We Keep Coding

Creating diagram for an extremely immense tree using Java

The problem is simple. I want to create a vertical tree of values, where as you descend down the levels, the amount of values gets exponentially larger. Let's say the 1st level has 1 numerical value, the next has 10, then the next has 100, then the next has 1000, and so on. The first level is connected to the 2nd level with the use of lines, and the 2nd to the 3rd, and so on, much like a game tree. These values are also evenly spaced, so let's say you have a JPanel which is 500x500. At a y of 100, you have 4 values, and so to evenly space them out, you would have a value at 100, one at 200, and so on.
I've tried incorporating drawString, and connecting them with the drawLine method, and placing this so called diagram on a JPanel. That is actually quite simple, and it works if you only have as many as about 50~ values in a singular level. However, when you only have a 1600x900 screen, you can't fit 100 values (on the x axis, which is 1600) without having a big jumbled up mess.
I was thinking there could be 2 possible solutions for this.
One is that the JPanel is not limited to a set resolution (a.k.a the size of your screen) and is scrollable. If it was 10000 x 900 then making this gigantic tree diagram would actually be quite simple, and I could easily fit the 100 values with enough space between them for the values to actually be discernable. However, as far as I know, it's not possible.
The second solution is that I write these values into a file, but I'm not sure how to go about this.
Does anyone know, theoretically speaking, what could be the simplest solution for properly displaying a large tree diagram filled with hundreds of values in a single level?

Oracle has a helpful tutorial, Creating a GUI With Swing. Skip the Learning Swing with the NetBeans IDE section. Pay particular attention to the Performing Custom Painting section.
It turns out it's possible to create one 10000 x 900 drawing JPanel. Adjust the JScrollPane preferred size to the size you want to display. The height should be at least 950 pixels to allow room for the horizontal scroll bar.
I created a checkerboard pattern so you can see that the drawing JPanel does scroll.
Here's the complete runnable code.
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.SwingUtilities;
public class LargeDrawingJPanel implements Runnable {
public static void main(String[] args) {
SwingUtilities.invokeLater(new LargeDrawingJPanel());
}
#Override
public void run() {
JFrame frame = new JFrame("Large Drawing JPanel");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel drawingPanel = new DrawingPanel();
JScrollPane scrollPane = new JScrollPane(drawingPanel);
scrollPane.setPreferredSize(new Dimension(1400, 950));
frame.add(scrollPane, BorderLayout.CENTER);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public class DrawingPanel extends JPanel {
private static final long serialVersionUID = 1L;
public DrawingPanel() {
this.setPreferredSize(new Dimension(10000, 900));
}
#Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g;
Color[] colors = { Color.RED, Color.BLACK };
int colorIndex = 0;
int x = 0;
int y = 0;
for (int i = 0; i < 100; i++) {
for (int j = 0; j < 9; j++) {
g2d.setColor(colors[colorIndex]);
colorIndex = (colorIndex == 0) ? 1 : 0;
g2d.fillRect(x, y, 100, 100);
y += 100;
}
x += 100;
y = 0;
}
}
}
}

Java JFrame issue with dialog box

When I run the program I'm facing some problem with JFrame Buffer, I don't know what the problem exactly is. When I run the program, it displays some dialog box part on the top left corner of the buffer.
Here is output of my program:
And following is the code
Thank you.
import java.awt.*;
import java.util.*;
import javax.swing.*;
public class Main extends JPanel
{
public void paintComponent(Graphics g)
{
super.paintComponent(g);
int[] x1 = new int[10];
int[] y1 = new int[10];
int i,n;
Polygon p=new Polygon();
n = Integer.parseInt(JOptionPane.showInputDialog("Enter no. of co-ordinates of polygon: "));
System.out.println(" no. of co-ordinates of polygon are :"+n);
for(i=0;i<n;i++)
{
x1[i] = Integer.parseInt(JOptionPane.showInputDialog("Enter x co-ordinates of polygon: "));
y1[i] = Integer.parseInt(JOptionPane.showInputDialog("Enter y co-ordinates of polygon: "));
}
for(i=0;i<n-1;i++)
{
g.drawLine(x1[i],y1[i],x1[i+1],y1[i+1]);
}
g.drawLine(x1[n-1],y1[n-1],x1[0],y1[0]);
}
public static void main(String[] args)
{
JFrame frame = new JFrame();
frame.setTitle("Polygon");
frame.setSize(500,500);
Container contentPane = frame.getContentPane();
contentPane.add(new Main());
frame.setVisible(true);
}
}

Never display an JOptionPane from a painting method. Painting methods are for painting only, they are not for getting user input.
Instead you need to do the following:
The JOptionPane should be displayed from the main method to gather the x/y parameters.
Modify your Main() class to have a method like addPoint(int x, int y).
The above method will then save the x/y values to an ArrayList object in your class. I would store Point objects in this list.
The painting method will then iterate through the List and then paint each line.

The paintComponent( ... ) method is called whenever 'something' (the AWT EDT thread) thinks the component needs to be repainted. That method is called often and often at moments you didn't expect it to be called. So, don't show a JOptionPane in the body of that method.
So it is better to call from main method only as camickr said.

How do I make the lines draw without an actionlistener?

I am writing a GUI that is supposed to write lines and circles to a panel and I am supposed to use sliders to change how fast they add to the panel. I am supposed to add a clear button that will clear the entire panel and then when I move the sliders they should make the circles and lines begin to write on the panel again. There should be a specific stop point at the beginning of the sliders. We have been told to do this without actionlisteners on the sliders. I am having some trouble understanding how to make that work.
Below are the requirements for the assignment:
Write a Swing program that provides the following functionality:
Draw random length lines of random color at random coordinates with pauses between the drawing of each line.
Allow the user to set the length of the pause between lines with a slider. Have the slowest value actually stop drawing lines (i.e., it slows to a stop once it is at that value on the slider).
Have a clear button that clears all the lines & circles. Be sure that the clear button is operational at all times.
Draw random size circles of random color at random coordinates with pauses between the drawing of each circle. (Use draw, not fill.)
Allow the user to set the length of the pause between circles with a slider. Have the slowest value actually stop drawing circles (i.e., it slows to a stop once it is at that value on the slider). This is independent of the lines' speed.
The circles and lines are both drawn independently, each in their own Thread.
Do not use Timer for this, extend Thread and/or Runnable.
public class OhMy extends JFrame
{
private static final int MAX_COLOR = 225;
private static final long STOP_SLEEP = 0;
public OhMy()
{
this.setTitle("Oh My Window");
Container canvas = this.getContentPane();
canvas.setLayout(new GridLayout(2,1));
JPanel panControl = new JPanel(new GridLayout(1,1));
JPanel panDraw = new JPanel(new GridLayout(1,1));
canvas.add(panControl);
canvas.add(panDraw);
panControl.add(createPanControl());
panDraw.add(createPanDraw());
this.setSize(800, 600);
this.setVisible(true);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
private JPanel createPanControl()
{
JPanel panControl = new JPanel();
JLabel lines = new JLabel("Lines");
panControl.add(lines);
lines.setForeground(Color.RED);
JSlider sldSpeedLines = new JSlider(1, 30, 5);
panControl.add(sldSpeedLines);
JButton btnClear = new JButton("Clear");
panControl.add(btnClear);
btnClear.setForeground(Color.RED);
JSlider sldSpeedCircles = new JSlider(0, 30, 5);
panControl.add(sldSpeedCircles);
JLabel circles = new JLabel("Circles");
panControl.add(circles);
circles.setForeground(Color.RED);
btnClear.addActionListener((e)->
{
repaint();
});
return panControl;
}
private JPanel createPanDraw()
{
JPanel panDraw = new JPanel();
class LinesThread extends Thread
{
#Override
public void run()
{
try
{
Graphics g = panDraw.getGraphics();
while(g == null)
{
Thread.sleep(STOP_SLEEP);
g = panDraw.getGraphics();
}
Random rand = new Random();
int red = rand.nextInt(MAX_COLOR);
int green = rand.nextInt(MAX_COLOR);
int blue = rand.nextInt(MAX_COLOR);
Color color = new Color(red, green, blue);
int x1 = rand.nextInt(panDraw.getWidth());
int y1 = rand.nextInt(panDraw.getHeight());
int x2 = rand.nextInt(panDraw.getWidth());
int y2 = rand.nextInt(panDraw.getHeight());
g.setColor(color);
g.drawLine(x1, y1, x2, y2);
}
catch(InterruptedException e1)
{
//awake now
}
}
}
return panDraw;
}
/**
* #param args
*/
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
#Override
public void run()
{
new OhMy();
}
});
}
}

You state:
"We have been told to do this without actionlisteners on the sliders..."
Good, because JSliders won't accept an ActionListener.
JSliders will accept a ChangeListener though, but you likely don't even need to use this.
Instead, give the clear button an ActionListener (you've no way to get around using ActionListeners at all).
In that ActionListener, reset the drawing and get the values from the JSliders by simply calling getValue() on it.
Don't get your Graphics object by calling getGraphics() on the JPanel since the Graphics object thus obtained will not be stable risking a broken image, or worse, a NullPointerException (to see what I mean, minimize and restore your current application while its drawing).
Instead either draw on a BufferedImage that is displayed in the JPanel's paintComponent method or draw directly in paintComponent itself.
Avoid using a Thread and Thread.sleep, but instead use a Swing Timer -- it's much easier this way to be sure that your code is threading appropriately.
Use this value to adjust the speed of your Swing Timer.
Edit
Thanks to Abishek Manoharan for pointing out problems in my answer...
If the JSliders need to change the speed of drawing while the drawing is proceeding, then you will in fact need to use ChangeListener on the slider.
In that listener change a field that will tell the Thread how long to sleep.
I see that you're also required to use background threads. If so, then be sure to make all Swing calls on the Swing event thread. So if you're in the background thread and need to make a Swing call, then queue it on the Swing event thread by calling SwingUtilities.invokeLater(...) and pass in a Runnable that has your Swing call.

Java: Animated Sprites on GridLayout Part 2

This is a continuation from my last post Java: Animated Sprites on GridLayout. Thanks to a reply, it gave me an idea in where I just had to insert a loop in the trigger condition and call pi[i].repaint() in it. So far it works. Though I tried to integrate it to my game which composed of multiple sprites, it had no improvement in it. Without the animation, the sprites show on the grid with no problems. I inserted the animation loop in the GridFile class and it didn't show. I also tried to insert the animation loop in the MainFile, it showed irregular animations, kinda like a glitch. Can someone tell me where did I went wrong? Ideas are welcome.
MainFile class
public class MainFile {
JFrame mainWindow = new JFrame();
public JPanel gridPanel;
public MainFile() {
gridPanel= new GridFile();
mainWindow.add(gridPanel,BorderLayout.CENTER);
mainWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainWindow.setSize(700,700);
mainWindow.setResizable(false);
mainWindow.setVisible(true);
}
public static void main(String[]args){
new MainFile();
}
}
GridFile class
public class GridFile extends JPanel{
ImageIcon gameBackground = new ImageIcon(getClass().getResource("Assets\\GridBackground.png"));
Image gameImage;
int[] pkmArray = new int[12];
int random = 0;
Pokemon[] pkm = new Pokemon[36];
JPanel[] pokeball = new JPanel[36];
int j = 0;
public GridFile(){
setLayout(new GridLayout(6,6,6,6));
setBorder(BorderFactory.createEmptyBorder(12,12,12,12));
gameImage = gameBackground.getImage();
for(int i = 0;i < 36;i++){
do{
random = (int)(Math.random() * 12 + 0);
if(pkmArray[random] <= 3){
pokeball[i] = new Pokemon(random);
pokeball[i].setOpaque(false);
pokeball[i].setLayout(new BorderLayout());
pkmArray[random]++;
}
}while(pkmArray[random] >= 4);
add(pokeball[i],BorderLayout.CENTER);
}
while(true){
for(int i = 0; i < 36; i++){
pokeball[i].repaint();
}
}
}
public void paintComponent(Graphics g){
if(gameImage != null){
g.drawImage(gameImage,0,0,getWidth(),getHeight(),this);
}
}
}

Use a swing Timer for the repainting, and give a bit time between the frames for swing to do the painting work. There's no point trying to draw faster than what could be displayed anyway. If you have the animation loop in main(), the repaint manager will try to drop some of the repaint requests that appear close to each other, which can be the cause of the irregular animation you see.
You should create and access swing components only in the event dispatch thread. You current approach is breaking the threading rules.
Addition: When the animation loop is where you have it now, the GridFile constructor never returns, which explains that you'll see nothing because the code never gets far enough to show the window.

Tiled images in swing

I have task to prepare two windows with swing. One contains grid of squares, with random numbers in them. In second I need to load pieces of tiled image and then show them in the correct order, forming tiled image.
Windows should look like this :
alt text http://img535.imageshack.us/img535/3129/lab8a.jpg
Okay so how to bite this? I've used swing only few times to draw some 2d polylines, so basically I just theoretically now what to do.
Ok, so window number 1:
I start with creating Jframe for the window. Then I do for loop and in it create 16 JLabels with random numbers in them? How to set margins between each tile and the whole window?
Window number 2:
So I start the same, but instead of loading numbers I add images? Now, how can I load image from file and then set it as background?

The following code lays out the JLabels using the GridLayout. The arguments to the GridLayout are the following: rows, cols, horizontal gap, vertical gap. In the example below I have 3 pixels wide gap between labels both vertically and horizontally.
To use images instead of numbers, you could pass an ImageIcon to the constructor of the JLabel instead of the text.
However, it looks like your doing a game where the user should be able to click on the tiles. This suggests that you perhaps should use buttons instead of labels, but it's up to you :-)
import java.awt.GridLayout;
import javax.swing.*;
import javax.swing.border.BevelBorder;
public class FrameTest {
public static void main(String[] args) {
final JFrame f = new JFrame("Frame Test");
JPanel panel = new JPanel(new GridLayout(4, 4, 3, 3));
for (int i = 0; i < 16; i++) {
JLabel l = new JLabel("" + i, JLabel.CENTER);
//JLabel l = new JLabel(new ImageIcon("image_file.png"), JLabel.CENTER);
l.setBorder(BorderFactory.createBevelBorder(BevelBorder.RAISED));
l.setFont(l.getFont().deriveFont(20f));
panel.add(l);
}
f.setContentPane(panel);
f.setSize(200, 200);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setVisible(true);
}
}