Thread: backspace action(deleting a character in a string) in a paint event, looping forever

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
 
public class BackSpaceSample extends JPanel {
 
    private String word;
 
    public BackSpaceSample() {
 
        setBackground(Color.BLACK);
        addKeyListener(new KeyListener());
        setFocusable(true);
        setLayout(null);
        word = "";
    }
 
    public void paint(Graphics g) {
 
        super.paint(g);
        Graphics2D g2d = (Graphics2D) g;
        g2d.setColor(Color.WHITE);
        g2d.setFont(new Font("Arial", Font.BOLD, 24));
        g2d.drawString(word, 100, 100);
        repaint();
    }
 
    private class KeyListener extends KeyAdapter {
 
        public void keyTyped(KeyEvent e) {
 
            String alphabet =  "abcdefghijklmnopqrstuvwxyz";
            Character charac = e.getKeyChar();
 
            for (int x = 0; x < alphabet.length(); x++) {
 
                if (charac.toString().equalsIgnoreCase("" + alphabet.charAt(x))) {
 
                    word = word + e.getKeyChar();
                }
            }
        }
 
        public void keyPressed(KeyEvent e) {
 
            if (e.getKeyCode() == KeyEvent.VK_BACK_SPACE) {
 
                System.out.println("Backspace is being pressed");
 
                // iterating action that will re-assign the string itself
                // but without the last character
                for (int x = 0; x < word.length() -1; x++) {
 
                    word = word + word.charAt(x);
 
                    System.out.println("What the hell??    :    " + x);
                }
            }
        }
    }
 
    public static void main(String[] args) {
 
        JFrame f = new JFrame();
        f.add(new BackSpaceSample());
        f.setSize(400, 200);
        f.setLocationRelativeTo(null);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setVisible(true);
    }
}

im trying to perform a backspace action in a paint method, i was trying to put the logic of it in the keyPressed event, where there is a loop that will iterate according to the length of the word (minus 1) and re-assgin the characters in the string instance but without the last character, but the loop is looping forever, my first assumption was that MAYBE I DONT HAVE A keyRelease event, so what i did is incuded a keyReleased event and put the same statements, still it loops forever, my second assumption was that MAYBE i should just put the statement in the released event, still the loop is going forever, i even put a statement that will check the value of 'x' of the for-loop counter, and i saw that it just keeps on iterating, i dont know what is going on. need help again please....

hat means you'll never be able to reach the end of the word.

oh thanks for guiding me through that,
i never thought that the word keeps on expanding each time im adding on it, i think i should use another string instance, or the substring() method

Or you could use a StringBuilder.

thanks again for the suggestion! finally got what i needed

if (word.length() > 0) {
 
                    StringBuilder strB = new StringBuilder(word);
                    strB.deleteCharAt(word.length() - 1);
                    word = strB.toString();
                }

i still dont get what i need using the substring method, but this one, it does all the things i needed with no time

you'll never be able to reach the end of the word.

- your statement really woke me up,

Or you could use a StringBuilder.

- thanks for refreshing me back, i forgot that there is a StringBuilder class that can manipulate strings

if (word.length() > 0) {
 
                    for (int x = 0; x < word.length() - 1; x++) {
 
                        temp = temp + word.charAt(x);
                    }
 
                    word = temp;
                }

im not putting my self in a harder way, but im still not satisfied not knowing and solving the problem that i encountered using other things tocompensate with it, well i finally managed to do the logic that i want, i just have to use a separate object (String object) to hold the final word without the last character, thanks man thanks for the help

oops, i didnt noticed substring() method returns a string LOL :p

word.substring(0, word.length()-1);

yeah i was frustrated like, what the hell!? this statement doesnt do anything to cut the letter from the word, i didnt know or i think i really forgot that this method returns a string value, and i should assign(re-assign) it to the string object itself again