Functions and Arrays
Random Colors and Arrays - Con't
This applet adds automatic refresh of our color applet once a second, so we add a getNewColors() method, which is called once in a second, to get 100 new colors for our array.
|
//Sourcecode
import java.awt.*;
import java.applet.*;
public class Project17 extends Applet implements Runnable
{
Image Buffer;
Graphics gBuffer;
//declare an array variable to hold our Colors
Color myColors[];
Thread runner;
public void init()
{
//create off-screen image we can draw to
Buffer=createImage(size().width,size().height);
gBuffer=Buffer.getGraphics();
//arrays are real objects, we have to declare them with "new"
myColors = new Color[100];
}
public void getNewColors()
{
for(int i=0;i<100;i++)
{
int red=(int)(Math.random()*255);
int green=(int)(Math.random()*255);
int blue=(int)(Math.random()*255);
//fill our array with random colors
myColors[i]=new Color(red, green, blue);
}
}
public void start()
{
if (runner == null)
{
runner = new Thread (this);
runner.start();
}
}
public void stop()
{
if (runner != null)
{
runner.stop();
runner = null;
}
}
public void run()
{
while(true)
{
//halt the thread for 1000 ms here
try {runner.sleep(1000);}
catch (Exception e) { }
//get new colors every second
getNewColors();
repaint();
}
}
public void update(Graphics g)
{
paint(g);
}
public void drawColors()
{
//draw tiles with random colors
//we use two nested loops to do this:
int i=0;
for(int x=0;x<300;x+=30)
for(int y=0;y<300;y+=30)
{
int red=(int)(Math.random()*255);
int green=(int)(Math.random()*255);
int blue=(int)(Math.random()*255);
gBuffer.setColor(myColors[i]);
gBuffer.fillRect(x,y,60,60);
//increment the index of our array here
i++;
}
}
public void paint (Graphics g)
{
drawColors();
//copy the buffer to the screen
g.drawImage (Buffer,0,0, this);
}
}
|
New on the Java Boutique:
New Review:
Time Management Made Easy with the Quartz Enterprise Job Scheduler
Why not just use the Java timer API? This open source scheduling
API boasts simplicity, ease-of-integration, a well-rounded feature
set, and it's free!
New Applet:
Reverse Complement
Reverse Complement is a simple applet that converts DNA or RNA
sequences into three useful formats.
Elsewhere on internet.com:
WebDeveloper Java
Lots of Java information on webdeveloper.com
WDVL Java
Thorough Java resource at the Web Developer's Virtual Library.
ScriptSearch Java
Hundreds of free Java code files to download.
jGuru: Your View of the Java Universe
Customizable portal with online training, FAQs, regular news updates, and tutorials.
