GUI question on drawing x & y axis

Question

hey, im in the process of creating a gui that prints and sorts the bar graph according to the sorting method the user chooses through a menu. i havent came across any problems on getting the data and sorting it until it came to drawing out the bar graph. question is ive looked every where even my labs and lecture notes on how to draw GUI's but none mentioned how to draw and label the x and y axis.
my y axis is the price which is 0-100 any suggestions on how i can draw out the y axis and have it increment with either $5 or $10 up till 100. and is it possible to put a letter on top of the bar graph that it belongs to?
such as bar graph #1 can be labeled as A, which is placed on top of it because my x axis will not be given values. so bar graph#1 will be A ,with a price of $7
any suggestions on how i can get started on drawing my graph or sites that i can learn from?

Answer 1

import java.awt.*;
import java.awt.font.*;
import java.awt.geom.*;
import java.text.NumberFormat;
import javax.swing.*;
public class GraphTest
    public static void main(String[] args)
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(new GraphPanel());
        f.setSize(400,400);
        f.setLocation(200,200);
        f.setVisible(true);
class GraphPanel extends JPanel
    final int PAD;
    Font font;
    NumberFormat nf;
    public GraphPanel()
        PAD = 38;
        font = new Font("lucida bright regular", Font.PLAIN, 14);
        nf = NumberFormat.getInstance();
        nf.setMaximumFractionDigits(2);
        nf.setMinimumFractionDigits(2);
        setBackground(Color.white);
    protected void paintComponent(Graphics g)
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D)g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        g2.setFont(font);
        FontRenderContext frc = g2.getFontRenderContext();
        int w = getWidth();
        int h = getHeight();
        double yInc = (h - 2*PAD)/10.0;
        // ordinate
        g2.draw(new Line2D.Double(PAD, PAD, PAD, h - PAD));
        // tick marks
        double x = PAD, y = h - PAD - yInc;
        for(int j = 0; j < 10; j++)
            g2.draw(new Line2D.Double(x - 2, y, x, y));
            y -= yInc;
        // labels
        y = h - PAD;
        float width, height, sx, sy;
        for(int j = 0; j <= 10; j++)
            String s = "$" + j;
            width = (float)font.getStringBounds(s, frc).getWidth();
            LineMetrics lm = font.getLineMetrics(s, frc);
            height = lm.getAscent() - lm.getDescent();
            sx = (float)(x - 4 - width);
            sy = (float)(y + height/2);
            g2.drawString(s, sx, sy);
            y -= yInc;
        // abcissa
        g2.draw(new Line2D.Double(PAD, h - PAD, w - PAD, h - PAD));
        // show value = 7
        double x1, x2, xInc = 40;
        double value = 7.00;
        String s = "$" + nf.format(value);
        width = (float)font.getStringBounds(s, frc).getWidth();
        LineMetrics lm = font.getLineMetrics(s, frc);
        height = lm.getAscent() - lm.getDescent();
        x1 = PAD + 3 * xInc;
        x2 = x1 + xInc;
        y = (h - PAD) - (value) * (h - 2*PAD)/10.0;
        g2.draw(new Line2D.Double(x1, y, x1, h - PAD));
        g2.draw(new Line2D.Double(x1, y, x2, y));
        g2.draw(new Line2D.Double(x2, y, x2, h - PAD));
        // label bar top
        sx = (float)(x2 - (xInc + width)/2);
        sy = (float)(y - 2);
        g2.drawString(s, sx, sy);
}