If you are not clear with the program aim then scroll down and see the output and read again!

Declaring and Defining Array of components:

import java.awt.*;
import java.applet.*;

public class ColorChooserApplet extends Applet 
{
	Button btn = new Button("Run");
	Label lbl[] = new Label[3];
	Scrollbar sc[] = new Scrollbar[3];
	TextField tf[] = new TextField[3];
	String[] slbl = {"Red","Green","Blue"};
	public void init()
	{
		for(int i=0;i<3;i++)
		{
			lbl[i] = new Label(slbl[i]);	
			sc[i] = new Scrollbar(Scrollbar.HORIZONTAL, 0, 20, 0, 275);
			tf[i] = new  TextField("0");
			add(lbl[i]);
			add(sc[i]);
			add(tf[i]);
		}
		add(btn);
	}
}

import java.awt.*;
import java.applet.*;
import java.awt.event.*;

public class ColorChooserApplet extends Applet 
{
	Button btn = new Button("Run");
	Label lbl[] = new Label[3];
	Scrollbar sc[] = new Scrollbar[3];
	TextField tf[] = new TextField[3];
	String[] slbl = {"Red","Green","Blue"};
	public void init()
	{
		setLayout(null);

		for(int i=0;i<3;i++)
		{
			lbl[i] = new Label(slbl[i]);	
			sc[i] = new Scrollbar(Scrollbar.HORIZONTAL, 0, 20, 0, 275);
			tf[i] = new  TextField("0");
			add(lbl[i]);
			add(sc[i]);
			add(tf[i]);
			lbl[i].setBounds(20,(75*i)+50, 50,30);
			sc[i].setBounds(70,(75*i)+50, 350,30);
			tf[i].setBounds(450,(75*i)+50, 50, 30);

		}
		add(btn);
		btn.setBounds(200,400,100,50);
	}
	
}

Code to sync Scrollbars and TextFields:
In our application, When user moves Scrollbar the current value of scroll bar is to be displayed/updated in text field and vice versa.

        public void adjustmentValueChanged(AdjustmentEvent e) 
        {
		for(int i=0;i<3;i++)
		{
			tf[i].setText(sc[i].getValue()+"");	
		}
			
        }
	 
        public void keyReleased(KeyEvent e) 
        {
		System.out.println("Release:"+tf[0].getText());

		for(int i=0;i<3;i++)
		{
			sc[i].setValue(Integer.parseInt(tf[i].getText()));	
		}
        }

Full Program:

import java.awt.*;
import java.applet.*;
import java.awt.event.*;

public class ColorChooserApplet extends Applet implements AdjustmentListener, KeyListener, ActionListener, Runnable
{
	int r=0,g=0,b=0;
	Thread t;
	Button btn = new Button("Run");
	Label lbl[] = new Label[3];
	Scrollbar sc[] = new Scrollbar[3];
	TextField tf[] = new TextField[3];
	String[] slbl = {"Red","Green","Blue"};
	public void init()
	{
		setLayout(null);
		
		for(int i=0;i<3;i++)
		{
			lbl[i] = new Label(slbl[i]);	
			sc[i] = new Scrollbar(Scrollbar.HORIZONTAL, 0, 20, 0, 275);
			tf[i] = new  TextField("0");
			add(lbl[i]);
			add(sc[i]);
			add(tf[i]);
			lbl[i].setBounds(20,(75*i)+50, 50,30);
			sc[i].setBounds(70,(75*i)+50, 350,30);
			tf[i].setBounds(450,(75*i)+50, 50, 30);
			
			sc[i].addAdjustmentListener(this);
			tf[i].addKeyListener(this);
		}
		add(btn);
		btn.setBounds(200,400,100,50);
		btn.addActionListener(this);
	}
	public void adjustmentValueChanged(AdjustmentEvent e) 
	{
		for(int i=0;i<3;i++)
		{
			tf[i].setText(sc[i].getValue()+"");	
		}
			
	}
	public void	keyPressed(KeyEvent e)
	{
		System.out.println("Pressed:"+tf[0].getText());
		
	} 
    public void	keyReleased(KeyEvent e) 
	{
		System.out.println("Release:"+tf[0].getText());

		for(int i=0;i<3;i++)
		{
			sc[i].setValue(Integer.parseInt(tf[i].getText()));	
		}
	}
    public void	keyTyped(KeyEvent e)
	{
		System.out.println("Typed:"+tf[0].getText());

	} 
	public void actionPerformed(ActionEvent e)
	{
		r = sc[0].getValue();
		g = sc[1].getValue();
		b = sc[2].getValue();
		Color clr = new Color(r,g,b);	
		setBackground(clr);
		t = new Thread(this);
		t.start();
	}
	
	public void run()
	{
		try
		{
			for(int i=0;i<10;i++)
			{
				t.sleep(1000);
				r = r - sc[0].getValue()/10;
				g = g - sc[1].getValue()/10;
				b = b - sc[2].getValue()/10;
				Color clr = new Color(r,g,b);	
				setBackground(clr);			
			}
		}
		catch(Exception e)
		{
			System.out.println(e);
		}
		
	}
}

/*
<applet code="ColorChooserApplet" width="550" height="550"></applet>
*/

The post Color Chooser – multiple event handling appeared first on Ankit Virparia.

To schedule/manage any thread we must have object of Thread class. As such main thread is not created by developer we have to get the object from Runtime by calling a simple method.

class mainThread
{
	public static void main(String[] s)
	{
		Thread t = Thread.currentThread();
	}
}

Now object “t” can be used to call any method of Thread class. Which will ultimately control the main Thread. e.g.

class mainThread
{
	public static void main(String[] s) throws InterruptedException
	{
		Thread t = Thread.currentThread();
		System.out.println("Thread Started");
		t.sleep(1000);
		System.out.println("After Sleep");
	}
}

On calling t.sleep(1000) method the execution will be paused for 1second and then it will execute further. Method sleep(int) throws an InterruptedException which can be handled by applying “throws InterruptedException” clause.

If we really want to track the execution, We can print the Date object as below:

The post What is Thread? appeared first on Ankit Virparia.