How to create a cube in swing? - java

I am trying to make a class that when invoked by a JPanel, creates a cube. What I have seen though, is something called a ColorCube, which requires a "Universe" of some sort, and a Canvas, though I didn't find this method to be compatible with JPanel.
TO clarify, I am not asking how to create a custom JComponent(exactly), nor am I asking how to add color or rotate it, just how to create a class that when invoked by a JPanel renders a cube to the screen.

All you really need are x, y, and size passed to the Cube class, then
Take those arguments and build an array of corners points for a first square and also corner points for a second shifted square. See methods getCubeOnePoints and getCubeTwoPoints methods in the Cube class.
Draw the first square. Draw the second square, and connect the points from the point arrays. See the drawCube method in the Cube class.
Create an instance of the Cube class passing necessary arguments, and draw the cube. See CubePanel constructor and paintComponent method
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
public class CubePanel extends JPanel{
private static final int D_W = 400;
private static final int D_H = 400;
Cube cube;
public CubePanel() {
cube = new Cube(75, 75, 200, 50);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
cube.drawCube(g);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(D_W, D_H);
}
public class Cube {
int x, y, size, shift;
Point[] cubeOnePoints;
Point[] cubeTwoPoints;
public Cube(int x, int y, int size, int shift) {
this.x = x;
this.y = y;
this.size = size;
this.shift = shift;
cubeOnePoints = getCubeOnePoints();
cubeTwoPoints = getCubeTwoPoints();
}
private Point[] getCubeOnePoints() {
Point[] points = new Point[4];
points[0] = new Point(x, y);
points[1] = new Point(x + size, y);
points[2] = new Point(x + size, y + size);
points[3] = new Point(x, y + size);
return points;
}
private Point[] getCubeTwoPoints() {
int newX = x + shift;
int newY = y + shift;
Point[] points = new Point[4];
points[0] = new Point(newX, newY);
points[1] = new Point(newX + size, newY);
points[2] = new Point(newX + size, newY + size);
points[3] = new Point(newX, newY + size);
return points;
}
public void drawCube(Graphics g) {
g.drawRect(x, y, size, size);
g.drawRect(x + shift, y + shift, size, size);
// draw connecting lines
for (int i = 0; i < 4; i++) {
g.drawLine(cubeOnePoints[i].x, cubeOnePoints[i].y,
cubeTwoPoints[i].x, cubeTwoPoints[i].y);
}
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
JFrame frame = new JFrame();
frame.add(new CubePanel());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}
UPDATE
"what if i wanted this in a 3d where the cube could be walked around "
Just create methods to shift all the xs or ys and call it, then repaint. The method could look something like
public void shiftLeft() {
x -= SHIFT_INC;
for (Point p : cubeOnePoints) {
p.x -= SHIFT_INC;
}
for (Point p : cubeTwoPoints) {
p.x -= SHIFT_INC;
}
}
In the example below, I just call it in a key bind with the ←key.
im.put(KeyStroke.getKeyStroke("LEFT"), "shiftLeft");
getActionMap().put("shiftLeft", new AbstractAction(){
public void actionPerformed(ActionEvent e) {
cube.shiftLeft();
repaint();
}
});
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.ActionEvent;
import javax.swing.AbstractAction;
import javax.swing.InputMap;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
import javax.swing.SwingUtilities;
public class CubePanel extends JPanel{
private static final int D_W = 400;
private static final int D_H = 300;
Cube cube;
public CubePanel() {
cube = new Cube(75, 75, 50, 15);
InputMap im = getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
im.put(KeyStroke.getKeyStroke("RIGHT"), "shiftRight");
getActionMap().put("shiftRight", new AbstractAction(){
public void actionPerformed(ActionEvent e) {
cube.shiftRight();
repaint();
}
});
im.put(KeyStroke.getKeyStroke("LEFT"), "shiftLeft");
getActionMap().put("shiftLeft", new AbstractAction(){
public void actionPerformed(ActionEvent e) {
cube.shiftLeft();
repaint();
}
});
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
cube.drawCube(g);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(D_W, D_H);
}
public class Cube {
private static final int SHIFT_INC = 5;
int x, y, size, shift;
Point[] cubeOnePoints;
Point[] cubeTwoPoints;
public Cube(int x, int y, int size, int shift) {
this.x = x;
this.y = y;
this.size = size;
this.shift = shift;
cubeOnePoints = getCubeOnePoints();
cubeTwoPoints = getCubeTwoPoints();
}
private Point[] getCubeOnePoints() {
Point[] points = new Point[4];
points[0] = new Point(x, y);
points[1] = new Point(x + size, y);
points[2] = new Point(x + size, y + size);
points[3] = new Point(x, y + size);
return points;
}
private Point[] getCubeTwoPoints() {
int newX = x + shift;
int newY = y + shift;
Point[] points = new Point[4];
points[0] = new Point(newX, newY);
points[1] = new Point(newX + size, newY);
points[2] = new Point(newX + size, newY + size);
points[3] = new Point(newX, newY + size);
return points;
}
public void shiftLeft() {
x -= SHIFT_INC;
for (Point p : cubeOnePoints) {
p.x -= SHIFT_INC;
}
for (Point p : cubeTwoPoints) {
p.x -= SHIFT_INC;
}
}
public void shiftRight() {
x += SHIFT_INC;
for (Point p : cubeOnePoints) {
p.x += SHIFT_INC;
}
for (Point p : cubeTwoPoints) {
p.x += SHIFT_INC;
}
}
public void drawCube(Graphics g) {
g.drawRect(x, y, size, size);
g.drawRect(x + shift, y + shift, size, size);
// draw connecting lines
for (int i = 0; i < 4; i++) {
g.drawLine(cubeOnePoints[i].x, cubeOnePoints[i].y,
cubeTwoPoints[i].x, cubeTwoPoints[i].y);
}
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
JFrame frame = new JFrame();
frame.add(new CubePanel());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
}

package Box;
import javax.swing.BorderFactory;
import javax.swing.JPanel;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ComponentListener;
import java.awt.event.ComponentEvent;
public class Box2 extends JPanel
{
public Box2()
{
this.addComponentListener(new ComponentListener(){
public void componentShown(ComponentEvent arg0) {
// TODO Auto-generated method stub
}
public void componentResized(ComponentEvent arg0) {
paintComponent(getGraphics());
}
public void componentMoved(ComponentEvent arg0) {
// TODO Auto-generated method stub
}
public void componentHidden(ComponentEvent arg0) {
// TODO Auto-generated method stub
}
});
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
this.setBackground(Color.white);
Dimension d;
d=getSize();
int height, width;
height =d.height;
width=d.width;
int w,h;
javax.swing.border.Border linebor =BorderFactory.createLineBorder(new Color(0xAD85FF),6 );
g.drawRect(0,0, w=width/2, h=height/2);
g.drawRect(w/2,h/2,w/2*2,h/2*2);
g.drawLine(0,0,w/2,h/2);
g.drawLine(w,h,w/2+w/2*2,h/2+h/2*2);
g.drawLine(w,0,w/2+w/2*2,h/2);
g.drawLine(0,h,w/2,h/2+h/2*2);
//g.drawLine(0, height – borderControl, width, height – borderControl);
}
}
Now make another class for Main File
package Box;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Box2_main extends JPanel
{
public static void main(String[] args)
{
Box2 cube = new Box2();
JFrame frame = new JFrame("Cube2");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(cube);
frame.setSize(500, 500);
frame.setVisible(true);
}
}
If you change the dimensions of the window then the size of the cube will also increase/decrease.

Related

Can't get MouseListener to work on Hexagon (a generated polygon)

I'm generating a hexagon grid and am able to do so but when I add a MouseListener to the individual hexagons (when they're created) it's almost as if they're behind something because hovering/clicking on a hexagon will not register or do anything for that matter. I want to be able to eventually interact with the hexagons but can't do that if I can't get this to work.
My main GUI elements:
import java.awt.*;
import javax.swing.*;
public class Game2
{
public Game2(int radius,int num_hexes)
{
if(num_hexes%2==0) throw new AssertionError("Can't generate map with
an even number of hexagons.");
JFrame frame=new JFrame();
JPanel panel=new JPanel();
panel.setBorder(BorderFactory.createLineBorder(Color.RED));
panel.setLayout(new BoxLayout(panel,1));
frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
frame.setTitle("HexGame");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.setLayout(new BorderLayout());
Rectangle r=frame.getBounds();
int screen_height=r.height;
int screen_width=r.width;
Hexes2 hexes2=new Hexes2(num_hexes,radius,screen_width,screen_height);
panel.add(hexes2);
JScrollPane scroll_pane=new JScrollPane(panel);
frame.getContentPane().add(scroll_pane);
panel.setOpaque(false);
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args)
{
Runnable r=new Runnable()
{
#Override
public void run()
{
new Game2(100,11);
}
};
SwingUtilities.invokeLater(r);
}
}
My multiple hexagons:
import java.awt.*;
import java.util.LinkedList;
import java.util.List;
import javax.swing.JPanel;
public class Hexes2 extends JPanel
{
private static final long serialVersionUID=1L;
private static List<Polygon> hexagons;
private static int[] rows;
private int radius;
public Hexes2(int num_columns,int radius,int screen_width,int screen_height)
{
super();
this.radius=radius;
hexagons=new LinkedList<Polygon>();
rows=Functions.columns(num_columns);
int x=screen_width/6;
int y=screen_height/2;
double height=radius*Math.sqrt(3);
double range=num_columns-rows[0];
//build by columns, first
for(int j=0;j<num_columns;j++)
{
x+=((3/2)*radius)*1.5015;
if(j<=Math.floor(num_columns/2)) y=(int) (100-(j*(height/2)));
else y=(int) ((100-(height*(range/2))+(num_columns-rows[j])*(height/2)));
for(int i=0;i<rows[j];i++)
{
y+=height;
Hex2 hex=new Hex2(i,radius,x,y);
hexagons.add(hex.getHex());
}
}
}
protected void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2=(Graphics2D) g;
setOpaque(false);
for(int i=0;i<hexagons.size();i++)
{
Stroke stroke=new BasicStroke(radius/20, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND);
g2.setStroke(stroke);
g2.setColor(Color.BLACK);
g2.drawPolygon(hexagons.get(i));
}
}
};
My singular hexagon class:
import java.awt.*;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JLabel;
public class Hex2 extends JLabel implements MouseListener
{
private static final long serialVersionUID = 1L;
private int ID;
private Polygon hexagon;
public Hex2(int ID,int r,int x,int y)
{
super();
this.ID=ID;
hexagon=generateHex(r,x,y);
addMouseListener(this);
}
public Polygon generateHex(int r, int x, int y)
{
Polygon hexagon=new Polygon();
for(int i=0;i<6;i++)
{
/*int _x=(int) (x + r*Math.cos(Math.PI / 3.0 * i));
int _y=(int) (y + r*Math.sin(Math.PI / 3.0 * i));*/
int _x=(int) (x + r*Math.cos(i*2*Math.PI/6));
int _y=(int) (y + r*Math.sin(i*2*Math.PI/6));
hexagon.addPoint(_x,_y);
}
return hexagon;
}
public int getID()
{
return ID;
}
public Polygon getHex()
{
return hexagon;
}
#Override
public void mouseClicked(MouseEvent arg0) {
System.out.println("Clicked on hexagon "+ID);
}
#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) {
// TODO Auto-generated method stub
}
};
Functions:
import java.awt.Dimension;
public class Functions
{
//takes in the max width, n (# hexagons), of the largest row (in the middle)
public static int[] columns(int n)
{
int[] columns=new int[n];
int deviation=(int) java.lang.Math.floor(n/2);
for(int i=0;i<n;i++)
{
columns[i]=n-(java.lang.Math.abs(i-deviation));
}
return columns;
}
public static Dimension getScreenSize()
{
return java.awt.Toolkit.getDefaultToolkit().getScreenSize();
}
}
I apologize for the long code, just wanted to be thorough. Any help greatly appreciated, thanks in advance.
You're adding your MouseListener to your Hex2 JLabels:
public Hex2(int ID, int r, int x, int y) {
super();
this.ID = ID;
hexagon = generateHex(r, x, y);
addMouseListener(this);
}
These are JLabels that you never add to the GUI, since you create them here in line A:
for (int j = 0; j < num_columns; j++) {
x += ((3 / 2) * radius) * 1.5015;
if (j <= Math.floor(num_columns / 2))
y = (int) (100 - (j * (height / 2)));
else
y = (int) ((100 - (height * (range / 2)) + (num_columns - rows[j]) * (height / 2)));
for (int i = 0; i < rows[j]; i++) {
y += height;
Hex2 hex = new Hex2(i, radius, x, y); // ****** [A] *****
hexagons.add(hex.getHex()); // ****** [B] *****
}
}
But hex never is added to the GUI. Instead something else, returned by getHex() is added, so the MouseListener won't work. A MouseListener needs to be added to a component that is visualized within the GUI for its actions to do anything.
I think that you're using too many components here. Only one component, a JPanel, should do all the drawings and should have the MouseLIstener added to it. Everything else should be logical classes that don't extend Swing component classes.
For example, run the code below. It shows that the hex as a non-component class, one that responds to a MouseListener since the listener is added only to the single drawing JLabel. Polygons are shapes and have a contains(Point p) method that can be used inside of the mouse listener to allow them to "know" when they've been pressed:
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Polygon;
import java.awt.RenderingHints;
import java.awt.Stroke;
import java.awt.Toolkit;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
import javax.swing.*;
public class HexPanel extends JPanel {
private static final long serialVersionUID = 1L;
private List<Hex2b> hex2bs = new ArrayList<>();
private int radius;
private int[] rows;
public HexPanel(int num_columns, int radius, int screen_width, int screen_height) {
super();
setBackground(Color.WHITE);
this.radius = radius;
hex2bs = new LinkedList<Hex2b>();
rows = Functions.columns(num_columns);
int x = screen_width / 6;
int y = screen_height / 2;
double height = radius * Math.sqrt(3);
double range = num_columns - rows[0];
// build by columns, first
for (int j = 0; j < num_columns; j++) {
x += ((3 / 2) * radius) * 1.5015;
if (j <= Math.floor(num_columns / 2))
y = (int) (100 - (j * (height / 2)));
else
y = (int) ((100 - (height * (range / 2)) + (num_columns - rows[j]) * (height / 2)));
for (int i = 0; i < rows[j]; i++) {
y += height;
Hex2b hex = new Hex2b(i, radius, x, y);
hex2bs.add(hex);
}
}
addMouseListener(new MyMouse());
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); // smooth graphics
// setOpaque(false); // doesn't belong in here
for (int i = 0; i < hex2bs.size(); i++) {
Stroke stroke = new BasicStroke(radius / 20, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND);
Hex2b hex2b = hex2bs.get(i);
Color color = hex2b.getColor();
g2.setColor(color);
g2.fill(hex2b.getHex());
g2.setStroke(stroke);
g2.setColor(Color.BLACK);
g2.draw(hex2b.getHex());
}
}
private class MyMouse extends MouseAdapter {
#Override
public void mousePressed(MouseEvent e) {
for (Hex2b hex2b : hex2bs) {
if (hex2b.getHex().contains(e.getPoint())) {
hex2b.changeColor();
repaint();
break;
}
}
}
}
private static void createAndShowGui() {
JFrame frame = new JFrame("Game2b");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Toolkit toolKit = Toolkit.getDefaultToolkit();
Dimension screen = toolKit.getScreenSize();
int width = screen.width;
int height = screen.height;
frame.getContentPane().add(new HexPanel(11, 100, width, height));
frame.setExtendedState(JFrame.MAXIMIZED_BOTH);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
class Hex2b {
private static final Color INIT_COLOR = Color.white;
private static final Color SELECTED_COLOR = Color.red;
private int ID;
private Polygon hexagon;
private Color color = INIT_COLOR;
public Hex2b(int ID, int r, int x, int y) {
super();
this.ID = ID;
hexagon = generateHex(r, x, y);
}
public Color getColor() {
return color;
}
public void changeColor() {
color = color == INIT_COLOR ? SELECTED_COLOR : INIT_COLOR;
}
public Polygon generateHex(int r, int x, int y) {
Polygon hexagon = new Polygon();
for (int i = 0; i < 6; i++) {
int _x = (int) (x + r * Math.cos(i * 2 * Math.PI / 6));
int _y = (int) (y + r * Math.sin(i * 2 * Math.PI / 6));
hexagon.addPoint(_x, _y);
}
return hexagon;
}
public int getID() {
return ID;
}
public Polygon getHex() {
return hexagon;
}
}

Swing threading vs timers in my program Java

I'm looking for some guidance in finishing my program for my project. It is a simple simulation where multiple graphical objects are drawn at runtime and using a button to add another ball in this case to the jpanel, I had to rewrite my whole code to take in multiple objects at once just 2 days ago and last night I did some research when I got an exception...changed some code then got another exception in thread AWT EventQueue 0, after doing some more research many people suggested that dynamically drawing objects on a jpanel at runtime with a thread is a pain in the.... and I should just use a timer instead so this is where I am at right now. The Grid_Bag_Constraints can be ignored for the time being as its just to lay it out at the moment.
My question is how could i make it so a new ball is added at runtime on the press of a button...sorry forgot to mention
Ps yeh i tried playing round with validating the jpanels already :/
All guidance is appreciated :)
Sim
=============
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;
import java.util.Random;
import javax.swing.*;
public class Sim extends JPanel
private static final int UPDATE_RATE = 60; // Number of refresh per second
public static int X = 640;
public static int Y = 480;
public static int numberOfBall = 3;
public static boolean isRunning = true;
public Sim() {
// have some code here all commented out
}
public static void main(String[] args) {
// Run GUI in the Event Dispatcher Thread (EDT) instead of main thread.
SwingUtilities.invokeLater(new Runnable() {
public void run() {
// Set up main window (using Swing's Frame)
JFrame frame = new JFrame("Simulation");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
c.gridwidth = 3;
c.gridheight = 3;
balls balls = new balls();
frame.add(balls);
gui GUI = new gui();
frame.add(GUI);
frame.setPreferredSize(new Dimension(1280,720));
frame.setResizable(false);
//frame.setContentPane(new Sim());
frame.pack();
frame.setVisible(true);
new Thread(new bounceEngine(balls)).start();
}
});
}
public static int random(int maxRange) {
return (int) Math.round((Math.random() * maxRange));
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
invalidate();
repaint();
}
gui
---------
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class gui extends JPanel {
boolean shouldFill;
public gui(){
setLayout(new GridBagLayout());
GridBagConstraints c = new GridBagConstraints();
if(shouldFill){
c.fill = GridBagConstraints.HORIZONTAL;
}
AbstractButton addBallButton = new JButton("Add Ball");
addBallButton.setMultiClickThreshhold(1500);
addBallButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent actionEvent) {
balls.listBalls.add(new Ball((new Color(Sim.random(255),Sim.random(255), Sim.random(255))),20));
for(Ball ball : balls.listBalls){
System.out.print("I work ");
}
invalidate();
//repaint();
}
});
c.fill = GridBagConstraints.HORIZONTAL;
c.weightx = 1;
c.weighty = 0.5;
add(addBallButton);
bounceEngine
------------------
import java.awt.*;
import javax.swing.*;
public class bounceEngine implements Runnable {
private balls parent;
private int UPDATE_RATE = 144;
public bounceEngine(balls parent) {
this.parent = parent;
}
public void run() {
int width = Sim.X;
int height = Sim.Y;
// Randomize the starting position...
for (Ball ball : getParent().getBalls()) {
int x = Sim.random(width);
int y = Sim.random(height);
int size = ball.getRadius();
if (x + size > width) {
x = width - size;
}
if (y + size > height) {
y = height - size;
}
ball.setLocation(new Point(x, y));
}
while (getParent().isVisible()) {
// Repaint the balls pen...
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
getParent().repaint();
}
});
//I know this is dangerous to update it as the repaint method is called
for (Ball ball : getParent().getBalls()) {
move(ball);
}
try{
Thread.sleep(1000/UPDATE_RATE);
}catch (InterruptedException e){
}
}
}
public balls getParent() {
return parent;
}
public void move(Ball ball) {
Point p = ball.getLocation();
Point speed = ball.getSpeed();
int size = ball.getRadius();
int vx = speed.x;
int vy = speed.y;
int x = p.x;
int y = p.y;
if (x + vx < 0 || x + (size*2) + vx > getParent().getWidth()) {
vx *= -1;
}
if (y + vy < 0 || y + (size*2) + vy > getParent().getHeight()) {
vy *= -1;
}
x += vx;
y += vy;
ball.setSpeed(new Point(vx, vy));
ball.setLocation(new Point(x, y));
}
balls(for all the balls)
---------------------------------
import java.awt.*;
import java.awt.event.*;
import java.util.ArrayList;
import java.util.Random;
import javax.swing.*;
public class balls extends JPanel {
public static ArrayList<Ball> listBalls;
public balls() {
setPreferredSize(new Dimension(640,480));
setBackground(Color.white);
listBalls = new ArrayList<Ball>(10);
for(int i = 0; i < Sim.numberOfBall; i++){
listBalls.add(new Ball((new Color(Sim.random(255),Sim.random(255), Sim.random(255))),20));
}
}
public ArrayList<Ball> getBall(){
return listBalls;
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
for (Ball ball : listBalls) {
ball.paint(g2d);
}
g2d.dispose();
}
public ArrayList<Ball> getBalls(){
return listBalls;
}
Ball(for 1 ball object blank class with basic constructor)
----------------------------------------------------------------------
import java.awt.*;
public class Ball {
private Color color;
private Point location;
private int radius;
private Point speed;
public Ball(Color color, int radius) {
setColor(color);
speed = new Point(5 - Sim.random(20), 5 - Sim.random(20));
this.radius = radius;
}
public int getRadius() {
return radius;
}
public void setColor(Color color) {
this.color = color;
}
public void setLocation(Point location) {
this.location = location;
}
public Color getColor() {
return color;
}
public Point getLocation() {
return location;
}
public Point getSpeed() {
return speed;
}
public void setSpeed(Point speed) {
this.speed = speed;
}
protected void paint(Graphics2D g2d) {
Point p = getLocation();
if (p != null) {
g2d.setColor(getColor());
g2d.fillOval(p.x, p.y, radius*2, radius*2);
}
}
}

java GUI to assign array value

There is one Paraview user interface as follow attracted me.
I think this interface can be used to assign value into array. It works like this :
I want to implement this into a Java program but I found no Java API can support my idea. The closest design from me would be adding multiple JSlider like this :
But what if it is a 100 size array, I wouldn't want to add 100 JSliders. Do you have better solution for this ?
Okay, so this is a pretty basic example. It needs a lot more work and optimisation, but should get you moving in the right direction
Have a look at Painting in AWT and Swing, Performing Custom Painting, 2D Graphics and How to Write a Mouse Listener for more details
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Shape;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Path2D;
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 TestGraph {
public static void main(String[] args) {
new TestGraph();
}
public TestGraph() {
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 GraphPane(0, 100, new int[100]));
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public static class GraphPane extends JPanel {
protected static final int COLUMN_WIDTH = 10;
protected static final int VERTICAL_INSETS = 10;
private int[] data;
private int minValue, maxValue;
private Path2D.Double graph;
private List<Shape> buttons;
private Point mousePoint;
public GraphPane(int minValue, int maxValue, int[] data) {
this.data = data;
this.minValue = minValue;
this.maxValue = maxValue;
buttons = new ArrayList<>(data == null ? 25 : data.length);
updateView();
MouseAdapter ma = new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
updateData(e);
}
#Override
public void mouseDragged(MouseEvent e) {
updateData(e);
}
};
addMouseListener(ma);
addMouseMotionListener(ma);
}
protected void updateData(MouseEvent e) {
// Which "column" was clicked on
int column = (int) Math.round(((double) e.getX() / (double) COLUMN_WIDTH)) - 1;
// Get the "height" of the clickable area
int clickRange = getHeight() - (VERTICAL_INSETS * 2);
// Adjust the y click point for the margins...
int yPos = e.getY() - VERTICAL_INSETS;
// Calculate the vertical position that was clicked
// this ensures that the range is between 0 and clickRange
// You could choose to ignore values out side of this range
int row = Math.min(Math.max(clickRange - yPos, 0), clickRange);
// Normalise the value between 0-1
double clickNormalised = row / (double) clickRange;
// Calculate the actual row value...
row = minValue + (int) (Math.round(clickNormalised * maxValue));
// Update the data
data[column] = row;
mousePoint = new Point(
COLUMN_WIDTH + (column * COLUMN_WIDTH),
getHeight() - (VERTICAL_INSETS + (int) Math.round((data[column] / 100d) * clickRange)));
updateView();
repaint();
}
#Override
public void invalidate() {
super.invalidate();
updateView();
}
protected Shape createButton(int xPos, int yPos) {
return new Ellipse2D.Double(xPos - COLUMN_WIDTH / 2, yPos - COLUMN_WIDTH / 2, COLUMN_WIDTH, COLUMN_WIDTH);
}
protected void updateView() {
graph = new Path2D.Double();
buttons.clear();
if (data != null && data.length > 0) {
int verticalRange = getHeight() - (VERTICAL_INSETS * 2);
int xPos = COLUMN_WIDTH;
int yPos = getHeight() - (VERTICAL_INSETS + (int) Math.round((data[0] / 100d) * verticalRange));
graph.moveTo(xPos, yPos);
if (data[0] > 0) {
buttons.add(createButton(xPos, yPos));
}
for (int index = 1; index < data.length; index++) {
xPos = (index * COLUMN_WIDTH) + COLUMN_WIDTH;
yPos = getHeight() - (VERTICAL_INSETS + (int) Math.round((data[index] / 100d) * verticalRange));
graph.lineTo(xPos, yPos);
if (data[index] > 0) {
buttons.add(createButton(xPos, yPos));
}
}
}
}
#Override
public Dimension getPreferredSize() {
return new Dimension(data == null ? 0 : (data.length + 1) * COLUMN_WIDTH, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (data != null) {
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(new Color(64, 64, 64, 32));
for (int index = 0; index < data.length; index++) {
int xPos = (index * COLUMN_WIDTH) + COLUMN_WIDTH;
g2d.drawLine(xPos, VERTICAL_INSETS, xPos, getHeight() - VERTICAL_INSETS);
}
g2d.setColor(Color.BLACK);
g2d.draw(graph);
for (Shape button : buttons) {
g2d.fill(button);
}
if (mousePoint != null) {
g2d.setColor(new Color(255, 192, 203));
Ellipse2D dot = new Ellipse2D.Double((mousePoint.x - COLUMN_WIDTH / 2) - 2, (mousePoint.y - COLUMN_WIDTH / 2) - 2, COLUMN_WIDTH + 4, COLUMN_WIDTH + 4);
g2d.draw(dot);
g2d.setColor(new Color(255, 192, 203, 128));
g2d.fill(dot);
}
g2d.dispose();
}
}
}
}
Before anyone says I didn't put the "fill" in, I deliberately used a Path2D to make it much simpler to achieve ;)
here is a small example how to create this using polygon class .i sorted x coordinate and use polygon class to make this.
GraphPane.class
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Polygon;
import java.awt.RenderingHints;
import java.util.ArrayList;
import java.util.Collections;
import javax.swing.JPanel;
public class GraphPane extends JPanel {
ArrayList<XYpoints> poinList = new ArrayList();
private int px;
private int py;
private XYpoints last;
private boolean drag;
private static Color graphColor=new Color(32, 178, 170);
public GraphPane() {
initComponents();
poinList.add(new XYpoints(50, 400));
poinList.add(new XYpoints(450, 50));
poinList.add(new XYpoints(600, 400));
}
private void initComponents() {
setBackground(new java.awt.Color(255, 255, 255));
addMouseMotionListener(new java.awt.event.MouseMotionAdapter() {
public void mouseDragged(java.awt.event.MouseEvent evt) {
System.out.println("drag");
if (drag) {
last.setY(evt.getY());
GraphPane.this.repaint();
}
}
});
addMouseListener(new java.awt.event.MouseAdapter() {
public void mousePressed(java.awt.event.MouseEvent evt) {
int x = evt.getX();
int y = evt.getY();
for (XYpoints poinList1 : poinList) {
px = poinList1.getpX();
py = poinList1.getpY();
if (x < px + 5 && x > px - 5 && y < py + 5 && y > py - 5) {
System.out.println("inter");
poinList1.setIntersect(true);
last = poinList1;
drag = true;
GraphPane.this.repaint();
return;
}
}
poinList.add(new XYpoints(x, y));
Collections.sort(poinList, new XComp());
GraphPane.this.repaint();
}
public void mouseReleased(java.awt.event.MouseEvent evt) {
if (drag) {
drag = false;
last.setIntersect(false);
GraphPane.this.repaint();
}
}
});
}
#Override
protected void paintComponent(Graphics gr) {
super.paintComponent(gr);
Graphics2D g = (Graphics2D) gr.create();
Polygon p = new Polygon();
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
for (XYpoints poinList1 : poinList) {
px = poinList1.getpX();
py = poinList1.getpY();
p.addPoint(px, py);
}
g.setColor(graphColor);
g.fillPolygon(p);
for (XYpoints poinList1 : poinList) {
px = poinList1.getpX();
py = poinList1.getpY();
g.setColor(Color.red);
if (poinList1.isIntersect()) {
g.setColor(Color.blue);
}
g.fillOval(px - 5, py - 5, 10, 10);
}
g.dispose();
}
}
XYpoints.class
import java.awt.Polygon;
import java.util.Comparator;
public class XYpoints extends Polygon {
private int x;
private int y;
private boolean inter;
public XYpoints(int x, int y) {
this.x = x;
this.y = y;
}
public void setIntersect(boolean state) {
inter = state;
}
public void setY(int y){
this.y=y;
}
public boolean isIntersect() {
return inter;
}
public int getpX() {
//System.out.println("send " + this.x);
return this.x;
}
public int getpY() {
return this.y;
}
}
XComp .class
class XComp implements Comparator<XYpoints> {
#Override
public int compare(XYpoints t, XYpoints t1) {
if (t.getpX() < t1.getpX()) {
return -1;
} else {
return 1;
}
}
}
myframe.class
import javax.swing.JFrame;
public class myframe extends JFrame {
public myframe() {
GraphPane pane = new GraphPane();
setContentPane(pane);
setSize(650, 500);
setVisible(true);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new myframe();
}
});
}
}

Java 4-Way Pong, Stuck With Checking for Collisions

I am working on a 4 Way Pong Program. I have it to the point where my paddles will move with mouse movement, and the ball will bounce around the screen.
I am stuck when it comes to figuring out how to check for collisions between the ball and the paddles (which will increase the score) and between the ball and the edges of the JPanel (which will end the game).
Any guidance is greatly appreciated...
Game Class
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.Font;
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.MouseEvent;
import java.awt.event.MouseMotionListener;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.RandomAccessFile;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.ArrayList;
import java.util.Date;
import java.util.Timer;
import java.util.TimerTask;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.Timer;
public class Game extends JPanel {
JFrame window = new JFrame();
Timer timer = new Timer(30, new ActionHandler());
ArrayList<Ball> balls = new ArrayList<Ball>();
ArrayList<Paddle> horizPaddles = new ArrayList<Paddle>();
ArrayList<Paddle> vertPaddles = new ArrayList<Paddle>();
Paddle pTop;
Paddle pBottom;
Paddle pRight;
Paddle pLeft;
Ball b;
int score = 0;
JLabel scoreLabel;
//==========================================================
public Game() {
window.setBounds(100,100,900,500);
window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
window.setTitle("4 Way Pong");
window.setResizable(false);
JPanel scorePanel = new JPanel(true);
scoreLabel = new JLabel("Current Score: " + Integer.toString(score));
scoreLabel.setFont(new Font("sansserif", Font.PLAIN, 20));
scoreLabel.setForeground(Color.RED);
scorePanel.add(scoreLabel);
JPanel buttons = new JPanel(true);
Container con = window.getContentPane();
con.setLayout(new BorderLayout());
con.add(this, BorderLayout.CENTER);
con.add(buttons, BorderLayout.SOUTH);
con.add(scorePanel, BorderLayout.NORTH);
this.setBackground(Color.BLACK);
this.addMouseMotionListener(new MouseMoved());
ButtonCatch bc = new ButtonCatch();
JButton btn;
btn = new JButton("New Game");
btn.addActionListener(bc);
buttons.add(btn);
btn = new JButton("Swap Colors");
btn.addActionListener(bc);
buttons.add(btn);
btn = new JButton("High Scores");
btn.addActionListener(bc);
buttons.add(btn);
btn = new JButton("Save Score");
btn.addActionListener(bc);
buttons.add(btn);
btn = new JButton("Quit");
btn.addActionListener(bc);
buttons.add(btn);
timer.start();
window.setVisible(true);
}
//==========================================================
public static void main(String[] args) {
new Game();
}
//==========================================================
public void update() {
for(Ball b : balls) {
b.move(getWidth() + 30, getHeight() + 25);
}
//checkSideCollision();
//checkHorizPaddleCollision();
//checkVertPaddleCollision();
repaint();
}
//==========================================================
public void checkSideCollision() {
if(b.getyPos() > getHeight()) {
JOptionPane.showMessageDialog(null, "Game Over. You Scored " + score + ".", "GAME OVER", JOptionPane.INFORMATION_MESSAGE);
System.exit(0);
}
}
//==========================================================
public void checkHorizPaddleCollision() {
if(b.getxPos() == pBottom.getX() && b.getyPos() == pBottom.getY()) {
//b.yPos = b.yPos - 5;
score++;
}
}
//==========================================================
public void checkVertPaddleCollision() {
}
//==========================================================
public class ButtonCatch implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
switch(e.getActionCommand()) {
case "Quit": JOptionPane.showMessageDialog(null, "You Quit... No Score Recorded", "Game Over", JOptionPane.INFORMATION_MESSAGE); System.exit(0);
case "New Game": newGame(); break;
case "Swap Colors": swapColors(); break;
case "High Scores": try { displayScores(); } catch (Exception e1) { System.out.println(e1.getMessage()); } break;
case "Save Score": try { saveScore(); } catch (Exception e2) { System.out.println(e2.getMessage()); } break;
}
}
}
//==========================================================
public void paint(Graphics g) {
super.paint(g);
for(Ball b : balls) {
b.draw(g);
}
for(Paddle p : horizPaddles) {
p.draw((Graphics2D) g);
}
for(Paddle p : vertPaddles) {
p.draw((Graphics2D) g);
}
}
//==========================================================
//FIX FOR DISPLAYING SCORES
private void displayScores() throws Exception {
}
//==========================================================
//FIX -- Store Score in a File
private void saveScore() throws Exception {
int userScore = score;
String name = JOptionPane.showInputDialog("Enter Your Name: ");
JOptionPane.showMessageDialog(null, "Saved!\n" + name + " scored " + userScore, "Score Recorded", JOptionPane.INFORMATION_MESSAGE);
}
//==========================================================
private void swapColors() {
for(Ball b : balls) {
if(b.color.equals(Color.red)) {
b.setColor(Color.yellow);
} else if (b.color.equals(Color.yellow)) {
b.setColor(Color.blue);
} else {
b.setColor(Color.red);
}
}
}
//==========================================================
private void newGame() {
//CREATE BALL
balls.clear();
b = new Ball();
b.color = Color.red;
b.dx = (int)(Math.random() * 4) + 1;
b.dy = (int)(Math.random() * 4) + 1;
b.xPos = (int)(Math.random() * 4) + 1;
b.yPos = (int)(Math.random() * 4) + 1;
balls.add(b);
//CREATE PADDLES
horizPaddles.clear();
vertPaddles.clear();
// bottom
pBottom = new Paddle();
pBottom.x = getWidth() / 2;
pBottom.y = getHeight();
pBottom.setX(pBottom.getX()-20);
pBottom.setY(pBottom.getY()-20);
pBottom.setWidth(100);
pBottom.setHeight(20);
horizPaddles.add(pBottom);
//top
pTop = new Paddle();
pTop.x = getWidth() / 2;
pTop.y = getHeight();
pTop.setX(0 + pTop.getX());
pTop.setY(0);
pTop.setWidth(100);
pTop.setHeight(20);
horizPaddles.add(pTop);
//left
pLeft = new Paddle();
pLeft.x = getWidth() / 2;
pLeft.y = getHeight();
pLeft.setX(0);
pLeft.setY(pLeft.getY() / 2);
pLeft.setWidth(20);
pLeft.setHeight(100);
vertPaddles.add(pLeft);
//right
pRight = new Paddle();
pRight.x = getWidth() / 2;
pRight.y = getHeight();
pRight.setX(875);
pRight.setY(pRight.getY() / 2);
pRight.setWidth(20);
pRight.setHeight(100);
vertPaddles.add(pRight);
timer.start();
}
//==========================================================
public class ActionHandler implements ActionListener {
#Override
public void actionPerformed(ActionEvent arg0) {
update();
}
}
//==========================================================
public class MouseMoved implements MouseMotionListener {
#Override
public void mouseMoved(MouseEvent e) {
for(Paddle p : horizPaddles) {
p.x = e.getX();
}
for(Paddle p : vertPaddles) {
p.y = e.getY();
}
}
#Override public void mouseDragged(MouseEvent e) {}
}
}
Paddle Class
import java.awt.Color;
import java.awt.Graphics2D;
public class Paddle implements Drawable{
public int x, y, width, height;
public Paddle() {
super();
}
public Paddle(int x, int y, int width, int height) {
super();
setX(x);
setY(y);
setWidth(width);
setHeight(height);
}
#Override
public void draw(Graphics2D g) {
g.setColor(Color.green);
g.fillRect(x, y, width, height);
}
public int getX() {
return x;
}
public void setX(int x) {
this.x = x;
}
public int getY() {
return y;
}
public void setY(int y) {
this.y = y;
}
public int getWidth() {
return width;
}
public void setWidth(int width) {
this.width = width;
}
public int getHeight() {
return height;
}
public void setHeight(int height) {
this.height = height;
}
}
Ball Class
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.io.IOException;
import java.io.RandomAccessFile;
import javax.swing.JPanel;
public class Ball implements Comparable<Ball>, Cloneable{
private static int count = 0;
public static final int NAME_LENGTH = 20;
public String name = "";
public int xPos=0, yPos=0, dx = 3, dy = 2;
public Color color = Color.red;
public static void resetCounter() { count = 0; }
public Ball() {name = "Rock: " + ++count;}
public Ball(RandomAccessFile file) {
load(file);
}
public void load(RandomAccessFile file) {
try {
xPos = file.readInt();
yPos = file.readInt();
dx = file.readInt();
dy = file.readInt();
color = new Color( file.readInt() );
byte[] n = new byte[NAME_LENGTH];
file.readFully(n);
name = new String(n).trim();
System.out.println(name);
} catch (IOException e) {
e.printStackTrace();
}
}
public void save(RandomAccessFile file) {
try {
file.writeInt(xPos);
file.writeInt(yPos);
file.writeInt(dx);
file.writeInt(dy);
file.writeInt(color.getRGB());
file.writeBytes( getStringBlock(name, NAME_LENGTH) );
} catch (IOException e) {
e.printStackTrace();
}
}
private String getStringBlock(String string, int len) {
StringBuilder sb = new StringBuilder(name);
sb.setLength(len);
return sb.toString();
}
public void draw(Graphics g) {
g.setColor(color);
g.fillOval(xPos, yPos, 25, 25);
g.setColor(Color.black);
g.drawOval(xPos, yPos, 25, 25);
}
public void setColor(Color c) {
color = c;
}
public void move(int width, int height) {
xPos+=dx;
yPos+=dy;
if(xPos + 50 > width) {
xPos = width - 50;
dx = -dx;
}
if(yPos + 50 > height) {
yPos = height - 50;
dy = -dy;
}
if(xPos < 0) {
xPos = 0;
dx = -dx;
}
if(yPos < 0) {
yPos = 0;
dy = -dy;
}
}
#Override
public int compareTo(Ball arg0) {
return 0;
}
public int getxPos() {
return xPos;
}
public int getyPos() {
return yPos;
}
}
Thanks again...
For the Paddle-Ball collisions, I think calling this method on a timer might suffice:
public void checkPaddleCollisions(){
Rectangle a = new Rectangle(pTop.getX(), pTop.getY(), pTop.getWidth(), pTop.getHeight());
Rectangle b = ... //Do this for all the paddles.
Rectangle ball = new Rectangle(ball.getX(), ball.getY(), ball.getWidth(), ball.getHeight());
if(a.intersects(ball) || b.intersects(ball) || c.intersects(ball) || d.intersects(ball)){
//Increment score and bounce ball.
}
}
As for collisions with the edge, I think you could do something similar, just create 4 rectangles representing the edges of the screen.

How to make an image move while listening to a keypress in Java.

I'm starting to learn java programming and I think it's cool to learn java through game development. I know how to draw image and listen to a keypress then move that image. But is it possible to make the image move back and forth to the window while the window is listening to a keypress? Like for example, while the image or object(like spaceship) is moving left to right in the window, then if I press space key, a laser will fire at the bottom of the screen( cool huh :D ). But basically I just want to know how to make the image move left to right while the window is listening to a keypress.
I'm thinking that I will add a key listener to my window then fire an infinite loop to move the image. Or do I need to learn about threading so that another thread will move the object?
Please advise.
Many thanks.
Yep, a Swing Timer and Key Bindings would work well. Here's another example (mine) :)
import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import javax.swing.*;
public class AnimationWithKeyBinding {
private static void createAndShowUI() {
AnimationPanel panel = new AnimationPanel(); // the drawing JPanel
JFrame frame = new JFrame("Animation With Key Binding");
frame.getContentPane().add(panel);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}
#SuppressWarnings("serial")
class AnimationPanel extends JPanel {
public static final int SPRITE_WIDTH = 20;
public static final int PANEL_WIDTH = 400;
public static final int PANEL_HEIGHT = 400;
private static final int MAX_MSTATE = 25;
private static final int SPIN_TIMER_PERIOD = 16;
private static final int SPRITE_STEP = 3;
private int mState = 0;
private int mX = (PANEL_WIDTH - SPRITE_WIDTH) / 2;
private int mY = (PANEL_HEIGHT - SPRITE_WIDTH) / 2;
private int oldMX = mX;
private int oldMY = mY;
private boolean moved = false;
// an array of sprite images that are drawn sequentially
private BufferedImage[] spriteImages = new BufferedImage[MAX_MSTATE];
public AnimationPanel() {
// create and start the main animation timer
new Timer(SPIN_TIMER_PERIOD, new SpinTimerListener()).start();
setPreferredSize(new Dimension(PANEL_WIDTH, PANEL_HEIGHT));
setBackground(Color.white);
createSprites(); // create the images
setupKeyBinding();
}
private void setupKeyBinding() {
int condition = JComponent.WHEN_IN_FOCUSED_WINDOW;
InputMap inMap = getInputMap(condition);
ActionMap actMap = getActionMap();
// this uses an enum of Direction that holds ints for the arrow keys
for (Direction direction : Direction.values()) {
int key = direction.getKey();
String name = direction.name();
// add the key bindings for arrow key and shift-arrow key
inMap.put(KeyStroke.getKeyStroke(key, 0), name);
inMap.put(KeyStroke.getKeyStroke(key, InputEvent.SHIFT_DOWN_MASK), name);
actMap.put(name, new MyKeyAction(this, direction));
}
}
// create a bunch of buffered images and place into an array,
// to be displayed sequentially
private void createSprites() {
for (int i = 0; i < spriteImages.length; i++) {
spriteImages[i] = new BufferedImage(SPRITE_WIDTH, SPRITE_WIDTH,
BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = spriteImages[i].createGraphics();
g2.setColor(Color.red);
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
double theta = i * Math.PI / (2 * spriteImages.length);
double x = SPRITE_WIDTH * Math.abs(Math.cos(theta)) / 2.0;
double y = SPRITE_WIDTH * Math.abs(Math.sin(theta)) / 2.0;
int x1 = (int) ((SPRITE_WIDTH / 2.0) - x);
int y1 = (int) ((SPRITE_WIDTH / 2.0) - y);
int x2 = (int) ((SPRITE_WIDTH / 2.0) + x);
int y2 = (int) ((SPRITE_WIDTH / 2.0) + y);
g2.drawLine(x1, y1, x2, y2);
g2.drawLine(y1, x2, y2, x1);
g2.dispose();
}
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
g.drawImage(spriteImages[mState], mX, mY, null);
}
public void incrementX(boolean right) {
oldMX = mX;
if (right) {
mX = Math.min(getWidth() - SPRITE_WIDTH, mX + SPRITE_STEP);
} else {
mX = Math.max(0, mX - SPRITE_STEP);
}
moved = true;
}
public void incrementY(boolean down) {
oldMY = mY;
if (down) {
mY = Math.min(getHeight() - SPRITE_WIDTH, mY + SPRITE_STEP);
} else {
mY = Math.max(0, mY - SPRITE_STEP);
}
moved = true;
}
public void tick() {
mState = (mState + 1) % MAX_MSTATE;
}
private class SpinTimerListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
tick();
int delta = 20;
int width = SPRITE_WIDTH + 2 * delta;
int height = width;
// make sure to erase the old image
if (moved) {
int x = oldMX - delta;
int y = oldMY - delta;
repaint(x, y, width, height);
}
int x = mX - delta;
int y = mY - delta;
// draw the new image
repaint(x, y, width, height);
moved = false;
}
}
}
enum Direction {
UP(KeyEvent.VK_UP), DOWN(KeyEvent.VK_DOWN), LEFT(KeyEvent.VK_LEFT), RIGHT(KeyEvent.VK_RIGHT);
private int key;
private Direction(int key) {
this.key = key;
}
public int getKey() {
return key;
}
}
// Actions for the key binding
#SuppressWarnings("serial")
class MyKeyAction extends AbstractAction {
private AnimationPanel draw;
private Direction direction;
public MyKeyAction(AnimationPanel draw, Direction direction) {
this.draw = draw;
this.direction = direction;
}
#Override
public void actionPerformed(ActionEvent e) {
switch (direction) {
case UP:
draw.incrementY(false);
break;
case DOWN:
draw.incrementY(true);
break;
case LEFT:
draw.incrementX(false);
break;
case RIGHT:
draw.incrementX(true);
break;
default:
break;
}
}
}
Here is another example that uses this sprite sheet:
obtained from this site.
Again it's an example of drawing within a JPanel's paintComponent method and using Key Bindings to tell which direction to move.
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Image;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.EnumMap;
import java.util.List;
import java.util.Map;
import javax.imageio.ImageIO;
import javax.swing.*;
#SuppressWarnings("serial")
public class Mcve3 extends JPanel {
private static final int PREF_W = 800;
private static final int PREF_H = 640;
private static final int TIMER_DELAY = 50;
private int spriteX = 400;
private int spriteY = 320;
private SpriteDirection spriteDirection = SpriteDirection.RIGHT;
private MySprite sprite = null;
private Timer timer = null;
public Mcve3() {
try {
sprite = new MySprite(spriteDirection, spriteX, spriteY);
} catch (IOException e) {
e.printStackTrace();
System.exit(-1);
}
setBackground(Color.WHITE);
setKeyBindings(SpriteDirection.LEFT, KeyEvent.VK_LEFT);
setKeyBindings(SpriteDirection.RIGHT, KeyEvent.VK_RIGHT);
setKeyBindings(SpriteDirection.FORWARD, KeyEvent.VK_DOWN);
setKeyBindings(SpriteDirection.AWAY, KeyEvent.VK_UP);
timer = new Timer(TIMER_DELAY, new TimerListener());
timer.start();
}
private void setKeyBindings(SpriteDirection dir, int keyCode) {
int condition = WHEN_IN_FOCUSED_WINDOW;
InputMap inputMap = getInputMap(condition);
ActionMap actionMap = getActionMap();
KeyStroke keyPressed = KeyStroke.getKeyStroke(keyCode, 0, false);
KeyStroke keyReleased = KeyStroke.getKeyStroke(keyCode, 0, true);
inputMap.put(keyPressed, keyPressed.toString());
inputMap.put(keyReleased, keyReleased.toString());
actionMap.put(keyPressed.toString(), new MoveAction(dir, false));
actionMap.put(keyReleased.toString(), new MoveAction(dir, true));
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(PREF_W, PREF_H);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
sprite.draw(g);
}
private class MoveAction extends AbstractAction {
private SpriteDirection dir;
private boolean released;
public MoveAction(SpriteDirection dir, boolean released) {
this.dir = dir;
this.released = released;
}
#Override
public void actionPerformed(ActionEvent e) {
if (released) {
sprite.setMoving(false);
} else {
sprite.setMoving(true);
sprite.setDirection(dir);
}
}
}
private class TimerListener implements ActionListener {
#Override
public void actionPerformed(ActionEvent e) {
if (sprite.isMoving()) {
sprite.tick();
}
repaint();
}
}
private static void createAndShowGui() {
Mcve3 mainPanel = new Mcve3();
JFrame frame = new JFrame("MCVE");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(() -> createAndShowGui());
}
}
class MySprite {
private static final String SPRITE_SHEET_PATH = "http://"
+ "orig12.deviantart.net/7db3/f/2010/338/3/3/"
+ "animated_sprite_sheet_32x32_by_digibody-d3479l2.gif";
private static final int MAX_MOVING_INDEX = 4;
private static final int DELTA = 4;
private SpriteDirection direction;
private Map<SpriteDirection, Image> standingImgMap = new EnumMap<>(SpriteDirection.class);
private Map<SpriteDirection, List<Image>> movingImgMap = new EnumMap<>(SpriteDirection.class);
private int x;
private int y;
private boolean moving = false;
private int movingIndex = 0;
public MySprite(SpriteDirection direction, int x, int y) throws IOException {
this.direction = direction;
this.x = x;
this.y = y;
createSprites();
}
public void draw(Graphics g) {
Image img = null;
if (!moving) {
img = standingImgMap.get(direction);
} else {
img = movingImgMap.get(direction).get(movingIndex);
}
g.drawImage(img, x, y, null);
}
private void createSprites() throws IOException {
URL spriteSheetUrl = new URL(SPRITE_SHEET_PATH);
BufferedImage img = ImageIO.read(spriteSheetUrl);
// get sub-images (sprites) from the sprite sheet
// magic numbers for getting sprites from sheet, all obtained by trial and error
int x0 = 0;
int y0 = 64;
int rW = 32;
int rH = 32;
for (int row = 0; row < 4; row++) {
SpriteDirection dir = SpriteDirection.values()[row];
List<Image> imgList = new ArrayList<>();
movingImgMap.put(dir, imgList);
int rY = y0 + row * rH;
for (int col = 0; col < 5; col++) {
int rX = x0 + col * rW;
BufferedImage subImg = img.getSubimage(rX, rY, rW, rH);
if (col == 0) {
// first image is standing
standingImgMap.put(dir, subImg);
} else {
// all others are moving
imgList.add(subImg);
}
}
}
}
public SpriteDirection getDirection() {
return direction;
}
public void setDirection(SpriteDirection direction) {
if (this.direction != direction) {
setMoving(false);
}
this.direction = direction;
}
public int getX() {
return x;
}
public void setX(int x) {
this.x = x;
}
public int getY() {
return y;
}
public void setY(int y) {
this.y = y;
}
public boolean isMoving() {
return moving;
}
public void setMoving(boolean moving) {
this.moving = moving;
if (!moving) {
movingIndex = 0;
}
}
public void tick() {
if (moving) {
switch (direction) {
case RIGHT:
x += DELTA;
break;
case LEFT:
x -= DELTA;
break;
case FORWARD:
y += DELTA;
break;
case AWAY:
y -= DELTA;
}
movingIndex++;
movingIndex %= MAX_MOVING_INDEX;
}
}
public int getMovingIndex() {
return movingIndex;
}
public void setMovingIndex(int movingIndex) {
this.movingIndex = movingIndex;
}
}
enum SpriteDirection {
FORWARD, LEFT, AWAY, RIGHT
}
As an alternative to KeyListener, consider using actions and key bindings, discussed here. Derived from this example, the program below moves a line left, down, up or right using either buttons or keys.
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.event.ActionEvent;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.AbstractAction;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.KeyStroke;
/**
* #see https://stackoverflow.com/questions/6991648
* #see https://stackoverflow.com/questions/6887296
* #see https://stackoverflow.com/questions/5797965
*/
public class LinePanel extends JPanel {
private MouseHandler mouseHandler = new MouseHandler();
private Point p1 = new Point(100, 100);
private Point p2 = new Point(540, 380);
private boolean drawing;
public LinePanel() {
this.setPreferredSize(new Dimension(640, 480));
this.addMouseListener(mouseHandler);
this.addMouseMotionListener(mouseHandler);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setColor(Color.blue);
g2d.setRenderingHint(
RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2d.setStroke(new BasicStroke(8,
BasicStroke.CAP_ROUND, BasicStroke.JOIN_BEVEL));
g.drawLine(p1.x, p1.y, p2.x, p2.y);
}
private class MouseHandler extends MouseAdapter {
#Override
public void mousePressed(MouseEvent e) {
drawing = true;
p1 = e.getPoint();
p2 = p1;
repaint();
}
#Override
public void mouseReleased(MouseEvent e) {
drawing = false;
p2 = e.getPoint();
repaint();
}
#Override
public void mouseDragged(MouseEvent e) {
if (drawing) {
p2 = e.getPoint();
repaint();
}
}
}
private class ControlPanel extends JPanel {
private static final int DELTA = 10;
public ControlPanel() {
this.add(new MoveButton("\u2190", KeyEvent.VK_LEFT, -DELTA, 0));
this.add(new MoveButton("\u2191", KeyEvent.VK_UP, 0, -DELTA));
this.add(new MoveButton("\u2192", KeyEvent.VK_RIGHT, DELTA, 0));
this.add(new MoveButton("\u2193", KeyEvent.VK_DOWN, 0, DELTA));
}
private class MoveButton extends JButton {
KeyStroke k;
int dx, dy;
public MoveButton(String name, int code, final int dx, final int dy) {
super(name);
this.k = KeyStroke.getKeyStroke(code, 0);
this.dx = dx;
this.dy = dy;
this.setAction(new AbstractAction(this.getText()) {
#Override
public void actionPerformed(ActionEvent e) {
LinePanel.this.p1.translate(dx, dy);
LinePanel.this.p2.translate(dx, dy);
LinePanel.this.repaint();
}
});
ControlPanel.this.getInputMap(
WHEN_IN_FOCUSED_WINDOW).put(k, k.toString());
ControlPanel.this.getActionMap().put(k.toString(), new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
MoveButton.this.doClick();
}
});
}
}
}
private void display() {
JFrame f = new JFrame("LinePanel");
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.add(this);
f.add(new ControlPanel(), BorderLayout.SOUTH);
f.pack();
f.setLocationRelativeTo(null);
f.setVisible(true);
}
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
new LinePanel().display();
}
});
}
}
But basically I just want to know how to make the image move left to right while the window is listening to a keypress
You can use a Swing Timer to animate an image:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class TimerAnimation extends JLabel implements ActionListener
{
int deltaX = 2;
int deltaY = 3;
int directionX = 1;
int directionY = 1;
public TimerAnimation(
int startX, int startY,
int deltaX, int deltaY,
int directionX, int directionY,
int delay)
{
this.deltaX = deltaX;
this.deltaY = deltaY;
this.directionX = directionX;
this.directionY = directionY;
setIcon( new ImageIcon("dukewavered.gif") );
// setIcon( new ImageIcon("copy16.gif") );
setSize( getPreferredSize() );
setLocation(startX, startY);
new javax.swing.Timer(delay, this).start();
}
public void actionPerformed(ActionEvent e)
{
Container parent = getParent();
// Determine next X position
int nextX = getLocation().x + (deltaX * directionX);
if (nextX < 0)
{
nextX = 0;
directionX *= -1;
}
if ( nextX + getSize().width > parent.getSize().width)
{
nextX = parent.getSize().width - getSize().width;
directionX *= -1;
}
// Determine next Y position
int nextY = getLocation().y + (deltaY * directionY);
if (nextY < 0)
{
nextY = 0;
directionY *= -1;
}
if ( nextY + getSize().height > parent.getSize().height)
{
nextY = parent.getSize().height - getSize().height;
directionY *= -1;
}
// Move the label
setLocation(nextX, nextY);
}
public static void main(String[] args)
{
JPanel panel = new JPanel();
JFrame frame = new JFrame();
frame.setContentPane(panel);
frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
frame.getContentPane().setLayout(null);
// frame.getContentPane().add( new TimerAnimation(10, 10, 2, 3, 1, 1, 10) );
frame.getContentPane().add( new TimerAnimation(300, 100, 3, 2, -1, 1, 20) );
// frame.getContentPane().add( new TimerAnimation(0, 000, 5, 0, 1, 1, 20) );
frame.getContentPane().add( new TimerAnimation(0, 200, 5, 0, 1, 1, 80) );
frame.setSize(400, 400);
frame.setLocationRelativeTo( null );
frame.setVisible(true);
// frame.getContentPane().add( new TimerAnimation(10, 10, 2, 3, 1, 1, 10) );
// frame.getContentPane().add( new TimerAnimation(10, 10, 3, 0, 1, 1, 10) );
}
}
You can add a KeyListener to the panel and it will operate independently of the image animation.

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