import java.awt.*;
import BreezyGUI.*;


public class PrimeNumberApplt extends GBApplet
{

	//Define the GUI elements
	Label endNumberLabel = addLabel ("Ending Number",1,1,1,1);
	IntegerField endNumberField = addIntegerField (0,1,2,1,1);

	Label primeTestAnswerLabel = addLabel ("Prime Numbers less than or",2,1,2,1);
	Label primeTestAnswer2Label = addLabel ("equal to Ending Number",3,1,2,1);

	TextArea primeTestAnswerField = addTextArea ("",4,1,2,7);

	Label primeCountLabel = addLabel ("No. of Primes in the List",12,1,1,1);
	IntegerField primeCountField = addIntegerField (0,12,2,1,1);
	
	Button calculateButton = addButton ("Calculate",14,1,2,1);

	//Declare Variables
	int endNum,count;														
	int i;
	int testNumber;
	String prime;



	public void buttonClicked (Button buttonObj) 
	{
		//Display wait message and Clear the Text Area and reset the count for subsequent runs		
		count = 0;
		prime = "Please Wait" + "\n" + "While the Program Runs";		
		displayData(prime, count);		

		//Start the calculations
		processPrime();

		//Display the results
		displayData(prime, count);

		//Return focus to the EndNumber Field for additional input		
		endNumberField.requestFocus();
		endNumberField.selectAll();
	}
	
	//This module initiates the calculations and calls the loopNumber module
	private void processPrime()
	{
		//This reads the ending number from the user input
		endNum = endNumberField.getNumber();

		//Test for Negative Numbers through Positive 7 for Ending Number
		if (endNum >= 8)
		{
			 //Assign values to variables and start loop to calculate prime numbers
			 prime = "2" + "\n" + "3" + "\n" + "5" + "\n" + "7" + "\n";
			 count = 4;			 
			 testNumber = 8;			 
			 loopNumber();		    		    
		}
		else if (endNum == 7)
		{		    
		        prime = "2" + "\n" + "3" + "\n" + "5" + "\n" + "7" + "\n";
		        count = 4;			 		        
		}
		else if ((endNum == 5) || (endNum == 6))
		{		    
		        prime = "2" + "\n" + "3" + "\n" + "5" + "\n";
		        count = 3;			 		        
		}
		else if ((endNum == 3) || (endNum == 4))
		{		    
		        prime = "2" + "\n" + "3" + "\n";
		        count = 2;			 		        
		}
		else if (endNum == 2)
		{		    
		        prime = "2" + "\n";
		        count = 1;			 		        
		}
		else 
		{
			prime = "You must enter a positive" + "\n" + "integer greater than 1.";
			count = 0;		
		}		
	}

	//This module runs a loop to test each number up to Ending Number
	private void loopNumber()
	{
		while (testNumber <= endNum)
		{
			//This tests for even numbers
			if(testNumber % 2 == 0)
			{
			   testNumber += 1;
			}
			else
			   //This module does the actual testing for prime
			   testPrime(testNumber);
		}
	}

	//This module runs a loop to test all the divisors of the TestNumber
	private void testPrime(int testNum)
	{		
		i = 3;
		while(i < testNum / 3 + 1)
		{			
		      //This tests if the number is evenly divisible and if so breaks out of the loop
		      if (testNum % i == 0)
		      {				    			           
		          i = testNum / 3 + 1;
		      } 
		      else 
		      {			                 
			     i += 2;
			     if(i >= testNum / 3 + 1)
			     {
				 //This adds the number being tested to the display of prime numbers
				 prime = prime + testNum + "\n";
				 //This increments the counter				 
				 count += 1;	 
 			      }				
		      }		 
		 }
		 //This increments the test number to test the next number in order
		 testNumber += 1;
	}

	// This module displays the Prime numbers and the count
	private void displayData(String prime, int count)
	{
		primeCountField.setNumber (count);
		primeTestAnswerField.setText (prime);				
	}
}