PercolationVisualizer.java

package a01;

/******************************************************************************
 *  Compilation:  javac PercolationVisualizer.java
 *  Execution:    java PercolationVisualizer input.txt
 *  Dependencies: Percolation.java
 *
 *  This program takes the name of a file as a command-line argument.
 *  From that file, it
 *
 *    - Reads the grid size n of the percolation system.
 *    - Creates an n-by-n grid of sites (intially all blocked)
 *    - Reads in a sequence of sites (row, col) to open.
 *
 *  After each site is opened, it draws full sites in light blue,
 *  open sites (that aren't full) in white, and blocked sites in black,
 *  with with site (0, 0) in the upper left-hand corner.
 *
 ******************************************************************************/

import java.awt.Font;

import edu.princeton.cs.algs4.In;
import edu.princeton.cs.algs4.StdDraw;

public class PercolationVisualizer
{

	// delay in milliseconds (controls animation speed)
	private static final int DELAY = 100;

	// draw n-by-n percolation system
	public static void draw(Percolation percolation, int n)
	{
		StdDraw.clear();
		StdDraw.setPenColor(StdDraw.BLACK);
		StdDraw.setXscale(-0.05 * n, 1.05 * n);
		StdDraw.setYscale(-0.05 * n, 1.05 * n); // leave a border to write text
		StdDraw.filledSquare(n / 2.0, n / 2.0, n / 2.0);

		// draw n-by-n grid
		for (int row = 0; row < n; row++)
		{
			for (int col = 0; col < n; col++)
			{
				if (percolation.isFull(row, col))
				{
					StdDraw.setPenColor(StdDraw.BOOK_LIGHT_BLUE);
				} else if (percolation.isOpen(row, col))
				{
					StdDraw.setPenColor(StdDraw.WHITE);
				} else
				{
					StdDraw.setPenColor(StdDraw.BLACK);
				}
				StdDraw.filledSquare(col + 0.5, n - row - 0.5, 0.45);
			}
		}

		// write status text
		StdDraw.setFont(new Font("SansSerif", Font.PLAIN, 12));
		StdDraw.setPenColor(StdDraw.BLACK);
		StdDraw.text(0.25 * n, -0.025 * n, percolation.numberOfOpenSites() + " open sites");
		if (percolation.percolates())
			StdDraw.text(0.75 * n, -0.025 * n, "percolates");
		else
			StdDraw.text(0.75 * n, -0.025 * n, "does not percolate");

	}

	private static void simulateFromFile(String filename)
	{
		In in = new In(filename);
		int n = in.readInt();
		Percolation percolation = new Percolation(n);

		// turn on animation mode
		StdDraw.enableDoubleBuffering();

		// repeatedly read in sites to open and draw resulting system
		draw(percolation, n);
		StdDraw.show();
		StdDraw.pause(DELAY);

		while (!in.isEmpty())
		{
			int row = in.readInt() - 1;
			int col = in.readInt() - 1;
			percolation.open(row, col);
			draw(percolation, n);
			StdDraw.show();
			StdDraw.pause(DELAY);
		}
	}

	public static void main(String[] args)
	{
		String filename = "src/a01/visualizerTest.txt";
		simulateFromFile(filename);
	}
}