huffman.java

import java.io.*;
import javax.swing.*;
import java.awt.event.*;   
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import java.awt.event.*;
import java.awt.*;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.PriorityQueue;
import java.util.Queue;

public  class huffman extends JFrame {

	JLabel l1;
	JTextField t1;
	JButton b1,b2;

//Screen for taking the string input// 
	
	public huffman(){
	
		super("GROUP-14 ADA ASSIGNMENT:HUFFMAN CODING");
		setLayout(new FlowLayout());
		setSize(1000,500);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		
		setVisible(true);
		build_component();
	}

	public void  build_component(){
		
		l1 = new JLabel("ENTER A STRING");
		l1.setFont(new Font("Serif", Font.BOLD, 25));
		t1 = new  JTextField(50);
		b1 = new JButton("ENTER");
		b1.setSize(50,50);
		b1.setLocation(95,45);
		b2 = new JButton("EXIT");
		b2.setSize(50,50);
		b2.setLocation(105,45);
		add(l1);	
		add(t1);
		add(b1);
		add(b2);
		b1.addActionListener(new mylistener());
		b2.addActionListener(new mylistener());
	}

//Defining actions of the buttons when pressed//


	private class mylistener implements ActionListener{
		
		public void actionPerformed(ActionEvent e){
			
			if(e.getSource()==b2)
				System.exit(0);
			else{
				String s = t1.getText();
				Tree t = new Tree();
				
				NewWindow NW= new NewWindow(t.buildTree(s));
			}
		}
	}
		
	
	
	public static void main(String args[]){
		
		huffman h = new huffman();
	}
	
}


// Node Class //


 class  Node implements Comparable<Node>{

public char ch;
public  int freq;
public Node left,right;
public int count;

Node(char ch,int freq,Node left,Node right,int count){
this.ch=ch;
this.freq=freq;
this.left=left;
this.right=right;
this.count=count;
}
private boolean isLeaf() {
            assert ((left == null) && (right == null)) || ((left != null) && (right != null));
            return (left == null) && (right == null);
        }
public int compareTo(Node a){

if(freq<a.freq)
return -1;
else if(freq>a.freq)
return 1;
else
return 0;
}
public void setcount(int c){
this.count=c;
}
}

//Tree Class//


class Tree extends JFrame{

//counting frequency of every token in the string//

public static int[] freqCount(String S){

int[] f=new int[10000];
for(int i=0;i<S.length();i++){

f[S.charAt(i)]++;

}

return f;
}


//building the huffman tree from a String S//


public static Node buildTree(String S){
PriorityQueue<Node>queue=new PriorityQueue<Node>();
int[]f=new int[10000];
f=freqCount(S);
for(char i=0;i<f.length;i++){
if(f[i]>0){
Node n=new Node(i,f[i],null,null,0);
queue.add(n);
}
}
int c=1;
while(queue.size()>1){
Node l1=queue.poll();
l1.setcount(c);
c++;
Node l2=queue.poll();
l2.setcount(c);
c++;
Node parent=new Node('\0',l1.freq+l2.freq,l1,l2,0);
queue.add(parent);
}
return queue.poll();
}
}

class NewWindow{
Node ab;
ArrayList<Node>node=new ArrayList<Node>();
public int width=700; // this may be changed accodingly to fit the tree in the screen//
public int height=10;
ArrayList<Integer>x = new ArrayList<Integer>(); //list of x coordinates of the nodes in the tree//
ArrayList<Integer>y = new ArrayList<Integer>(); //list of y coordinates of the nodes in the tree//


public int index(Node n){
int a=0;
for(int i=0;i<node.size();i++){
if(n==node.get(i))
{
a=i;
break;
}
}
return a;
}

//LevelFirstSearch traversal of the tree//

public void bfs(Node root){
Queue<Node> q= new LinkedList<Node>();
int c=1;

q.add(root);
while(!q.isEmpty()){
Node n=(Node)q.remove();
node.add(n);
if(n.left!=null)
q.add(n.left);
if(n.right!=null)
q.add(n.right);
}
for(int i=0;i<node.size();i++){
x.add(0);
y.add(0);
}
x.set(0,width);
y.set(0,height);

for(int j=0;j<node.size();j++){
if(node.get(j).left!=null && node.get(j).right!=null){
x.set(index(node.get(j).left),x.get(j)-25*c);
x.set(index(node.get(j).right),x.get(j)+25*c);

y.set(index(node.get(j).left),y.get(j)+100);
y.set(index(node.get(j).right),y.get(j)+100);
c++;
}

}

ab.setcount(node.size());
}


//CREATING THE NEW WINDOW FOR TREE ANIMATION //

public NewWindow(Node b) {

	ab=b;
	        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("GROUP-14 ADA PROJECT:HUFFMAN TREE GENERATION ANIMATION ");
             
   
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());

//ADDING TestPane() object //

                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);

            }
        });
	 bfs(ab);

}


// TesPane Class ,animation done here //
public class TestPane extends JPanel {

	private int b=node.size();
        @Override
        public Dimension getPreferredSize() {
            return new Dimension(2800, 2800);
        }

	public TestPane(){
		ActionListener animate = new ActionListener() {
            public void actionPerformed(ActionEvent ae) {
                repaint();
		b--;
            }
       	 };
        Timer timer = new Timer(100,animate);
        timer.start();
	setBackground(Color.PINK);
	}


        @Override
        protected void paintComponent(Graphics g) {
	   
	    
            super.paintComponent(g);
	    Graphics2D g2d = (Graphics2D) g;
	    g.setColor(Color.RED);
	    

	    for(int j=node.size()-1;j>=0;j--){
		if(node.get(j).count<node.size()-b){			
				g2d.setColor(Color.YELLOW);
				g2d.fillRect(x.get(j),y.get(j), 23, 23);
				

				g2d.setColor(Color.RED);
				g2d.drawRect(x.get(j), y.get(j), 23, 23);
				g2d.setColor(Color.RED);
				g2d.drawString(Integer.toString(node.get(j).freq),x.get(j)+5 , y.get(j)+13);
				g2d.drawString(Character.toString(node.get(j).ch),x.get(j)+10 , y.get(j)+20);
				g2d.setColor(Color.RED);
				if((node.get(j)).left!=null){
					
					g2d.drawLine(x.get(j)+20,y.get(j)+20,x.get(index(node.get(j).left)),y.get(index(node.get(j).left)));

					g2d.drawString("1",(x.get(j)+x.get(index(node.get(j).left)))/2, (y.get(j)+y.get(index(node.get(j).left)))/2);
					g2d.setColor(Color.RED);

				}
				if((node.get(j)).right!=null){
					
					g2d.drawLine(x.get(j)+20,y.get(j)+20,x.get(index(node.get(j).right)),y.get(index(node.get(j).right)));
					g2d.drawString("0",(x.get(j)+x.get(index(node.get(j).right)))/2, (y.get(j)+y.get(index(node.get(j).right)))/2);
					g2d.setColor(Color.RED);
				}
			}
	}
		
           
    }
}
}