I have a problem with a JComboBox. I have an upper JPanel with the JComboBox and another JPanel below with a BufferedImage where I can draw some ovals (it has a listener to the mouse clicks). The problem, as you will see in the video, is that sometimes when I change the option in the JComboBox it does not show that change.
For example, if I select 'ALL' and then I select 'L4', 'ALL' remains shown instead of changing to 'L4', but when I click on the JComboBox, in the other drawing JPanel or on another window of the desktop, it changes to 'L4' (it should have changed before). I think that the problem is something related with having a JPanel listening for mouse clicks below the JComboBox, but I'm not sure.
Can anyone tell me how can I fix that?
Here's the link to the video I made to show the problem: http://youtu.be/8Gg2Uq3SCYw
It is also important to say that when I record the video with the QuickTime Player, all is recorded working correctly even if it hasn't worked correctly (what I mean is that I see what is in the video (link) but QuickTime records it running correctly, very very weird...)
Here's the link to the Example eclipse project I made for you, try to select different options many times, you will see what I say: https://app.sugarsync.com/iris/wf/D6421069_60887018_228038
Look at LapPanel of CircuitTracePlotView.java, there is the JComboBox.
I'm running it on a MacBookPro 10.8 (Mountain Lion)
And here is the code for the view (it is also on the link of the Example):
package view;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.util.LinkedList;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class CircuitTracePlotView extends JFrame {
private static final long serialVersionUID = 5125304890914235274L;
private int numberOfLaps;
private CircuitTracePlot plot;
private LapPanel lapPanel;
public CircuitTracePlotView() {
this.setVisible(false);
this.plot = new CircuitTracePlot();
this.lapPanel = new LapPanel();
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
this.getContentPane().add(this.plot, BorderLayout.CENTER);
this.getContentPane().add(this.lapPanel, BorderLayout.NORTH);
this.pack();
this.setLocationRelativeTo(null);
}
public void init(CircuitTracePlotViewController circuitTracePlotViewController, int numberOfLaps) {
this.setController(circuitTracePlotViewController);
this.setNumberOfLaps(numberOfLaps);
this.lapPanel.setLapSelection();
}
private void setController(CircuitTracePlotViewController circuitTracePlotViewController) {
this.plot.init(circuitTracePlotViewController);
}
private int getNumberOfLaps() {
return this.numberOfLaps;
}
public void setNumberOfLaps(int laps) {
this.numberOfLaps = laps;
System.out.println("NumberOfLaps" + this.numberOfLaps);
}
public void drawPoint(int x, int y) {
this.plot.drawPoint(x, y);
this.repaint();
}
public void drawLine(int x1, int y1, int x2, int y2) {
this.plot.drawLine(x1, y1, x2, y2);
}
public Dimension getPlotDimension() {
return this.plot.getPreferredSize();
}
//Drawing panel
private class CircuitTracePlot extends JPanel {
private static final long serialVersionUID = -7915054480476755069L;
private final static short LINE = 0;
private final static short OVAL = 1;
private final static int OVALHEIGHT = 10;
private final static int OVALWIDTH = 10;
BufferedImage plot;
Graphics2D plotGraphics;
private int x1;
private int x2;
private int y1;
private int y2;
private int paintType;
private CircuitTracePlot() {
this.setBackground(Color.WHITE);
}
private void init(CircuitTracePlotViewController circuitTracePlotViewController) {
this.addListeners(circuitTracePlotViewController);
this.plot = (BufferedImage)this.createImage(this.getPreferredSize().width, this.getPreferredSize().height);
this.plotGraphics = this.plot.createGraphics();
}
private void drawLine(int x1, int y1, int x2, int y2) {
this.x1 = x1;
this.y1 = y1;
this.x2 = x2;
this.y2 = y2;
this.paintType = LINE;
this.repaint();
}
private void drawPoint(int x1, int y1) {
this.x1 = x1;
this.y1 = y1;
this.paintType = OVAL;
this.repaint();
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
switch (this.paintType) {
case LINE:
plotGraphics.drawLine(x1, y1, x2, y2);
g.drawImage(this.plot,0,0, this);
break;
case OVAL:
plotGraphics.fillOval(x1 - OVALWIDTH/2, y1 - OVALHEIGHT/2, OVALWIDTH, OVALHEIGHT);
g.drawImage(this.plot,0,0, this);
break;
}
}
#Override
public Dimension getPreferredSize() {
return new Dimension(700, 500);
}
private void addListeners(CircuitTracePlotViewController circuitTracePlotViewController) {
this.addMouseListener(circuitTracePlotViewController);
}
}
private class LapPanel extends JPanel{
private static final long serialVersionUID = -287427935273603789L;
//private LinkedList<JIDButton> list_LapButtons;
private JComboBox<String> JCB_Laps;
private LapPanel() {
this.setBorder(BorderFactory.createTitledBorder("Lap Selection"));
//this.list_LapButtons = new LinkedList<JIDButton>();
//JIDButton auxButton = new JIDButton(0, "<html><u>A</u>LL<html>");
//this.list_LapButtons.add(auxButton);
//this.add(auxButton);
System.out.println("NumberOfLaps" + CircuitTracePlotView.this.numberOfLaps);
}
private void setLapSelection() {
String[] auxLaps = new String[CircuitTracePlotView.this.getNumberOfLaps() + 1];
auxLaps[0] = "<html>" + "<u>" + "A" + "</u>" + "LL" + "<html>";
for (int i = 1; i <= CircuitTracePlotView.this.getNumberOfLaps(); i++) {
auxLaps[i] = "<html>" + "L" + "<u>" + i + "</u>" + "<html>";
}
this.JCB_Laps = new JComboBox<String>(auxLaps);
this.add(JCB_Laps);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(700, 65);
}
}
}
I've posted all the information that I think it's relevant, if someone needs more information just ask for it.
Related
I'm currently working on a 2D game in Java for school. We have to use an Abstract Factory design pattern. For the 2D implementation I use a factory as follows:
public class Java2DFact extends AbstractFactory {
public Display display;
private Graphics g;
public Java2DFact() {
display = new Display(2000, 1200);
}
#Override
public PlayerShip getPlayership()
{
return new Java2DPlayership(display.panel);
}
In my display class I create a JFrame and Jpanel
public class Display {
public JFrame frame;
public JPanel panel;
public int width, height;
public Display(int width, int height) {
this.width = width;
this.height = height;
frame = new JFrame();
frame.setTitle("SpaceInvaders");
frame.setSize(1200,800);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setResizable(false);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
panel = new JPanel(){
#Override
protected void paintComponent(Graphics g){
super.paintComponent(g);
}
};
panel.setFocusable(true);
frame.add(panel);
}
}
Now from my main gameloop I call the visualize method inside the Java2DPLayership class to visualize my Playership
public class Java2DPlayership extends PlayerShip {
private JPanel panel;
private Graphics2D g2d;
private Image image;
private BufferStrategy bs;
public Java2DPlayership(JPanel panel) {
super();
this.panel = panel;
}
public void visualize() {
try {
image = ImageIO.read(new File("src/Bee.gif"));
Graphics2D g = (Graphics2D) bs.getDrawGraphics();
//g.setColor(new Color(0, 0, 0));
//g.fillRect(10, 10, 12, 8);
g.drawImage(image, (int) super.getMovementComponent().x, (int) super.getMovementComponent().y, null);
Toolkit.getDefaultToolkit().sync();
g.dispose();
panel.repaint();
} catch(Exception e){
System.out.println(e.toString());
}
}
}
My goal is to pass around the JPanel to every entity and let it draw its contents onto the panel before showing it. However I can't seem to figure out how to do this. When using this approach by changing the Graphics of the panel I get a lot of flickering.
Here is a fully functional, albeit simple example, I wrote some time ago. It just has a bunch of balls bouncing off the sides of the panel. Notice that the render method of the Ball class accepts the graphics context from paintComponent. If I had more classes that needed to be rendered, I could have created a Renderable interface and have each class implement it. Then I could have a list of Renderable objects and just go thru them and call the method. But as I also said, that would need to happen quickly to avoid tying up the EDT.
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
public class Bounce extends JPanel {
private static final int COLOR_BOUND = 256;
private final static double INC = 1;
private final static int DIAMETER = 40;
private final static int NBALLS = 20;
private final static int DELAY = 5;
private final static int PANEL_WIDTH = 800;
private final static int PANEL_HEIGHT = 600;
private final static int LEFT_EDGE = 0;
private final static int TOP_EDGE = 0;
private JFrame frame;
private double rightEdge;
private double bottomEdge;
private List<Ball> balls = new ArrayList<>();
private Random rand = new Random();
private List<Long> times = new ArrayList<>();
private int width;
private int height;
public Bounce(int width, int height) {
this.width = width;
this.height = height;
frame = new JFrame("Bounce");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(this);
addComponentListener(new MyComponentListener());
frame.pack();
frame.setLocationRelativeTo(null);
rightEdge = width - DIAMETER;
bottomEdge = height - DIAMETER;
for (int j = 0; j < NBALLS; j++) {
int r = rand.nextInt(COLOR_BOUND);
int g = rand.nextInt(COLOR_BOUND);
int b = rand.nextInt(COLOR_BOUND);
Ball bb = new Ball(new Color(r, g, b), DIAMETER);
balls.add(bb);
}
frame.setVisible(true);
}
public Dimension getPreferredSize() {
return new Dimension(width, height);
}
public static void main(String[] args) {
new Bounce(PANEL_WIDTH, PANEL_HEIGHT).start();
}
public void start() {
/**
* Note: Using sleep gives a better response time than
* either the Swing timer or the utility timer. For a DELAY
* of 5 msecs between updates, the sleep "wakes up" every 5
* to 6 msecs while the other two options are about every
* 15 to 16 msecs. Not certain why this is happening though
* since the other timers are run on threads.
*
*/
Timer timer = new Timer(0,(ae)-> {repaint();
for (Ball b : balls) {
b.updateDirection();
}} );
timer.setDelay(5); // 5 ms.
timer.start();
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
for (Ball ball : balls) {
ball.render(g2d);
}
}
class MyComponentListener extends ComponentAdapter {
public void componentResized(ComponentEvent ce) {
Component comp = ce.getComponent();
rightEdge = comp.getWidth() - DIAMETER;
bottomEdge = comp.getHeight() - DIAMETER;
for (Ball b : balls) {
b.init();
}
}
}
class Ball {
private Color color;
public double x;
private double y;
private double yy;
private int ydir = 1;
private int xdir = 1;
private double slope;
private int diameter;
public Ball(Color color, int diameter) {
this.color = color;
this.diameter = diameter;
init();
}
public void init() {
// Local constants not uses outside of method
// Provides default slope and direction for ball
slope = Math.random() * .25 + .50;
x = (int) (rightEdge * Math.random());
yy = (int) (bottomEdge * Math.random()) + diameter;
xdir = Math.random() > .5 ? -1
: 1;
ydir = Math.random() > .5 ? -1
: 1;
y = yy;
}
public void render(Graphics2D g2d) {
g2d.setColor(color);
g2d.fillOval((int) x, (int) y, diameter, diameter);
}
public void updateDirection() {
x += (xdir * INC);
yy += (ydir * INC);
y = yy * slope;
if (x < LEFT_EDGE || x > rightEdge) {
xdir = -xdir;
}
if (y < TOP_EDGE || y > bottomEdge) {
ydir = -ydir;
}
}
}
}
I am developing the peg game in java, and I have been stuck on getting a hole to change color when it is clicked on to indicate that it has been selected. I currently have 3 classes, all of which extend JPanel:
Display.java: creates the JFrame and renders the gameboard to the JFrame.
GameBoard.java: Holds the logic for rendering the gameboard.
Hole.java: Renders a hole and holds the logic for the MouseListener. When one clicks on a hole, it should turn blue to indicate that it is selected.
I am able to render the holes onto the gameboard, however, the MouseListener does not work; When I click on a hole, it does not turn blue.
Below are the three classes:
Display.java
import javax.swing.JFrame;
import javax.swing.JPanel;
import java.util.logging.*;
public class Display extends JPanel {
private static final long serialVersionUID = 1L;
private static String staticClassName = Display.class.getName();
private static Logger logger = Logger.getLogger(staticClassName);
private final static Logger LOGGER = Logger.getLogger(staticClassName);
private static String title;
private static int width;
private static int height;
private static JFrame frame;
private static JPanel mainPanel;
private static GameBoard gameBoard;
public Display(String title, int width, int height){
logger.info(staticClassName +".Constructor: Constructing Display");
Display.title = title;
Display.width = width;
Display.height = height;
logger.info(staticClassName +".Constructor: Display constructed.");
initDisplay();
}
private static void initDisplay() {
logger.info(staticClassName +".initDisplay(): Entering method");
try {
logger.info(staticClassName +".initDisplay(): About to create JFrame");
frame = new JFrame(title);
frame.setLocationByPlatform(true);
frame.setVisible(true);
frame.setSize(width, height);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainPanel = new JPanel();
logger.info(staticClassName +".initDisplay(): About to create GameBoard object");
gameBoard = new GameBoard();
mainPanel.add(gameBoard);
frame.getContentPane().add(mainPanel);
frame.pack();
} catch (Exception e) {
logger.info(staticClassName +".initDisplay(): Failed to render display: " + e);
}
logger.info(staticClassName +".initDisplay(): Exiting Method");
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
try {
LOGGER.setLevel(Level.INFO);
Display d = new Display("Peg Game", 800, 800);
} catch (Exception e) {
}
}
});
}
}
GameBoard.java
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.geom.Path2D;
import java.util.logging.Logger;
import javax.swing.JPanel;
public class GameBoard extends JPanel {
private static final long serialVersionUID = 1L;
private static String staticClassName = GameBoard.class.getName();
private static Logger logger = Logger.getLogger(staticClassName);
private static final int RGB1 = 223;
private static final int RGB2 = 191;
private static final int RGB3 = 159;
private static final int WIDTH = 800;
private static final int HEIGHT = WIDTH;
private Path2D path = new Path2D.Double();
private static Color boardColor = new Color(RGB1, RGB2, RGB3);
private int [] adjacentHoles1;
public GameBoard() {
logger.info(staticClassName +".Constructor: Constructing GameBoard");
double firstX = (WIDTH / 2.0) * (1 - 1 / Math.sqrt(3));
double firstY = 3.0 * HEIGHT / 4.0;
path.moveTo(firstX, firstY);
path.lineTo(WIDTH - firstX, firstY);
path.lineTo(WIDTH / 2.0, HEIGHT / 4.0);
path.closePath();
logger.info(staticClassName +".Constructor: GameBoard constructed");
}
#Override
protected void paintComponent(Graphics g) {
logger.info(staticClassName +".paintComponent(): Entering method");
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setPaint(boardColor);
g2.fill(path);
int xPos = 390;
int yPos = 310;
// I was rendering up to 15 holes, but took them out for purpose of
// shortening my example
for (int i = 0; i < 15; i ++ ) {
if (i == 0) {
// Declare the hole here
Hole hole = new Hole(i, xPos, yPos, adjacentHoles1);
// Render it here
hole.paintComponent(g2);
yPos += 50;
}
}
logger.info(staticClassName +".paintComponent(): Exiting method");
}
#Override
public Dimension getPreferredSize() {
logger.info(staticClassName +".getPreferredSize(): Entering method");
if (isPreferredSizeSet()) {
logger.info(staticClassName +".getPreferredSize(): isPreferredSizeSet() == true. Exiting method");
return super.getPreferredSize();
}
logger.info(staticClassName +".getPreferredSize(): isPreferredSizeSet() == false. Exiting method");
return new Dimension(WIDTH, HEIGHT);
}
}
Hole.java
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.util.logging.Logger;
import javax.swing.JPanel;
public class Hole extends JPanel {
private static final long serialVersionUID = 1235245435988434L;
private static String staticClassName = Hole.class.getName();
private static Logger logger = Logger.getLogger(staticClassName);
private int holeNumber;
private int xPos, yPos;
private final int HOLEWIDTH = 20;
private final int HOLEHEIGHT = HOLEWIDTH;
private static final int RGB1 = 0;
private static final int RGB2 = 0;
private static final int RGB3 = 0;
private static Color defaultCircleColor = new Color(RGB1, RGB2, RGB3);
private static Color selectedCircleColor = Color.BLUE;
private static Color circleColor = defaultCircleColor;
private int [] adjacentHoles;
public Hole (int holeNumber, int xPos, int yPos, int [] adjacentHoles) {
logger.info(staticClassName +".Constructor: Constructing Hole");
this.holeNumber = holeNumber;
this.xPos = xPos;
this.yPos = yPos;
this.adjacentHoles = adjacentHoles;
initComponents();
}
#Override
protected void paintComponent(Graphics g) {
logger.info(staticClassName +".paintComponent(): Entering method");
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setPaint(circleColor);
g2.fillOval(xPos,yPos,HOLEWIDTH,HOLEHEIGHT);
logger.info(staticClassName +".paintComponent(): Exiting method");
}
private void initComponents() {
addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent event) {
selectHole(event);
}});
}
public void selectHole(java.awt.event.MouseEvent event) {
logger.info(staticClassName +"------------------------------------------------");
logger.info(staticClassName +".selectHole(): Entering method");
if (circleColor == defaultCircleColor) {
circleColor = selectedCircleColor;
repaint();
}
else {
circleColor = defaultCircleColor;
repaint();
}
logger.info(staticClassName +".selectHole(): Exiting method");
logger.info(staticClassName +"------------------------------------------------");
}
#Override
public Dimension getPreferredSize() {
logger.info(staticClassName +".getPreferredSize(): Getting the preferred size of the circle.");
return new Dimension(800, 800);
}
}
As a side note, if you notice that I could be using better coding practices anywhere in my code, please let me know.
So, your basic problem is right here...
for (int i = 0; i < 15; i ++ ) {
if (i == 0) {
// Declare the hole here
Hole hole = new Hole(i, xPos, yPos, adjacentHoles1);
// Render it here
hole.paintComponent(g2);
yPos += 50;
}
}
Hole is component, you should never call any paint method of component, but, you component is also not "live", meaning that it can never receive ANY events.
What you should do instead, is attach the MouseListener to the GameBoard and test if the mouse was clicked at a place there is a hole.
The simplest solution is to make use of the "shapes" API and generate a list of "holes". This can then be simply iterated over to paint and check to see if the mouse was clicked within it.
I've not gone to a great deal of effort in determining the location of the holes, instead I've just laid them out in rows/cols, but you should get the basic idea of the intended solution
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
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.logging.Level;
import java.util.logging.Logger;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Display extends JPanel {
private static final long serialVersionUID = 1L;
private static String staticClassName = Display.class.getName();
private static Logger logger = Logger.getLogger(staticClassName);
private final static Logger LOGGER = Logger.getLogger(staticClassName);
private static String title;
private static int width;
private static int height;
private static JFrame frame;
private static JPanel mainPanel;
private static GameBoard gameBoard;
public Display(String title, int width, int height) {
logger.info(staticClassName + ".Constructor: Constructing Display");
Display.title = title;
Display.width = width;
Display.height = height;
logger.info(staticClassName + ".Constructor: Display constructed.");
initDisplay();
}
private static void initDisplay() {
frame = new JFrame(title);
frame.setLocationByPlatform(true);
frame.setVisible(true);
frame.setSize(width, height);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainPanel = new JPanel();
gameBoard = new GameBoard();
mainPanel.add(gameBoard);
frame.getContentPane().add(mainPanel);
frame.pack();
}
public static void main(String[] args) {
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
try {
LOGGER.setLevel(Level.INFO);
Display d = new Display("Peg Game", 800, 800);
} catch (Exception e) {
}
}
});
}
public static class GameBoard extends JPanel {
private static final long serialVersionUID = 1L;
private static String staticClassName = GameBoard.class.getName();
private static Logger logger = Logger.getLogger(staticClassName);
private static final int RGB1 = 223;
private static final int RGB2 = 191;
private static final int RGB3 = 159;
private static final int WIDTH = 800;
private static final int HEIGHT = WIDTH;
private Path2D path = new Path2D.Double();
private static Color boardColor = new Color(RGB1, RGB2, RGB3);
private int[] adjacentHoles1;
private Shape[] holes;
private Shape selectedHole;
public GameBoard() {
logger.info(staticClassName + ".Constructor: Constructing GameBoard");
double firstX = (WIDTH / 2.0) * (1 - 1 / Math.sqrt(3));
double firstY = 3.0 * HEIGHT / 4.0;
path.moveTo(firstX, firstY);
path.lineTo(WIDTH - firstX, firstY);
path.lineTo(WIDTH / 2.0, HEIGHT / 4.0);
path.closePath();
logger.info(staticClassName + ".Constructor: GameBoard constructed");
holes = new Shape[15];
int yPos = 310;
int index = 0;
for (int row = 0; row < 3; row++) {
int xPos = 390;
for (int col = 0; col < 5; col++) {
holes[index] = new Ellipse2D.Double(xPos, yPos, 50, 50);
index++;
xPos += 50;
}
yPos += 50;
}
addMouseListener(new MouseAdapter() {
#Override
public void mouseClicked(MouseEvent e) {
selectedHole = null;
for (Shape hole : holes) {
if (hole.contains(e.getPoint())) {
selectedHole = hole;
break;
}
}
repaint();
}
});
}
#Override
protected void paintComponent(Graphics g) {
logger.info(staticClassName + ".paintComponent(): Entering method");
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setPaint(boardColor);
g2.fill(path);
g2.setColor(Color.BLACK);
for (Shape hole : holes) {
g2.fill(hole);
}
if (selectedHole != null) {
g2.setColor(Color.RED);
g2.fill(selectedHole);
}
logger.info(staticClassName + ".paintComponent(): Exiting method");
}
#Override
public Dimension getPreferredSize() {
logger.info(staticClassName + ".getPreferredSize(): Entering method");
if (isPreferredSizeSet()) {
logger.info(staticClassName + ".getPreferredSize(): isPreferredSizeSet() == true. Exiting method");
return super.getPreferredSize();
}
logger.info(staticClassName + ".getPreferredSize(): isPreferredSizeSet() == false. Exiting method");
return new Dimension(WIDTH, HEIGHT);
}
}
}
I am trying to make a Mandelbrot Set renderer with a GUI where you can click and drag to zoom into a specific area. When run, it will do the initial calculations and rendering fine, but when you try to click and drag to zoom in, the console says it is doing the calculations, but the content of the JFrame is not updated.
However, I'm not even positive that it is recalculating, because the initial calculation takes about 8 seconds but when you click/drag to zoom it takes about 6 ms.
I have posted my code below.
Complex Numbers Class
public class Complex {
private double real, imag;
// Constructors
public Complex(){
real=0.0;
imag=0.0;
}
public Complex(double real, double imag) {
this.real=real;
this.imag=imag;
}
// add given complex number to this one, returning the Complex result
public Complex add(Complex other) {
return new Complex(this.real+other.real, this.imag+other.imag);
}
// multiply given complex number by this one, returning the Complex result
public Complex multiply(Complex other) {
return new Complex((this.real*other.real)-(this.imag*other.imag), (this.imag*other.real)+(this.real*other.imag));
}
// get the magnitude of this complex number
public double getMagnitude() {
return Math.sqrt((real*real)+(imag*imag));
}
}
Runnable MandelbrotTask Class
public class MandelbrotTask implements Runnable {
private double x1, y1, x2, y2;
private int startCol, endCol, startRow, endRow, maxIters;
private int[][] iterCounts;
public MandelbrotTask(int maxIters, double x1, double y1, double x2, double y2, int startCol, int endCol, int startRow, int endRow, int[][] iterCounts) {
this.x1 = x1;
this.y1 = y1;
this.x2 = x2;
this.y2 = y2;
this.startCol = startCol;
this.endCol = endCol;
this.startRow = startRow;
this.endRow = endRow;
this.iterCounts = iterCounts;
this.maxIters=maxIters;
}
#Override
public void run() {
for (int i = startRow; i < endRow; i++) {
for (int j = startCol; j < endCol; j++) {
Complex c = getComplex(i, j);
int iterCount = countIters(c);
iterCounts[i][j] = iterCount;
}
}
}
public Complex getComplex(int i, int j){
//output image is 600 X 600 pixels
double incrementX;
double incrementY;
if(x2!=x1){
incrementX=(Math.abs(x2-x1)/600);
}
else{
throw new ArithmeticException("Error: area=0");
}
if(y2!=y1){
incrementY=(Math.abs(y2-y1)/600);
}
else{
throw new ArithmeticException("Error: area=0");
}
return new Complex(x1+((double)i*incrementX), y1+((double)j*incrementY));
}
public int countIters(Complex c){
Complex z=new Complex(0, 0);
int iters=0;
while(z.getMagnitude()<2 && iters<=maxIters){
z=z.multiply(z).add(c);
iters++;
}
return iters;
}
}
Main Mandelbrot Class
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Scanner;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
public class Mandelbrot {
private static final int HEIGHT = 600;
private static final int WIDTH = 600;
private static final int maxIters=50000;
private static Rectangle zoomBox;
private static Point initialClick;
private static JLabel content; //bufferedImage will be put into this JLabel
private static int[][] iterCounts;
private static BufferedImage bufferedImage; //rendering will be written to this bufferedImage
private static JFrame frame;
public static void main(String[] args) throws IOException {
zoomBox=null;
Scanner keyboard = new Scanner(System.in);
double x1 = -2;
double y1 = -2;
double x2 = 2;
double y2 = 2;
/*System.out.print("Max iterations (16,581,375 supported): ");
int maxIters=50000;
if(maxIters>16581375){
throw new UnsupportedOperationException("Error: Max Iterations: Overflow.");
}
System.out.print("Output filename: ");
String fileName = keyboard.next();
if(!fileName.endsWith(".png") && !fileName.endsWith(".PNG")){
fileName=fileName + ".png";
}*/
// TODO: create the rendering, save it to a file
iterCounts=new int[WIDTH][HEIGHT];
recalculate(x1, y1, x2, y2, iterCounts);
bufferedImage = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_ARGB);
MouseAdapter listener = new MouseAdapter() {
#Override
public void mousePressed(MouseEvent e) {
handleMousePressed(e);
}
#Override
public void mouseDragged(MouseEvent e) {
handleMouseDragged(e);
}
#Override
public void mouseReleased(MouseEvent e) {
handleMouseReleased(e);
}
};
content=new JLabel(new ImageIcon(render(iterCounts, bufferedImage, zoomBox, true)));
content.addMouseListener(listener);
content.addMouseMotionListener(listener);
/*OutputStream os = new BufferedOutputStream(new FileOutputStream(fileName));
try {
ImageIO.write(bufferedImage, "PNG", os);
} finally {
os.close();
}*/
frame = new JFrame("Mandelbrot Viewer");
frame.getContentPane().add(content);
frame.pack();
frame.setSize(new Dimension(WIDTH, HEIGHT));
frame.setResizable(false);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
public static BufferedImage render(int[][] iterCounts, BufferedImage bufferedImage, Rectangle zoomBox, boolean updated){
bufferedImage = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_ARGB);
Graphics g = bufferedImage.getGraphics();
Graphics2D g2=(Graphics2D) g;
if(updated){
for(int i=0; i<WIDTH; i++){
for(int j=0; j<HEIGHT; j++){
if(iterCounts[i][j]<maxIters){
String hexCode= String.format("#%06x", (0xFFFFFF & (32*iterCounts[i][j])));
g.setColor(Color.decode(hexCode));
}
else{
g.setColor(Color.CYAN);
}
g.drawLine(i, j, i, j);
}
}
}
else{
if(zoomBox!=null){
g2.setStroke(new BasicStroke(7));
g2.draw(zoomBox);
}
}
return bufferedImage;
}
public static int[][] recalculate(double x1, double y1, double x2, double y2, int[][] iterCounts){
MandelbrotTask[] tasks=new MandelbrotTask[4];
tasks[0]=new MandelbrotTask(maxIters, x1, y1, x2, y2, 0, WIDTH, 0, HEIGHT/4, iterCounts);
tasks[1]=new MandelbrotTask(maxIters, x1, y1, x2, y2, 0, WIDTH, HEIGHT/4, 2*(HEIGHT/4), iterCounts);
tasks[2]=new MandelbrotTask(maxIters, x1, y1, x2, y2, 0, WIDTH, 2*(HEIGHT/4), 3*(HEIGHT/4), iterCounts);
tasks[3]=new MandelbrotTask(maxIters, x1, y1, x2, y2, 0, WIDTH, 3*(HEIGHT/4), 4*(HEIGHT/4), iterCounts);
//parallelize computation
Thread[] threads=new Thread[4];
for(int i=0; i<4; i++){
threads[i]=new Thread(tasks[i]);
}
System.out.println("Working...");
//start timer, start computation
long start=System.currentTimeMillis();
for(int i=0; i<4; i++){
threads[i].start();
}
for(int i=0; i<4; i++){
try {
threads[i].join();
} catch (InterruptedException e) {
System.err.println("A thread was interrupted.");
}
}
//end timer
long end=System.currentTimeMillis();
long elapsed=end-start;
System.out.println("Done.");
System.out.println("Took " + elapsed + " ms.");
return iterCounts;
}
protected static void handleMousePressed(MouseEvent e) {
initialClick=e.getPoint();
}
protected static void handleMouseDragged(MouseEvent e) {
if(e.getX()>e.getY()){
zoomBox=new Rectangle((int)initialClick.getX(), (int)initialClick.getY(), (int)(e.getX()-initialClick.getX()), (int)(e.getY()-initialClick.getX()));
}
else if(e.getY()>e.getX()){
zoomBox=new Rectangle((int)initialClick.getX(), (int)initialClick.getY(), (int)(e.getX()-initialClick.getY()), (int)(e.getY()-initialClick.getY()));
}
else{
zoomBox=new Rectangle((int)initialClick.getX(), (int)initialClick.getY(), (int)(e.getX()-initialClick.getX()), (int)(e.getY()-initialClick.getY()));
}
content=new JLabel(new ImageIcon(render(iterCounts, bufferedImage, zoomBox, false)));
content.repaint();
}
protected static void handleMouseReleased(MouseEvent e) {
recalculate(initialClick.getX(), initialClick.getY(), e.getX(), e.getY(), iterCounts);
SwingUtilities.invokeLater(new Runnable(){
#Override
public void run() {
zoomBox=null;
content=new JLabel(new ImageIcon(render(iterCounts, bufferedImage, zoomBox, false)));
content.repaint();
}
});
}
}
For one, you're creating a new JLabel with each re-iteration, and this JLabel is being added to nothing.
Instead use the same JLabel but rather create a new ImageIcon and set the viewed JLabel's Icon.
ImageIcon icon = new ImageIcon(render(iterCounts, bufferedImage, zoomBox, false));
content.setIcon(icon);
You also don't seem to be doing anything with the int arrays returned from recalculate.
Shouldn't your handleMouseReleased method have:
iterCounts = recalculate(initialClick.getX(), initialClick.getY(),
e.getX(), e.getY(), iterCounts);
Also, you still have bad threading -- you're calling join on your Threads from within the Swing event thread, something almost sure to freeze your GUI. Use a SwingWorker and then after getting notified from the worker when it's done, use its data. Also you're grossly over using static variables in your GUI. Make your GUI components instance fields, not static fields.
There are more logical errors that I've yet to find I'm afraid...
Second iteration of program -- With the Mandelbrot calculations:
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Window;
import java.awt.Dialog.ModalityType;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.image.BufferedImage;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.util.concurrent.ExecutionException;
import javax.swing.*;
#SuppressWarnings("serial")
public class Mandel2 extends JPanel {
private static final int GUI_HEIGHT = 600;
private static final int GUI_WIDTH = 600;
private static final int MAX_ITERS = 50000;
private BufferedImage image = new BufferedImage(GUI_WIDTH, GUI_HEIGHT,
BufferedImage.TYPE_INT_ARGB);
private Rectangle zoomRect;
private double myX0 = -2.5;
private double myY0 = -2.0;
private double myX1 = 1.5;
private double myY1 = 2.0;
private JDialog waitDialog;
public Mandel2() {
final MyMouse myMouse = new MyMouse();
int delayStartingCalc = 2 * 1000; // 2 second delay
Timer timer = new Timer(delayStartingCalc, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
addMouseListener(myMouse);
addMouseMotionListener(myMouse);
Rectangle myRect = new Rectangle(0, 0, GUI_WIDTH, GUI_HEIGHT);
createMandel(myRect);
}
});
timer.setRepeats(false);
timer.start();
}
#Override
public Dimension getPreferredSize() {
if (isPreferredSizeSet()) {
return super.getPreferredSize();
}
return new Dimension(GUI_WIDTH, GUI_HEIGHT);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
if (image != null) {
g.drawImage(image, 0, 0, this);
}
Graphics2D g2 = (Graphics2D) g;
if (zoomRect == null) {
return;
}
g2.setXORMode(Color.gray);
g2.draw(zoomRect);
}
private double screenToLogicalX(double screenX) {
return myX0 + (screenX * (myX1 - myX0)) / GUI_WIDTH;
}
private double screenToLogicalY(double screenY) {
return myY0 + ((GUI_HEIGHT - screenY) * (myY1 - myY0)) / GUI_HEIGHT;
}
private void createMandel(Rectangle myRect) {
double x0 = screenToLogicalX(myRect.x);
double y0 = screenToLogicalY(myRect.y + myRect.height);
double x1 = screenToLogicalX(myRect.x + myRect.width);
double y1 = screenToLogicalY(myRect.y);
myX0 = x0;
myY0 = y0;
myX1 = x1;
myY1 = y1;
MandelWorker mandelWorker = new MandelWorker(MAX_ITERS, x0, y0, x1, y1);
mandelWorker.addPropertyChangeListener(new MandelWorkerListener());
mandelWorker.execute();
if (waitDialog == null) {
Window win = SwingUtilities.getWindowAncestor(Mandel2.this);
JProgressBar jProgressBar = new JProgressBar();
jProgressBar.setIndeterminate(true);
waitDialog = new JDialog(win, "Please Wait", ModalityType.APPLICATION_MODAL);
waitDialog.add(jProgressBar);
waitDialog.pack();
waitDialog.setLocationRelativeTo(win);
}
waitDialog.setVisible(true);
}
private class MyMouse extends MouseAdapter {
private Point p;
#Override
public void mousePressed(MouseEvent e) {
p = e.getPoint();
}
public void mouseDragged(MouseEvent e) {
zoomRect = createRect(e);
repaint();
};
#Override
public void mouseReleased(MouseEvent e) {
zoomRect = createRect(e);
repaint();
createMandel(zoomRect);
}
private Rectangle createRect(MouseEvent e) {
int x = Math.min(p.x, e.getX());
int y = Math.min(p.y, e.getY());
int width = Math.abs(p.x - e.getX());
int height = Math.abs(p.y - e.getY());
return new Rectangle(x, y, width, height);
}
}
private class MandelWorkerListener implements PropertyChangeListener {
#Override
public void propertyChange(PropertyChangeEvent evt) {
if (evt.getNewValue() == SwingWorker.StateValue.DONE) {
waitDialog.setVisible(false);
waitDialog.dispose();
MandelWorker worker = (MandelWorker) evt.getSource();
try {
image = worker.get();
zoomRect = null;
repaint();
} catch (InterruptedException e) {
e.printStackTrace();
} catch (ExecutionException e) {
e.printStackTrace();
}
}
}
}
private class MandelWorker extends SwingWorker<BufferedImage, Void> {
private int maxIters;
private double x1;
private double y1;
private double x2;
private double y2;
public MandelWorker(int maxIters, double x1, double y1, double x2, double y2) {
this.maxIters = maxIters;
this.x1 = x1;
this.y1 = y1;
this.x2 = x2;
this.y2 = y2;
}
#Override
protected BufferedImage doInBackground() throws Exception {
int[][] iterGrid = new int[GUI_HEIGHT][GUI_WIDTH];
for (int i = 0; i < GUI_HEIGHT; i++) {
double y = y1 + i * (y2 - y1) / GUI_HEIGHT;
for (int j = 0; j < GUI_WIDTH; j++) {
double x = x1 + j * (x2 - x1) / GUI_WIDTH;
int iIndex = GUI_HEIGHT - i - 1;
iterGrid[iIndex][j] = calcMandel(x, y);
}
}
return render(iterGrid);
}
private BufferedImage render(int[][] iterGrid) {
int w = GUI_WIDTH;
int h = GUI_HEIGHT;
BufferedImage img = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
Graphics2D g2 = img.createGraphics();
for (int i = 0; i < w; i++) {
for (int j = 0; j < h; j++) {
if (iterGrid[i][j] < maxIters) {
String hexCode = String.format("#%06x", (0xFFFFFF & (32 * iterGrid[i][j])));
g2.setColor(Color.decode(hexCode));
} else {
g2.setColor(Color.CYAN);
}
g2.drawLine(j, i, j, i);
}
}
g2.dispose();
return img;
}
private int calcMandel(double x, double y) {
Complex c = new Complex(x, y);
Complex z = new Complex();
int iters = 0;
while (z.getMagnitude() < 2 && iters <= maxIters) {
z = z.multiply(z).add(c);
iters++;
}
return iters;
}
}
private class Complex {
private double real, imag;
// Constructors
public Complex() {
real = 0.0;
imag = 0.0;
}
public Complex(double real, double imag) {
this.real = real;
this.imag = imag;
}
// add given complex number to this one, returning the Complex result
public Complex add(Complex other) {
return new Complex(this.real + other.real, this.imag + other.imag);
}
// multiply given complex number by this one, returning the Complex
// result
public Complex multiply(Complex other) {
return new Complex((this.real * other.real) - (this.imag * other.imag),
(this.imag * other.real) + (this.real * other.imag));
}
// get the magnitude of this complex number
public double getMagnitude() {
return Math.sqrt((real * real) + (imag * imag));
}
}
private static void createAndShowGui() {
Mandel2 mainPanel = new Mandel2();
JFrame frame = new JFrame("Mandel2");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.setResizable(false);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}
Second iteration -- it does the calculations, but is not very efficient at it.
I am trying to draw two circle on a panel with a line joining them, all after a button is pressed. So far (apart from tweaking locations of the line) this is ok. However, I would like to animate it using a timer. The first circle should appear, then gradually the line will be revealed, and finally the second circle.
I have looked at many examples of timers, but I can't seem to get it to work for me. I must be misunderstanding something.
here is the ball class (for each circle):
package twoBalls;
import java.awt.Color;
import java.awt.Point;
public class Ball {
private int x;
private int y;
private int r;
private Color color;
private Point location;
private Ball parent;
public Ball(int x, int y, int r) {
this.x = x;
this.y = y;
this.r = r;
Point p = new Point(x, y);
setLocation(p);
}
public void setParent(Ball b) {
parent = b;
}
public Ball getParent() {
return parent;
}
public void setx(int x) {
this.x = x;
}
public void sety(int y) {
this.y = y;
}
public int getx() {
return x;
}
public int gety() {
return y;
}
public int getr() {
return r;
}
public void setPreferedSize() {
}
public void setLocation(Point p) {
setx(p.x);
sety(p.y);
location = p;
}
public Point getLocation() {
return location;
}
public void setColor(Color color) {
this.color = color;
}
public Color getColor() {
return color;
}
}
then the class that will store balls in an arrayList. And I think that this is where the actual drawing should take place, along with the timer.
I am trying to set the start and end point of the line to be the same, and increment the end point until it is where it should be, using the timer. I'm probably way of track, but that was the intention!
I have change this class, the if statements in the while loop can now be entered, as I am now comparing different point. But the line doesn't get drawn at all still.
package twoBalls;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Line2D;
import java.util.ArrayList;
import javax.swing.JPanel;
import javax.swing.Timer;
public class BallsArray extends JPanel implements ActionListener {
private ArrayList<Ball> balls;
private Timer timer;
private final int DELAY = 25;
private int xDest;
private int yDest;
private Point dest;
private Point starts;
private int xStart;
private int yStart;
public BallsArray() {
balls = new ArrayList<Ball>();
timer = new Timer(DELAY, this);
yDest = 0;
xDest = 0;
dest = new Point(xDest, yDest);
starts = new Point(xStart, yStart);
}
public void setDestXY(int x, int y) {
xDest = x;
yDest = y;
dest = new Point(xDest, yDest);
setDest(dest);
}
public void setDest(Point p) {
dest = p;
}
public Point getDest() {
return dest;
}
public void setStartsXY(int x, int y) {
xStart = x;
yStart = y;
starts = new Point(xStart, yStart);
setStarts(starts);
}
public void setStarts(Point p) {
starts = p;
}
public Point getStarts() {
return starts;
}
public void addBall(Ball b) {
balls.add(b);
}
public void addBall(int x, int y, int r) {
balls.add(new Ball(x, y, r));
}
public void paintComponent(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
for (int i = 0; i < balls.size(); i++) {
if (i == 0) {
paintBall(balls.get(0), g2);
}
if (i != 0) {
int j = i - 1;
Ball bp = balls.get(j);
Ball bc = balls.get(i);
bc.setParent(bp);
paintLine(bc, g2);
paintBall(bc, g2);
}
}
}
public void paintBall(Ball b, Graphics2D g2d) {
Ellipse2D circ = new Ellipse2D.Float(b.getx(), b.gety(), b.getr(),
b.getr());
g2d.draw(circ);
}
public void paintLine(Ball b, Graphics2D g2d) {
timer.start();
if (b != null && b.getLocation() != null) {
Ball parent = b.getParent();
if (parent != null) {
g2d.setColor(Color.GRAY);
if (parent.getLocation() != null && b.getLocation() != null) {
setDest(parent.getLocation());
setStarts(parent.getLocation());
g2d.draw(new Line2D.Float(starts, dest));
}
}
}
}
#Override
public void actionPerformed(ActionEvent e) {
// Not sure what I need to do here
// increment second location somehow
// Point s = getStarts();
Point p = getDest();
Point t = this.getLocation();
while (p != t) {
if (p.x != t.x && p.y != t.y) {
System.out.println("hello");
int x = dest.x;
int y = dest.y;
x++;
y++;
setDestXY(x, y);
p = getDest();
repaint();
} else if (p.x == t.x && p.y != t.y) {
System.out.println("part 2");
int y = dest.y;
y++;
setDestXY(dest.x, y);
p = getDest();
repaint();
} else if (p.x != t.x && p.y == t.y) {
System.out.println("part 3");
int x = dest.x;
x++;
setDestXY(x, dest.y);
p = getDest();
repaint();
}
repaint();
}
}
}
I have had a lot of help online getting this far, I worry I am just beyond my depth now!. I am unsure about the EventQueue/run part below. Here is the class to set it all up:
package twoBalls;
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
public class Display implements ActionListener {
private JFrame frame;
private JButton button;
private BallsArray b;
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
Display ex = new Display();
}
});
}
public Display() {
b = new BallsArray();
frame = new JFrame();
frame.setSize(800, 500);
frame.setTitle("Show balls");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
button = new JButton("New Ball");
frame.add(button, BorderLayout.SOUTH);
frame.setVisible(true);
button.addActionListener(this);
}
#Override
public void actionPerformed(ActionEvent e) {
Ball ball1 = new Ball(100, 100, 50);
b.addBall(ball1);
b.addBall(200, 200, 50);
frame.add(b, BorderLayout.CENTER);
frame.revalidate();
frame.repaint();
}
}
At the moment it draws the two circles, but not the line at all.
When you make an animation, it helps to use the model / view / controller pattern.
Here's the GUI I created from your code.
I simplified your Ball class. This is all you need to define a ball.
package twoBalls;
import java.awt.Color;
import java.awt.Point;
public class Ball {
private final int radius;
private final Color color;
private final Point center;
public Ball(int x, int y, int radius, Color color) {
this(new Point(x, y), radius, color);
}
public Ball(Point center, int radius, Color color) {
this.center = center;
this.radius = radius;
this.color = color;
}
public int getRadius() {
return radius;
}
public Color getColor() {
return color;
}
public Point getCenter() {
return center;
}
}
I created the GUIModel class to hold all of the information your GUI needs. This separates the model from the view.
package twoBalls;
import java.awt.Point;
import java.util.ArrayList;
import java.util.List;
public class GUIModel {
private double direction;
private double distance;
private List<Ball> balls;
private Point lineStartPoint;
private Point lineEndPoint;
public GUIModel() {
this.balls = new ArrayList<>();
}
public void addBall(Ball ball) {
this.balls.add(ball);
}
public List<Ball> getBalls() {
return balls;
}
public void calculatePoints() {
this.lineStartPoint = balls.get(0).getCenter();
this.lineEndPoint = balls.get(1).getCenter();
this.distance = Point.distance(lineStartPoint.x, lineStartPoint.y,
lineEndPoint.x, lineEndPoint.y);
this.direction = Math.atan2(lineEndPoint.y - lineStartPoint.y,
lineEndPoint.x - lineStartPoint.x);
}
public Point getCurrentPoint(int pos, int total) {
double increment = distance / total;
double length = increment * pos;
double x = lineStartPoint.x + Math.cos(direction) * length;
double y = lineStartPoint.y - Math.sin(direction) * length;
x = Math.round(x);
y = Math.round(y);
return new Point((int) x, (int) y);
}
public Point getLineStartPoint() {
return lineStartPoint;
}
}
This class holds the two Ball instances, and calculates the length and direction of the line, divided into total increments.
Now that we've defined the model classes, let's look at the view classes. The first is your Display class.
package twoBalls;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class Display implements Runnable {
private GUIModel guiModel;
private JFrame frame;
public static void main(String[] args) {
EventQueue.invokeLater(new Display());
}
public Display() {
this.guiModel = new GUIModel();
Ball ball1 = new Ball(150, 200, 50, Color.BLUE);
Ball ball2 = new Ball(450, 200, 50, Color.GREEN);
guiModel.addBall(ball1);
guiModel.addBall(ball2);
guiModel.calculatePoints();
}
#Override
public void run() {
frame = new JFrame();
frame.setTitle("Show Balls Animation");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel();
panel.setLayout(new BorderLayout());
DrawingPanel drawingPanel = new DrawingPanel(guiModel);
panel.add(drawingPanel, BorderLayout.CENTER);
panel.add(createButtonPanel(drawingPanel), BorderLayout.SOUTH);
frame.add(panel);
frame.pack();
frame.setVisible(true);
}
private JPanel createButtonPanel(DrawingPanel drawingPanel) {
JPanel panel = new JPanel();
JButton startButton = new JButton("Start Animation");
startButton.addActionListener(new StartAnimation(drawingPanel));
panel.add(startButton);
return panel;
}
public class StartAnimation implements ActionListener {
private DrawingPanel drawingPanel;
public StartAnimation(DrawingPanel drawingPanel) {
this.drawingPanel = drawingPanel;
}
#Override
public void actionPerformed(ActionEvent event) {
LineRunnable runnable = new LineRunnable(drawingPanel);
new Thread(runnable).start();
}
}
}
The constructor of the Display class sets up the GUI model.
The run method of the Display class constructs the GUI, and starts the animation.
See how I've separated the model and view.
The StartAnimation class is your controller. It starts the animation when you left click on the JButton. I'll discuss the LineRunnable class later.
Next, let's take a look at the DrawingPanel class.
package twoBalls;
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import javax.swing.JPanel;
public class DrawingPanel extends JPanel {
private static final long serialVersionUID = -3709678584255542338L;
private boolean drawLine;
private int pos;
private int total;
private GUIModel guiModel;
public DrawingPanel(GUIModel guiModel) {
this.guiModel = guiModel;
this.drawLine = false;
this.setPreferredSize(new Dimension(600, 400));
}
public boolean isDrawLine() {
return drawLine;
}
public void setDrawLine(boolean drawLine) {
this.drawLine = drawLine;
}
public void setPos(int pos) {
this.pos = pos;
repaint();
}
public void setTotal(int total) {
this.total = total;
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
for (Ball ball : guiModel.getBalls()) {
g2d.setColor(ball.getColor());
Point center = ball.getCenter();
int radius = ball.getRadius();
g2d.fillOval(center.x - radius, center.y - radius, radius + radius,
radius + radius);
}
if (isDrawLine()) {
g2d.setColor(Color.BLACK);
g2d.setStroke(new BasicStroke(5.0F));
Point a = guiModel.getLineStartPoint();
Point b = guiModel.getCurrentPoint(pos, total);
g2d.drawLine(a.x, a.y, b.x, b.y);
}
}
}
The only thing this view class does is draw the balls and the line. The responsibility for calculating the length of the line belongs in the model.
I set the preferred size here, and use the pack method in the Display class to get the size of the JFrame. You usually want to know the dimensions of the drawing area, rather than the entire window.
Finally, let's look at the LineRunnable class. This is the class that controls the animation.
package twoBalls;
import java.awt.EventQueue;
public class LineRunnable implements Runnable {
private int total;
private DrawingPanel drawingPanel;
public LineRunnable(DrawingPanel drawingPanel) {
this.drawingPanel = drawingPanel;
this.total = 240;
}
#Override
public void run() {
setDrawLine();
for (int pos = 0; pos <= total; pos++) {
setPos(pos);
sleep(50L);
}
}
private void setDrawLine() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
drawingPanel.setDrawLine(true);
drawingPanel.setTotal(total);
}
});
}
private void setPos(final int pos) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
drawingPanel.setPos(pos);
}
});
}
private void sleep(long delay) {
try {
Thread.sleep(delay);
} catch (InterruptedException e) {
}
}
}
In the run method, we divide the line into 240 segments, and draw a segment every 50 milliseconds. It takes the GUI 12 seconds to draw the line. You can play with these numbers if you wish.
The for loop is a classic animation loop. First you update the model, which I'm doing through the drawing panel. Then you sleep.
This animation loop is running on a different thread from the GUI thread. This keeps the GUI responsive. Since the loop is running on a different thread, we have to use the invokeLater method to draw on the Event Dispatch thread.
I hope this was helpful to you. Divide and conquer. Don't let a class do more than one thing.
So I've got this challenge to make one of those spirograph drawrings in an applet. The problem is, I'm new to Java and have absolutely no idea how to get any components appearing on the screen. I'm hoping someone can just add an extra line of code to fix this, though I'm really grateful for any answers :)
import javax.swing.JApplet;
import javax.swing.JOptionPane;
import javax.swing.JTextField;
import java.awt.BorderLayout;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Rectangle;
import java.awt.Dimension;
import java.awt.Toolkit;
public class SpaceCadets3_WB extends JApplet {
int numOfPoints = 1080;
int[] x = new int[numOfPoints];
int[] y = new int[numOfPoints];
int x1, x2, y1, y2, width, height, animationSleep = 0;
int R = 75;
int r = 10;
int O = 75;
JTextField changeNumOfPoints = new JTextField(15);
public SpaceCadets3_WB() {
}
public void start() {
this.setSize(600, 600);
this.setBackground(new Color(100,100,255));
this.getContentPane().setLayout(null);
this.getContentPane().add(changeNumOfPoints);
changeNumOfPoints.setVisible(true);
changeNumOfPoints.setLocation(width - changeNumOfPoints.getSize().width - 25, 25);
}
public void calculatePoints(){
width = SpaceCadets3_WB.this.getWidth();
height = SpaceCadets3_WB.this.getHeight();
for(int t = 0; t<numOfPoints; t++){
x[t] = (int) ((R+r)*Math.cos(t) - (r+O)*Math.cos(((R+r)/r)*t) + width/2);
y[t] = (int) ((R+r)*Math.sin(t) - (r+O)*Math.sin(((R+r)/r)*t) + height/2);
}
}
public void paint(Graphics g){
g.setColor(Color.RED);
calculatePoints();
for(int i = 0; i<numOfPoints;i++){
x1 = x[i];
x2 = x[i+1];
y1 = y[i];
y2 = y[i+1];
g.drawLine(x1, y1, x2, y2);
try {
Thread.sleep(animationSleep);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
Your sleeping the paint method, something you should never do. It's bad to call Thread.sleep(...) on the Swing event thread, but it's a sin to do it in any painting method. So now the applet can't draw. Remember that any painting method must do nothing but painting, and must do it blazingly fast. It shouldn't do any program logic, it shouldn't directly do animation, it should just paint. Use a Swing timer as any similar question will show you how to do.
Also, never draw directly in the applet but instead in the paintComponent method of a JPanel that the applet holds.
So create your JPanel, override its paintComponent method, and draw using fields of the class. Then change the state of those fields in your Timer and call repaint() on the JPanel.
Edit
And yes, you should avoid using null layouts as that's preventing you from easily and adequately adding components to your GUI. Instead in this situation, a FlowLayout, the default layout for JPanel, would work great.
For example:
import java.awt.Color;
import java.awt.Dimension;
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.ActionListener;
import java.awt.image.BufferedImage;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.lang.reflect.InvocationTargetException;
import java.util.concurrent.ExecutionException;
import javax.swing.*;
#SuppressWarnings("serial")
public class SpaceCadets extends JApplet {
#Override
public void init() {
try {
SwingUtilities.invokeAndWait(new Runnable() {
public void run() {
SpaceCadetsPanel panel = new SpaceCadetsPanel();
getContentPane().add(panel);
setSize(SpaceCadetsPanel.PREF_W, SpaceCadetsPanel.PREF_H);
}
});
} catch (InvocationTargetException | InterruptedException e) {
e.printStackTrace();
}
}
}
#SuppressWarnings("serial")
class SpaceCadetsPanel extends JPanel {
public static final int PREF_W = 600;
public static final int PREF_H = 600;
public final static int TOTAL_POINTS = 1080;
private static final int R = 75;
private static final int R2 = 10;
private static final int O = 75;
private static final Color DRAW_COLOR = Color.RED;
private static final int ANIMATION_DELAY = 20;
private Point[] pts;
private JSpinner pointCountSpinner = new JSpinner(new SpinnerNumberModel(
800, 100, 1080, 1));
private JButton doItButton = new JButton(new DoItBtnAction("Do It!"));
private BufferedImage bufImg = new BufferedImage(PREF_W, PREF_H,
BufferedImage.TYPE_INT_ARGB);
private Timer timer;
public int imageIndex;
private CalcWorker calcWorker;
public Graphics2D g2;
public SpaceCadetsPanel() {
System.out.println(pointCountSpinner.getEditor().getClass());
add(pointCountSpinner);
add(doItButton);
setBackground(Color.white);
}
#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);
if (bufImg != null) {
g.drawImage(bufImg, 0, 0, this);
}
}
class DoItBtnAction extends AbstractAction {
public DoItBtnAction(String name) {
super(name);
int mnemonic = (int) name.charAt(0);
putValue(MNEMONIC_KEY, mnemonic);
}
#Override
public void actionPerformed(ActionEvent e) {
imageIndex = 0;
if (timer != null && timer.isRunning()) {
timer.stop();
}
if (g2 != null) {
g2.dispose();
}
pts = new Point[0];
bufImg = new BufferedImage(PREF_W, PREF_H, BufferedImage.TYPE_INT_ARGB);
g2 = bufImg.createGraphics();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON);
g2.setColor(DRAW_COLOR);
int totalPoints = 0;
totalPoints = ((Integer) pointCountSpinner.getValue()).intValue();
timer = new Timer(ANIMATION_DELAY, new TimerListener(totalPoints));
calcWorker = new CalcWorker(totalPoints);
calcWorker.addPropertyChangeListener(new CalcWorkerListener());
calcWorker.execute();
}
}
class CalcWorker extends SwingWorker<Point[], Void> {
private int totalPoints;
public CalcWorker(int totalPoints) {
this.totalPoints = totalPoints;
}
#Override
protected Point[] doInBackground() throws Exception {
Point[] pts2 = new Point[totalPoints];
for (int i = 0; i < pts2.length; i++) {
int x = (int) ((R + R2) * Math.cos(i) - (R2 + O)
* Math.cos(((R + R2) / R2) * i) + PREF_W / 2);
int y = (int) ((R + R2) * Math.sin(i) - (R2 + O)
* Math.sin(((R + R2) / R2) * i) + PREF_H / 2);
pts2[i] = new Point(x, y);
}
return pts2;
}
}
class CalcWorkerListener implements PropertyChangeListener {
#Override
public void propertyChange(PropertyChangeEvent evt) {
if (SwingWorker.StateValue.DONE == evt.getNewValue()) {
try {
pts = calcWorker.get();
timer.start();
} catch (InterruptedException | ExecutionException e) {
e.printStackTrace();
}
}
}
}
class TimerListener implements ActionListener {
private int totalPoints;
public TimerListener(int totalPoints) {
this.totalPoints = totalPoints;
}
#Override
public void actionPerformed(ActionEvent e) {
int x1 = pts[imageIndex].x;
int y1 = pts[imageIndex].y;
int x2 = pts[imageIndex + 1].x;
int y2 = pts[imageIndex + 1].y;
g2.drawLine(x1, y1, x2, y2);
repaint();
imageIndex++;
if (imageIndex == totalPoints - 1) {
((Timer) e.getSource()).stop();
}
}
}
}
Which displays as,