// steve eilertsen
// String ex 3 number 3
package string3_3;


public class String3_3_UI {
    
    public static void main(String[] args) 
    {
        String firstLast = null;
        String backwards = null;
        String frontBack = null;
        String middleChar = null;
        String isVowel = null;
        String spaces = null;
       
    
        System.out.println("Hello UI class");
        String3_3_Manager sm = new String3_3_Manager();
        
        
        // Each called manager method returns a String to the UI class for printing
        // to the monitor.
        firstLast = sm.isolateFirstLast();
        System.out.println(firstLast);
        
        backwards = sm.backwards();
        System.out.println(backwards);
        
        frontBack = sm.frontBack();
        System.out.println(frontBack);
        
        middleChar = sm.middleCharacter();
        System.out.println("The middle characters are: " + middleChar);
        
        isVowel = sm.vowelsOnly();
        System.out.println(isVowel);
        
        spaces = sm.numberSpaces();
        System.out.println(spaces);
    }
    
}
======================================================

// steve eilertsen
// Ex 3 3 String handling method exercise
// Featurs some defensive coding ie the work must be longer than zero
// characters.

/*
    SAMPLE OUTPUT
    =============
    Hello UI class
    Hello String Manager
    Word: abcde
    The first letter is: a
    The last letter is: e
    The word backwards is: edcba
    Letter from the front, letter from the back: aebdc
    The middle characters are: c
    The vowels are: ae
    The number of spaces is: 0

*/

package string3_3;

import javax.swing.JOptionPane;


public class String3_3_Manager 

{
    //global varialbles
    String word = null;
    int theLength = 0;
    
    // Constructor method
    // 3.1
    public String3_3_Manager()
    {     
        System.out.println("Hello String Manager");
        
        // 3.1
        word = JOptionPane.showInputDialog(null, "Enter your word or phrase");
        if(word.length() == 0)
        {
            System.out.println("Word must be longer than zero characters");
            System.exit(0);
        }
        System.out.println("Word: " + word);
        
    } // end constructor
    
    
    // All regular methods return a String back to the UI class for
    // printing to the monitor
    
    // 3.2
    public String isolateFirstLast()
    {
        char first = word.charAt(0);
        
        theLength = word.length();
        char last = word.charAt(theLength - 1);
        
        return "The first letter is: " + first + "\n" + "The last letter is: " + last;
        
    } // end isolateFirstLast
    
    // 3.3
    public String backwards()
    {
        String temp = "";
        int thePosition = theLength;
        
        for(int x = 0; x < theLength; x++)
        {
            temp = temp + word.charAt(thePosition - 1);
            thePosition = thePosition - 1;
            
        }
        
        return "The word backwards is: " + temp;
   
    } // end backwards
    
    // 3.4
    public String frontBack()
    {
        // local variables the must be outside the loop
        // default temp String
        String temp = "";
        char middleCharacter;
        
        // if the word is only one letter this method cannot run
        if(word.length() == 1)
        {
            System.out.println("Word is too short for this method");
        }
        
        else
        {
            // integer division throws away the decimal fraction and gives
            // a whole number answer (it truncates the answer
            int halfLoop = theLength/2;
            int counterF = 0;
            int counterL = word.length() - 1;
            
            for(int x = 0; x < halfLoop; x++)
            {
                char letterF = word.charAt(counterF);  // letter first
                char letterL = word.charAt(counterL); // letter last
            
                // code the exception first
                if((counterL - counterF) == 2)
                {
                    // harvest from front, from the back
                    temp = temp + letterF + letterL;
                
                    // harvest the middle character
                    counterF = counterF + 1;
                    middleCharacter = word.charAt(counterF);
                    temp = temp + middleCharacter;
                }
            
                else // now code the default
                {
                    // harvest a letter from front and from the back only
                    temp = temp + letterF + letterL;
                    counterF = counterF + 1;
                    counterL = counterL - 1;
                }
            
            } // end loop
        
        } 
    
        return "Letter from the front, letter from the back: " + temp; 
        
    } // end front back method
    
    // 3.5
    public String middleCharacter()
    {
        int theMiddleInt = theLength / 2;
        int theMiddleMOD = theLength % 2;
        String middleChar = "";
        
        if(theMiddleMOD > 0)
            middleChar = word.substring(theMiddleInt, 
                    theMiddleInt + 1);
        else
            middleChar = word.substring(theMiddleInt -1,
                    theMiddleInt + 1);
        
        return middleChar;
        
    }
    
    // 3.6
    public String vowelsOnly()
    {
        boolean isVowel = false;
        String temp = "";
        
        for(int x = 0;x < word.length();x++)
        {
            char a = word.charAt(x);
            
            // pass letter to the check_for_vowel method
            isVowel = checkVowels(a);
            
            // if true, build the temp String
            if(isVowel)
                temp = temp + word.charAt(x);
                    
        } // end loop
        
        return "The vowels are: " + temp;
        
    } // end vowelsOnly
    
    // This private helper method reduces redundant code for 3.6 which
    // reduces possible typo or logic errors.
    private boolean checkVowels(char a)
    {
        // test for presence of vowel
        boolean flag = false;
        
        // map the parameter to the local variable
        char checkForVowel = a;
        
        // parse the char to a String so that we can use the equals method
        // because char does not have such a method
        String checkForVowelSt = "" + checkForVowel;
        
        if(checkForVowelSt.equalsIgnoreCase("a")
            || checkForVowelSt.equalsIgnoreCase("e")
            || checkForVowelSt.equalsIgnoreCase("i")
            || checkForVowelSt.equalsIgnoreCase("o")
            || checkForVowelSt.equalsIgnoreCase("u"))
        {
            
            flag = true;
        }
        
        return flag;
    } // end checkVowels
    
    // 3.7
    public String numberSpaces()
    {
        int spaces = 0;
        
        if(!word.contains(" ")) // does NOT contain spaces
            spaces = 0;
        
        String temp = word;  // make a duplicate copy of the word
        
        // Reduce temp removing spaces one at a time.
        // Count until there are no more spaces
        while(temp.contains(" "))
        {
            int position = temp.indexOf(" ");
            temp = temp.substring(position + 1);
            spaces = spaces + 1;
        }
        
        return "The number of spaces is: " + spaces;    
    } // end numberSpaces
    
} // end class


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