Bola de rebote de Java

Intento escribir una aplicación Java que dibuje múltiples bolas en la pantalla que rebotan en los bordes del marco. Puedo dibujar con éxito una pelota. Sin embargo, cuando agrego la segunda bola sobrescribe la bola inicial que he dibujado. El código es:

import java.awt.*; import javax.swing.*; import java.util.ArrayList; import java.util.List; public class Ball extends JPanel implements Runnable { List balls = new ArrayList(); Color color; int diameter; long delay; private int x; private int y; private int vx; private int vy; public Ball(String ballcolor, int xvelocity, int yvelocity) { if(ballcolor == "red") { color = Color.red; } else if(ballcolor == "blue") { color = Color.blue; } else if(ballcolor == "black") { color = Color.black; } else if(ballcolor == "cyan") { color = Color.cyan; } else if(ballcolor == "darkGray") { color = Color.darkGray; } else if(ballcolor == "gray") { color = Color.gray; } else if(ballcolor == "green") { color = Color.green; } else if(ballcolor == "yellow") { color = Color.yellow; } else if(ballcolor == "lightGray") { color = Color.lightGray; } else if(ballcolor == "magenta") { color = Color.magenta; } else if(ballcolor == "orange") { color = Color.orange; } else if(ballcolor == "pink") { color = Color.pink; } else if(ballcolor == "white") { color = Color.white; } diameter = 30; delay = 40; x = 1; y = 1; vx = xvelocity; vy = yvelocity; } protected void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2 = (Graphics2D)g; g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); g.setColor(color); g.fillOval(x,y,30,30); //adds color to circle g.setColor(Color.black); g2.drawOval(x,y,30,30); //draws circle } public void run() { while(isVisible()) { try { Thread.sleep(delay); } catch(InterruptedException e) { System.out.println("interrupted"); } move(); repaint(); } } public void move() { if(x + vx  getWidth()) { vx *= -1; } if(y + vy  getHeight()) { vy *= -1; } x += vx; y += vy; } private void start() { while(!isVisible()) { try { Thread.sleep(25); } catch(InterruptedException e) { System.exit(1); } } Thread thread = new Thread(this); thread.setPriority(Thread.NORM_PRIORITY); thread.start(); } public static void main(String[] args) { Ball ball1 = new Ball("red",3,2); Ball ball2 = new Ball("blue",6,2); JFrame f = new JFrame(); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.getContentPane().add(ball1); f.getContentPane().add(ball2); f.setSize(400,400); f.setLocation(200,200); f.setVisible(true); new Thread(ball1).start(); new Thread(ball2).start(); } } 

Quería crear una lista de bolas y luego seguir dibujando cada una de las bolas, pero todavía tengo problemas para agregar ambas bolas al panel de contenido.

Gracias por cualquier ayuda.

Con su enfoque actual …

  • El principal problema que puedo ver es que estás colocando dos componentes opacos uno encima del otro … en realidad, es posible que descubras que estás eludiendo a uno de ellos por el otro …
  • Debería utilizar un gestor de diseño null , de lo contrario tomará el control y distribuirá sus bolas como lo considere oportuno.
  • Debe asegurarse de controlar el tamaño y la ubicación del panel de bolas. Esto significa que ha asumido el rol de administrador de diseño …
  • Es necesario aleatorizar la velocidad y la ubicación de las bolas para que tengan menos posibilidades de comenzar en la misma ubicación y moverse en la misma ubicación …
  • Solo actualice la Ball dentro del contexto del EDT.
  • Realmente no necesita los valores X / Y, puede usar los paneles.

.

 public class AnimatedBalls { public static void main(String[] args) { new AnimatedBalls(); } public AnimatedBalls() { EventQueue.invokeLater(new Runnable() { @Override public void run() { try { UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); } catch (ClassNotFoundException ex) { } catch (InstantiationException ex) { } catch (IllegalAccessException ex) { } catch (UnsupportedLookAndFeelException ex) { } JFrame frame = new JFrame(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setLayout(new BorderLayout()); frame.add(new Balls()); frame.setSize(400, 400); frame.setVisible(true); } }); } public class Balls extends JPanel { public Balls() { setLayout(null); // Randomize the speed and direction... add(new Ball("red", 10 - (int) Math.round((Math.random() * 20)), 10 - (int) Math.round((Math.random() * 20)))); add(new Ball("blue", 10 - (int) Math.round((Math.random() * 20)), 10 - (int) Math.round((Math.random() * 20)))); } } public class Ball extends JPanel implements Runnable { Color color; int diameter; long delay; private int vx; private int vy; public Ball(String ballcolor, int xvelocity, int yvelocity) { if (ballcolor == "red") { color = Color.red; } else if (ballcolor == "blue") { color = Color.blue; } else if (ballcolor == "black") { color = Color.black; } else if (ballcolor == "cyan") { color = Color.cyan; } else if (ballcolor == "darkGray") { color = Color.darkGray; } else if (ballcolor == "gray") { color = Color.gray; } else if (ballcolor == "green") { color = Color.green; } else if (ballcolor == "yellow") { color = Color.yellow; } else if (ballcolor == "lightGray") { color = Color.lightGray; } else if (ballcolor == "magenta") { color = Color.magenta; } else if (ballcolor == "orange") { color = Color.orange; } else if (ballcolor == "pink") { color = Color.pink; } else if (ballcolor == "white") { color = Color.white; } diameter = 30; delay = 100; vx = xvelocity; vy = yvelocity; new Thread(this).start(); } protected void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2 = (Graphics2D) g; int x = getX(); int y = getY(); g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); g.setColor(color); g.fillOval(0, 0, 30, 30); //adds color to circle g.setColor(Color.black); g2.drawOval(0, 0, 30, 30); //draws circle } @Override public Dimension getPreferredSize() { return new Dimension(30, 30); } public void run() { try { // Randamize the location... SwingUtilities.invokeAndWait(new Runnable() { @Override public void run() { int x = (int) (Math.round(Math.random() * getParent().getWidth())); int y = (int) (Math.round(Math.random() * getParent().getHeight())); setLocation(x, y); } }); } catch (InterruptedException exp) { exp.printStackTrace(); } catch (InvocationTargetException exp) { exp.printStackTrace(); } while (isVisible()) { try { Thread.sleep(delay); } catch (InterruptedException e) { System.out.println("interrupted"); } try { SwingUtilities.invokeAndWait(new Runnable() { @Override public void run() { move(); repaint(); } }); } catch (InterruptedException exp) { exp.printStackTrace(); } catch (InvocationTargetException exp) { exp.printStackTrace(); } } } public void move() { int x = getX(); int y = getY(); if (x + vx < 0 || x + diameter + vx > getParent().getWidth()) { vx *= -1; } if (y + vy < 0 || y + diameter + vy > getParent().getHeight()) { vy *= -1; } x += vx; y += vy; // Update the size and location... setSize(getPreferredSize()); setLocation(x, y); } } } 

El problema “principal” con este enfoque es que cada Ball tiene su propio Thread . Esto consumirá los recursos de tu sistema muy rápido a medida que escalas el número de bolas …

Un enfoque diferente

Tal como lo inició Hovercraft, es mejor crear un contenedor para las bolas en el que vivir, donde las bolas no son componentes, sino conceptos “virtuales” de una bola, que contienen suficiente información como para hacer rebotarlas en las paredes. ..

enter image description here

 public class SimpleBalls { public static void main(String[] args) { new SimpleBalls(); } public SimpleBalls() { EventQueue.invokeLater(new Runnable() { @Override public void run() { try { UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); } catch (ClassNotFoundException ex) { } catch (InstantiationException ex) { } catch (IllegalAccessException ex) { } catch (UnsupportedLookAndFeelException ex) { } JFrame frame = new JFrame("Spot"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setLayout(new BorderLayout()); Balls balls = new Balls(); frame.add(balls); frame.setSize(400, 400); frame.setVisible(true); new Thread(new BounceEngine(balls)).start(); } }); } public static int random(int maxRange) { return (int) Math.round((Math.random() * maxRange)); } public class Balls extends JPanel { private List ballsUp; public Balls() { ballsUp = new ArrayList(25); for (int index = 0; index < 10 + random(90); index++) { ballsUp.add(new Ball(new Color(random(255), random(255), random(255)))); } } @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 : ballsUp) { ball.paint(g2d); } g2d.dispose(); } public List getBalls() { return ballsUp; } } public class BounceEngine implements Runnable { private Balls parent; public BounceEngine(Balls parent) { this.parent = parent; } @Override public void run() { int width = getParent().getWidth(); int height = getParent().getHeight(); // Randomize the starting position... for (Ball ball : getParent().getBalls()) { int x = random(width); int y = random(height); Dimension size = ball.getSize(); if (x + size.width > width) { x = width - size.width; } if (y + size.height > height) { y = height - size.height; } ball.setLocation(new Point(x, y)); } while (getParent().isVisible()) { // Repaint the balls pen... SwingUtilities.invokeLater(new Runnable() { @Override public void run() { getParent().repaint(); } }); // This is a little dangrous, as it's possible // for a repaint to occur while we're updating... for (Ball ball : getParent().getBalls()) { move(ball); } // Some small delay... try { Thread.sleep(100); } catch (InterruptedException ex) { } } } public Balls getParent() { return parent; } public void move(Ball ball) { Point p = ball.getLocation(); Point speed = ball.getSpeed(); Dimension size = ball.getSize(); int vx = speed.x; int vy = speed.y; int x = px; int y = py; if (x + vx < 0 || x + size.width + vx > getParent().getWidth()) { vx *= -1; } if (y + vy < 0 || y + size.height + vy > getParent().getHeight()) { vy *= -1; } x += vx; y += vy; ball.setSpeed(new Point(vx, vy)); ball.setLocation(new Point(x, y)); } } public class Ball { private Color color; private Point location; private Dimension size; private Point speed; public Ball(Color color) { setColor(color); speed = new Point(10 - random(20), 10 - random(20)); size = new Dimension(30, 30); } public Dimension getSize() { return size; } 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()); Dimension size = getSize(); g2d.fillOval(px, py, size.width, size.height); } } } } 

Debido a que esto es impulsado por un único hilo, es mucho más escalable.

También puede ver que las imágenes no se están cargando, que es una pregunta similar;)

Necesita usar dos clases completamente distintas aquí: una para BallContainer que extiende JPanel y es el componente que dibuja las Bolas, y otra para Ball que no extiende nada sino que contiene las coordenadas y el Color de una Bola. BallContainer debería tener una List que itere cuando los mueve y cuando los pinta.

Lo que necesita hacer es boost su método paintComponent .

En lugar de simplemente dibujar una bola, debe recorrer todas ellas y dibujar cada una.

Ejemplo:

 protected void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2 = (Graphics2D)g; g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); for (Ball b: balls) { g.setColor(color); g.fillOval(x,y,30,30); //adds color to circle g.setColor(Color.black); g2.drawOval(x,y,30,30); //draws circle } } 
 package BouncingBallApp.src.copy; import java.awt.*; public class Ball { private Point location; private int radius; private Color color; private int dx, dy; //private Color[] ballArr; public Ball(Point l, int r, Color c){ location = l; radius = r; color = c; } public Ball(Point l, int r){ location = l; radius = r; color = Color.RED; } public Point getLocation() { return location; } public void setLocation(Point location) { this.location = location; } public int getRadius() { return radius; } public void setRadius(int radius) { this.radius = radius; } public Color getColor() { return color; } public void setColor(Color color) { this.color = color; } public void setMotion(int dx, int dy){ this.dx = dx; this.dy = dy; } public void move(){ location.translate(dx, dy); } public void moveTo(int x, int y){ location.move(x, y); } public void paint (Graphics g) { g.setColor (color); g.fillOval (location.x-radius, location.y-radius, 2*radius, 2*radius); } public void reclectHoriz() { dy = -dy; } public void reclectVert() { dx = -dx; } } package BouncingBallApp.src.copy; public class MyApp { public static void main(String[] args) { MyFrame frm = new MyFrame(10); frm.setVisible(true); for (int i=0; i<1000; i++){ frm.stepTheBall(); } } } package BouncingBallApp.src.copy; import java.awt.Color; import java.awt.Graphics; import java.awt.Point; import java.util.Random; import javax.swing.JFrame; public class MyFrame extends JFrame { public final int FRAMEWIDTH = 600; public final int FRAMEHEIGHT = 400; private Ball[] ballArr; private Random random =new Random (); private Color[] colors={Color.RED,Color.blue,Color.yellow}; private int ballCnt; public MyFrame(int ballCnt){ super(); setSize(FRAMEWIDTH, FRAMEHEIGHT); setTitle("My Bouncing Ball Application"); ballArr = new Ball[ballCnt]; this.ballCnt = ballCnt; int c; for (int i=0; i < ballCnt; i++){ int bcn =random.nextInt(colors.length); Color ballcolor=colors[bcn]; ballArr[i] = new Ball(new Point(50,50),c=(int) (Math.random()*10+3)%8,ballcolor); int ddx = (int) (Math.random()*10+2)%8; int ddy = (int) (Math.random()*10+2)%8; ballArr[i].setMotion(ddx, ddy); //c++; } } public void paint(Graphics g){ super.paint(g); for (int i=0; i < ballCnt; i++){ ballArr[i].paint(g); } } public void stepTheBall(){ for (int i=0; i < ballCnt; i++){ ballArr[i].move(); Point loc = ballArr[i].getLocation(); if (loc.x < ballArr[i].getRadius() || loc.x > FRAMEWIDTH-ballArr[i].getRadius()){ ballArr[i].reclectVert(); } if (loc.y < ballArr[i].getRadius() || loc.y > FRAMEHEIGHT-ballArr[i].getRadius()){ ballArr[i].reclectHoriz(); } } repaint(); try { Thread.sleep(20); } catch (InterruptedException e) { e.printStackTrace(); } } }