Thread: How do you get this fountain to animate with paint method?

I thought a for loop would do it. While I now know that what I did isn't entirely useless as I could probably use that technique to draw things a whole lot quicker than doing the code for each individual one, I still can't make the drops continually move. All it does is move the blue over and draw the black ovals. I was trying to make the water keep moving and appear to move and perhaps even keep the shape of the droplets to let the user know that the water is moving.

However, it's not working out just right. I was using this one to become more familiar with paint method so that I could later use features on JToolBar and stuff to mess with images, though I think I'd need to somehow draw to an image to do that. But anyway, I'm worried about the smaller project right now.

import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.JOptionPane; import java.util.*; import java.io.*;   public class PaintDemo1 extends JFrame {     private JPanel aPanel;   public PaintDemo1() { setVisible(true); aPanel = new JPanel(); aPanel.setVisible(true); Graphics graphics = getGraphics(); System.out.println(graphics); drawFountain(graphics);       setContentPane(aPanel); }   public void drawFountain(Graphics g) { g.setColor(new Color(95,95,95)); g.drawOval(300, 120, 65, 65); g.setColor(Color.BLACK); g.drawOval(320, 140, 25, 25); g.setColor(new Color(95,95,95)); g.fillOval(320, 140, 25, 25);   g.setColor(new Color(50,50,50)); Polygon poly = new Polygon(); poly.addPoint(325, 153); poly.addPoint(325, 125); poly.addPoint(330, 115); poly.addPoint(340, 125); poly.addPoint(340, 153); g.fillPolygon(poly);   g.setColor(Color.BLACK); g.drawPolygon(poly);     }   public void animateFountain(Graphics g) { int newRed = Color.BLUE.getRed() + 10; int newGreen = Color.BLUE.getGreen() + 10; int newBlue = Color.BLUE.getBlue();   g.setColor(new Color(newRed, newGreen, newBlue));   for (int x = 325; x < 352; x++) {   for (int y = 125; y < 155; y++) { // this spot is where the animation is supposed to be happening g.setColor(new Color(newRed, newGreen, newBlue)); g.fillOval(x,y, 10, 10); g.setColor(Color.BLACK); g.drawOval(x,y,10,10);   } }     // repaint(); }       public void paint(Graphics g) {   super.paint(g); g.setColor(new Color(88,88,88)); Polygon poly = new Polygon();   poly.addPoint(200, 200); poly.addPoint(400, 200); poly.addPoint(400, 300); poly.addPoint(100, 300); g.fillPolygon(poly);   g.setColor(Color.BLACK);   g.drawPolygon(poly);   Polygon poly2 = new Polygon(); poly2.addPoint(200, 200); poly2.addPoint(250, 100); poly2.addPoint(450, 110); poly2.addPoint(400, 200); g.setColor(Color.BLUE); g.fillPolygon(poly2);   g.setColor(Color.BLACK); g.drawLine(200, 200, 250, 100); g.drawLine(250, 100, 450, 110); g.drawLine(450, 110, 400, 200);     Polygon poly3 = new Polygon();   poly3.addPoint(100, 300); poly3.addPoint(100, 200); poly3.addPoint(250, 100); poly3.addPoint(200, 200);   g.setColor(new Color (88, 88,88)); g.fillPolygon(poly3);   g.setColor(Color.BLACK); g.drawLine(100, 300, 100, 200); g.drawLine(100, 200, 250, 100);   Polygon poly4 = new Polygon(); g.setColor(new Color(88,88,88));   poly4.addPoint(450, 110); poly4.addPoint(510, 270); poly4.addPoint(400,300); poly4.addPoint(400, 200); g.fillPolygon(poly4); g.setColor(Color.BLACK); g.drawPolygon(poly4);     System.out.println(g.getColor());   drawFountain(g); animateFountain(g);   }   public static void main(String[] args) { PaintDemo1 pd1 = new PaintDemo1(); pd1.setVisible(true);   }   }

While I could avoid drawing the black ovals and just use the blue to make the water appear, I'd like it to move too.

Do you really write code without any indentations? Or is there some problem with the way you copy and paste your code on the forum?

I usually do, though I can easily indent it.

Anyway, I was looking at another thing where I got some words to move to random places across a screen and I used a Thread method.

Should I do the same here?

Anyway, why do I often get a "you cannot post because the token has expired" or something like that message very often, usually after I leave the internet running for a while as I never shut it off? It's starting to become a little annoying.

Anyway, am going to try that Thread thing.

What's a SwingTimer?

Don't know how to use one.

I'll look that up too I guess.

I was able to get words to move across the screen with just this simple code. I didn't use a Swing Timer or anything like that.

 import java.lang.Thread; import java.awt.*; import java.util.*; import java.io.*; import javax.swing.*;       public class Melissa extends Thread {     Background b; private class Background extends JFrame { private String text; public Background(String name) { super(name); setVisible(true); setString(name); setDefaultCloseOperation(EXIT_ON_CLOSE); }   public void paint(Graphics g) { super.paint(g); Random r = new Random(); Random r2 = new Random(); int x = r.nextInt(300); int y = r.nextInt(300);   int red = r2.nextInt(256); int green = r2.nextInt(256); int blue = r2.nextInt(256);     g.setColor(new Color(red,green,blue)); g.drawString(getString(), x, y);       }   public void setString(String text) { this.text = text; }   public String getString() { return text; } } public Melissa(String name) { super(name); b = new Background(name);   System.out.println(this); start(); }   public void run() { //Display info about this particular thread System.out.println(Thread.currentThread().getName()); try {   boolean b2= false; while (b2 == false) { Thread.sleep(5000); b.repaint(); }   }   catch(InterruptedException ieRef) { System.out.println("Error!"); }     }   public static void main(String[] args) {     String text3 = JOptionPane.showInputDialog(null, "Enter text", "Input required", JOptionPane.INFORMATION_MESSAGE);     Melissa m2 = new Melissa(text3);     }   }

Is this the Timer you guys are talking about? I think there might be more than one Timer class in Java so I have to be certain. It's in swing package so I'm pretty sure this is it, but just making sure. How to Use Swing Timers (The Java™ Tutorials > Creating a GUI With JFC/Swing > Using Other Swing Features)

I think there might be more than one Timer class in Java

Look at the API doc and you'll see how many there are.

But if I had an ActionListener, which I'd need to make a Timer object, then should I add some ActionListener to the JPanel or something then?

You can create a new inner class and make it the listener

So I use the paint method for the inner class for repaint()?

If I'm using the regular repaint(), that will likely repaint the entire image and that's not what I want it to do, just the fountain water only.

I have paint method calling a Graphics method to draw the fountain and stuff too, in addition to having the main paint method itself draw the base.

I don't want it calling all of these methods over and over. Just the fountain water part. But how do I tell it that?

I had thought of using the ActionListener to do that, but how do I call a Graphics method inside the ActionListener to get it to draw something?

I'm just very confused now.

how do I call a Graphics method inside the ActionListener to get it to draw something?

You don't. You compute the values that control what is to be drawn, then call repaint().
When the paint method is later called by the JVM it uses the computed values to make the drawing.

You need a Swing Timer if you want to use a timer to make changes to the GUI (painting, etc). All GUI changes must be done in the Swing Event Dispatch Thread (EDT), and a Swing Timer action is designed to enable this. You can use an ordinary Timer (java.util.Timer) for non-GUI timed actions.

Should I use a Swing Worker, whatever that is, too?

I can't run the call to MyThread inside the main method as it keeps saying "non-static variable this cannot be referenced from a static context".

Why won't it work? I don't know how to work a Timer to do what I want it to and can't find any info that seems to help me. I've looked at some but so far haven't found anything definitive that will help.

 import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.JOptionPane; import java.util.*; import java.io.*; import javax.swing.Timer; public class PaintDemo1 extends JFrame implements ActionListener {     private FountainAnimator animator; private Timer timer; public PaintDemo1() { setVisible(true); animator = new FountainAnimator(); animator.setVisible(true);   timer = new Timer(1000, this); timer.start();   Graphics graphics = getGraphics(); System.out.println(graphics);         setContentPane(animator); MyThread mth = new MyThread(); mth.run();   }       public static void main(String[] args) { PaintDemo1 pd1 = new PaintDemo1(); pd1.setVisible(true);   }   public class FountainAnimator extends JPanel implements ActionListener {   public FountainAnimator() { super(new BorderLayout()); setBackground(Color.GREEN);   }   protected void paintComponent(Graphics g) { super.paintComponent(g); g.setColor(new Color(88,88,88)); Polygon poly = new Polygon();   poly.addPoint(200, 200); poly.addPoint(400, 200); poly.addPoint(400, 300); poly.addPoint(100, 300); g.fillPolygon(poly);   g.setColor(Color.BLACK);   g.drawPolygon(poly);   Polygon poly2 = new Polygon(); poly2.addPoint(200, 200); poly2.addPoint(250, 100); poly2.addPoint(450, 110); poly2.addPoint(400, 200); g.setColor(Color.BLUE); g.fillPolygon(poly2);   g.setColor(Color.BLACK); g.drawLine(200, 200, 250, 100); g.drawLine(250, 100, 450, 110); g.drawLine(450, 110, 400, 200);     Polygon poly3 = new Polygon();   poly3.addPoint(100, 300); poly3.addPoint(100, 200); poly3.addPoint(250, 100); poly3.addPoint(200, 200);   g.setColor(new Color (88, 88,88)); g.fillPolygon(poly3);   g.setColor(Color.BLACK); g.drawLine(100, 300, 100, 200); g.drawLine(100, 200, 250, 100);   Polygon poly4 = new Polygon(); g.setColor(new Color(88,88,88));   poly4.addPoint(450, 110); poly4.addPoint(510, 270); poly4.addPoint(400,300); poly4.addPoint(400, 200); g.fillPolygon(poly4); g.setColor(Color.BLACK); g.drawPolygon(poly4);     System.out.println(g.getColor());   drawFountain(g); animateFountain(g); drawLake(g); }   public void drawFountain(Graphics g) { g.setColor(new Color(95,95,95)); g.drawOval(300, 120, 65, 65); g.setColor(Color.BLACK); g.drawOval(320, 140, 25, 25); g.setColor(new Color(95,95,95)); g.fillOval(320, 140, 25, 25);   g.setColor(new Color(50,50,50)); Polygon poly = new Polygon(); poly.addPoint(325, 153); poly.addPoint(325, 125); poly.addPoint(330, 115); poly.addPoint(340, 125); poly.addPoint(340, 153); g.fillPolygon(poly);   g.setColor(Color.BLACK); g.drawPolygon(poly);     }   public void animateFountain(Graphics g) { int newRed = Color.BLUE.getRed() + 10; int newGreen = Color.BLUE.getGreen() + 10; int newBlue = Color.BLUE.getBlue();   g.setColor(new Color(newRed, newGreen, newBlue));   for (int x = 325; x < 352; x++) {   for (int y = 125; y < 155; y++) {   g.setColor(new Color(newRed, newGreen, newBlue)); g.fillOval(x,y, 10, 10); g.setColor(Color.BLACK); g.drawOval(x,y,10,10);   } }     // repaint(); }     public void drawLake(Graphics g) { g.setColor(new Color(9,34, 136)); g.fillOval(500,500, 300, 200); g.setColor(Color.BLACK); g.drawOval(500,500,300,200);       } public void actionPerformed(ActionEvent e) { repaint(); }   }   public void actionPerformed(ActionEvent e) { animator.repaint();   }   public abstract class MyGraphics extends Graphics {     }   public class MyThread extends Thread {   public MyThread() { start(); } public void run() { //Display info about this particular thread System.out.println(Thread.currentThread().getName()); try {   boolean b2= false; while (b2 == false) { Thread.sleep(5000); animator.repaint(); }   }   catch(InterruptedException ieRef) { System.out.println("Error!"); }     }     }   }

For Timers read this:
How to Use Swing Timers (The Java™ Tutorials > Creating a GUI With JFC/Swing > Using Other Swing Features)

I read it. However, how do I get the code to draw things using Graphics inside an ActionListener if I can't use getGraphics()?

You don't.
Call repaint which will cause paintComponent to be called.
Do your drawing there.

I was able to get something that looked like crude animation, not what I wanted, when I called getGraphics() inside the ActionListener that the Timer uses, but you told me not to do this.

Also, for some reason, despite where I put it, the drawSidewalk() is drawing over my fountain. I thought that if I put it first, it would draw it and then draw the fountain over parts of it, which it's only doing for the animateFountain() part, but the fountain is gone. How do I get it back and yet keep the sidewalk?

Also, how do I get the Timer to work. Read that thing and it's still not making sense.

 import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.JOptionPane; import java.util.*; import java.io.*; import javax.swing.Timer; public class PaintDemo1 extends JFrame implements ActionListener {     private FountainAnimator animator; private Timer timer; private JScrollPane jsp; public PaintDemo1() {   setVisible(true); animator = new FountainAnimator(); animator.setVisible(true);   timer = new Timer(1000, animator); timer.start();   Graphics graphics = getGraphics(); System.out.println(graphics);     jsp = new JScrollPane(animator, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS , JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS); Dimension d = new Dimension(9000,9000); animator.setPreferredSize(d); animator.revalidate(); animator.setSize(d);   animator.setAutoscrolls(true);   setContentPane(jsp);     }       public static void main(String[] args) { PaintDemo1 pd1 = new PaintDemo1(); pd1.setVisible(true);   }   public class FountainAnimator extends JPanel implements ActionListener {   public FountainAnimator() { super(new BorderLayout()); setBackground(Color.GREEN);   }   protected void paintComponent(Graphics g) { super.paintComponent(g); g.setColor(new Color(88,88,88)); Polygon poly = new Polygon();   poly.addPoint(200, 200); poly.addPoint(400, 200); poly.addPoint(400, 300); poly.addPoint(100, 300); g.fillPolygon(poly);   g.setColor(Color.BLACK);   g.drawPolygon(poly);   Polygon poly2 = new Polygon(); poly2.addPoint(200, 200); poly2.addPoint(250, 100); poly2.addPoint(450, 110); poly2.addPoint(400, 200); g.setColor(Color.BLUE); g.fillPolygon(poly2);   g.setColor(Color.BLACK); g.drawLine(200, 200, 250, 100); g.drawLine(250, 100, 450, 110); g.drawLine(450, 110, 400, 200);     Polygon poly3 = new Polygon();   poly3.addPoint(100, 300); poly3.addPoint(100, 200); poly3.addPoint(250, 100); poly3.addPoint(200, 200);   g.setColor(new Color (88, 88,88)); g.fillPolygon(poly3);   g.setColor(Color.BLACK); g.drawLine(100, 300, 100, 200); g.drawLine(100, 200, 250, 100);   Polygon poly4 = new Polygon(); g.setColor(new Color(88,88,88));   poly4.addPoint(450, 110); poly4.addPoint(510, 270); poly4.addPoint(400,300); poly4.addPoint(400, 200); g.fillPolygon(poly4); g.setColor(Color.BLACK); g.drawPolygon(poly4);     System.out.println(g.getColor());   drawSidewalk(g);   drawFountain(g);   animateFountain(g);   drawLake(g); g.fillOval(8000,300, 100,100);       }   public void drawFountain(Graphics g) { g.setColor(new Color(95,95,95)); g.drawOval(300, 120, 65, 65); g.setColor(Color.BLACK); g.drawOval(320, 140, 25, 25); g.setColor(new Color(95,95,95)); g.fillOval(320, 140, 25, 25);   g.setColor(new Color(50,50,50)); Polygon poly = new Polygon(); poly.addPoint(325, 153); poly.addPoint(325, 125); poly.addPoint(330, 115); poly.addPoint(340, 125); poly.addPoint(340, 153); g.fillPolygon(poly);   g.setColor(Color.BLACK); g.drawPolygon(poly);     }   public void drawSidewalk(Graphics g) {   g.setColor(new Color(183,183,183)); g.fill3DRect(100,50,420,300,true);     }   public void animateFountain(Graphics g) { int newRed = Color.BLUE.getRed() + 10; int newGreen = Color.BLUE.getGreen() + 10; int newBlue = Color.BLUE.getBlue();   g.setColor(new Color(newRed, newGreen, newBlue));   for (int x = 325; x < 352; x++) {   for (int y = 125; y < 155; y++) {   g.setColor(new Color(newRed, newGreen, newBlue)); g.fillOval(x,y, 10, 10); g.setColor(Color.BLACK); g.drawOval(x,y,10,10);   } }     // repaint(); }     public void drawLake(Graphics g) { g.setColor(new Color(9,34, 136)); g.fillOval(500,500, 300, 200); g.setColor(Color.BLACK); g.drawOval(500,500,300,200);       } public void actionPerformed(ActionEvent e) {   // what do I do here     }   }   public void actionPerformed(ActionEvent e) { // animator.repaint(); // Do I even need this listener? }   public abstract class MyGraphics extends Graphics {     }     }

how do I get the Timer to work

Copy the example code from the tutorial and make a small program from it. Have the action listener print out a message to show when it is executed.
If you have problems copy the code here with your questions.

Ok, so I have yet another problem though. I think I may have it drawing everything inside paintComponent() yet I only want the water to move (may add more animation later once I get this part to work), to move, and not to have it keep redrawing the fountain itself.

How do I fix that problem?

You have to redraw everything every time if you clear the panel each paint.

I printed the message

What message?

what I wanted animation-wise.

Explain what your code is NOW doing that will make it animated?
Is it using a Timer?

What code? The AcfionListener or the paintComponent()?

I told it to print "Execute now" or something like that and it does every 1 or 2 (probably 2) seconds.

 import java.awt.*; import java.awt.event.*; import javax.swing.*; import javax.swing.JOptionPane; import java.util.*; import java.io.*; import javax.swing.Timer; public class PaintDemo1 extends JFrame implements ActionListener {     private FountainAnimator animator; private Timer timer; private JScrollPane jsp; public PaintDemo1() {   setVisible(true); animator = new FountainAnimator(); animator.setVisible(true);   timer = new Timer(1000, animator); timer.setDelay(1000); timer.start();   Graphics graphics = getGraphics();       jsp = new JScrollPane(animator, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS , JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS); Dimension d = new Dimension(9000,9000); animator.setPreferredSize(d); animator.revalidate(); animator.setSize(d);   animator.setAutoscrolls(true);   setContentPane(jsp);     }       public static void main(String[] args) { PaintDemo1 pd1 = new PaintDemo1(); pd1.setVisible(true);   }   public class FountainAnimator extends JPanel implements ActionListener {   public FountainAnimator() { super(new BorderLayout()); setBackground(Color.GREEN);   }   protected void paintComponent(Graphics g) { super.paintComponent(g); g.setColor(new Color(88,88,88)); Polygon poly = new Polygon();   poly.addPoint(200, 200); poly.addPoint(400, 200); poly.addPoint(400, 300); poly.addPoint(100, 300); g.fillPolygon(poly);   g.setColor(Color.BLACK);   g.drawPolygon(poly);   Polygon poly2 = new Polygon(); poly2.addPoint(200, 200); poly2.addPoint(250, 100); poly2.addPoint(450, 110); poly2.addPoint(400, 200); g.setColor(Color.BLUE); g.fillPolygon(poly2);   g.setColor(Color.BLACK); g.drawLine(200, 200, 250, 100); g.drawLine(250, 100, 450, 110); g.drawLine(450, 110, 400, 200);     Polygon poly3 = new Polygon();   poly3.addPoint(100, 300); poly3.addPoint(100, 200); poly3.addPoint(250, 100); poly3.addPoint(200, 200);   g.setColor(new Color (88, 88,88)); g.fillPolygon(poly3);   g.setColor(Color.BLACK); g.drawLine(100, 300, 100, 200); g.drawLine(100, 200, 250, 100);   Polygon poly4 = new Polygon(); g.setColor(new Color(88,88,88));   poly4.addPoint(450, 110); poly4.addPoint(510, 270); poly4.addPoint(400,300); poly4.addPoint(400, 200); g.fillPolygon(poly4); g.setColor(Color.BLACK); g.drawPolygon(poly4);         drawSidewalk(g);   drawFountain(g);   animateFountain(g);   drawLake(g); g.fillOval(8000,300, 100,100);       }   public void drawFountain(Graphics g) { g.setColor(new Color(95,95,95)); g.drawOval(300, 120, 65, 65); g.setColor(Color.BLACK); g.drawOval(320, 140, 25, 25); g.setColor(new Color(95,95,95)); g.fillOval(320, 140, 25, 25);   g.setColor(new Color(50,50,50)); Polygon poly = new Polygon(); poly.addPoint(325, 153); poly.addPoint(325, 125); poly.addPoint(330, 115); poly.addPoint(340, 125); poly.addPoint(340, 153); g.fillPolygon(poly);   g.setColor(Color.BLACK); g.drawPolygon(poly);     }   public void drawSidewalk(Graphics g) {   g.setColor(new Color(183,183,183)); g.fill3DRect(100,50,420,300,true);     }   public void animateFountain(Graphics g) { int newRed = Color.BLUE.getRed() + 10; int newGreen = Color.BLUE.getGreen() + 10; int newBlue = Color.BLUE.getBlue();   g.setColor(new Color(newRed, newGreen, newBlue));   for (int x = 325; x < 352; x++) {   for (int y = 125; y < 155; y++) {   g.setColor(new Color(newRed, newGreen, newBlue)); g.fillOval(x,y, 10, 10); g.setColor(Color.BLACK); g.drawOval(x,y,10,10);   } }     // repaint(); }     public void drawLake(Graphics g) { g.setColor(new Color(9,34, 136)); g.fillOval(500,500, 300, 200); g.setColor(Color.BLACK); g.drawOval(500,500,300,200);       } public void actionPerformed(ActionEvent e) {   animator.repaint(); System.out.println("Executed now"); timer.restart();     }   }   public void actionPerformed(ActionEvent e) { // animator.repaint(); // Do I even need this listener? }   public abstract class MyGraphics extends Graphics {     }     }

Explain what your code is NOW doing that will make it animated?

I assume that animation means showing things differently over time.