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PORepaint() method causes UI to flash and flicker
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copied!<p>So I have been coding this little UI for a while and for some reason the repaint() method seems to cause the image generated on the screen to flicker and flash. Is there a way to prevent this?</p> <pre><code>import javax.swing.*; import java.awt.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.util.*; import java.util.Timer; public class userInterfaceSimple extends JFrame implements ActionListener { static ArrayList<Creature> list = new ArrayList<Creature>(); static JButton next = new JButton("Begin"); static Timer timer = new Timer(); static JFrame frame = new JFrame(); final static JPanel pane = new JPanel(); public static void main(String[] args) { new userInterfaceSimple(); } public userInterfaceSimple() { super("Toy Planet: Life, a Simulation"); setSize(1000,1000); setVisible(true); setDefaultCloseOperation(EXIT_ON_CLOSE); setLayout(new BorderLayout()); add(pane, BorderLayout.CENTER); next.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { if(next.getText().equals("Begin")) { next.setText("Stop"); timer.scheduleAtFixedRate(new TimerTask() { @Override public void run() { checkRules(); repaint(); } }, 250, 250); } else { next.setText("Begin"); timer.cancel(); timer = new Timer(); } } }); add(next, BorderLayout.SOUTH); for(int j = 0; j < 3; j ++) { Creature orgArc = new Creature(); for(int i = 0; i < 20; i++) { list.add(new Creature(orgArc.gene)); } } sortList(); } public void paint(Graphics g) { super.paint(g); for(int i = 0; i < list.size(); i++) { g.setColor(list.get(i).getColor()); int size = list.get(i).getSize(); g.fillOval(list.get(i).getX() - size/2, list.get(i).getY() - size/2,size,size); } } public static void checkRules() { int size = list.size(); for(int i = 0; i < size; i++) { try { for(int j = 0; j < size; j++) { boolean alreadyMoved = false; if(!(list.get(i)).equals(list.get(j))) { int x = list.get(j).getX() - (list.get(i)).getX(); int y = list.get(j).getY() - (list.get(i)).getY(); double z = Math.sqrt(x*x + y*y); //Passive Interaction Rules //Sight Check if(list.get(j).getSense() > z) { list.get(j).moveTo(list.get(i)); alreadyMoved = true; } if(z <= 1.5) { //Active Interaction Rules //Breeding Check if(list.get(j).isCompatible(list.get(i))) { list.add(list.get(j).breed(list.get(i))); sortList(); } //Eating Check else if(list.get(j).getAggro() > 15 || list.get(j).getDiet() > 3) { list.get(j).eat(list.get(i)); } } } //If no checks fire then move randomly if(alreadyMoved == false) { Organism temp = new Organism(); list.get(j).moveTo(temp); } } //Hunger Check list.get(i).hungerCheck(); } catch(Exception e) { } list.get(i).validate(); size = size - validateList(); } /*for(int i = 0; i < list.size(); i ++) //for debugging. { System.out.println(list.get(i).getInfo()); } System.out.println("----");*/ } public static int getClosestCreature(Organism org) { int x,y; double z; double tempZ = 100000; int closest = 0; for(int i = 0; i < list.size(); i++) { if(!(list.get(i)).equals(org)) { x = org.getX() - (list.get(i)).getX(); y = org.getY() - (list.get(i)).getY(); z = Math.sqrt(x*x + y*y); if(z < tempZ) { closest = i; tempZ = z; } } } return (closest); } public static int validateList() { int netLoss = 0; for(int i = 0; i < list.size(); i++) { if((list.get(i)).getAlive() == false) { list.remove(i); netLoss = netLoss + 1; } } return netLoss; } public static void sortList() { Creature temp; for(int i = 0; i < list.size(); i ++) { for(int j = 1; j < list.size() - i; j++) { if(list.get(j - 1).getSpeed() > list.get(j).getSpeed()) { temp = list.get(j - 1); list.set(j - 1, list.get(j)); list.set(j, temp); } } } } @Override public void actionPerformed(ActionEvent e) { // TODO Auto-generated method stub } } </code></pre> <p>Thanks for you help!</p>

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