Java Applet Game 2D Window Scrolling - java

I'm trying to develop a 2D RPG Game in a Java Applet. Right now I've got a simple oval that the player can use Left, Right, Up and Down to move, and collisions against the borders of the applet stops them. The problem is, I want to create a giant world(2000px by 2000x) of area that the player can move. However, I want them only to see 600px by 400x of the screen at one time. If they keep moving right, I want the screen to follow them, same goes for up, down and left. Can anyone tell me how to do this? Here is my code so far:
import java.awt.*;
import java.awt.event.KeyEvent;
import java.applet.Applet;
import java.awt.event.KeyListener;
import javax.swing.*;
public class Main extends Applet implements Runnable, KeyListener
{
private Image dbImage;
private Graphics dbg;
Thread t1;
int x = 0;
int y = 0;
int prevX = x;
int prevY = y;
int radius = 40;
boolean keyReleased = false;
public void init()
{
setSize(600, 400);
}
public void start()
{
addKeyListener(this);
t1 = new Thread(this);
t1.start();
}
public void destroy()
{
}
public void stop()
{
}
public void paint(Graphics g)
{
//player
g.setColor(Color.RED);
g.fillOval(x, y, radius, radius);
}
public void update(Graphics g)
{
dbImage = createImage (this.getSize().width, this.getSize().height);
dbg = dbImage.getGraphics();
// initialize buffer
if (dbImage == null)
{
}
// clear screen in background
dbg.setColor(getBackground());
dbg.fillRect(0, 0, this.getSize().width, this.getSize().height);
// draw elements in background
dbg.setColor(getForeground());
paint(dbg);
// draw image on the screen
g.drawImage(dbImage, 0, 0, this);
}
#Override
public void run()
{
while (true)
{
//x++;
repaint();
try
{
t1.sleep(17);
}
catch (Exception e)
{
}
}
}
public boolean CheckCollision(String dir)
{
if (x <= 0 && dir.equals("L"))
{
x = prevX;
return true;
}
else if (y <= 0 && dir.equals("U"))
{
y = prevY;
return true;
}
else if (x >= (getWidth() - radius) && dir.equals("R"))
{
System.out.println(getWidth());
x = prevX;
return true;
}
else if (y >= (getHeight() - radius) && dir.equals("D"))
{
y = prevY;
return true;
}
return false;
}
#Override
public void keyPressed(KeyEvent e)
{
switch (e.getKeyCode())
{
case KeyEvent.VK_RIGHT:
if (!CheckCollision("R"))
{
x += 4;
prevX = x;
}
break;
case KeyEvent.VK_LEFT:
if (!CheckCollision("L"))
{
x -= 4;
prevX = x;
}
break;
case KeyEvent.VK_UP:
if (!CheckCollision("U"))
{
y -= 4;
prevY = y;
}
break;
case KeyEvent.VK_DOWN:
if (!CheckCollision("D"))
{
y += 4;
prevY = y;
}
break;
}
}
#Override
public void keyReleased(KeyEvent arg0)
{
// TODO Auto-generated method stub
}
#Override
public void keyTyped(KeyEvent arg0)
{
// TODO Auto-generated method stub
}
}

This is a basic example of scrolling viewable area, where the virtual world is large then the view area.
This basically maintains a number of parameters. It maintains the point where in the world the top/left of the view is and the players position within the world.
These values are converted back to real world coordinates (where 0x0 is the top left corner of the viewable area).
The examples also use BufferedImage#getSubImage to make it easier to render. You could calculate the offset position of the map to the view as well, but that comes down to needs...
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.AbstractAction;
import javax.swing.ActionMap;
import javax.swing.InputMap;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class MiddleEarth {
public static void main(String[] args) {
new MiddleEarth();
}
public MiddleEarth() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(new WorldPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class WorldPane extends JPanel {
private BufferedImage map;
private BufferedImage party;
private Point viewPort;
private Point partyPoint;
private BufferedImage view;
public WorldPane() {
try {
map = ImageIO.read(getClass().getResource("/MiddleEarth.jpg"));
party = ImageIO.read(getClass().getResource("/8BitFrodo.png"));
viewPort = new Point(0, (map.getHeight() / 2) - 100);
partyPoint = new Point(party.getWidth() / 2, (map.getHeight() / 2)); // Virtual Point...
} catch (IOException exp) {
exp.printStackTrace();
}
InputMap im = getInputMap(WHEN_IN_FOCUSED_WINDOW);
ActionMap am = getActionMap();
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0), "goRight");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0), "goLeft");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_UP, 0), "goUp");
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_DOWN, 0), "goDown");
am.put("goRight", new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
moveParty(10, 0);
}
});
am.put("goLeft", new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
moveParty(-10, 0);
}
});
am.put("goUp", new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
moveParty(0, -10);
}
});
am.put("goDown", new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
moveParty(0, 10);
}
});
}
protected void moveParty(int xDelta, int yDelta) {
partyPoint.x += xDelta;
partyPoint.y += yDelta;
Point view = fromWorld(partyPoint);
if (view.x > getWidth() - (party.getWidth() / 2)) {
viewPort.x += xDelta;
if (viewPort.x + getWidth() > map.getWidth()) {
viewPort.x = map.getWidth() - getWidth();
partyPoint.x = map.getWidth() - (party.getWidth() / 2) - 1;
}
invalidate();
} else if (view.x < party.getWidth() / 2) {
viewPort.x += xDelta;
if (viewPort.x < 0) {
viewPort.x = 0;
partyPoint.x = (party.getWidth() / 2);
}
invalidate();
}
System.out.println(view + "; " + getHeight());
if (view.y > getHeight() - (party.getHeight() / 2)) {
viewPort.y += yDelta;
if (viewPort.y + getHeight() > map.getHeight()) {
viewPort.y = map.getHeight() - getHeight();
partyPoint.y = map.getHeight() - (party.getHeight() / 2) - 1;
}
invalidate();
} else if (view.y < party.getHeight() / 2) {
viewPort.y += yDelta;
if (viewPort.y < 0) {
viewPort.y = 0;
partyPoint.y = (party.getHeight() / 2);
}
invalidate();
}
repaint();
}
#Override
public void invalidate() {
view = null;
super.invalidate();
}
public BufferedImage getView() {
if (view == null && getWidth() > 0 && getHeight() > 0) {
view = map.getSubimage(viewPort.x, viewPort.y, getWidth(), getHeight());
}
return view;
}
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
if (map != null) {
g2d.drawImage(getView(), 0, 0, this);
Point real = fromWorld(partyPoint);
int x = real.x - (party.getWidth() / 2);
int y = real.y - (party.getHeight()/ 2);
g2d.drawImage(party, x, y, this);
}
g2d.dispose();
}
protected Point fromWorld(Point wp) {
Point p = new Point();
p.x = wp.x - viewPort.x;
p.y = wp.y - viewPort.y;
return p;
}
}
}

This is how I do in my engine.
I'll keep two variables OffSetX and OffSetY
And calculate them every step to center the player like this.
OffSetX = 0;
OffSetY = 0;
if (MAP_WIDTH > WINDOW_WIDTH) {
OffSetX = Math.round(WINDOW_WIDTH / 2 - obj.getX() - TILE_SIZE);
OffSetX = Math.min(OffSetX, 0);
OffSetX = Math.max(OffSetX, WINDOW_WIDTH - MAP_WIDTH);
}
if (MAP_HEIGHT > WINDOW_HEIGHT) {
OffSetY = Math.round(WINDOW_HEIGHT / 2 - obj.getY() - TILE_SIZE);
OffSetY = Math.min(OffSetY, 0);
OffSetY = Math.max(OffSetY, WINDOW_HEIGHT - MAP_HEIGHT);
}
And then draw the map at the position (OffSetX, OffSetY) i.e., just add these to the original position of the object to draw.
You may want to skip rendering objects which are not visible.

Related

How do I make a top down view with the ability to rotate with built in java graphics?

I'm trying to make a racing game with the top down view on a static player in the middle of the screen, so instead of moving the player through the map, the map would move around the player. Since it's a racing game, I wanted it to also be somewhat similar to a car, but I've been having trouble with rotating the map around the player and having that work with translations.
I've tried keeping track of the center by adding or subtracting from it, which is what I did for the translations, but it doesn't work with the rotate method. The rotate function wouldn't rotate about the player and instead would rotate the player around some other point, and the translations would snap to a different location from the rotations. I'm sure my approach is flawed, and I have read about layers and such, but I'm not sure what I can do with them or how to use them. Also, any recommendations as to how to use java graphics in general would be greatly appreciated!
This is what I have in my main:
import javax.swing.JFrame;
import java.awt.BorderLayout;
public class game
{
public static void main(String []args)
{
JFrame frame = new JFrame();
final int FRAME_WIDTH = 1000;
final int FRAME_HEIGHT = 600;
frame.setSize(FRAME_WIDTH, FRAME_HEIGHT);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final Map b = new Map();
frame.add(b,BorderLayout.CENTER);
frame.setVisible(true);
b.startAnimation();
}
}
And this is the class that handles all the graphics
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JComponent;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
public class Map extends JComponent implements Runnable, KeyListener
{
private int speed = 5;
private int xcenter = 500; // starts on player
private int ycenter = 300;
private double angle = 0.0;
private int[] xcords = {xcenter+10, xcenter, xcenter+20};
private int[] ycords = {ycenter-10, ycenter+20, ycenter+20};
private boolean moveNorth = false;
private boolean moveEast = false;
private boolean moveSouth = false;
private boolean moveWest = false;
public Map()
{
addKeyListener(this);
setFocusable(true);
setFocusTraversalKeysEnabled(false);
}
public void startAnimation()
{
Thread t = new Thread(this);
t.start();
}
public void paintComponent(Graphics g)
{
g.fillPolygon(xcords, ycords, 3);
// move screen
if(moveNorth)
{
ycenter += speed;
g.translate(xcenter, ycenter);
}
else if(moveEast)
{
angle += ((1 * Math.PI/180) % (2 * Math.PI));
((Graphics2D) g).rotate(angle, 0, 0);
}
else if(moveSouth)
{
System.out.println(xcenter + ", " + ycenter);
ycenter -= speed;
((Graphics2D) g).rotate(angle, 0, 0);
g.translate(xcenter, ycenter);
}
else if(moveWest)
{
angle -= Math.toRadians(1) % (2 * Math.PI);
((Graphics2D) g).rotate(angle, 0, 0);
}
for(int i = -10; i < 21; i++)
{
g.drawLine(i * 50, -1000, i * 50, 1000);
g.drawLine(-1000, i * 50, 1000, i * 50);
}
g.drawOval(0, 0, 35, 35);
}
public void run()
{
while (true)
{
try
{
if(moveNorth || moveEast || moveSouth || moveWest)
{
repaint();
}
Thread.sleep(10);
}
catch (InterruptedException e)
{
}
}
}
public void keyPressed(KeyEvent e)
{
if(e.getExtendedKeyCode() == 68) // d
{
moveEast = true;
}
else if(e.getExtendedKeyCode() == 87) // w
{
moveNorth = true;
}
else if(e.getExtendedKeyCode() == 65) // a
{
moveWest = true;
}
else if(e.getExtendedKeyCode() == 83) // s
{
moveSouth = true;
}
}
public void keyReleased(KeyEvent e)
{
moveNorth = false;
moveEast = false;
moveSouth = false;
moveWest = false;
}
public void keyTyped(KeyEvent e)
{
}
}
You have to keep in mind that transformations are compounding, so if you rotate the Graphics context by 45 degrees, everything painted after it will be rotated 45 degrees (around the point of rotation), if you rotate it again by 45 degrees, everything painted after it will be rotated a total of 90 degrees.
If you want to paint additional content after a transformation, then you either need to undo the transformation, or, preferably, take a snapshot of the Graphics context and dispose of it (the snapshot) when you're done.
You also need to beware of the point of rotation, Graphics2D#rotate(double) will rotate the Graphics around the point of origin (ie 0x0), which may not be desirable. You can change this by either changing the origin point (ie translate) or using Graphics2D#rotate(double, double, double), which allows you to define the point of rotation.
For example...
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.event.KeyEvent;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Set;
import java.util.TreeSet;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.AbstractAction;
import javax.swing.ActionMap;
import javax.swing.InputMap;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
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() {
try {
JFrame frame = new JFrame();
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
} catch (IOException ex) {
Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
}
}
});
}
public class TestPane extends JPanel {
enum Direction {
LEFT, RIGHT;
}
protected enum InputAction {
PRESSED_LEFT, PRESSED_RIGHT, RELEASED_LEFT, RELEASED_RIGHT
}
private BufferedImage car;
private BufferedImage road;
private Set<Direction> directions = new TreeSet<>();
private double directionOfRotation = 0;
public TestPane() throws IOException {
car = ImageIO.read(getClass().getResource("/images/Car.png"));
road = ImageIO.read(getClass().getResource("/images/Road.png"));
InputMap im = getInputMap(WHEN_IN_FOCUSED_WINDOW);
ActionMap am = getActionMap();
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0, false), InputAction.PRESSED_LEFT);
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0, true), InputAction.RELEASED_LEFT);
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0, false), InputAction.PRESSED_RIGHT);
im.put(KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0, true), InputAction.RELEASED_RIGHT);
am.put(InputAction.PRESSED_LEFT, new DirectionAction(Direction.LEFT, true));
am.put(InputAction.RELEASED_LEFT, new DirectionAction(Direction.LEFT, false));
am.put(InputAction.PRESSED_RIGHT, new DirectionAction(Direction.RIGHT, true));
am.put(InputAction.RELEASED_RIGHT, new DirectionAction(Direction.RIGHT, false));
Timer timer = new Timer(5, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (directions.contains(Direction.RIGHT)) {
directionOfRotation += 1;
} else if (directions.contains(Direction.LEFT)) {
directionOfRotation -= 1;
}
// No doughnuts for you :P
if (directionOfRotation > 180) {
directionOfRotation = 180;
} else if (directionOfRotation < -180) {
directionOfRotation = -180;
}
repaint();
}
});
timer.start();
}
protected void setDirectionActive(Direction direction, boolean active) {
if (active) {
directions.add(direction);
} else {
directions.remove(direction);
}
}
#Override
public Dimension getPreferredSize() {
return new Dimension(213, 216);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
drawRoadSurface(g2d);
drawCar(g2d);
g2d.dispose();
}
protected void drawCar(Graphics2D g2d) {
g2d = (Graphics2D) g2d.create();
int x = (getWidth() - car.getWidth()) / 2;
int y = (getHeight() - car.getHeight()) / 2;
g2d.drawImage(car, x, y, this);
g2d.dispose();
}
protected void drawRoadSurface(Graphics2D g2d) {
g2d = (Graphics2D) g2d.create();
// This sets the point of rotation at the center of the window
int midX = getWidth() / 2;
int midY = getHeight() / 2;
g2d.rotate(Math.toRadians(directionOfRotation), midX, midY);
// We then need to offset the top/left corner so that what
// we want draw appears to be in the center of the window,
// and thus will be rotated around it's center
int x = midX - (road.getWidth() / 2);
int y = midY - (road.getHeight() / 2);
g2d.drawImage(road, x, y, this);
g2d.dispose();
}
protected class DirectionAction extends AbstractAction {
private Direction direction;
private boolean active;
public DirectionAction(Direction direction, boolean active) {
this.direction = direction;
this.active = active;
}
#Override
public void actionPerformed(ActionEvent e) {
setDirectionActive(direction, active);
}
}
}
}

How to change an image after a keyboard input in java?

I have the following code to show you:
public class Test extends JPanel implements ActionListener, KeyListener
{
Timer tm = new Timer(5, this);
int x = 0, y = 0, velX = 0, velY = 0;
public Test()
{
tm.start(); //starts the timer
addKeyListener(this);
setFocusable(true);
setFocusTraversalKeysEnabled(false);
}
public void paint(Graphics g)
{
super.paint(g);
ImageIcon s = new ImageIcon("C:\\Users\\Owner\\Pictures\\Stick.jpg");
s.paintIcon(this,g,x,y);
}
public void actionPerformed(ActionEvent e)
{
if (x < 0)
{
velX = 0;
x = 0;
}
if (x > 630)
{
velX = 0;
x = 630;
}
if(y < 0)
{
velY = 0;
y = 0;
}
if(y > 430)
{
velY = 0;
y = 430;
}
x = x + velX;
y = y + velY;
repaint();
}
public void keyPressed(KeyEvent e)
{
int c = e.getKeyCode();
if (c == KeyEvent.VK_LEFT)
{
velX = -1;
velY = 0;
}
if(c == KeyEvent.VK_UP)
{
velX = 0;
velY = -1;
}
if(c == KeyEvent.VK_RIGHT)
{
velX = 1;
velY = 0;
}
if(c == KeyEvent.VK_DOWN)
{
velX = 0;
velY = 1;
}
}
public void keyTyped(KeyEvent e){}
public void keyReleased(KeyEvent e)
{
velX = 0;
velY = 0;
}
public static void main(String[] args)
{
Test t = new Test();
JFrame jf = new JFrame();
jf.setTitle("Tutorial");
jf.setSize(700, 600);
jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
jf.add(t);
jf.setVisible(true);
}
My problem is I whenever the user holds the right arrow on the keyboard it changes an image, when the user lets go it goes back the the default image. Please tell me how to do that. I think it is a series of if statements in the Graphics class then calling them to the key input but I'm not quite sure. I am also using Eclipse. Thank You.
Override paintComponent instead of paint. See Performing Custom Painting and Painting in AWT and Swing for more details
Use the key bindings API instead of KeyListener, it will cause you less issues. See How to Use Key Bindings for more details
Essentially, you could just have a Image as a class instance field, which was painted by the paintComponent method. When the key was pressed, you would change the image to the "move image" and when it was released, change it back to the "default image"
Updated with example
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.event.KeyEvent;
import java.awt.image.BufferedImage;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.ActionMap;
import javax.swing.InputMap;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new TestPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public interface Mover {
public enum Direction {
LEFT, RIGHT, NONE;
}
public void setDirection(Direction direction);
public Direction getDirection();
}
public class TestPane extends JPanel implements Mover {
private BufferedImage left;
private BufferedImage right;
private BufferedImage stand;
private BufferedImage current;
private Direction direction = Direction.NONE;
private int xPos;
private int yPos;
public TestPane() {
try {
left = ImageIO.read(getClass().getResource("/Left.png"));
right = ImageIO.read(getClass().getResource("/Right.png"));
stand = ImageIO.read(getClass().getResource("/Stand.png"));
current = stand;
xPos = 100 - (current.getWidth() / 2);
yPos = 100 - (current.getHeight() / 2);
} catch (IOException exp) {
exp.printStackTrace();
}
bindKeyStrokeTo(WHEN_IN_FOCUSED_WINDOW, "move.left", KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0, false), new MoveAction(this, Direction.LEFT));
bindKeyStrokeTo(WHEN_IN_FOCUSED_WINDOW, "stop.left", KeyStroke.getKeyStroke(KeyEvent.VK_LEFT, 0, true), new MoveAction(this, Direction.NONE));
bindKeyStrokeTo(WHEN_IN_FOCUSED_WINDOW, "move.right", KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0, false), new MoveAction(this, Direction.RIGHT));
bindKeyStrokeTo(WHEN_IN_FOCUSED_WINDOW, "stop.right", KeyStroke.getKeyStroke(KeyEvent.VK_RIGHT, 0, true), new MoveAction(this, Direction.NONE));
Timer timer = new Timer(40, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
updatePosition();
repaint();
}
});
timer.start();
}
protected void bindKeyStrokeTo(int condition, String name, KeyStroke keyStroke, Action action) {
InputMap im = getInputMap(condition);
ActionMap am = getActionMap();
im.put(keyStroke, name);
am.put(name, action);
}
#Override
public Direction getDirection() {
return direction;
}
#Override
public void setDirection(Direction direction) {
this.direction = direction;
}
protected void updatePosition() {
switch (getDirection()) {
case LEFT:
current = left;
xPos -= 1;
break;
case RIGHT:
current = right;
xPos += 1;
break;
case NONE:
current = stand;
break;
}
if (xPos < 0) {
xPos = 0;
current = stand;
} else if (xPos + current.getWidth() > getWidth()) {
current = stand;
xPos = getWidth() - current.getWidth();
}
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.drawImage(current, xPos, yPos, this);
g2d.dispose();
}
}
public class MoveAction extends AbstractAction {
private Mover mover;
private Mover.Direction direction;
public MoveAction(Mover mover, Mover.Direction direction) {
this.mover = mover;
this.direction = direction;
}
#Override
public void actionPerformed(ActionEvent e) {
mover.setDirection(direction);
}
}
}

I need help on moving the small box created to move smoothly as I click and drag near the outside layer. Here is my code: [duplicate]

I made a mini code that draw oval and link each other , now i try to move the oval(Circle) but I have a problem (in coding)
// Panneau.java
public class Panneau extends JPanel {
private int R = 20;
private boolean isDrag = false;
String text = "stack";
int x = 250, y = 200;
int height = 50, width = 50;
Random Rnd = new Random();
int rand=Rnd.nextInt();
int r=Math.abs(rand%250);
int r2=Math.abs(rand%250);
public Panneau() {
addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
if ((x<=e.getX() && x+R>=e.getX()) && ( y<=e.getY() && y+R>=e.getY())) {
moveVertex(e.getX(),e.getY());
isDrag = true;
}
}
#Override
public void mouseReleased(MouseEvent e) {
isDrag = false;
}
});
addMouseMotionListener(new MouseAdapter() {
#Override
public void mouseDragged(MouseEvent e) {
if (isDrag) moveVertex(e.getX(),e.getY());
}
});
}
private void moveVertex(int x1, int y1) {
if ((x!=x1) || (y!=y1)) {
x=x1-10;
y=y1-10;
repaint();
}
}
#Override
protected void paintComponent(Graphics g){
// declaration
super.paintComponent(g);
g.setColor(Color.black);
g.drawLine(x,y,x+r,y+r2);
g.setColor(Color.yellow);
g.fillOval(x-height/2, y-width/2,width, height);
g.fillOval((x-height/2)+r, (y-width/2)+r2,width, height);
FontMetrics fm = g.getFontMetrics();
double textWidth = fm.getStringBounds(text, g).getWidth();
g.setColor(Color.blue);
g.drawString(text, (int) (x - textWidth/2),(int) (y + fm.getMaxAscent() / 2));
g.drawString(text, (int) (x - textWidth/2)+r,(int) (y + fm.getMaxAscent() / 2)+r2);
}
}
I must move the two circles and the line must not move(Graph node)
please help me and thanks :)
After the update ( thanks to MadProgrammer) now I can move all the figure ( but if I clicked in the red circle only) , I want to move just circles thanks :)
Basically, because instead of using reapint(int, int) you could use repaint()
private void moveVertex(int x1, int y1) {
int OFFSET = 1;
if ((x != x1) || (y != y1)) {
x = x1 - 10;
y = y1 - 10;
repaint();
}
}
This will ensure that the entire component is repainted.
While I wouldn't discount the use of repaint(int, int), because your painting process is relatively simple, it's not going to provide you with a great deal of benefit at this stage
Updated with additional example
IF I understand, you want to be able to move a single node and have the line remain joined.
While it might be possible to implement within the code you have available, a simpler soltution would be to take advantage of the 2D Graphics Shape API, this provides a number of really useful functions, including determining of points fall within a given shape.
It also means you don't need to keep track of a large number of parameters, but instead, get a self contained object that just knows how it should be painted...
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Line2D;
import java.awt.geom.Rectangle2D;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class TestGraphNode {
public static void main(String[] args) {
new TestGraphNode();
}
public TestGraphNode() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new Panneau());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class Panneau extends JPanel {
private int radius = 50;
private String text = "stack";
private List<Ellipse2D> nodes;
private Ellipse2D dragged;
private Point offset;
public Panneau() {
nodes = new ArrayList<>(25);
nodes.add(new Ellipse2D.Float(50 - (radius / 2), 100 - (radius / 2), radius, radius));
nodes.add(new Ellipse2D.Float(350 - (radius / 2), 100 - (radius / 2), radius, radius));
addMouseListener(new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
for (Ellipse2D node : nodes) {
if (node.contains(e.getPoint())) {
System.out.println("Clicked...");
dragged = node;
// Adjust for the different between the top/left corner of the
// node and the point it was clicked...
offset = new Point(node.getBounds().x - e.getX(), node.getBounds().y - e.getY());
// Highlight the clicked node
repaint();
break;
}
}
}
#Override
public void mouseReleased(MouseEvent e) {
// Erase the "click" highlight
if (dragged != null) {
repaint();
}
dragged = null;
offset = null;
}
});
addMouseMotionListener(new MouseAdapter() {
#Override
public void mouseDragged(MouseEvent e) {
if (dragged != null && offset != null) {
// Adjust the position of the drag point to allow for the
// click point offset
Point to = e.getPoint();
to.x += offset.x;
to.y += offset.y;
// Modify the position of the node...
Rectangle bounds = dragged.getBounds();
bounds.setLocation(to);
dragged.setFrame(bounds);
// repaint...
repaint();
}
}
});
}
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
#Override
protected void paintComponent(Graphics g) {
// declaration
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
// Draw the connecting lines first
// This ensures that the lines are under the nodes...
Point p = null;
for (Ellipse2D node : nodes) {
g2d.setColor(Color.BLACK);
Point to = node.getBounds().getLocation();
to.x += radius / 2;
to.y += radius / 2;
if (p != null) {
g2d.draw(new Line2D.Float(p, to));
}
p = to;
}
// Draw the nodes...
for (Ellipse2D node : nodes) {
g2d.setColor(Color.yellow);
g2d.fill(node);
if (node == dragged) {
g2d.setColor(Color.BLUE);
g2d.draw(node);
}
g2d.setColor(Color.BLUE);
FontMetrics fm = g.getFontMetrics();
int textWidth = fm.stringWidth(text);
int x = node.getBounds().x;
int y = node.getBounds().y;
int width = node.getBounds().width;
int height = node.getBounds().height;
g.drawString(text,
x + ((width - textWidth)) / 2,
y + ((height - fm.getHeight()) / 2) + fm.getAscent());
}
g2d.dispose();
}
}
}

How to drop a ball when clicked with mouse?

I'm working on a game project. The aim is clicking the balls and drop them into the basket which is below in the JPanel. I created some ways to do that but I can't achieve it. In my opinion, when the user click the ball's center with a margin of error (because the program can't catch the real point of balls), the program understands the action and runs the function of this issue. After clicking the ball it should be dropped down straight but the other balls should be continued. I use MouseListener#mousePressed method, but it doesn't work or I'm missing some parts. In addition, I made some changes in my source code, but I want to listen your advices so I am writing this topic.
I wrote a method which finds the mouse and ball coordinates. So when I make some changes to it, I can achieve my project goal. You can see the editing in the picture.
This is my source code ;
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.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.AdjustmentEvent;
import java.awt.event.AdjustmentListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.util.ArrayList;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollBar;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Game {
public Game() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager
.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException
| IllegalAccessException
| UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("MultipleBallApp");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new BallControl());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class BallControl extends JPanel {
/**
*
*/
private static final long serialVersionUID = 1L;
private BallPanel ballPanel = new BallPanel();
private JButton Suspend = new JButton("Suspend");
private JButton Resume = new JButton("Resume");
private JButton Add = new JButton("+1");
private JButton Subtract = new JButton("-1");
private JScrollBar Delay = new JScrollBar();
public BallControl() {
// Group buttons in a panel
JPanel panel = new JPanel();
panel.add(Suspend);
panel.add(Resume);
panel.add(Add);
panel.add(Subtract);
// Add ball and buttons to the panel
ballPanel.setBorder(new javax.swing.border.LineBorder(Color.red));
Delay.setOrientation(JScrollBar.HORIZONTAL);
ballPanel.setDelay(Delay.getMaximum());
setLayout(new BorderLayout());
add(Delay, BorderLayout.NORTH);
add(ballPanel, BorderLayout.CENTER);
add(panel, BorderLayout.SOUTH);
this.addMouseListener(new MouseListener() {
#Override
public void mouseReleased(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mousePressed(MouseEvent clickEvent) {
// TODO Auto-generated method stub
System.out.println("X coordinate =" + clickEvent.getX());
System.out.println("Y coordinate = " + clickEvent.getY());
double radius1;
int x = 0;
double y = 0;
int radius = 15;
double xM = clickEvent.getX();
double yM = clickEvent.getY();
radius1 = Math.sqrt((xM - x) * (xM - x) + (yM - y)
* (yM - y));
System.out.println("Radius1 =" + radius1);
// ballPanel.list.get(0).setD
}
#Override
public void mouseExited(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseEntered(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void mouseClicked(MouseEvent arg0) {
// TODO Auto-generated method stub
}
});
// Register listeners
Suspend.addActionListener(new Listener());
Resume.addActionListener(new Listener());
Add.addActionListener(new Listener());
Subtract.addActionListener(new Listener());
Delay.addAdjustmentListener(new AdjustmentListener() {
public void adjustmentValueChanged(AdjustmentEvent e) {
ballPanel.setDelay(Delay.getMaximum() - e.getValue());
}
});
}
class Listener implements ActionListener {
public void actionPerformed(ActionEvent e) {
if (e.getSource() == Suspend) {
ballPanel.suspend();
} else if (e.getSource() == Resume) {
ballPanel.resume();
} else if (e.getSource() == Add) {
ballPanel.add();
} else if (e.getSource() == Subtract) {
ballPanel.subtract();
}
}
}
}
class BallPanel extends JPanel {
/**
*
*/
private static final long serialVersionUID = 1L;
private int delay = 30;
public ArrayList<AnimatedShape> list = new ArrayList<AnimatedShape>();
private AnimatedRectange rectangle;
public BallPanel() {
this.rectangle = new AnimatedRectange(-25, 373, 50, 25, Color.BLACK);
timer.start();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(400, 400);
}
// Create a timer with the initial delay
protected Timer timer = new Timer(delay, new ActionListener() {
/**
* Handle the action event
*/
#Override
public void actionPerformed(ActionEvent e) {
for (AnimatedShape ball : list) {
ball.update(getBounds());
}
rectangle.update(getBounds());
repaint();
}
});
public void add() {
int radius = 15;
// Randomised position
int x = (int) (Math.random() * (getWidth() - (radius * 2)))
+ radius;
int y = (int) (Math.random() * (getHeight() - (radius * 2)))
+ radius;
Color color = new Color((int) (Math.random() * 256),
(int) (Math.random() * 256), (int) (Math.random() * 256));
AnimatedBall ball = new AnimatedBall(x, y, radius, color);
list.add(ball);
}
// public void formula(MouseEvent clickEvent) {
// double radius1;
// int x = 0;
// double y = 0;
// int radius = 15;
// double xM = clickEvent.getX();
// double yM = clickEvent.getY();
// radius1 = Math.sqrt((xM - x) * (xM - x) + (yM - y) * (yM - y));
// System.out.println("Radius1 =" + radius1);
// }
public void subtract() {
if (list.size() > 0) {
list.remove(list.size() - 1); // Remove the last ball
}
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
for (AnimatedShape ball : list) {
ball.paint(this, g2d);
}
rectangle.paint(this, g2d);
}
public void suspend() {
timer.stop();
}
public void resume() {
timer.start();
}
public void setDelay(int delay) {
this.delay = delay;
timer.setDelay(delay);
}
}
public interface AnimatedShape {
public void update(Rectangle bounds);
public void paint(JComponent parent, Graphics2D g2d);
}
public abstract class AbstractAnimatedShape implements AnimatedShape {
private Rectangle bounds;
private int dx, dy;
public AbstractAnimatedShape() {
}
public void setBounds(Rectangle bounds) {
this.bounds = bounds;
}
public Rectangle getBounds() {
return bounds;
}
public int getDx() {
return dx;
}
public int getDy() {
return dy;
}
public void setDx(int dx) {
this.dx = dx;
}
public void setDy(int dy) {
this.dy = dy;
}
#Override
public void update(Rectangle parentBounds) {// ball
Rectangle bounds = getBounds();
int dx = getDx();
int dy = getDy();
bounds.x += dx;
bounds.y += dy;
if (bounds.x < parentBounds.x) {
bounds.x = parentBounds.x;
setDx(dx *= -1);
} else if (bounds.x + bounds.width > parentBounds.x
+ parentBounds.width) {
bounds.x = parentBounds.x + (parentBounds.width - bounds.width);
setDx(dx *= -1);
}
if (bounds.y < parentBounds.y) {
bounds.y = parentBounds.y;
setDy(dy *= -1);
} else if (bounds.y + bounds.height > parentBounds.y
+ parentBounds.height) {
bounds.y = parentBounds.y
+ (parentBounds.height - bounds.height);
setDy(dy *= -1);
}
}
}
public class AnimatedBall extends AbstractAnimatedShape {
private Color color;
public AnimatedBall(int x, int y, int radius, Color color) {
setBounds(new Rectangle(x, y / 2, radius * 2, radius * 2));
this.color = color;
setDx(Math.random() > 0.5 ? 2 : -2);
// setDy(Math.random() > 0.5 ? 2 : -2);
}
public Color getColor() {
return color;
}
#Override
public void paint(JComponent parent, Graphics2D g2d) {
Rectangle bounds = getBounds();
g2d.setColor(getColor());
g2d.fillOval(bounds.x, bounds.y, bounds.width, bounds.height);
}
}
public class AnimatedRectange extends AbstractAnimatedShape {
private Color color;
public AnimatedRectange(int x, int y, int width, int height, Color color) {
setBounds(new Rectangle(x, y, width, height));
this.color = color;
setDx(2);
}
// Don't want to adjust the vertical speed
#Override
public void setDy(int dy) {
}
#Override
public void paint(JComponent parent, Graphics2D g2d) {
Rectangle bounds = getBounds();
g2d.setColor(color);
g2d.fill(bounds);
}
}
/**
* Main method
*/
public static void main(String[] args) {
new Game();
}
}
At the end of your mousePressed method, you can go though all AnimatedShape objects, check whether they are an AnimatedBall. When the object is a ball, you can test whether the mouse click hits the ball. The mouse click hits the ball when the distance between the center of the ball and the mouse position is smaller than the ball radius. When the ball is hit, you can set its horizontal speed to 0, and the vertical speed to 5 or so.
for (AnimatedShape as : ballPanel.list)
{
if (as instanceof AnimatedBall)
{
AnimatedBall ball = (AnimatedBall)as;
Rectangle b = ball.getBounds();
int ballCenterX = b.x + b.width / 2;
int ballCenterY = b.y + b.height / 2;
Point p = new Point(ballCenterX, ballCenterY);
double d = p.distance(clickEvent.getPoint());
if (d < radius)
{
ball.setDx(0);
ball.setDy(5);
}
}
}
Note
In order to make this work properly, you have to attach this listener to the ballPanel. Originally, you had the line
this.addMouseListener(new MouseListener() {
in your code. You have to change this to
ballPanel.addMouseListener(new MouseListener() {
Otherwise, the mouse coordinates will refer to the wrong component!
Concerning the question from the comment
how can I stop and disapper clickedball's when they crash the bound
You may probably insert method to check this, and call this method in the actionPerformed method of your timer. Further explainations are probably beyond the scope of an anser on a Q&A site. Stackoverflow is not a homework-solution-generator.

Intersection of Two Rectangles with paintComponent

I am writing a program that allows a user to paint rectangles onto a JLabel, and show the intersection and union of these rectangles. I have setup the GUI for the class but am struggling to find a way to integrate the intersection and union methods from the rectangle class. I know these methods work when used separately from the GUI.
When I try to run the program I keep getting an IndexOutOfBoundsException and the drawn rectangles are cleared from the gui. The intersections of each rectangle should show up in a different color on the JLabel. I tried to debug the program and for some reason when I create two rectangles and store them in my array list many many rectangle objects of the same characteristics are being created.
For the union method, a new rectangle should be create that contains all of the rectangles on the inside.
RectangleFrame1:
public class RectangleFrame1 extends JFrame implements ActionListener
{
JPanel buttonPanel;
JButton saveImage;
JButton clearImage;
JCheckBox intersections;
JCheckBox union;
RectangleLabel drawingArea;
boolean intersect = false;
boolean uni = false;
public RectangleFrame1()
{
super();
setTitle("Rectangles");
setSize(600,600);
setResizable(false);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
buttonPanel = new JPanel();
buttonPanel.setBorder(BorderFactory.createLineBorder(Color.black));
this.add(buttonPanel, BorderLayout.SOUTH);
intersections = new JCheckBox("Draw Intersections");
buttonPanel.add(intersections);
intersections.addActionListener(this);
intersections.setActionCommand("Intersections");
union = new JCheckBox("Draw Union");
buttonPanel.add(union);
union.addActionListener(this);
union.setActionCommand("Union");
saveImage = new JButton("Save Image");
saveImage.setMargin(new Insets(0,0,0,0));
buttonPanel.add(saveImage);
saveImage.addActionListener(this);
saveImage.setActionCommand("Save Image");
clearImage = new JButton("Clear Image");
clearImage.setMargin(new Insets(0,0,0,0));
buttonPanel.add(clearImage);
clearImage.addActionListener(this);
clearImage.setActionCommand("Clear Image");
drawingArea = new RectangleLabel();
drawingArea.setBorder(BorderFactory.createLineBorder(Color.blue));
this.add(drawingArea, BorderLayout.CENTER);
drawingArea.addMouseListener((MouseListener) drawingArea);
drawingArea.addMouseMotionListener((MouseMotionListener) drawingArea);
}
#Override
public void actionPerformed(ActionEvent arg0)
{
switch(arg0.getActionCommand())
{
case "Intersections":
if(intersections.isSelected())
{
intersect = true;
}
else
{
intersect = false;
}
case "Union":
if(union.isSelected())
{
uni = true;
}
else
{
uni = false;
}
case "Clear Image": drawingArea.clearImage();
case "Save Image": drawingArea.saveImage();
}
}
class RectangleLabel extends JLabel implements MouseListener, MouseMotionListener
{
Rectangle rectangle = null;
int x, y, x2, y2;
ArrayList<Rectangle> a = new ArrayList();
int counter;
public RectangleLabel()
{
super();
}
#Override
public void mousePressed(MouseEvent arg0)
{
x = arg0.getX();
y = arg0.getY();
rectangle = new Rectangle(x, y, 0, 0);
}
#Override
public void mouseDragged(MouseEvent arg0)
{
// TODO Auto-generated method stub
x2 = arg0.getX();
y2 = arg0.getY();
if(rectangle.getX() > x2)
{
rectangle.setWidth(x-x2);
}
if(x2 > rectangle.getX())
{
rectangle.setWidth(x2-x);
}
if(y > y2)
{
rectangle.setHeight(y-y2);
}
if(y2 > y)
{
rectangle.setHeight(y2-y);
}
a.add(rectangle);
counter++;
repaint();
}
#Override
public void mouseReleased(MouseEvent arg0)
{
repaint();
}
#Override
public void mouseMoved(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#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 mouseClicked(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void paintComponent(Graphics g)
{
super.paintComponent(g);
if(rectangle != null)
{
for(int i = 0; i < a.size(); i++)
{
float thickness = 2;
((Graphics2D) g).setStroke(new BasicStroke(thickness));
g.setColor(Color.BLUE);
g.drawRect(a.get(i).getX(), a.get(i).getY(), a.get(i).getWidth(), a.get(i).getHeight());
g.setColor(Color.gray);
g.fillRect(a.get(i).getX(), a.get(i).getY(), a.get(i).getWidth(), a.get(i).getHeight());
}
}
if(intersect == true && counter > 0)
{
for(int h = 0; h < counter-1; h++)
{
for(int j = 1; j < counter; j++)
{ if(a.get(h).overlaps(a.get(j)))
{
Rectangle rect = a.get(h).intersect(a.get(j));
g.setColor(Color.RED);
g.fillRect(rect.getX(), rect.getY(), rect.getWidth(), rect.getHeight());
}
}
}
}
if(uni == true && counter > 0)
{
for(int h = 0; h < counter - 1; h++)
{
for(int j = 1; j < counter; j++)
{
Rectangle rect = a.get(h).union(a.get(j));
g.setColor(Color.WHITE);
g.drawRect(rect.getX(), rect.getY(), rect.getWidth(), rect.getHeight());
}
}
}
}
public void saveImage()
{
BufferedImage image = new BufferedImage(this.getWidth(), this.getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics2D aaaaa = image.createGraphics();
aaaaa.setBackground(Color.WHITE);
aaaaa.clearRect(0, 0, this.getWidth(), this.getHeight());
this.paintAll(aaaaa);
try
{
File output = new File("rectangle.png");
ImageIO.write(image, "Rectangles", output);
}
catch(IOException ie)
{
}
}
public void clearImage()
{
a.clear();
repaint();
}
}
}
Rectangle:
public class Rectangle
{
private int x,y,width,height;
public Rectangle(int x,int y,int width,int height)
{
this.x = x;
this.y = y;
this.width = width;
this.height = height;
}
public Rectangle(Rectangle a)
{
this.x = a.x;
this.y = a.y;
this.width = a.width;
this.height = a.height;
}
public String toString()
{
return "Start: ("+x+","+y+"), Width: "+width+", Height: "+height+"\n";
}
public int getX()
{
return x;
}
public int getY()
{
return y;
}
public int getWidth()
{
return width;
}
public int getHeight()
{
return height;
}
public void setX(int x)
{
this.x = x;
}
public void setY(int y)
{
this.y = y;
}
public void setWidth(int width)
{
this.width = width;
}
public void setHeight(int height)
{
this.height = height;
}
public int area()
{
return width*height;
}
public boolean overlaps(Rectangle a)
{
if ((x>a.x+a.width) || (a.x>x+width) || (y>a.y+a.height) || (a.y>y+height))
{
return false;
}
return true;
}
public Rectangle intersect(Rectangle a)
{
if (!overlaps(a))
return null;
int left,right,top,bottom;
if (x<a.x)
left = a.x;
else
left = x;
if (y<a.y)
bottom = a.y;
else
bottom = y;
if ((x+width)<(a.x+a.width))
right = x+width;
else
right = a.x+a.width;
if ((y+height)<(a.y+a.height))
top = y+height;
else
top = a.y+a.height;
return new Rectangle(left,bottom,right-left,top-bottom);
}
public Rectangle union(Rectangle a)
{
int left,right,top,bottom;
if (x<a.x)
left = x;
else
left = a.x;
if (y<a.y)
bottom = y;
else
bottom = a.y;
if ((x+width)<(a.x+a.width))
right = a.x+a.width;
else
right = x+width;
if ((y+height)<(a.y+a.height))
top = a.y+a.height;
else
top = y+height;
return new Rectangle(left,bottom,right-left,top-bottom);
}
}
There are a number of problems...
You're mouseDragged event handler is adding the same Rectangle to the a ArrayList, over and over again, increasing the counter value along with it.
This is not required. All you need to do is add the Rectangle on the mousePressed event. When mouseReleased is called, you could evaluate the Rectangle to check if the size is greater than 0x0 and remove it if it's not (ie remove any Rectangle whose size is 0x0)
Don't rely on the counter variable, it's too easy for the value to become misaligned with the size of the a List. Instead, rely on a.size instead.
The switch statement in your ActionListener is evaluating the matching case, but also all the following cases below it. This is a feature of switch. If you don't want to evaluate the following cases, you need to add a break at the end of each case (or where ever you want to "break" the processing).
For example, when you click Draw Intersections, it is also evaluating Union, Clear Image and Save Image cases...
You could try using something like...
switch (arg0.getActionCommand()) {
case "Intersections":
intersect = intersections.isSelected();
break;
case "Union":
uni = union.isSelected();
break;
case "Clear Image":
drawingArea.clearImage();
break;
case "Save Image":
drawingArea.saveImage();
break;
}
instead...
Logic Errors in Painting Code...
There's also a logic area with your intersect paint code, where it is comparing a rectangle with itself, which ends up painting the whole rectangle.
Instead of
if (a.get(h).overlaps(a.get(j))) {
You might consider using
if (!a.get(h).equals(a.get(j)) && a.get(h).overlaps(a.get(j))) {
This is possibly occurring in you union painting logic as well, but I didn't really check that
Works fine for me...
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import javax.imageio.ImageIO;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JCheckBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class RectangleFrame1 extends JFrame implements ActionListener {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
RectangleFrame1 frame = new RectangleFrame1();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
JPanel buttonPanel;
JButton saveImage;
JButton clearImage;
JCheckBox intersections;
JCheckBox union;
RectangleLabel drawingArea;
boolean intersect = false;
boolean uni = false;
public RectangleFrame1() {
super();
setTitle("Rectangles");
setSize(600, 600);
// setResizable(false);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
buttonPanel = new JPanel();
buttonPanel.setBorder(BorderFactory.createLineBorder(Color.black));
this.add(buttonPanel, BorderLayout.SOUTH);
intersections = new JCheckBox("Draw Intersections");
buttonPanel.add(intersections);
intersections.addActionListener(this);
intersections.setActionCommand("Intersections");
union = new JCheckBox("Draw Union");
buttonPanel.add(union);
union.addActionListener(this);
union.setActionCommand("Union");
saveImage = new JButton("Save Image");
saveImage.setMargin(new Insets(0, 0, 0, 0));
buttonPanel.add(saveImage);
saveImage.addActionListener(this);
saveImage.setActionCommand("Save Image");
clearImage = new JButton("Clear Image");
clearImage.setMargin(new Insets(0, 0, 0, 0));
buttonPanel.add(clearImage);
clearImage.addActionListener(this);
clearImage.setActionCommand("Clear Image");
drawingArea = new RectangleLabel();
drawingArea.setBorder(BorderFactory.createLineBorder(Color.blue));
this.add(drawingArea, BorderLayout.CENTER);
drawingArea.addMouseListener((MouseListener) drawingArea);
drawingArea.addMouseMotionListener((MouseMotionListener) drawingArea);
}
#Override
public void actionPerformed(ActionEvent arg0) {
switch (arg0.getActionCommand()) {
case "Intersections":
intersect = intersections.isSelected();
break;
case "Union":
uni = union.isSelected();
break;
case "Clear Image":
drawingArea.clearImage();
break;
case "Save Image":
drawingArea.saveImage();
break;
}
repaint();
}
class RectangleLabel extends JLabel implements MouseListener, MouseMotionListener {
Rectangle rectangle = null;
int x, y, x2, y2;
ArrayList<Rectangle> a = new ArrayList();
public RectangleLabel() {
super();
}
#Override
public void mousePressed(MouseEvent arg0) {
x = arg0.getX();
y = arg0.getY();
rectangle = new Rectangle(x, y, 0, 0);
a.add(rectangle);
}
#Override
public void mouseDragged(MouseEvent arg0) {
// TODO Auto-generated method stub
x2 = arg0.getX();
y2 = arg0.getY();
if (rectangle.getX() > x2) {
rectangle.setWidth(x - x2);
}
if (x2 > rectangle.getX()) {
rectangle.setWidth(x2 - x);
}
if (y > y2) {
rectangle.setHeight(y - y2);
}
if (y2 > y) {
rectangle.setHeight(y2 - y);
}
repaint();
}
#Override
public void mouseReleased(MouseEvent arg0) {
rectangle = null;
repaint();
}
#Override
public void mouseMoved(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#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 mouseClicked(MouseEvent arg0) {
// TODO Auto-generated method stub
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
for (Rectangle rect : a) {
float thickness = 2;
((Graphics2D) g).setStroke(new BasicStroke(thickness));
g.setColor(Color.BLUE);
g.drawRect(rect.getX(), rect.getY(), rect.getWidth(), rect.getHeight());
g.setColor(Color.gray);
g.fillRect(rect.getX(), rect.getY(), rect.getWidth(), rect.getHeight());
}
if (intersect) {
for (int h = 0; h < a.size() - 1; h++) {
for (int j = 1; j < a.size(); j++) {
if (!a.get(h).equals(a.get(j)) && a.get(h).overlaps(a.get(j))) {
Rectangle rect = a.get(h).intersect(a.get(j));
g.setColor(Color.RED);
g.fillRect(rect.getX(), rect.getY(), rect.getWidth(), rect.getHeight());
}
}
}
}
if (uni) {
for (int h = 0; h < a.size() - 1; h++) {
for (int j = 1; j < a.size(); j++) {
if (!a.get(h).equals(a.get(j)) && a.get(h).overlaps(a.get(j))) {
Rectangle rect = a.get(h).union(a.get(j));
g.setColor(Color.WHITE);
g.drawRect(rect.getX(), rect.getY(), rect.getWidth(), rect.getHeight());
}
}
}
}
}
public void saveImage() {
BufferedImage image = new BufferedImage(this.getWidth(), this.getHeight(), BufferedImage.TYPE_INT_ARGB);
Graphics2D aaaaa = image.createGraphics();
aaaaa.setBackground(Color.WHITE);
aaaaa.clearRect(0, 0, this.getWidth(), this.getHeight());
this.paintAll(aaaaa);
try {
File output = new File("rectangle.png");
ImageIO.write(image, "Rectangles", output);
} catch (IOException ie) {
}
}
public void clearImage() {
a.clear();
repaint();
}
}
public class Rectangle {
private int x, y, width, height;
public Rectangle(int x, int y, int width, int height) {
this.x = x;
this.y = y;
this.width = width;
this.height = height;
}
public Rectangle(Rectangle a) {
this.x = a.x;
this.y = a.y;
this.width = a.width;
this.height = a.height;
}
public String toString() {
return "Start: (" + x + "," + y + "), Width: " + width + ", Height: " + height + "\n";
}
public int getX() {
return x;
}
public int getY() {
return y;
}
public int getWidth() {
return width;
}
public int getHeight() {
return height;
}
public void setX(int x) {
this.x = x;
}
public void setY(int y) {
this.y = y;
}
public void setWidth(int width) {
this.width = width;
}
public void setHeight(int height) {
this.height = height;
}
public int area() {
return width * height;
}
public boolean overlaps(Rectangle a) {
if ((x > a.x + a.width) || (a.x > x + width) || (y > a.y + a.height) || (a.y > y + height)) {
return false;
}
return true;
}
public Rectangle intersect(Rectangle a) {
if (!overlaps(a)) {
return null;
}
int left, right, top, bottom;
if (x < a.x) {
left = a.x;
} else {
left = x;
}
if (y < a.y) {
bottom = a.y;
} else {
bottom = y;
}
if ((x + width) < (a.x + a.width)) {
right = x + width;
} else {
right = a.x + a.width;
}
if ((y + height) < (a.y + a.height)) {
top = y + height;
} else {
top = a.y + a.height;
}
return new Rectangle(left, bottom, right - left, top - bottom);
}
public Rectangle union(Rectangle a) {
int left, right, top, bottom;
if (x < a.x) {
left = x;
} else {
left = a.x;
}
if (y < a.y) {
bottom = y;
} else {
bottom = a.y;
}
if ((x + width) < (a.x + a.width)) {
right = a.x + a.width;
} else {
right = x + width;
}
if ((y + height) < (a.y + a.height)) {
top = a.y + a.height;
} else {
top = y + height;
}
return new Rectangle(left, bottom, right - left, top - bottom);
}
}
}

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