Develop Reference

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.

Adding Start, Stop, Reset button to simple java game

I am a new coder. I am having trouble adding a start and stop button for this piece of example code that i am working off. I'm sure i have to mess with with Thread.sleep(10); in the game class. This code starts the game when the program is run. is there a way i could add start button to start the thread. I have created j button already. Thanks.
Game Class
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
#SuppressWarnings("serial")
public class Game extends JPanel {
Ball ball = new Ball(this);
Racquet racquet = new Racquet(this);
public Game() {
addKeyListener(new KeyListener() {
#Override
public void keyTyped(KeyEvent e) {
}
#Override
public void keyReleased(KeyEvent e) {
racquet.keyReleased(e);
}
#Override
public void keyPressed(KeyEvent e) {
racquet.keyPressed(e);
}
});
setFocusable(true);
}
private void move() {
ball.move();
racquet.move();
}
#Override
public void paint(Graphics g) {
super.paint(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
ball.paint(g2d);
racquet.paint(g2d);
}
public void gameOver() {
JOptionPane.showMessageDialog(this, "Game Over", "Game Over", JOptionPane.YES_NO_OPTION);
System.exit(ABORT);
}
public static void main(String[] args) throws InterruptedException {
JFrame frame = new JFrame("Mini Tennis");
Game game = new Game();
frame.add(game);
frame.setSize(300, 400);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
while (true) {
game.move();
game.repaint();
Thread.sleep(10);
}
}
}
Ball Class
import java.awt.Graphics2D;
import java.awt.Rectangle;
public class Ball {
private static final int DIAMETER = 30;
int x = 0;
int y = 0;
int xa = 1;
int ya = 1;
private Game game;
public Ball(Game game) {
this.game= game;
}
void move() {
if (x + xa < 0)
xa = 1;
if (x + xa > game.getWidth() - DIAMETER)
xa = -1;
if (y + ya < 0)
ya = 1;
if (y + ya > game.getHeight() - DIAMETER)
game.gameOver();
if (collision()){
ya = -1;
y = game.racquet.getTopY() - DIAMETER;
}
x = x + xa;
y = y + ya;
}
private boolean collision() {
return game.racquet.getBounds().intersects(getBounds());
}
public void paint(Graphics2D g) {
g.fillOval(x, y, DIAMETER, DIAMETER);
}
public Rectangle getBounds() {
return new Rectangle(x, y, DIAMETER, DIAMETER);
}
}
Racquet Class
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.KeyEvent;
public class Racquet {
private static final int Y = 330;
private static final int WIDTH = 60;
private static final int HEIGHT = 10;
int x = 0;
int xa = 0;
private Game game;
public Racquet(Game game) {
this.game = game;
}
public void move() {
if (x + xa > 0 && x + xa < game.getWidth() - WIDTH)
x = x + xa;
}
public void paint(Graphics2D g) {
g.fillRect(x, Y, WIDTH, HEIGHT);
}
public void keyReleased(KeyEvent e) {
xa = 0;
}
public void keyPressed(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_LEFT)
xa = -1;
if (e.getKeyCode() == KeyEvent.VK_RIGHT)
xa = 1;
}
public Rectangle getBounds() {
return new Rectangle(x, Y, WIDTH, HEIGHT);
}
public int getTopY() {
return Y;
}
}

This is an mcve demonstrating the structure outlined in Hovercraft Full Of Eels comment :
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.RenderingHints;
import java.awt.event.ActionListener;
import java.awt.geom.Area;
import java.awt.geom.Ellipse2D;
import java.awt.image.BufferedImage;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class AnimationUsingTimer {
private Timer timer;
AnimationUsingTimer() {
JFrame window = new JFrame();
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
AnimationPanel animationPanel = new AnimationPanel();
window.add(animationPanel);
JButton start = new JButton("Start");
start.addActionListener(e -> animationPanel.start());
window.add(start, BorderLayout.PAGE_START);
JButton stop = new JButton("Stop");
stop.addActionListener(e -> animationPanel.stop());
window.add(stop, BorderLayout.PAGE_END);
window.pack();
window.setVisible(true);
}
class AnimationPanel extends JPanel{
private BufferedImage img;
private Area ball, walls;
private final static int W = 450, H = 300, DIAMETER = 20;
private int x = W/2, y = H/2, xDelta = 3, yDelta = 2;
AnimationPanel() {
img = new BufferedImage(W, H, BufferedImage.TYPE_INT_RGB);
JLabel imageLabel = new JLabel(new ImageIcon(img));
add(imageLabel);
walls = new Area(new Rectangle(0,0,W,H));
ActionListener animate = e -> {
animate();
repaint();
};
timer = new Timer(50, animate);
}
public void animate() {
x+=xDelta; y+=yDelta;
ball = new Area(new Ellipse2D.Double(x, y, DIAMETER, DIAMETER));
if (checkCollision(ball,walls)) {
if ( x+DIAMETER>img.getWidth() || x<0 ) {
xDelta *= -1;
}
if(y+DIAMETER>img.getHeight() || y<0 ) {
yDelta *= -1;
}
}
}
#Override
protected void paintComponent(Graphics g){
super.paintComponent(g);
Graphics2D g2D = img.createGraphics();
g2D.setRenderingHint(
RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2D.setColor(Color.CYAN);
g2D.fillRect(0, 0, img.getWidth(), img.getHeight());
if(ball != null){
g2D.setColor(Color.RED);
g2D.fill(ball);
}
g2D.dispose();
}
void start(){
timer.start();
}
void stop(){
timer.stop();
}
private boolean checkCollision(Area area1, Area area2) {
return area1.getBounds().intersects(area2.getBounds());
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> new AnimationUsingTimer());
}
}

Coordinates in paint

When you click in a box, it should create a circle in that box from the designated coordinate. Unless if its already there then its removed. How do I get currentx and currenty coordinates into the fill oval?
public class Grid extends Applet{
boolean click;
public void init()
{
click = false;
addMouseListener(new MyMouseListener());
}
public void paint(Graphics g)
{
super.paint(g);
g.drawRect(100, 100, 400, 400);
//each box
g.drawRect(100, 100, 100, 100);
g.drawRect(200, 100, 100, 100);
g.drawRect(300, 100, 100, 100);
g.drawRect(400, 100, 100, 100);
//2y
g.drawRect(100, 200, 100, 100);
g.drawRect(200, 200, 100, 100);
g.drawRect(300, 200, 100, 100);
g.drawRect(400, 200, 100, 100);
//3y1x
g.drawRect(100, 300, 100, 100);
g.drawRect(200, 300, 100, 100);
g.drawRect(300, 300, 100, 100);
g.drawRect(400, 300, 100, 100);
//4y1x
g.drawRect(100, 400, 100, 100);
g.drawRect(200, 400, 100, 100);
g.drawRect(300, 400, 100, 100);
g.drawRect(400, 400, 100, 100);
if (click)
{
g.fillOval(currentx, currenty, 100, 100); // problem HERE
}
}
private class MyMouseListener implements MouseListener
{
public void mouseClicked(MouseEvent e)
{
int nowx = e.getX();
int nowy = e.getY();
nowx = nowx / 100;
String stringx = Integer.toString(nowx);
stringx = stringx+"00";
int currentx = Integer.parseInt(stringx);
nowy = nowy /100;
String stringy = Integer.toString(nowy);
stringy = stringy+"00";
int currenty = Integer.parseInt(stringy);
click = true;
repaint();
}
#Override
public void mousePressed(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseReleased(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseEntered(MouseEvent e) {
// TODO Auto-generated method stub
}
#Override
public void mouseExited(MouseEvent e) {
// TODO Auto-generated method stub
}
}
}

Your main problem is, painting in Swing/AWT is destructive, that is, each time your paint method is called, you are expected to repaint the current state of the component.
In that case, what you really need is some way to model the state of the game so when paint is called, you can repaint it in some meaningful way. This a basic concept of a Model-View-Controller paradigm, where you separate the responsibility of the program into separate layers.
The problem then becomes, how do you translate from the view to model?
The basic idea is take the current x/y coordinates of the mouse and divide it by the cell size. You also need to ensure that the results are within the expected ranges, as you could get a result which is beyond the columns/rows of grids
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.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
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 static class TestPane extends JPanel {
protected static final int CELL_COUNT = 3;
private int[][] board;
private int[] cell;
private boolean isX = true;
public TestPane() {
board = new int[CELL_COUNT][CELL_COUNT];
addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
int[] cell = getCellAt(e.getPoint());
if (board[cell[0]][cell[1]] == 0) {
board[cell[0]][cell[1]] = isX ? 1 : 2;
isX = !isX;
repaint();
}
}
});
addMouseMotionListener(new MouseAdapter() {
#Override
public void mouseMoved(MouseEvent e) {
cell = getCellAt(e.getPoint());
repaint();
}
});
}
protected int[] getCellAt(Point p) {
Point offset = getOffset();
int cellSize = getCellSize();
int x = p.x - offset.x;
int y = p.y - offset.y;
int gridx = Math.min(Math.max(0, x / cellSize), CELL_COUNT - 1);
int gridy = Math.min(Math.max(0, y / cellSize), CELL_COUNT - 1);
return new int[]{gridx, gridy};
}
protected Point getOffset() {
int cellSize = getCellSize();
int x = (getWidth() - (cellSize * CELL_COUNT)) / 2;
int y = (getHeight() - (cellSize * CELL_COUNT)) / 2;
return new Point(x, y);
}
protected int getCellSize() {
return Math.min(getWidth() / CELL_COUNT, getHeight() / CELL_COUNT) - 10;
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
Point offset = getOffset();
int cellSize = getCellSize();
if (cell != null) {
g2d.setColor(new Color(0, 0, 255, 128));
g2d.fillRect(
offset.x + (cellSize * cell[0]),
offset.y + (cellSize * cell[1]),
cellSize,
cellSize);
}
g2d.setColor(Color.BLACK);
FontMetrics fm = g2d.getFontMetrics();
for (int col = 0; col < CELL_COUNT; col++) {
for (int row = 0; row < CELL_COUNT; row++) {
int value = board[col][row];
int x = offset.x + (cellSize * col);
int y = offset.y + (cellSize * row);
String text = "";
switch (value) {
case 1:
text = "X";
break;
case 2:
text = "O";
break;
}
x = x + ((cellSize - fm.stringWidth(text)) / 2);
y = y + ((cellSize - fm.getHeight()) / 2) + fm.getAscent();
g2d.drawString(text, x, y);
}
}
int x = offset.x;
int y = offset.y;
for (int col = 1; col < CELL_COUNT; col++) {
x = offset.x + (col * cellSize);
g2d.drawLine(x, y, x, y + (cellSize * CELL_COUNT));
}
x = offset.x;
for (int row = 1; row < CELL_COUNT; row++) {
y = offset.x + (row * cellSize);
g2d.drawLine(x, y, x + (cellSize * CELL_COUNT), y);
}
g2d.dispose();
}
}
}

First off, if you want to truncate a number to the nearest 100, e.g. 142 becomes 100, all you have to do is:
num = (num/100)*100;
this is because when you divide 2 integers it automatically truncates it, and you can just multiply it back to get the number. And what I think you want in this case is to create some field variables and some accessor methods. At the top of your MouseListener class, you will need to add:
private int mouseX=0;
private int mouseY=0;
then to be able to access these variables from outside of the mouselistener class you will need to add accessor methods:
public int getMouseX(){
return mouseX;
}
in your Grid Class, you can add the field:
private MyMouseListener listener;
and then initialize it in your init by doing:
listener = new MyMouseListener();
addMouseListener(listener);
then you can do the same for mouseY, and finally from your paint method you can then call:
int mouseX = listener.getMouseX();
int mouseY = listener.getMouseY();
and from there it is as simple as doing if statements or switch statements to find which box you clicked in!

Moving a background image in Swing

hello im new in programming and we have a project.We created a simple racing game with a moving background but I'm stuck on my code and i don't know how to do it. i need a moving background when the game starts please somebody help me. I'm begging T_T
here is my code:
public class Game extends JFrame implements KeyListener, ActionListener {
Random s = new Random();
int x = 0, y = 50, a = 0, b = 250, f = 900, a1 = 0, b2 = 350, a2 = 0, b3 = 150;
int Move;
int value;
JLabel spriteLabel1 = new JLabel(new ImageIcon("ss.gif"));
JLabel spriteLabel2 = new JLabel(new ImageIcon("ss.gif"));
JLabel spriteLabel3 = new JLabel(new ImageIcon("ss.gif"));
JLabel spriteLabel4 = new JLabel(new ImageIcon("ss.gif"));
JLabel background = new JLabel(new ImageIcon("geren.png"));
Timer T1 = new Timer(5000, this);
Timer T = new Timer(5, this);
public static void main(String args[]) {
new Game();
}
public Game() {
Container c = getContentPane();
c.setLayout(null);
c.add(spriteLabel1);
c.add(spriteLabel2);
c.add(spriteLabel3);
c.add(spriteLabel4);
c.add(background);
background.setBounds(0, 0, 1024, 768);
addKeyListener(this);
setSize(1000, 750);
setVisible(true);
}
public void paint(Graphics g) {
super.paint(g);
spriteLabel1.setBounds(x, y, 60, 1000);
spriteLabel2.setBounds(a, b, 60, 800);
spriteLabel3.setBounds(a1, b2, 60, 500);
spriteLabel4.setBounds(a2, b3, 60, 650);
}
public void keyPressed(KeyEvent e) {
String k = e.getKeyText(e.getKeyCode());
if (k.equals("D")) {
if (a != f) {
x = x + 15;
spriteLabel1.setIcon(new ImageIcon("ss.gif"));
repaint();
if (x > f) {
x = f;
spriteLabel1.setIcon(new ImageIcon("ss.gif"));
//JOptionPane.showMessageDialog(null,"Congratulations!!
//Sanji wins!","Result",JOptionPane.PLAIN_MESSAGE,
//new ImageIcon("evolve sanji.gif"));
//System.exit(0);
}
repaint();
}
}
T.stop();
}
if(k.equals (
"D"))
{
if (x != f) {
T.start();
Move = 3;
}
}
public void keyReleased(KeyEvent e) {
}
public void keyTyped(KeyEvent e) {
}
public void actionPerformed(ActionEvent e) {
if (Move == 3) {
a = a + (s.nextInt(3));
a = a + value;
if (a > f) {
a = f;
}
spriteLabel2.setIcon(new ImageIcon("ss.gif"));
spriteLabel2.setBounds(a, b, 100, 800);
}
if (a == f) {
if (Move == 3) {
a1 = a1 + (s.nextInt(3));
a1 = a1 + value;
if (a1 > f) {
a1 = f;
}
spriteLabel3.setIcon(new ImageIcon("ss.gif"));
spriteLabel3.setBounds(a1, b2, 100, 500);
}
if (Move == 3) {
a2 = a2 + (s.nextInt(5));
a2 = a2 + value;
if (a2 > f) {
a2 = f;
}
spriteLabel4.setIcon(new ImageIcon("ss.gif"));
spriteLabel4.setBounds(a2, b3, 100, 650);
}
}
}
}

Here's the spoiler
Here's the meat
There a a few things I see you doing wrong:
Constantly creating new Images. Just use the same image.
I would, instead of using label, just paint an Image/BufferedImage onto the painting surface.
Forget two timers. You can make due with one. It's just how you manage your state.
Don't do any logic in the paint method. In your current case, since are not even painting anything, you don't even need it. In my example though I do paint the image.
Don't Paint on JFrame and override paint. Override paintComponent instead in a JPanel and add that panel to the frame.
Finally, the key ingredient, use the method (from Graphics) -
public abstract boolean drawImage(Image img,
int dx1,
int dy1,
int dx2,
int dy2,
int sx1,
int sy1,
int sx2,
int sy2,
ImageObserver observer)
You can get a better explanation about it in this post. Basically, the s points are the source image, so you can just move the sx1 and sx2 during the animation, and it will move the part of the image to be drawn at the d points of the painting surface.
If you don't know how to really do custom painting, I suggest you run through Performing Custom Painting
Here's the full example
(Note the image I used for the background was 2000x350)
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class MovingBackgroundDemo {
public MovingBackgroundDemo() {
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new AnimatingPanel());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
private class AnimatingPanel extends JPanel {
private static final int DIM_W = 350;
private static final int DIM_H = 350;
private static final int INCREMENT = 10;
private BufferedImage backgroundImage;
private Image runnerImage;
private int dx1, dy1, dx2, dy2;
private int srcx1, srcy1, srcx2, srcy2;
private int IMAGE_WIDTH;
public AnimatingPanel() {
initImages();
initImagePoints();
Timer timer = new Timer(40, new ActionListener() {
public void actionPerformed(ActionEvent e) {
moveBackground();
repaint();
}
});
timer.start();
FlowLayout layout = (FlowLayout)getLayout();
layout.setHgap(0);
layout.setVgap(0);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.setColor(Color.WHITE);
g.fillRect(0, 0, getWidth(), getHeight());
g.drawImage(backgroundImage, dx1, dy1, dx2, dy2, srcx1, srcy1,
srcx2, srcy2, this);
g.drawImage(runnerImage, 0, 0, getWidth(), getHeight(), this);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(350, 350);
}
private void initImagePoints() {
dx1 = 0;
dy1 = 0;
dx2 = DIM_W;
dy2 = DIM_H;
srcx1 = 0;
srcy1 = 0;
srcx2 = DIM_W;
srcy2 = DIM_H;
}
private void initImages() {
try {
runnerImage = new ImageIcon(getClass().getResource("runner.gif")).getImage();
backgroundImage = ImageIO.read(getClass().getResource(
"background.png"));
IMAGE_WIDTH = backgroundImage.getWidth();
System.out.println(IMAGE_WIDTH);
} catch (Exception ex) {
ex.printStackTrace();
}
}
private void moveBackground() {
if (srcx1 > IMAGE_WIDTH) {
srcx1 = 0 - DIM_W;
srcx2 = 0;
} else {
srcx1 += INCREMENT;
srcx2 += INCREMENT;
}
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new MovingBackgroundDemo();
}
});
}
}

JAVA Bounding Box / Collison Detection

I am trying to build a basic Arcanoid/Breakout style game in JAVA. I am having trouble with the collision detection between the ball and the bricks. I am using bounding boxes around all entities in the game. When the ball hits the player's paddle, the collision is detected. When the ball hits the bricks coordinates, no collision is detected. Any one have any ideas. Code below.
Game.java
package com.seadnamcgillycuddy.unipong;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import javax.swing.JOptionPane;
import javax.swing.JFrame;
import javax.swing.JPanel;
#SuppressWarnings("serial")
public class Game extends JPanel {
Ball ball = new Ball(this);
Paddle paddle = new Paddle(this);
Brick brick = new Brick(this, 50, 20);
Brick brick2 = new Brick(this, 75, 20);
Brick brick3 = new Brick(this, 100, 20);
Brick brick4 = new Brick(this, 125, 20);
Brick brick5 = new Brick(this, 150, 20);
Brick brick6 = new Brick(this, 175, 20);
Brick brick7 = new Brick(this, 200, 20);
Brick brick8 = new Brick(this, 225, 20);
Brick brick9 = new Brick(this, 250, 20);
int speed = 1;
private int getScore() {
return speed - 1;
}
public Game() {
addKeyListener(new KeyListener() {
#Override
public void keyTyped(KeyEvent e) {
}
#Override
public void keyReleased(KeyEvent e) {
paddle.keyReleased(e);
}
#Override
public void keyPressed(KeyEvent e) {
paddle.keyPressed(e);
}
});
setFocusable(true);
}
private void move() {
ball.move();
paddle.move();
}
#Override
public void paint(Graphics g) {
super.paint(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
ball.paint(g2d);
paddle.paint(g2d);
brick.paint(g2d);
brick2.paint(g2d);
brick3.paint(g2d);
brick4.paint(g2d);
brick5.paint(g2d);
brick6.paint(g2d);
brick7.paint(g2d);
brick8.paint(g2d);
brick9.paint(g2d);
g2d.setColor(Color.GRAY);
g2d.setFont(new Font("Verdana", Font.BOLD, 30));
g2d.drawString(String.valueOf(getScore()), 10, 30);
}
public void gameOver() {
JOptionPane.showMessageDialog(this, "Your Score Is: " + getScore(), "Game Over", JOptionPane.YES_NO_OPTION);
System.exit(ABORT);
}
public static void main(String[] args) throws InterruptedException {
JFrame frame = new JFrame("UniPong");
Game game = new Game();
frame.add(game);
frame.setSize(400, 750);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
while (true){
game.move();
game.repaint();
Thread.sleep(10);
}
}
}
Ball.java
package com.seadnamcgillycuddy.unipong;
import java.awt.Graphics2D;
import java.awt.Rectangle;
public class Ball {
private static final int DIAMETER = 10;
int x = 0;
int y = 0;
int xa = 1;
int ya = 1;
private Game game;
public Ball(Game game) {
this.game = game;
}
void move() {
boolean changeDirection = true;
if (x + xa < 0)
xa = game.speed;
else if (brickCollision()){
System.out.println("Collission!!!!");
}
else if (x + xa > game.getWidth() - DIAMETER)
xa = -game.speed;
else if (y + ya < 0)
ya = game.speed;
else if (y + ya > game.getHeight() - DIAMETER)
game.gameOver();
else if (collision()) {
ya = -game.speed;
y = game.paddle.getTopY() - DIAMETER;
game.speed++;
} else
changeDirection = false;
x = x + xa;
y = y + ya;
}
private boolean collision() {
return game.paddle.getBounds().intersects(getBounds());
}
private boolean brickCollision() {
return game.brick.getBounds().intersects(getBounds());
//return game.ball.getBounds().intersects(getBounds());
}
public void paint (Graphics2D g) {
g.fillOval(x, y, DIAMETER, DIAMETER);
}
public Rectangle getBounds() {
return new Rectangle(x, y, DIAMETER, DIAMETER);
}
}
Brick.java
package com.seadnamcgillycuddy.unipong;
import java.awt.Graphics2D;
import java.awt.Rectangle;
public class Brick {
int Y;
int X;
private static final int WIDTH = 20;
private static final int HEIGHT = 10;
private Game game;
public Brick(Game game, int X, int Y) {
this.X = X;
this.Y = Y;
this.game = game;
}
public void paint(Graphics2D g) {
g.fillRect(X, Y, WIDTH, HEIGHT);
}
public Rectangle getBounds() {
return new Rectangle(X, Y, WIDTH, HEIGHT);
}
public int getBrickBottomY() {
return Y - HEIGHT;
}
}
Paddle.java
package com.seadnamcgillycuddy.unipong;
import java.awt.Graphics2D;
import java.awt.event.KeyEvent;
import java.awt.Rectangle;
public class Paddle {
private static final int Y = 680;
private static final int WIDTH = 60;
private static final int HEIGHT = 10;
int x = 0;
int xa = 0;
private Game game;
public Paddle(Game game) {
this.game = game;
}
public void move () {
if (x + xa > 0 && x + xa < game.getWidth() - 60)
x = x + xa;
}
public void paint(Graphics2D g) {
g.fillRect(x, Y, WIDTH, HEIGHT);
}
public void keyReleased(KeyEvent e) {
xa = 0;
}
public void keyPressed(KeyEvent e) {
if (e.getKeyCode() == KeyEvent.VK_LEFT)
xa = -game.speed;
if (e.getKeyCode() == KeyEvent.VK_RIGHT)
xa = game.speed;
}
public Rectangle getBounds() {
return new Rectangle(x, Y, WIDTH, HEIGHT);
}
public int getTopY() {
return Y - HEIGHT;
}
}

When you check for collisions with this line
return game.brick.getBounds().intersects(getBounds());
you're only checking intersection with one brick, brick, and not with the other 9 bricks you made, brick1, ..., brick9.
I'd recommend making an array of bricks, and then looping through them and checking collisions with each of them. Then, you can have as many bricks as you want and it won't take more code to check.