package examples;

// Insertion sort visualizer

import java.awt.Color;

import java.awt.Dimension;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.geom.Rectangle2D;

import java.util.Random;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.SwingUtilities;

import javax.swing.SwingWorker;

public class InsertionSort extends JPanel {

private final int WIDTH = 800, HEIGHT = WIDTH * 9 /16;

private final int SIZE = 200; // the number if sorting elements

private final float BAR_WIDTH = (float)WIDTH / SIZE; // bar width

private float[] bar_height = new float[SIZE]; // height of bars

private SwingWorker<Void, Void> shuffler, sorter;

private int current_index, traversing_index;

InsertionSort() {

setBackground(Color.BLACK);

setPreferredSize(new Dimension(WIDTH, HEIGHT));

initBarHeight(); // initialize the height of each bar

initSorter();

initShuffler();

}

@Override

public void paintComponent(Graphics g) {

super.paintComponent(g);

Graphics2D g2d = (Graphics2D)g;

g2d.setColor(Color.CYAN);

Rectangle2D.Float bar;

for(int i = 0; i < SIZE; i++ ) {

bar = new Rectangle2D.Float(i * BAR_WIDTH, 0, BAR_WIDTH, bar_height[i]);

g2d.fill(bar); // g2d.draw(bar);

}

g2d.setColor(Color.RED);

bar = new Rectangle2D.Float(current_index * BAR_WIDTH, 0, BAR_WIDTH, bar_height[current_index]);

g2d.fill(bar);

g2d.setColor(Color.GREEN);

bar = new Rectangle2D.Float(traversing_index * BAR_WIDTH, 0, BAR_WIDTH, bar_height[traversing_index]);

g2d.fill(bar);

}

public void initBarHeight() {

float interval = (float)HEIGHT / SIZE;

for(int i = 0; i < SIZE; i++) {

bar_height[i] = i * interval;

}

}

public void initSorter() {

sorter = new SwingWorker<>() {

@Override

public Void doInBackground() throws InterruptedException {

for(current_index = 1; current_index < SIZE; current_index++) {

traversing_index = current_index;

while(traversing_index > 0 && bar_height[traversing_index] < bar_height[traversing_index - 1]) {

swap(traversing_index, traversing_index - 1);

traversing_index--;

Thread.sleep(1);

repaint();

}

}

current_index = 0;

traversing_index = 0;

return null;

}

};

}

public void initShuffler() {

shuffler = new SwingWorker<>() {

@Override

public Void doInBackground() throws InterruptedException {

int middle = SIZE / 2;

for (int i = 0, j = middle; i < middle; i++, j++) {

int randow_index = new Random().nextInt(SIZE);

swap(i, randow_index);

randow_index = new Random().nextInt(SIZE);

swap(j, randow_index);

Thread.sleep(10);

repaint();

}

return null;

}

@Override

public void done() {

super.done();

sorter.execute();

}

};

shuffler.execute();

}

public void swap(int indexA, int indexB) {

float temp = bar_height[indexA];

bar_height[indexA] = bar_height[indexB];

bar_height[indexB] = temp;

}

public static void main(String args[]) {

SwingUtilities.invokeLater(() -> {

JFrame frame = new JFrame("Insertion Sort");

//frame.setResizable(false);

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

frame.setContentPane(new InsertionSort());

frame.validate();

frame.pack();

frame.setLocationRelativeTo(null);

frame.setVisible(true);

});

}

}