Tuesday, December 23, 2014

Display a pie chart

import java.awt.Color;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.Rectangle;

import javax.swing.JComponent;

import javax.swing.JFrame;

class Slice

   double value;

   Color color;

   public Slice(double value, Color color)

      this.value = value;

      this.color = color;

class MyComponent extends JComponent

   Slice[] slices = { new Slice(5, Color.black),

   new Slice(33, Color.green),

   new Slice(20, Color.yellow), new Slice(15, Color.red) };

   MyComponent() {}

   public void paint(Graphics g)

      drawPie((Graphics2D) g, getBounds(), slices);

   void drawPie(Graphics2D g, Rectangle area, Slice[] slices)

      double total = 0.0D;

      for (int i = 0; i < slices.length; i++)

         total += slices[i].value;

      double curValue = 0.0D;

      int startAngle = 0;

      for (int i = 0; i < slices.length; i++)

         startAngle = (int) (curValue * 360 / total);

         int arcAngle = (int) (slices[i].value * 360 / total);

         g.setColor(slices[i].color);

         g.fillArc(area.x, area.y, area.width, area.height,

         startAngle, arcAngle);

         curValue += slices[i].value;

public class Main

   public static void main(String[] argv)

      JFrame frame = new JFrame();

      frame.getContentPane().add(new MyComponent());

      frame.setSize(300, 200);

      frame.setVisible(true);

Draw text using GUI

import java.awt.Font;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.RenderingHints;

import javax.swing.JFrame;

import javax.swing.JPanel;

public class Main extends JPanel

   public void paint(Graphics g)

      Graphics2D g2 = (Graphics2D)g;

      g2.setRenderingHint(RenderingHints.key_antialiasing,

      RenderingHints.Value_antialias_on);

      Font font = new Font("Serif", Font.plain, 96);

      g2.setFont(font);

      g2.drawString("Text", 40, 120);

   public static void main(String[] args)

      JFrame f = new JFrame();

      f.getContentPane().add(new Main());

      f.setSize(300, 200);

      f.setVisible(true);