Develop Reference

How to make ball drawn with Java bounce off the edges of the panel?

I have java code that draws a red ball inside a class that extends the JPanel class, I have a timer that is enabled by a button that updates the position of the ball with timer ctor variable elapse. I am trying to get the difference of the height of the panel and the YPOSITION where the circle is drawn if its less than 0 the the bounce ball needs to keep moving down else it should move up, my ball hits the wall and keeps hitting it. Help me debug the code that is causing that to happen.
RightPanel class
import javax.swing.*;
import java.awt.*;
public class RightPanel extends JPanel {
//define the position where the circle will be drawn
private int positionX=150;
private int positionY=150;
private int radius=100;//as the shape is a circle
//override the paint method to draw the bounce ball on the second panel
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d= (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setColor(Color.RED);
g2d.fillOval(positionX,positionY,radius,radius);
}
//let's us update the position of the ball from another class
public int getPositionY(){
public void setPositionX(int positionX) {
this.positionX = positionX;
}
public void setPositionY(int positionY){
this.positionY=positionY;
}
public int getPositionX(){
return this.positionX;
}
return this.positionY;
}
}
The logic in the timer class below is the one I need help with
GameInterface class
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
public class GameInterface extends JFrame {
//declare a Timer object to start the movement
Graphics ctx;
RightPanel rightpanel;
private int height;
//declare a timer to start moving the ball
Timer mytimer= new Timer(50, new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
//check this and keep moving the ball down
if(rightpanel.getPositionY()- rightpanel.getHeight()<0){
rightpanel.setPositionY(rightpanel.getPositionY()+5);
rightpanel.paint(rightpanel.getGraphics());
}else{
//move the ball up
rightpanel.setPositionY(rightpanel.getPositionY()-5);
rightpanel.paint(rightpanel.getGraphics());
}
}
});
public GameInterface(){
setSize(new Dimension(800, 600));
height=this.getHeight();
setResizable(false);
setTitle("Bounce Game");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBackground(Color.black);
//define a new JSplitPane and use it to add two JPanels
JPanel leftpanel= new JPanel();
//add buttons to the left panel programatically
JButton up= new JButton("Move up");
//set the event listeners for the buttons
up.addActionListener(new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
//start he timer
mytimer.start();
}
});
JButton down = new JButton("Move down");
down.addActionListener(new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
//move my ball down
rightpanel.setPositionX(rightpanel.getPositionX());
rightpanel.setPositionY(rightpanel.getPositionY()+5);
rightpanel.paint(rightpanel.getGraphics());
}
});
leftpanel.add(up);
leftpanel.add(down);
rightpanel= new RightPanel();
JSplitPane splitpane= new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,leftpanel,rightpanel);
this.add(splitpane);
setVisible(true);
ctx=this.getGraphics();
}
}

The basic idea is, when you "drop" the ball, you need to determine the direction of movement that the ball should move in. When the timer ticks, it will apply that direction of movement until it either reaches the bottom, at which time the delta is reversed, or it reaches the top.
The important part here is, all the state the timer needs should be determined before the timer is started and not calculated within the timer itself, as the state it needs is no longer relevant.
For example...
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.GridBagLayout;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Ellipse2D;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
public class Main {
public static void main(String[] args) {
new Main();
}
public Main() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
Ball ball = new Ball(20);
JFrame frame = new JFrame();
frame.add(new MainPane(ball));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class Ball {
private Point location;
private Dimension size;
private Shape shape;
public Ball(int radius) {
location = new Point(0, 0);
size = new Dimension(radius * 2, radius * 2);
shape = new Ellipse2D.Double(0, 0, radius * 2, radius * 2);
}
public Rectangle getBounds() {
return new Rectangle(location, size);
}
public void setLocation(Point p) {
location = new Point(p);
}
public void paint(Graphics2D g2d) {
g2d = (Graphics2D) g2d.create();
g2d.setColor(Color.RED);
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2d.translate(location.x, location.y);
g2d.fill(shape);
g2d.dispose();
}
}
public class SurfacePane extends JPanel {
private Ball ball;
private Timer timer;
private int yDelta;
public SurfacePane(Ball ball) {
this.ball = ball;
this.ball.setLocation(new Point(200 - (ball.getBounds().width / 2), 0));
}
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
ball.paint(g2d);
g2d.dispose();
}
public void moveBallDown() {
Rectangle bounds = ball.getBounds();
Dimension size = ball.size;
Point location = bounds.getLocation();
location.y += size.height;
if (location.y + size.height > getHeight()) {
location.y = getHeight() - size.height;
}
ball.setLocation(location);
repaint();
}
public void dropBall() {
if (timer != null) {
return;
}
Rectangle bounds = ball.getBounds();
Dimension size = ball.size;
Point location = bounds.getLocation();
if (location.y + size.height > getHeight()) {
yDelta = -1;
} else {
yDelta = 1;
}
timer = new Timer(5, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
Rectangle bounds = ball.getBounds();
Dimension size = ball.size;
Point location = bounds.getLocation();
location.y += yDelta;
if (location.y < 0) {
location.y = 0;
yDelta = 0;
timer.stop();
timer = null;
} else if (location.y + size.height > getHeight()) {
location.y = getHeight() - size.height;
yDelta *= -1;
}
ball.setLocation(location);
repaint();
}
});
timer.start();
}
}
public class MainPane extends JPanel {
private Ball ball;
private SurfacePane surfacePane;
public MainPane(Ball ball) {
setLayout(new BorderLayout());
this.ball = ball;
surfacePane = new SurfacePane(ball);
add(surfacePane);
JPanel actionPane = new JPanel(new GridBagLayout());
JButton up = new JButton("Up");
JButton down = new JButton("Down");
actionPane.add(up);
actionPane.add(down);
add(actionPane, BorderLayout.SOUTH);
up.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
surfacePane.dropBall();
}
});
down.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
surfacePane.moveBallDown();
}
});
}
}
}

Swing: How to reduce the response time of MouseInputAdapter?

I've made a tool which could allow user to draw on screenshot.Here is my code:
package GUI.Views;
import javax.swing.*;
import javax.swing.event.MouseInputAdapter;
import java.awt.*;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
public class Canvas extends JPanel {
public static int radius = 5;
public class DrawPointListener extends MouseInputAdapter{
private void draw(Point p, int radius){
Graphics2D g2 = (Graphics2D)getGraphics();
int x = (int)p.getX() - radius/2;
int y = (int)p.getY() - radius/2;
g2.fillOval(x, y, radius, radius);
}
#Override
public void mousePressed(MouseEvent e) {
draw(e.getPoint(), radius);
}
#Override
public void mouseDragged(MouseEvent e) {
draw(e.getPoint(), radius);
}
}
private BufferedImage screenShot;
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.drawImage(this.screenShot, 0, 0, null);
}
public Canvas() {
this.setVisible(true);
this.screenShot = getScreenShot();
this.setCursor(new Cursor(Cursor.CROSSHAIR_CURSOR));
DrawPointListener drawListener = new DrawPointListener();
this.addMouseListener(drawListener);
this.addMouseMotionListener(drawListener);
}
private BufferedImage getScreenShot() {
try {
return new Robot().createScreenCapture(new Rectangle(Toolkit.getDefaultToolkit().getScreenSize()));
} catch (AWTException e) {
System.out.println("Error");
return null;
}
}
public static void main(String[] args) {
JFrame f = new JFrame();
Canvas canvas = new Canvas();
f.setUndecorated(true);
f.add(canvas);
f.setExtendedState(JFrame.MAXIMIZED_BOTH);
f.setVisible(true);
}
}
Code worked fine when you try to "draw" on the screen slowly, but when you move your mouse quickly, you would see those points are not consecutive, like this:
I think that because there is a time interval of Listener.How could I improve it?

You can't change the time interval of the listener. You are NOT guaranteed to generate an event for every pixel.
So instead of drawing a single point, you need to draw a line between the current and previous point.
Something like:
import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import javax.swing.JFrame;
import javax.swing.JPanel;
class DrawingPanel extends JPanel
{
private ArrayList<ArrayList<Point>> previous = new ArrayList<ArrayList<Point>>();
private ArrayList<Point> current = new ArrayList<Point>();
private BasicStroke basicStroke;
public DrawingPanel(int strokeSize)
{
basicStroke = new BasicStroke(strokeSize, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND);
MouseAdapter ma = new MouseAdapter()
{
#Override
public void mousePressed(MouseEvent e)
{
current.add( new Point(e.getX(), e.getY()) );
}
#Override
public void mouseDragged(MouseEvent e)
{
current.add( new Point(e.getX(), e.getY()) );
repaint();
}
#Override
public void mouseReleased(MouseEvent e)
{
if (current.size() > 1)
{
previous.add( current );
}
current = new ArrayList<Point>();
}
};
addMouseMotionListener( ma );
addMouseListener( ma );
}
#Override
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setStroke( basicStroke );
// Paint lines from previous drags
for (int i = 0; i < previous.size(); i++)
{
drawLines(g, previous.get(i));
}
// Paint line from current drag
drawLines(g, current);
}
private void drawLines(Graphics g, ArrayList<Point> points)
{
for (int i = 0; i < points.size() - 1; i++)
{
int x = (int) points.get(i).getX();
int y = (int) points.get(i).getY();
int x2 = (int) points.get(i + 1).getX();
int y2 = (int) points.get(i + 1).getY();
g.drawLine(x, y, x2, y2);
}
}
private static void createAndShowGUI()
{
JFrame frame = new JFrame("Drawing Panel");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new DrawingPanel(15));
frame.setSize(400, 400);
frame.setLocationByPlatform( true );
frame.setVisible( true );
}
public static void main(String[] args) throws Exception
{
EventQueue.invokeLater( () -> createAndShowGUI() );
/*
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowGUI();
}
});
*/
}
}

Trying to draw on a canvas with sliders

I am attempting to use jsliders to allow a user to pinpoint the origin of a circle to be drawn on a canvas. I am using a button to show and hide the circle. I am using paint on an inner jpanel so that paint will not write over components. However, the coordinates inside the jpanel are different than the coordinates for the entire frame. So, it is very difficult for me to get the coordinates of the jslider and then translate it to the jpanel to draw the circle. Is there an easy way to figure this out without a ton of guess and check? I am also using the custom layout miglayout. I have included the code for my GUI class as well as my custom JPanel I made so I could mess with the paint method.
public class CircleGUI extends JFrame implements ActionListener {
private MigLayout layout = new MigLayout();
private CustomPanel innerpanel;
private JSlider x,y;
private JColorChooser colorpick;
private JButton state;
private boolean bstate;
CircleGUI() {
initialize();
}
private void initialize() {
Border blackline = BorderFactory.createLineBorder(Color.black);
bstate = false;
x = new JSlider(JSlider.HORIZONTAL,650,325);
x.setPaintTicks(true);
x.setPaintLabels(true);
x.setPreferredSize(new Dimension(650,0));
y = new JSlider(JSlider.HORIZONTAL,650,325);
y.setPaintTicks(true);
y.setPaintLabels(true);
y.setInverted(true);
y.setOrientation(JSlider.VERTICAL);
y.setPreferredSize(new Dimension (0,600));
colorpick = new JColorChooser();
state = new JButton("Show");
state.addActionListener(e -> {
if(!bstate) {
int positionx = x.getValue() - 80;
int positiony = y.getValue();
Color c = colorpick.getColor();
innerpanel.setColor(c);
innerpanel.setX(positionx);
innerpanel.setY(positiony);
innerpanel.repaint();
state.setText("Hide");
bstate = true;
} else {
Color transparent = new Color(0,0,0,0);
innerpanel.setColor(transparent);
innerpanel.repaint();
state.setText("Show");
bstate = false;
}
});
JPanel outerpanel = new JPanel(layout);
innerpanel = new CustomPanel();
innerpanel.setPreferredSize(new Dimension(600,600));
innerpanel.setBorder(blackline);
outerpanel.add(x,"wrap");
outerpanel.add(y,"split 2");
outerpanel.add(innerpanel);
outerpanel.add(state,"wrap");
outerpanel.add(colorpick);
this.setSize(1000, 1000);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.add(outerpanel);
}
#Override
public void actionPerformed(ActionEvent e) {
}
}
public class CustomPanel extends JPanel implements ActionListener {
private Color c;
private int x;
private int y;
public CustomPanel() {
c = null;
}
#Override
public void actionPerformed (ActionEvent e) {
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setPaint(c);
g2.fill(new Ellipse2D.Double(x, y, 100, 100));
}
public void setColor(Color c) {
this.c = c;
}
public void setX(int x) {
this.x = x;
}
public void setY(int y) {
this.y = y;
}
}

Your problem is you are trying to make a one-to-one mapping between the value of the JSlider and the coordinate in your CustomPanel. You should use the JSlider value as a percentage, i.e. minimum value zero and maximum value 100. If you want the circle to appear in the middle of the CustomPanel so you place both JSliders in their mid-points, i.e. both at 50%. Then you calculate 50% of the corresponding dimension to get the coordinate. If the width of CustomPanel is 600, then 50% of 600 is 300 so positionx needs to be 300.
The only thing I changed in your code is the calculation of positionx and positiony.
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Ellipse2D;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JColorChooser;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.border.Border;
import net.miginfocom.swing.MigLayout;
public class CircleGUI extends JFrame implements ActionListener {
private MigLayout layout = new MigLayout();
private CustomPanel innerpanel;
private JSlider x,y;
private JColorChooser colorpick;
private JButton state;
private boolean bstate;
CircleGUI() {
initialize();
}
private void initialize() {
Border blackline = BorderFactory.createLineBorder(Color.black);
bstate = false;
// x = new JSlider(JSlider.HORIZONTAL, 650, 325);
x = new JSlider(0, 100, 10);
x.setPaintTicks(true);
x.setPaintLabels(true);
x.setPreferredSize(new Dimension(650, 0));
// y = new JSlider(JSlider.HORIZONTAL, 650, 325);
y = new JSlider(0, 100, 10);
y.setPaintTicks(true);
y.setPaintLabels(true);
y.setInverted(true);
y.setOrientation(JSlider.VERTICAL);
y.setPreferredSize(new Dimension(0, 600));
colorpick = new JColorChooser();
state = new JButton("Show");
state.addActionListener(e -> {
if (!bstate) {
int positionx = Math.round(x.getValue() / 100.0f * innerpanel.getSize().width) - 50;
int positiony = Math.round(y.getValue() / 100.0f * innerpanel.getSize().height) - 50;
Color c = colorpick.getColor();
innerpanel.setColor(c);
innerpanel.setX(positionx);
innerpanel.setY(positiony);
innerpanel.repaint();
state.setText("Hide");
bstate = true;
}
else {
Color transparent = new Color(0, 0, 0, 0);
innerpanel.setColor(transparent);
innerpanel.repaint();
state.setText("Show");
bstate = false;
}
});
JPanel outerpanel = new JPanel(layout);
innerpanel = new CustomPanel();
innerpanel.setPreferredSize(new Dimension(600, 600));
innerpanel.setBorder(blackline);
outerpanel.add(x, "wrap");
outerpanel.add(y, "split 2");
outerpanel.add(innerpanel);
outerpanel.add(state, "wrap");
outerpanel.add(colorpick);
this.setSize(1000, 1000);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.add(outerpanel);
}
#Override
public void actionPerformed(ActionEvent e) {
}
public static void main(String[] args) {
EventQueue.invokeLater(() -> {
CircleGUI cg = new CircleGUI();
cg.setVisible(true);
});
}
}
class CustomPanel extends JPanel implements ActionListener {
private Color c;
private int x;
private int y;
public CustomPanel() {
c = null;
}
#Override
public void actionPerformed(ActionEvent e) {
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setPaint(c);
g2.fill(new Ellipse2D.Double(x, y, 100, 100));
}
public void setColor(Color c) {
this.c = c;
}
public void setX(int x) {
this.x = x;
}
public void setY(int y) {
this.y = y;
}
}

Draw shapes on scrollable JPanel

I'm trying to draw rectangles on fairly large images in order to get the pixel coordinates of objects within the image. I am able to display the image and make it scrollable, or display the image and be able to draw rectangles on top of it....but not both.
It's obvious that I'm drawing the image on top of the canvas that I'm trying to draw the rectangles on, but I can't for the life of me figure out how to make it all coexist.
import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.logging.Level;
import java.util.logging.Logger;
public class DrawRect extends JPanel {
int x, y, x2, y2;
private static final long serialVersionUID = 1L;
private BufferedImage image;
private JPanel canvas;
public static void main(String[] args) {
JPanel p = new DrawRect();
JFrame f = new JFrame();
f.setContentPane(p);
f.setSize(400, 300);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
}
DrawRect() {
x = y = x2 = y2 = 0; //
MyMouseListener listener = new MyMouseListener();
addMouseListener(listener);
addMouseMotionListener(listener);
try {
this.image = ImageIO.read(new URL("https://previews.123rf.com/images/victoroancea/victoroancea1201/victoroancea120100059/12055848-tv-color-test-pattern-test-card-for-pal-and-ntsc.jpg"));
}catch(IOException ex) {
Logger.getLogger(DrawRect.class.getName()).log(Level.SEVERE, null, ex);
}
this.canvas = new JPanel() {
private static final long serialVersionUID = 1L;
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(image, 0, 0, null);
}
};
canvas.setPreferredSize(new Dimension(image.getWidth(), image.getHeight()));
JScrollPane sp = new JScrollPane(canvas);
setLayout(new BorderLayout());
add(sp, BorderLayout.CENTER);
}
public void setStartPoint(int x, int y) {
this.x = x;
this.y = y;
}
public void setEndPoint(int x, int y) {
x2 = (x);
y2 = (y);
}
public void drawRect(Graphics g, int x, int y, int x2, int y2) {
int px = Math.min(x,x2);
int py = Math.min(y,y2);
int pw=Math.abs(x-x2);
int ph=Math.abs(y-y2);
g.drawRect(px, py, pw, ph);
}
class MyMouseListener extends MouseAdapter {
public void mousePressed(MouseEvent e) {
setStartPoint(e.getX(), e.getY());
}
public void mouseDragged(MouseEvent e) {
setEndPoint(e.getX(), e.getY());
repaint();
}
public void mouseReleased(MouseEvent e) {
setEndPoint(e.getX(), e.getY());
repaint();
}
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.RED);
drawRect(g, x, y, x2, y2);
}
}

Your image-drawing JPanel must be the same JPanel that draws the rectangle and that has the MouseAdapter added to it. For instance:
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.Image;
import java.io.IOException;
import java.net.URL;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
#SuppressWarnings("serial")
public class DrawRect2 extends JPanel {
public static final String IMG_PATH = "https://previews.123rf.com/images/victoroancea"
+ "/victoroancea1201/victoroancea120100059"
+ "/12055848-tv-color-test-pattern-test-card-for-pal-and-ntsc.jpg";
private static final int PREF_W = 600;
private static final int PREF_H = PREF_W;
private DrawingPanel drawingPanel;
public DrawRect2(Image img) {
drawingPanel = new DrawingPanel(img);
JScrollPane scrollPane = new JScrollPane(drawingPanel);
MyMouse myMouse = new MyMouse();
drawingPanel.addMouseListener(myMouse);
drawingPanel.addMouseMotionListener(myMouse);
setLayout(new BorderLayout());
add(scrollPane);
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
private static void createAndShowGui() {
Image img = null;
try {
URL url = new URL(IMG_PATH);
img = ImageIO.read(url);
} catch (IOException e) {
e.printStackTrace();
System.exit(-1);
}
DrawRect2 mainPanel = new DrawRect2(img);
JFrame frame = new JFrame("DrawRect2");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Rectangle;
import javax.swing.JPanel;
#SuppressWarnings("serial")
public class DrawingPanel extends JPanel {
private Image img;
private Rectangle rectangle;
public DrawingPanel(Image img) {
this.img = img;
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (img != null) {
g.drawImage(img, 0, 0, this);
}
if (rectangle != null) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setXORMode(Color.WHITE);
g2.draw(rectangle);
g2.dispose(); // since we created this object
}
}
#Override
public Dimension getPreferredSize() {
Dimension superSize = super.getPreferredSize();
if (img == null) {
return super.getPreferredSize();
} else {
int w = img.getWidth(this);
int h = img.getHeight(this);
return new Dimension(w, h);
}
}
public void setRectangle(Rectangle rectangle) {
this.rectangle = rectangle;
}
}
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
public class MyMouse extends MouseAdapter {
private Point p1;
#Override
public void mousePressed(MouseEvent e) {
p1 = e.getPoint();
}
#Override
public void mouseDragged(MouseEvent e) {
if (p1 != null) {
createRect(e);
}
}
private void createRect(MouseEvent e) {
Point p2 = e.getPoint();
int x = Math.min(p1.x, p2.x);
int y = Math.min(p1.y, p2.y);
int width = Math.abs(p1.x - p2.x);
int height = Math.abs(p1.y - p2.y);
Rectangle r = new Rectangle(x, y, width, height);
((DrawingPanel) e.getSource()).setRectangle(r);
((DrawingPanel) e.getSource()).repaint();
}
#Override
public void mouseReleased(MouseEvent e) {
if (p1 != null) {
createRect(e);
}
p1 = null;
}
}
So in this paintComponent method, I draw both the image and the Rectangle, using Graphics2D XOR mode to help show the lines regardless of the background color:
#SuppressWarnings("serial")
public class DrawingPanel extends JPanel {
private Image img;
private Rectangle rectangle;
public DrawingPanel(Image img) {
this.img = img;
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (img != null) {
g.drawImage(img, 0, 0, this);
}
if (rectangle != null) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setXORMode(Color.WHITE);
g2.draw(rectangle);
g2.dispose(); // since we created this object
}
}
I also have this method:
public void setRectangle(Rectangle rectangle) {
this.rectangle = rectangle;
}
To allow the MouseListener/Adapter to pass in the Rectangle into this JPanel.
Rectangle r = new Rectangle(x, y, width, height);
((DrawingPanel) e.getSource()).setRectangle(r);
((DrawingPanel) e.getSource()).repaint();

Call JDialog from JDialog

I'm trying to build an application, in which allows calling JDialog from JDialog. I've tried it, but at the time of the call dialog B of A, B dialog appears and then immediately disappears. Is there a solution to these problems?
My code :
I have a class A which extends javax.swing.JDialog. Then there is a label that has the action to call dialog from class PadAndZoom as below:
private void lblSuratRekomendasiMouseClicked(java.awt.event.MouseEvent evt) {
try {
PadAndZoom app = new PadAndZoom();
BufferedImage img = ImageIO.read(PadAndZoom.class.getResource("/tampilan/background5.jpg"));
app.tes(img);
} catch (IOException ex) {
Logger.getLogger(RincianBukuBesar.class.getName()).log(Level.SEVERE, null, ex);
}
}
then I have one more class to be invoked by the method lblSuratRekomendasiMouseClicked (java.awt.event.MouseEvent evt) of class A
package dispertasih;
import java.awt.*;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.geom.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.*;
import javax.swing.event.*;
public class PadAndZoom implements ChangeListener {
BufferedImage image;
PanPanelX label;
public void stateChanged(ChangeEvent e) {
int value = ((JSlider) e.getSource()).getValue();
double scale = value / 200.0;
BufferedImage scaled = getScaledImage(scale);
label.setImage(scaled);
}
public BufferedImage getScaledImage(double scale) {
int w = (int)(scale*image.getWidth());
int h = (int)(scale*image.getHeight());
BufferedImage bi = new BufferedImage(w, h, image.getType());
Graphics2D g2 = bi.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BICUBIC);
AffineTransform at = AffineTransform.getScaleInstance(scale, scale);
g2.drawRenderedImage(image, at);
g2.dispose();
return bi;
}
public PanPanelX getContent() {
// createAnImage();
label = new PanPanelX(image);
//label.setHorizontalAlignment(JLabel.CENTER);
return label;
}
public void createAnImage(BufferedImage imgbuf) {
int w = 500;
int h = 500;
int type = BufferedImage.TYPE_INT_RGB; // many options
image = imgbuf;
}
public JSlider getControl() {
JSlider slider = new JSlider(JSlider.HORIZONTAL, 50, 200, 50);
slider.setMajorTickSpacing(50);
slider.setMinorTickSpacing(10);
slider.setPaintTicks(true);
slider.setPaintLabels(true);
slider.addChangeListener(this);
return slider;
}
public void tes(BufferedImage img) {
PadAndZoom app = new PadAndZoom();
JDialog f = new JDialog();
JButton b = new JButton();
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException e) { }
app.createAnImage(img);
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
f.getContentPane().add(new JScrollPane(app.getContent()));
//f.getContentPane().add(new JButton("tessss"));
f.getContentPane().add(app.getControl(), "Last");
f.setSize(400, 400);
f.setLocation(200,200);
f.setVisible(true);
}
}
class PanPanelX extends JPanel {
public int x, y;
public int width = 800, height = 800;
BufferedImage img;
public final static RenderingHints textRenderHints = new RenderingHints(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
public final static RenderingHints imageRenderHints = new RenderingHints(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
public final static RenderingHints renderHints = new RenderingHints(RenderingHints.KEY_RENDERING, RenderingHints.VALUE_RENDER_QUALITY);
static int startX, startY;
public void setImage(BufferedImage img) {
this.img = img;
revalidate();
repaint();
}
public PanPanelX(BufferedImage img) {
x = 20;
y = 20;
this.img = img;
addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(MouseEvent me) {
super.mousePressed(me);
startX = me.getX();
startY = me.getY();
}
});
addMouseMotionListener(new MouseMotionAdapter() {
#Override
public void mouseDragged(MouseEvent me) {
super.mouseDragged(me);
if (me.getX() < startX) {//moving image to right
x -= 2;
} else if (me.getX() > startX) {//moving image to left
x += 2;
}
if (me.getY() < startY) {//moving image up
y -= 2;
} else if (me.getY() > startY) {//moving image to down
y += 2;
}
repaint();
}
});
}
#Override
protected void paintComponent(Graphics grphcs) {
super.paintComponent(grphcs);
Graphics2D g2d = (Graphics2D) grphcs;
//turn on some nice effects
applyRenderHints(g2d);
g2d.drawImage(img, x, y, null);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(width, height);
}
public static void applyRenderHints(Graphics2D g2d) {
g2d.setRenderingHints(textRenderHints);
g2d.setRenderingHints(imageRenderHints);
g2d.setRenderingHints(renderHints);
}
}
thanks u ..