How to draw an array of Graphics - java

OK so i'm working on a school project (little animation) and I am currently trying to make rain. I'm not sure how I would go about drawing individual "drops" using JPanel. My Code so far:
Main Class:
public class RainPanel extends JPanel {
private static final long serialVersionUID = 1L;
public static void main(String[] args) {
new RainPanel();
}
private final int WIDTH = 800, HEIGHT = 800;
Drop drop;
public RainPanel() {
init();
}
public void init() {
JFrame frame = new JFrame("Rain");
JPanel drop = new Drop();
frame.setVisible(true);
frame.setSize(WIDTH, HEIGHT);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLocationRelativeTo(null);
frame.add(drop);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
drop.paint(g);
}
Drop class:
public class Drop extends JPanel implements ActionListener{
private static final long serialVersionUID = 1L;
int x,y;
int yVel = 2;
Timer t = new Timer(5, this);
Random r = new Random();
ArrayList<Drop> DropArray;
public Drop() {
x = r.nextInt(800);
y = r.nextInt(800);
t.start();
}
public void paint(Graphics g) {
super.paintComponent(g);
DropArray = new ArrayList<>(100);
for (int i = 0; i < DropArray.size(); i++) {
DropArray.add(new Drop());
}
g.setColor(Color.BLUE);
g.fillRect(x, y, 3, 15);
}
public void update() {
y += yVel;
if (y > 800)
y = r.nextInt(800);
}
#Override
public void actionPerformed(ActionEvent e) {
update();
repaint();
}
I understand if you might be cringing hard right now (I'm fairly new to graphics coding and mostly familiar with Java itself). All i'm getting drawn currently is a single rain drop. Any suggestions are appreciated.

Don't call super.paintComponent from within paint, you're breaking the paint chain which could cause no end of issues. Override paintComponent directly instead
You shouldn't be modifying the state of a component or anything the component relies on from within any paint method, paint can be called a number of times in quick succession and this can cause no end of issues
Component based animation is not a simple task and unless you really, really need it, you should try and avoid it. Instead, write a class which is "paintable", which you can call from your paintComponent method
For example..
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Rectangle2D;
import java.util.ArrayList;
import java.util.List;
import java.util.Random;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class RainDropsKeepFalling {
public static void main(String[] args) {
new RainDropsKeepFalling();
}
public RainDropsKeepFalling() {
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 RainPane());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class RainPane extends JPanel {
private List<Drop> drops = new ArrayList<>(100);
public RainPane() {
for (int index = 0; index < 100; index++) {
drops.add(new Drop(getPreferredSize()));
}
Timer timer = new Timer(5, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
for (Drop drop : drops) {
drop.update(getSize());
repaint();
}
}
});
timer.start();
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
for (Drop drop : drops) {
Graphics2D g2d = (Graphics2D) g.create();
drop.paint(g2d);
g2d.dispose();
}
}
}
protected static final Random random = new Random();
public static class Drop {
private double vDelta = random.nextDouble() + 0.5;
private int height = 15;
private int width = 3;
private double x;
private double y = -height;
private Rectangle2D shape;
public Drop(Dimension size) {
x = random.nextInt(size.width - width) + width;
y = random.nextInt(size.height - height) + height;
shape = new Rectangle2D.Double(x, y, width, height);
}
public void paint(Graphics2D g2d) {
g2d.setColor(Color.BLUE);
g2d.fill(shape);
}
public void update(Dimension size) {
y += vDelta;
if (y > size.height) {
y = -height;
x = random.nextInt(size.width - width) + width;
}
shape.setRect(x, y, width, height);
}
}
}

Related

The repaint method stops working for short delays

I'm trying to create a simple panel where a 2-dimensional ball is bouncing up and down. I can't get it to work because for some reason I can't call the repaint method more than once a second. The design is basically that there is an object that can be given "an impulse" with the method move(). Everytime the evaluatePosition method is called, the current position will be calculated through the time that has passed, the velocity and the acceleration. The code for the panel is:
public class Display extends JPanel {
private MovableObject object = new MovableObject(new Ellipse2D.Double(5,5,50,50));
private static final int DELAY = 1000;
public Display(){
object.move(50,50);
Timer timer = new Timer(DELAY, new ActionListener(){
#Override
public void actionPerformed(ActionEvent e){
object.evaluatePosition();
repaint();
}
});
timer.start();
}
}
#Override
public void paintComponent(Graphics g){
super.paintComponent(g);
Graphics2D g2 = (Graphics2D)g;
g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g.drawOval((int)object.getPosition().getX(), (int)object.getPosition.getY()
(int)object.getShape().getWidth(), object.getShape().getHeight());
}
This code works for DELAY=1000 but not for DELAY=100 or DELAY=10 and so on. I read some example code here on SO but they all seem to me like what I already did. So why is my code not working?
EDIT (2016-01-30):
Since it really seems to be a performance issue, here's the code for the MovableObject (I just thought it would be irrelevant and you will probably see why):
public class MovableObject {
// I would really like to use Shape instead of Ellipse2D so that
// objects of any shape can be created
private Ellipse2D.Double shape;
private Point position;
// Vector is my own class. I want to have some easy vector addition and
// multiplication and magnitude methods
private Vector velocity = new Vector(0, 0);
private Vector acceleration = new Vector(0, 0);
private Date lastEvaluation = new Date();
public MovableObject(Ellipse2D.Double objectShape){
shape = objectShape;
}
public void evaluatePosition(){
Date currentTime = new Date();
long deltaTInS = (currentTime.getTime()-lastEvaluation.getTime())/1000;
// s = s_0 + v*t + 0.5*a*t^2
position = new Point((int)position.getX()+ (int)(velocity.getX()*deltaTInS) + (int)(0.5*acceleration.getX()*deltaTInS*deltaTInS),
(int)position.getY()+ (int)(velocity.getY()*deltaTInS) + (int)(0.5*acceleration.getY()*deltaTInS*deltaTInS));
lastEvaluation = currentTime;
}
}
public void move(Vector vector){
velocity = velocity.add(vector);
evaluatePosition();
}
public Point getPosition(){
return position;
}
public Ellipse2D.Double getShape(){
return shape;
}
My move method does not change position but velocity. Please notice that I just changed the shape Object from Shape to Ellipse2D for testing if my code has a performance issue because of the additional code. So if you think this is more complex than it needs to be: I actually want to add some complexity so that the MovableObject can have the shape of any subclass of shape. I've seen a lot of code that seemed more complex to me and rendered fast. So I'd like to know what's wrong with this (besides the fact that it's a bit too complex for just rendering an ellipse).
Okay, so this is a simple example, based on the out-of-context code snippet you left which doesn't seem to have any problems. It has variable speed controlled by a simple slider...
import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.AffineTransform;
import java.awt.geom.Ellipse2D;
import java.awt.geom.GeneralPath;
import java.awt.geom.PathIterator;
import java.util.Random;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JSlider;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;
public class Display extends JPanel {
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new Display());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
private MovableObject object = new MovableObject(new Ellipse2D.Double(5, 5, 50, 50));
private int delay = 40;
private Timer timer = new Timer(40, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
object.evaluatePosition(getSize());
repaint();
}
});
private JSlider slider = new JSlider(5, 1000);
public Display() {
object.move(50, 50);
slider = new JSlider(5, 1000);
slider.setSnapToTicks(true);
slider.setMajorTickSpacing(10);
slider.setMinorTickSpacing(5);
setLayout(new BorderLayout());
add(slider, BorderLayout.SOUTH);
// This is simply designed to put an artificate delay between the
// change listener and the time the update takes place, the intention
// is to stop it from pausing the "main" timer...
Timer delay = new Timer(250, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (timer != null) {
timer.stop();
}
timer.setDelay(slider.getValue());
timer.start();
}
});
slider.addChangeListener(new ChangeListener() {
#Override
public void stateChanged(ChangeEvent e) {
delay.restart();
repaint();
}
});
slider.setValue(40);
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.draw(object.getTranslatedShape());
FontMetrics fm = g2.getFontMetrics();
String text = Integer.toString(slider.getValue());
g2.drawString(text, 0, fm.getAscent());
g2.dispose();
}
public class MovableObject {
private Shape shape;
private Point location;
private int xDelta, yDelta;
public MovableObject(Shape shape) {
this.shape = shape;
location = shape.getBounds().getLocation();
Random rnd = new Random();
xDelta = rnd.nextInt(8);
yDelta = rnd.nextInt(8);
if (rnd.nextBoolean()) {
xDelta *= -1;
}
if (rnd.nextBoolean()) {
yDelta *= -1;
}
}
public void move(int x, int y) {
location.setLocation(x, y);
}
public void evaluatePosition(Dimension bounds) {
int x = location.x + xDelta;
int y = location.y + yDelta;
if (x < 0) {
x = 0;
xDelta *= -1;
} else if (x + shape.getBounds().width > bounds.width) {
x = bounds.width - shape.getBounds().width;
xDelta *= -1;
}
if (y < 0) {
y = 0;
yDelta *= -1;
} else if (y + shape.getBounds().height > bounds.height) {
y = bounds.height - shape.getBounds().height;
yDelta *= -1;
}
location.setLocation(x, y);
}
public Shape getTranslatedShape() {
PathIterator pi = shape.getPathIterator(AffineTransform.getTranslateInstance(location.x, location.y));
GeneralPath path = new GeneralPath();
path.append(pi, true);
return path;
}
}
}
You could also have a look at
Swing animation running extremely slow
Rotating multiple images causing flickering. Java Graphics2D
Java Bouncing Ball
for some more examples...

Removing a rectangle with color on mouse release

I am developing a game and in some part of my game I want the rectangle to disappear on mouse release. I have placed 26 rectangles in an arrayList and remove the particular rectangle clicked as the mouse is released. So if I remove the fill methods, the rectangle disappears successfully but if the fill methods are there, it does not work anymore.
Here is my paint method:
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Image img = Toolkit.getDefaultToolkit().getImage(Rectangles2.class.getResource("background.jpg"));
g.drawImage(img, 0, 0, this.getWidth(), this.getHeight(), this);
Graphics2D g2 = (Graphics2D) g;
for (Rectangle s : rectanglesList) {
g2.draw(s);
}
g2.setColor(bColor);
g2.fill(box1);
g2.fill(box2);
g2.fill(box3);
g2.fill(box4);
g2.fill(box5);
g2.fill(box6);
g2.fill(box7);
g2.fill(box8);
g2.fill(box9);
g2.fill(box10);
g2.fill(box11);
g2.fill(box12);
g2.fill(box25);
g2.setColor(wColor);
g2.fill(box13);
g2.fill(box14);
g2.fill(box15);
g2.fill(box16);
g2.fill(box17);
g2.fill(box18);
g2.fill(box19);
g2.fill(box20);
g2.fill(box21);
g2.fill(box22);
g2.fill(box23);
g2.fill(box24);
g2.fill(box26);
}
Here is how I did the removing of the rectangle (Just an excerpt):
if (box1.getBounds().contains(x, y)) {
pickedPanelNum = 0;
rectanglesList.remove(box1);
panelsPane.repaint();
}
Here are the values of the bColor and wColor:
Color bColor = Color.BLACK;
Color wColor = Color.WHITE;
NOTE:
The pickedPanelNum is just for assigning an int value and has no connection to the problem.
I think it is because when I repaint, the fill methods are still there. However I have no idea for an alternate way of painting the rectangles.
I hope my problem is stated clearly. If you have ideas how I could solve this, please tell me. Thank you!
UPDATE:
Here is a shorter, runnable version of my program. (Background image isn't included though):
import java.awt.*;
import java.awt.Color.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
import java.awt.geom.Rectangle2D;
public class Rec extends JComponent
{
public ArrayList<Rectangle> rectanglesList = new ArrayList<Rectangle>();
public int arrx[] = new int[120];
public int arry[] = new int[120];
JFrame frame = new JFrame();
public int xSize = 2000;
public int ySize = 1000;
public int x;
public int y;
public int pickedPanelNum = 0;
public String pickedPanelDash = "";
public String pickedPanelColor = "";
Color bColor = Color.BLACK;
Color wColor = Color.WHITE;
boolean removedPanel = false;
public void launchFrame()
{
Random rand = new Random();
for(int x = 0;x<120;x++)
{
arrx[x] = rand.nextInt(640);
arry[x] = rand.nextInt(590);
}
Rectangle box1 = new Rectangle(arrx[103],arry[59],80,90);
Rectangle box2 = new Rectangle(arrx[105],arry[3],80,90);
rectanglesList.add(box1);
rectanglesList.add(box2);
JPanel mainPanel = new JPanel();
JPanel panelsPane = new JPanel()
{
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Image img = Toolkit.getDefaultToolkit().getImage(Rectangles2.class.getResource("background.jpg"));
g.drawImage(img, 0, 0, this.getWidth(), this.getHeight(), this);
Graphics2D g2 = (Graphics2D) g;
for (Rectangle s : rectanglesList) {
g2.draw(s);
}
g2.setColor(bColor);
g2.fill(box1);
g2.setColor(wColor);
g2.fill(box2);
}
};
JPanel rightPane = new JPanel();
panelsPane.addMouseListener (new MouseAdapter ()
{
public void mousePressed(MouseEvent event)
{
x = event.getX();
y = event.getY();
}
public void mouseReleased(MouseEvent event)
{
if (box1.getBounds().contains(x, y)) {
pickedPanelNum = 0;
rectanglesList.remove(box1);
panelsPane.repaint();
}
if (box2.getBounds().contains(x, y)) {
pickedPanelNum = 1;
rectanglesList.remove(box2);
panelsPane.repaint();
}
}
});
panelsPane.addMouseMotionListener (new MouseAdapter ()
{
public void mouseDragged(MouseEvent event)
{
Rec obj = new Rec();
int dx = event.getX() - x;
int dy = event.getY() - y;
if (box1.getBounds().contains(x, y)) {
box1.x += dx;
box1.y += dy;
panelsPane.repaint();
}
if (box2.getBounds().contains(x, y)) {
box2.x += dx;
box2.y += dy;
panelsPane.repaint();
}
x += dx;
y += dy;
}
public void mouseReleased(MouseEvent event) {}
public void mouseClicked(MouseEvent event) {}
public void mouseEntered(MouseEvent event) {}
public void mouseExited(MouseEvent event) {}
});
panelsPane.setPreferredSize(new Dimension (800, ySize-315));
rightPane.setPreferredSize(new Dimension (530, ySize-315));
mainPanel.setPreferredSize(new Dimension (xSize, ySize));
frame.setPreferredSize(new Dimension (xSize, ySize));
rightPane.setBackground(Color.gray);
mainPanel.add(panelsPane);
mainPanel.add(rightPane);
frame.add(mainPanel);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
}
public static void main(String args[])
{
Rec obj = new Rec();
obj.launchFrame();
}
}
Even if you remove box1 from the List, there is nothing stopping it from getting filled in your paintComponent method, the for-loop is only drawing the outline of the rectangles within the list, but you code implicitly fills them anyway.
So, first, get rid of all the box{n} variables. Next change the paintComponent method...
public void paintComponent(Graphics g) {
super.paintComponent(g);
//Image img = Toolkit.getDefaultToolkit().getImage(Rectangles2.class.getResource("background.jpg"));
//g.drawImage(img, 0, 0, this.getWidth(), this.getHeight(), this);
Graphics2D g2 = (Graphics2D) g;
for (Rectangle s : rectanglesList) {
g2.setColor(bColor);
g2.fill(s);
g2.setColor(wColor);
g2.draw(s);
}
}
So, this just uses the rectanglesList to first draw the rectangles and the fill them
Then, lets update the mouseReleased...
public void mouseReleased(MouseEvent event) {
// Because the rectangles are painted in order, the later
// rectangles are painted over the eailer ones, so, we reverse
// the list so we can check for the higher positioned
// rectangles
List<Rectangle> copy = new ArrayList<>(rectanglesList);
Collections.reverse(copy);
for (Rectangle r : copy) {
if (r.contains(event.getPoint())) {
rectanglesList.remove(r);
break;
}
}
event.getComponent().repaint();
}
Okay, this is little more funky, but basically, we reverse the list of rectangles (because those rectangles that appear later in the list are painted over those that appear before them) and checks to see if the mouse was clicked within any one of them. The moment we find a match, we break out of the loop and repaint the component which generated the event
And, because it's nice to see this stuff running, a complete example...
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Random;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
public class Rec extends JComponent {
public ArrayList<Rectangle> rectanglesList = new ArrayList<Rectangle>();
public int arrx[] = new int[120];
public int arry[] = new int[120];
JFrame frame = new JFrame();
public int xSize = 2000;
public int ySize = 1000;
public int x;
public int y;
public int pickedPanelNum = 0;
public String pickedPanelDash = "";
public String pickedPanelColor = "";
Color bColor = Color.BLACK;
Color wColor = Color.WHITE;
boolean removedPanel = false;
public void launchFrame() {
Random rand = new Random();
for (int x = 0; x < 10; x++) {
arrx[x] = rand.nextInt(640);
arry[x] = rand.nextInt(590);
rectanglesList.add(new Rectangle(arrx[x], arry[x], 80, 90));
}
JPanel mainPanel = new JPanel();
JPanel panelsPane = new JPanel() {
public void paintComponent(Graphics g) {
super.paintComponent(g);
// Image img = Toolkit.getDefaultToolkit().getImage(Rectangles2.class.getResource("background.jpg"));
// g.drawImage(img, 0, 0, this.getWidth(), this.getHeight(), this);
Graphics2D g2 = (Graphics2D) g;
for (Rectangle s : rectanglesList) {
g2.setColor(bColor);
g2.fill(s);
g2.setColor(wColor);
g2.draw(s);
}
}
};
JPanel rightPane = new JPanel();
panelsPane.addMouseListener(new MouseAdapter() {
public void mousePressed(MouseEvent event) {
x = event.getX();
y = event.getY();
}
public void mouseReleased(MouseEvent event) {
// Because the rectangles are painted in order, the later
// rectangles are painted over the eailer ones, so, we reverse
// the list so we can check for the higher positioned
// rectangles
List<Rectangle> copy = new ArrayList<>(rectanglesList);
Collections.reverse(copy);
for (Rectangle r : copy) {
if (r.contains(event.getPoint())) {
rectanglesList.remove(r);
break;
}
}
event.getComponent().repaint();
}
});
panelsPane.addMouseMotionListener(new MouseAdapter() {
public void mouseDragged(MouseEvent event) {
}
public void mouseReleased(MouseEvent event) {
}
public void mouseClicked(MouseEvent event) {
}
public void mouseEntered(MouseEvent event) {
}
public void mouseExited(MouseEvent event) {
}
});
panelsPane.setPreferredSize(new Dimension(800, ySize - 315));
rightPane.setPreferredSize(new Dimension(530, ySize - 315));
mainPanel.setPreferredSize(new Dimension(xSize, ySize));
frame.setPreferredSize(new Dimension(xSize, ySize));
rightPane.setBackground(Color.gray);
mainPanel.add(panelsPane);
mainPanel.add(rightPane);
frame.add(mainPanel);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
}
public static void main(String args[]) {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
Rec obj = new Rec();
obj.launchFrame();
}
});
}
}

java graphics isn't drawing anything

The program draws a bunch of rectangles for a bar graph. I know the bar class works perfectly fine because I've got it working before adding in the graph panel class. I was drawing straight onto the frame instead of the graph panel. I assume its a problem in the way my set visible methods are called as it was pointed out to me before. I tried looking into it but I've had no luck after playing around and reading documentation.
import java.awt.Color;
import java.util.ArrayList;
import java.util.Random;
import javax.swing.JFrame;
import javax.swing.JPanel;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.util.concurrent.Semaphore;
#SuppressWarnings("serial")
public class GraphPanel extends JPanel {
private ArrayList<Bar> graphBars;
private int nBars;
public GraphPanel(int nBars, JFrame mainFrame) {
this.setSize(400, 400);
this.graphBars = new ArrayList<Bar>(nBars);
this.nBars = nBars;
this.initBars(mainFrame.getWidth());
for(Bar b: this.graphBars) {
this.add(b);
}
}
private void initBars(int frameW) {
Random random = new Random();
float hue;
Color color;
int barPadding = frameW/this.nBars;
for(int i = 0; i < this.nBars; i++) {
hue = random.nextFloat();
color = Color.getHSBColor(hue, 0.9f, 1.0f);
this.graphBars.add(new Bar(i*barPadding + 30, 350, color));
}
}
public ArrayList<Bar> getBarList() {
return this.graphBars;
}
}
#SuppressWarnings("serial")
public class Bar extends JPanel implements Runnable {
int height = 0;
Color barColor;
Rectangle bar;
private final int WIDTH = 20;
Thread bartender;
private Semaphore s;
public Bar(int x, int y, Color barColor) {
this.barColor= barColor;
this.bar = new Rectangle(x, y, this.WIDTH, this.height);
this.bartender= new Thread(this);
this.s = new Semaphore(1);
}
public boolean setNewHeight(int h) {
try {
this.s.acquire();
this.height = h;
this.s.release();
return true;
} catch (InterruptedException e) {
e.printStackTrace();
return false;
}
}
#SuppressWarnings("deprecation")
public void update() {
if (this.bar.height < this.height) {
bar.reshape(this.bar.x, --this.bar.y, this.bar.width, ++this.bar.height);
} else {
bar.reshape(this.bar.x, ++this.bar.y, this.bar.width, --this.bar.height);
}
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(this.barColor);
g2d.fill(this.bar);
}
#SuppressWarnings("deprecation")
public void callBarTender() {
this.bartender.resume();
}
#SuppressWarnings("deprecation")
#Override
public void run() {
System.out.println("sdf");
while(true) {
if (this.bar.height < this.height) {
for(int i = this.bar.height; i<this.height; i++ ) {
try {
update();
repaint();
Thread.sleep(15);
} catch(Exception e) {
System.out.println(e);
}
}
} else if (this.height < this.bar.height) {
for(int i = this.bar.height; i>this.height; i-- ) {
try {
update();
repaint();
Thread.sleep(15);
} catch(Exception e) {
System.out.println(e);
}
}
}
this.bartender.suspend();
}
}
}
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setSize(400, 400);
frame.setResizable(false);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
GraphPanel gPane = new GraphPanel(3, frame);
frame.add(gPane);
gPane.getBarList().get(0).setVisible(true);
gPane.getBarList().get(1).setVisible(true);
gPane.getBarList().get(2).setVisible(true);
gPane.setVisible(true);
frame.setVisible(true);
gPane.getBarList().get(0).setNewHeight(100);
gPane.getBarList().get(1).setNewHeight(100);
gPane.getBarList().get(2).setNewHeight(100);
gPane.getBarList().get(0).bartender.start();
gPane.getBarList().get(1).bartender.start();
gPane.getBarList().get(2).bartender.start();
}
You should override getPreferredSize of your GraphPanel to ensure that they are laid out correctly
The x/y positions you are passing to the Bar class are irrelevant, as this is causing your Rectangle to paint outside of the visible context of the Bar pane. Painting is done from within the context of the component (0x0 been the top/left corner of the component)
The use of Rectangle or the way you are using it, is actually causing issues. It's impossible to know exactly how big you component will be until it's layed or painted
There is a reason why resume and suspend are deprecated, this could cause no end of "weird" (and wonderful) issues
Take a look at Laying Out Components Within a Container for why you're bars aren't been updated correctly and why the x/y coordinates are pointless
Take a look at How to use Swing Timers for an alternative to your use of Thread
Possibly, something more like...
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.Random;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import javax.swing.border.LineBorder;
public class Test {
public static void main(String[] args) {
new Test();
}
public Test() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
ex.printStackTrace();
}
JFrame frame = new JFrame();
frame.setSize(400, 400);
// frame.setResizable(false);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
GraphPanel gPane = new GraphPanel(3, frame);
frame.add(gPane);
gPane.getBarList().get(1).setFill(false);
gPane.getBarList().get(0).start();
gPane.getBarList().get(1).start();
gPane.getBarList().get(2).start();
frame.setVisible(true);
}
});
}
public class GraphPanel extends JPanel {
private ArrayList<Bar> graphBars;
private int nBars;
public GraphPanel(int nBars, JFrame mainFrame) {
this.graphBars = new ArrayList<Bar>(nBars);
this.nBars = nBars;
this.initBars(mainFrame.getWidth());
for (Bar b : this.graphBars) {
this.add(b);
}
}
private void initBars(int frameW) {
Random random = new Random();
float hue;
Color color;
for (int i = 0; i < this.nBars; i++) {
hue = random.nextFloat();
color = Color.getHSBColor(hue, 0.9f, 1.0f);
this.graphBars.add(new Bar(color));
}
}
public ArrayList<Bar> getBarList() {
return this.graphBars;
}
}
#SuppressWarnings("serial")
public class Bar extends JPanel {
private Color barColor;
private boolean fill = true;
private float fillAmount = 0;
private float delta = 0.01f;
private Timer timer;
private Rectangle bar;
public Bar(Color barColor) {
bar = new Rectangle();
setBorder(new LineBorder(Color.RED));
this.barColor = barColor;
timer = new Timer(15, new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
fillAmount += isFill() ? delta : -delta;
// System.out.println(fillAmount);
if (fillAmount < 0) {
fillAmount = 0;
((Timer) e.getSource()).stop();
} else if (fillAmount > 1.0f) {
fillAmount = 1f;
((Timer) e.getSource()).stop();
}
repaint();
}
});
}
public void start() {
timer.start();
}
public void stop() {
timer.stop();
}
public void setFill(boolean fill) {
this.fill = fill;
if (!timer.isRunning()) {
if (fill && fillAmount == 1) {
fillAmount = 0;
} else if (!fill && fillAmount == 0) {
fillAmount = 1;
}
}
}
public boolean isFill() {
return fill;
}
#Override
public Dimension getPreferredSize() {
return new Dimension(20, 100);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
g2d.setColor(this.barColor);
int height = Math.round(getHeight() * fillAmount);
bar.setSize(getWidth(), height);
bar.setLocation(0, getHeight() - height);
g2d.fill(bar);
g2d.dispose();
}
}
}

Change the background color on a custom Button?

I want my button to change color on the mod == 0 of i % 3. The paintComponent(...) is called when the form is re-sized and index is passed in so I would think that this should change the color of my button ever time I start moving the form around the screen.
I have two components on the screen but both will not show up this might be a factor.
Code:
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class testform {
public static void main (String[] p) {
testBall3 j1 = new testBall3();
myButton b1 = new myButton("test");
JPanel testPane = new JPanel();
testPane.setBackground(Color.green);
testPane.setLayout(new BorderLayout());
j1.setPreferredSize(new Dimension(10,10));
//testPane.add(b1);
testPane.add(j1);
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setLayout(new BorderLayout());
frame.add(testPane);
frame.pack();
frame.setSize(300, 200);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
//j1.setColorBall(Color.BLACK);
//j1.repaint();
}
}
class myButton extends JButton {
private static final long serialVersionUID = 1L;
public myButton(String s) {
super(s);
}
public void setPrefferedSize(Dimension d) {
//this.setBounds(x, y, width, height)
setPreferredSize(d);
}
public void paintComponent(Graphics g) {
super.paintComponent(g);
index += i;
System.out.println(i);
if (index % 3 == 0) {
setBackground(Color.RED);
}
else {
setBackground(Color.BLACK);
}
}
}
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JComponent;
class testBall3 extends JComponent
{
private static final long serialVersionUID = 1L;
private Color colorBall = Color.red;
private int x1, y1;
int index = 0;
public void setColorBall(Color c)
{
this.colorBall = c;
}
public testBall3()
{
super();
System.out.println("MyBall (0)");
}
public testBall3(int x, int y, int diameter)
{
super();
this.setLocation(x, y);
this.setSize(diameter, diameter);
System.out.println("MyBall (1)");
x1 = x;
y1 = y;
}
public void paintBorder(Graphics g)
{
super.paintBorder(g);
g.setColor(Color.YELLOW);
g.fillOval(100, 100, 50, 50);
System.out.println("PaintBorder");
}
public void paintComponent(Graphics g)
{
super.paintComponent(g);
g.setColor(colorBall);
g.fillOval(x1, y1, 10, 10);
System.out.println("paintComponent");
}
public void paint(Graphics g)
{
super.paint(g);
paintComponent(g);
paintBorder(g);
paintChildren(g);
System.out.println("Paint");
}
}
But paintComponent doesn't take a second parameter, how are you passing it? I would think that instead of trying to pass i, you would want make i an attribute of class myButton instead and initialize it to 0 upon instantiation. That is, if you want each button to have its own counter. That sounds like the better plan.
You've got a lot of strange stuff going on...
You've got a component where you override all four major painting methods for no good reason.
In this component, your paint method override calls the super method, and calls the other 3 methods, which in essence will make those 3 methods be called twice.
You've got program logic (advancement of i) inside of your myButton's paintComponent method -- something that should never be done. You do not have full control over when or even if this method is called.
You are calling setBackground(...) from within paintComponent, something which shouldn't be done.
Your class names do not begin with an upper case letter, going against coding conventions, and potentially confusing anyone who tries to read your code.
If you want to change the state of a component on resize, use a ComponentListener.
e.g.
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Toolkit;
import java.awt.Window;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import javax.swing.*;
#SuppressWarnings("serial")
public class Foo2 extends JPanel {
protected static final Color MAGIC_BACKGROUND = Color.red;
protected static final int MAGIC_NUMBER = 3;
private static final int TIMER_DELAY = 20;
private int index = 0;
private JButton myButton = new JButton("My Button");
protected int DELTA_SIZE = 2;
public Foo2() {
add(myButton);
addComponentListener(new ComponentAdapter() {
#Override
public void componentResized(ComponentEvent e) {
index++;
if (index % MAGIC_NUMBER == 0) {
myButton.setBackground(MAGIC_BACKGROUND);
} else {
myButton.setBackground(null);
}
}
});
new Timer(TIMER_DELAY, new ActionListener() {
private Toolkit toolkit = Toolkit.getDefaultToolkit();
private int screenWidth = toolkit.getScreenSize().width;
private int screenHeight = toolkit.getScreenSize().height;
#Override
public void actionPerformed(ActionEvent e) {
if (getWidth() >= screenWidth || getHeight() >= screenHeight) {
((Timer)e.getSource()).stop();
} else {
int width = getWidth() + DELTA_SIZE;
int height = getHeight() + DELTA_SIZE;
setPreferredSize(new Dimension(width, height));
Window win = SwingUtilities.getWindowAncestor(Foo2.this);
win.pack();
win.setLocationRelativeTo(null);
}
}
}).start();
}
private static void createAndShowGui() {
JFrame frame = new JFrame("Foo2");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(new Foo2());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}

How to change locations of drawn objects with user input

I'm attempting to draw multiple fish (very simple ones), as many as the user specifies. But the circles aren't drawn in the proper places when the user specifies they want more than one fish to be drawn. All ovals are drawn, they just aren't in the right spots, so they no longer look like fish.
public class FishList extends JPanel {
static int fn = Integer.parseInt(JOptionPane.showInputDialog(null, "How many fish would you like to draw? "));
static int w = 200;
static int h = 100;
static int x;
static int y;
static int a = x + 20;
static int b = y + 30;
static int d = 50;
static int c = x + 195;
public FishList() {
setPreferredSize(
new Dimension(400,400));
}
public void paint(Graphics g) {
g.setColor(Color.GREEN);
g.fillOval(x, y, w, h);
g.fillOval(c, y, d, h);
g.setColor(Color.BLACK);
g.fillOval(a, b, 25, 25);
}
public static void main(String[] args) {
MyFrame frame1 = new MyFrame("Drawing Fish");
JPanel outer = new JPanel();
for(int i=0; i<fn; i++){
x = 0 + (i*(w+d+1));
y = 0;
FishList sPanel1 = new FishList();
outer.add(sPanel1);
}
frame1.add(outer);
frame1.pack();
frame1.setVisible(true);
}
}
JPanel, by default, uses a FlowLayout. FlowLayout also uses the component's preferred size to determine how to layout each component within the Container.
Failing to call super.paint is going to cause you serious issues. In fact, you should use paintComponent instead of paint and make sure you are calling super.paintComponent.
Take a look at Performing Custom Painting and Painting in AWT and Swing for more details
Components already have a sense of location and size, which you are ignoring. The use of static variables in this context isn't going to help, because basically, each instance of your fish will be painted in the exact same location, as they will share the same value of the each of the static variables...
A better solution would be to generate a class that is capable of begin painted, which then paints the "fish".
These would be included inside a component capable of painting them, which you could then just add to a Container which is using a BorderLayout.
For example...
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.geom.Ellipse2D;
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 Fishies {
public static void main(String[] args) {
new Fishies();
}
public Fishies() {
EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
JFrame frame = new JFrame("Testing");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add(new FishBowel());
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
public class FishBowel extends JPanel {
private List<Fish> fishes = new ArrayList<>(25);
public FishBowel() {
for (int index = 0; index < 10; index++) {
int width = random(20);
int height = width;
int x = random(200 - 20);
int y = random(200 - 20);
fishes.add(new Fish(new Rectangle(x, y, width, height)));
}
}
#Override
public Dimension getPreferredSize() {
return new Dimension(200, 200);
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
for (Fish fish : fishes) {
fish.paint(g2d);
}
g2d.dispose();
}
}
public static int random(int max) {
return (int)(Math.round(Math.random() * max));
}
public class Fish {
private Color color;
private Ellipse2D fish;
public Fish(Rectangle bounds) {
this(new Color(random(255), random(255), random(255)), bounds);
}
public Fish(Color color, Rectangle bounds) {
this.color = color;
fish = new Ellipse2D.Float(bounds.x, bounds.y, bounds.width, bounds.height);
}
public Ellipse2D getFish() {
return fish;
}
public Color getColor() {
return color;
}
public void paint(Graphics2D g2d) {
g2d.setColor(getColor());
g2d.fill(fish);
}
}
}

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