// The Canvas object plots objects in a two-dimensional array.
// The write method writes these objects to an output file.

import java.io.PrintWriter;
import java.io.FileNotFoundException;
public class Canvas
{
    private String fileName;
    private int width;
    private int height;
    private char[ ][ ] array;

    public Canvas(String theFileName, int theWidth, int theHeight)
    {
        fileName = theFileName;

        if (theWidth >= 1)
            width = theWidth;
        else
            width = 1;

        if (theHeight >= 1)
            height = theHeight;
        else
            height = 1;

        array = new char[height][width];
    }

    public String getFileName( )
    {
        return fileName;
    }

    public int getWidth( )
    {
        return width;
    }

    public int getHeight( )
    {
        return height;
    }

    public void setPoint(char symbol, int x, int y)
    {
        if (0 <= x && x < width && 0 <= y && y < height)
            array[y][x] = symbol;
    }

    protected void write( ) throws FileNotFoundException
    {
        // Create PrintWriter object.
        PrintWriter pw = new PrintWriter(fileName);

        // Plot header for file.
        pw.print("  ");
        for(int i = 0; i < width; i++)
            if (i / 10 >= 1)
                pw.print(i / 10);
            else
                pw.print(" ");

        pw.println( );
        pw.print("  ");
        for(int i = 0; i < width; i++)
            pw.print(i % 10);
        pw.println( );

        // Write plot to output file.
        for(int j = 0; j < height; j++)
        {
            pw.printf("%2d", j);
            for(int i = 0; i < width; i++)
                pw.print(array[j][i]);
            pw.println( );
        }
        pw.close( );
    }

    public String toString( )
    {
        return String.format("File:%s %dx%d", 
            fileName, width, height);
    }

    public static void main(String[ ] args) throws FileNotFoundException
    {
        Canvas c = new Canvas("output.txt", 100, 50);
        System.out.println("Canvas filename is " + c.getFileName( ));
        System.out.println("Canvas width is " + c.getWidth( ));
        System.out.println("Canvas height is " + c.getHeight( ));

        c.setPoint('$', 30, 40);
        c.setPoint('#', 50, 20);

        c.write( );
    }
}