame:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FileDialog;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.zip.ZipInputStream;
import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JToolBar;
import javax.swing.border.BevelBorder;
import javax.swing.border.Border;
public class SSCE extends JFrame {
private JComicPanel panel;
private JToolBar toolbar;
private JButton buttonZoom;
private JButton buttonPrev;
private JButton buttonNext;
private JMenuBar menuBar;
private Dimension dim;
private BufferedImage img;
private int currentPage;
private JFrame parentFrame;
public SSCE(){
super("JComic");
BorderLayout layout = new BorderLayout();
setLayout(layout);
dim = Toolkit.getDefaultToolkit().getScreenSize();
setSize((int)(dim.width /2.5),dim.height);
this.setPreferredSize(new Dimension((int) (dim.width /2.5),dim.height));
createToolbar();
createPanel();
add(toolbar,BorderLayout.NORTH);
add(panel,BorderLayout.CENTER);
createMenu();
add(menuBar);
setJMenuBar(menuBar);
panel.setVisible(true);
img = null;
pack();
parentFrame = this;
}
private void createPanel(){
Border raisedbevel, loweredbevel;
raisedbevel = BorderFactory.createRaisedBevelBorder();
loweredbevel = BorderFactory.createLoweredBevelBorder();
panel = new JComicPanel(img);
panel.setBorder(BorderFactory.createCompoundBorder(raisedbevel,loweredbevel));
}
private void createToolbar(){
toolbar = new JToolBar();
toolbar.setPreferredSize(new Dimension(dim.width,45));
toolbar.setFloatable(false);
buttonZoom = new JButton("+");
toolbar.add(buttonZoom);
buttonPrev = new JButton("<-");
toolbar.add(buttonPrev);
buttonNext = new JButton("->");
toolbar.add(buttonNext);
toolbar.setBackground(Color.RED);
}
private void createMenu(){
JMenu menuFile,menuJComic;
JMenuItem fileOpen;
JMenuItem quitJComic,aboutJComic;
menuBar = new JMenuBar();
menuJComic = new JMenu("JComic");
aboutJComic = new JMenuItem("About JComic...");
menuJComic.add(aboutJComic);
quitJComic = new JMenuItem("Quit");
quitJComic.addActionListener(
new ActionListener(){
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
}
);
menuJComic.add(quitJComic);
menuBar.add(menuJComic);
menuFile = new JMenu("File");
fileOpen = new JMenuItem("Open...");
fileOpen.addActionListener(
new ActionListener(){
public void actionPerformed(ActionEvent e) {
try {
img = ImageIO.read(new File("superman.jpg"));
currentPage = 1;
int offset = menuBar.getHeight() + toolbar.getHeight();
panel.setImage(img,parentFrame,offset);
}
catch (IOException e1) {
System.out.println(e1.getMessage());
}
}
}
);
menuFile.add(fileOpen);
menuBar.add(menuFile);
}
/**
* #param args
*/
#SuppressWarnings("deprecation")
public static void main(String[] args) {
// TODO Auto-generated method stub
SSCE f = new SSCE();
f.show();
}
}
Class of panel
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.RenderingHints;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class JComicPanel extends JPanel{
private BufferedImage img;
private int offset;
private final float scaling = 0.5f;
public JComicPanel(BufferedImage img){
super();
this.img = img;
addComponentListener(new ComponentAdapter() {
#Override
public void componentResized(ComponentEvent e)
{
repaint();
}
});
}
public void setImage(BufferedImage img,JFrame parentFrame,int offset){
try{
int w = img.getWidth();
int h = img.getHeight();
int newW = (int)(w * scaling);
int newH = (int)(h * scaling);
BufferedImage dimg = new BufferedImage(newW, newH, img.getType());
Graphics2D g = dimg.createGraphics();
g.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g.drawImage(img, 0, 0, newW, newH, 0, 0, w, h, null);
this.img = img;
System.out.printf("dim %d x %d",newW,newH);
this.setSize(new Dimension(newW,newH+offset));
parentFrame.pack();
}
catch(Exception e){
}
}
public Dimension getPreferredSize(){
return new Dimension(img.getWidth(),img.getHeight());
}
public void paintComponent(Graphics g){
// Draw our Image object.
super.paintComponent(g);
g.drawImage(img,0,0,getSize().width,getSize().height, this); // at location 50,10
System.out.println("painting 2");
}
}
Image superman.jpg can be found here http://i50.tinypic.com/2yxnc3n.jpg. As you can see the image is below the toolbar, but in my full code it goes also above.
Let's start here...
public void setImage(BufferedImage img,JFrame parentFrame,int offset){
try{
// You're scaling the incoming image, which means you no longer
// have a reference to the original image should you want to
// change that scale...
// You're previous code...
// Don't do this. The parent container's layout manager will simple
// override it, so it's useless...
this.setSize(newW,newH);
repaint();
// This is a bad idea (personally)...
parentFrame.setSize(newW,newH+offset);
} catch(Exception e){
}
}
Calling setSize in this way will temporarily allow the component to assume the size you have set. If you were to call invalidate() after it, the component would actually be re-sized back to meet the requirements of the layout manager.
The larger problem is the fact that you are setting the parent frame's size, but you have no idea of the frame's layout requirements with regards to it's other components, such as the tool bar, menu bar and frame (for example)
This is drawing the image without consideration to the ratio of the original image
g.drawImage(img,0,0,getSize().width,getSize().height, this);
As it has being suggested, after scaling the image, it might be easier to simply set the image as the icon of a JLabel which has been added to the image pane using a BorderLayout
You're assuming that the size of the panel is correct, but it won't be as the panel's layout manager will take over.
This is redundant as Swing will automatically repaint the component when it's resized.
addComponentListener(new ComponentAdapter() {
#Override
public void componentResized(ComponentEvent e)
{
repaint();
}
});
You're best bet is to either drop the image pane into a scroll pane and or rescale the image to fit the size of the pane dynamically.
For example...
Scalable Page
public class ComicPage {
public static void main(String[] args) {
new ComicPage();
}
public ComicPage() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException ex) {
} catch (InstantiationException ex) {
} catch (IllegalAccessException ex) {
} catch (UnsupportedLookAndFeelException ex) {
}
try {
BufferedImage page = ImageIO.read(getClass().getResource("/1346.gif"));
ComicPagePane comicPagePane = new ComicPagePane();
comicPagePane.setComicPage(page);
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(comicPagePane);
frame.setSize(200, 200);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
} catch (Exception exp) {
exp.printStackTrace();
}
}
});
}
public class ComicPagePane extends JPanel {
private BufferedImage comicPage;
private Image scaledInstance;
public void setComicPage(BufferedImage page) {
if (page != comicPage) {
comicPage = page;
scaledInstance = null;
repaint();
}
}
#Override
public void invalidate() {
scaledInstance = null;
super.invalidate();
}
public BufferedImage getComicPage() {
return comicPage;
}
public double getScaleFactor(int iMasterSize, int iTargetSize) {
return (double) iTargetSize / (double) iMasterSize;
}
public double getScaleFactorToFit(BufferedImage img) {
double dScale = 1d;
double dScaleWidth = getScaleFactor(img.getWidth(), getWidth());
double dScaleHeight = getScaleFactor(img.getHeight(), getHeight());
dScale = Math.min(dScaleHeight, dScaleWidth);
return dScale;
}
protected Image getScaledInstance(BufferedImage master) {
if (scaledInstance == null) {
double scaleFactor = getScaleFactorToFit(master);
System.out.println("scaleFactor = " + NumberFormat.getNumberInstance().format(scaleFactor));
// This is not the best scaling alorithm
scaledInstance = master.getScaledInstance(
(int) Math.round(master.getWidth() * scaleFactor),
(int) Math.round(master.getHeight() * scaleFactor), Image.SCALE_SMOOTH);
}
return scaledInstance;
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
BufferedImage comicPage = getComicPage();
if (comicPage != null) {
Graphics2D g2d = (Graphics2D) g.create();
int width = getWidth();
int height = getHeight();
// Normally, I would put this into a background worker as this
// operation can be expensive....
Image scaledInstance = getScaledInstance(comicPage);
int x = (width - scaledInstance.getWidth(this)) / 2;
int y = (height - scaledInstance.getHeight(this)) / 2;
g2d.drawImage(scaledInstance, x, y, this);
g2d.dispose();
}
}
}
}
Scrollable Page
public class ScrollableComicPage {
public static void main(String[] args) {
new ScrollableComicPage();
}
public ScrollableComicPage() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException ex) {
} catch (InstantiationException ex) {
} catch (IllegalAccessException ex) {
} catch (UnsupportedLookAndFeelException ex) {
}
try {
BufferedImage page = ImageIO.read(getClass().getResource("/1346.gif"));
ComicPagePage comicPagePane = new ComicPagePage();
comicPagePane.setComicPage(page);
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new JScrollPane(comicPagePane));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
} catch (Exception exp) {
exp.printStackTrace();
}
}
});
}
public class ComicPagePage extends JPanel {
private BufferedImage comicPage;
#Override
public Dimension getPreferredSize() {
return comicPage != null ? new Dimension(comicPage.getWidth(), comicPage.getHeight()) : new Dimension(0, 0);
}
public void setComicPage(BufferedImage page) {
if (page != comicPage) {
comicPage = page;
invalidate();
repaint();
}
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (comicPage != null) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.drawImage(comicPage, 0, 0, this);
g2d.dispose();
}
}
}
}
You can have a read through Java: maintaining aspect ratio of JPanel background image for more information on scaling techniques.
The technical reason is that you are temporarily adding the menuBar to the center of the contentPane, that is the same logical location as the previously added panel:
add(panel, BorderLayout.CENTER);
// following line is wrong - must be removed!!!
add(menuBar); // no constraint == BorderLayout.CENTER
setJMenuBar(menuBar);
Doing so pushes the panel out off the control of the LayoutManager, but not out of the panel - the net effect is that it has no constraint.
That's not special to being a menuBar (which needs to be added to the layeredPane of the rootPane, not the contentPane - that's why it has its own specialized method setJMenuBar), the same mess would happen with any other arbitrary component at the center.
Apart from that, I would recommend you cleaning up your code:
remove all setXXSize (some reasons)
decide whether the frame should come up at its preferred (using pack) or an arbitrary fixed size (using setSize). The former is the correct thingy to do in most cases, the latter has its use-cases - but doing both doesn't make sense
components are visible by default

Trying to paint image to JFrame with Java BufferedImage, Graphics

I'm trying to capture the screen and then paint the image to a JFrame recursively while scaling the image (to create that effect you get when you look at a mirror in a mirror).
I'm having trouble with my code - it doesn't paint any graphics. What am I doing wrong?
import java.awt.AWTException;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.HeadlessException;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.image.BufferedImage;
import javax.swing.JFrame;
public class ScreenCapture extends JFrame {
BufferedImage screenCapture;
Graphics screenCaptureGraphics;
private static int recurseCount = 0;
private static float $scale = 0.9f;
private static float scale = 1.0f;
private static int height;
private static int width;
ScreenCapture() {
try {
screenCapture = new Robot().createScreenCapture(
new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()) );
height = screenCapture.getHeight();
width = screenCapture.getWidth();
setSize(new Dimension(width, height));
addWindowListener(new LocalWindowListener());
Graphics g = recursiveDraw(screenCapture, getGraphics());
paint(g);
} catch (HeadlessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (AWTException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
private Graphics recursiveDraw(BufferedImage img, Graphics imgG) {
updateScale(++recurseCount);
float newWidth = scale*width;
float newHeight = scale*height;
int w = (int) newWidth;
int h = (int) newHeight;
System.out.println("W: " + w + "; H: " + h);
if (w >= 10 && h >= 10) {
//scale image
System.out.print("Creating scaled Image...");
Image scaled = img.getScaledInstance(w, h, Image.SCALE_SMOOTH);
BufferedImage resized = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
imgG = resized.createGraphics();
imgG.drawImage(scaled, 0, 0, null);
System.out.println("...Image drawn to graphics");
//return new graphics
return recursiveDraw(resized, imgG);
} else {
//otherwise return old graphics
System.out.println("Completed.");
return imgG;
}
}
private void updateScale(int count) {
for (int i=0; i<count; i++) {
scale *= $scale;
}
System.out.println("Updated scale: " + scale + "; Recurse count: " + recurseCount);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
new ScreenCapture().setVisible(true);
}
});
}
private class LocalWindowListener extends WindowAdapter {
#Override
public void windowClosing(WindowEvent e) {
System.exit(0); return;
}
}
}
EDIT:
This is what I tried after #andrew-thompson 's answer:
ScreenCapture() {
try {
screenCapture = new Robot().createScreenCapture(
new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()) );
height = screenCapture.getHeight();
width = screenCapture.getWidth();
setSize(new Dimension(width, height));
addWindowListener(new LocalWindowListener());
setLayout(new GridLayout());
add(new PaintPanel());
} catch (HeadlessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (AWTException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
private class PaintPanel extends JPanel {
#Override
public void paintComponent(Graphics g) {
g=recursiveDraw(screenCapture, g);
//what to do with g?
}
}
I still have the same problem where I don't know how to make the BufferedImage paint to the graphics.
would separate out your Swing code from your recursive image creation code. In fact consider creating a static method that creates and returns the BufferedImage and that has no Swing code in it. Then have your GUI call the method when it wishes, and take the image and either write it to disk or display it in a JLabel's ImageIcon.
When I did this (today in fact), I created a recursive method with this signature
private static void recursiveDraw(BufferedImage img, Graphics imgG, double scale) {
and with this method body (in pseudo-code)
start recursiveDraw method
// most important: all recursions must have a good ending condition:
get img height and width. If either <= a min, return
create a BufferedImage, smlImg, for the smaller image using the height,
width and scale factor
Get the Graphics object, smlG, from the small image
Use smlG.drawImage(...) overload to draw the big image in shrunken
form onto the little image
recursively call recursiveDraw passing in smlImg, smlG, and scale.
dispose of smlG
draw smlImg (the small image) onto the bigger one using the bigger's
Graphics object (passed into this method) and a different
overload of the drawImage method.
end recursiveDraw method
This algorithm resulted in images like:
For example:
import java.awt.*;
import java.awt.Dialog.ModalityType;
import java.awt.event.ActionEvent;
import java.awt.image.BufferedImage;
import javax.swing.*;
public class RecursiveDrawTest {
private static final Color BACKGRND_1 = Color.green;
private static final Color BACKGRND_2 = Color.MAGENTA;
private static final Color FOREGRND_1 = Color.blue;
private static final Color FOREGRND_2 = Color.RED;
private static void createAndShowGui() {
final JPanel mainPanel = new JPanel(new BorderLayout());
final JSlider slider = new JSlider(50, 90, 65);
slider.setMajorTickSpacing(10);
slider.setMinorTickSpacing(5);
slider.setPaintLabels(true);
slider.setPaintTicks(true);
JPanel southPanel = new JPanel();
southPanel.add(new JLabel("Percent Size Reduction:"));
southPanel.add(slider);
southPanel.add(new JButton(new AbstractAction("Create Recursive Image") {
#Override
public void actionPerformed(ActionEvent arg0) {
try {
double scale = slider.getValue() / 100.0;
BufferedImage img = createRecursiveImg(scale);
ImageIcon icon = new ImageIcon(img);
JLabel label = new JLabel(icon);
Window win = SwingUtilities.getWindowAncestor(mainPanel);
JDialog dialog = new JDialog(win, "Image", ModalityType.MODELESS);
dialog.getContentPane().add(label);
dialog.pack();
dialog.setLocationRelativeTo(null);
dialog.setVisible(true);
} catch (AWTException e) {
e.printStackTrace();
}
}
}));
mainPanel.add(new JScrollPane(new JLabel(new ImageIcon(createLabelImg()))),
BorderLayout.CENTER);
mainPanel.add(southPanel, BorderLayout.PAGE_END);
JFrame frame = new JFrame("RecursiveDrawTest");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
// create a background image to display in a JLabel so that the GUI
// won't be boring.
private static BufferedImage createLabelImg() {
Dimension d = Toolkit.getDefaultToolkit().getScreenSize();
int width = (5 * d.width) / 6;
int height = (5 * d.height) / 6;
BufferedImage img = new BufferedImage(width, height,
BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = img.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setPaint(new GradientPaint(0, 0, BACKGRND_1, 40, 40, BACKGRND_2, true));
g2.fillRect(0, 0, width, height);
g2.setPaint(new GradientPaint(0, height, FOREGRND_1, 40, height - 40, FOREGRND_2, true));
g2.fillOval(0, 0, 2 * width, 2 * height);
g2.dispose();
return img;
}
// non-recursive image to get the initial image that will be drawn recursively
public static BufferedImage createRecursiveImg(double scale) throws AWTException {
Robot robot = new Robot();
Dimension screenSz = Toolkit.getDefaultToolkit().getScreenSize();
Rectangle screenRect = new Rectangle(screenSz);
BufferedImage img = robot.createScreenCapture(screenRect);
Graphics g = img.getGraphics();
recursiveDraw(img, g, scale); // call recursive method
g.dispose();
return img;
}
// recursive method to draw image inside of image
private static void recursiveDraw(BufferedImage img, Graphics g, double scale) {
int w = img.getWidth();
int h = img.getHeight();
int smlW = (int)(w * scale);
int smlH = (int)(h * scale);
// criteria to end recursion
if (smlW <= 1 || smlH <= 1) {
return;
}
BufferedImage smlImg = new BufferedImage(smlW, smlH, BufferedImage.TYPE_INT_ARGB);
Graphics smlG = smlImg.getGraphics();
// draw big image in little image, scaled to little image
smlG.drawImage(img, 0, 0, smlW, smlH, null);
// recursive call
recursiveDraw(smlImg, smlG, scale);
smlG.dispose(); // clear resources when done with them
// these guys center the smaller img on the bigger
int smlX = (w - smlW) / 2;
int smlY = (h - smlH) / 2;
// draw small img on big img
g.drawImage(smlImg, smlX, smlY, smlW, smlH, null);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Graphics g = recursiveDraw(screenCapture, getGraphics());
Don't call getGraphics(). Override paint(Graphics)1 & use the supplied Graphics instance.
When using Swing, it is actually best to override the paintComponent(Graphics) method of a JComponent or JPanel. Then add that to the top-level container.
Is this what you are hoping for :
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;
import javax.swing.*;
public class CaptureScreen extends JPanel
{
private BufferedImage screenShot;
private JLabel imageLabel;
private BufferedImage secondScreenShot;
public void createAndDisplayGUI()
{
JFrame frame = new JFrame("CAPTURE SCREEN");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationByPlatform(true);
//imageLabel = new JLabel();
//getImageForLabel();
//add(imageLabel);
frame.getContentPane().add(this);
frame.setSize(600, 600);
frame.setVisible(true);
}
private void getImageForLabel()
{
Robot robot = null;
try
{
robot = new Robot();
}
catch(Exception e)
{
e.printStackTrace();
}
screenShot = robot.createScreenCapture(new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()));
ImageIcon icon = new ImageIcon(screenShot);
imageLabel.setIcon(icon);
}
public void paintComponent(Graphics g)
{
Robot robot = null;
try
{
robot = new Robot();
}
catch(Exception e)
{
e.printStackTrace();
}
screenShot = robot.createScreenCapture(new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()));
secondScreenShot = getScaledImage((Image) screenShot, 300, 300);
g.drawImage(screenShot, 0, 0, null);
g.drawImage(secondScreenShot, 150, 150, null);
}
private BufferedImage getScaledImage(Image srcImg, int w, int h)
{
BufferedImage resizedImg = new BufferedImage(w, h, BufferedImage.TRANSLUCENT);
Graphics2D g2 = resizedImg.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION, RenderingHints.VALUE_INTERPOLATION_BILINEAR);
g2.drawImage(srcImg, 0, 0, w, h, null);
g2.dispose();
return resizedImg;
}
public static void main(String... args)
{
SwingUtilities.invokeLater(new Runnable()
{
public void run()
{
new CaptureScreen().createAndDisplayGUI();
}
});
}
}
Here is the output :
Get rid of the recursion. Create a single buffered image of the correct size and create a Graphics object for it. Just use a loop to draw progressively smaller scaled images down to whatever threshold you choose. Finally use g.drawImage() inside paintComponent() to draw your image to the screen. If you keep the recursion you need to pass the image and continually overlay the scaled down image. You do not need to return anything from the method.

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