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coder04
coder04 wrote ...

2015/2/17

Can you help me Encrypt and Decrypt text like Caesar Cipher

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coder04 coder04

2015/2/17

#
This is my text file I would like to make a caesar cipher. Can you tell me what to add? 
import greenfoot.*;  // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)
import java.awt.Color;

/**
 * Write a description of class TextField here.
 * 
 * @author (your name) 
 * @version (a version number or a date)
 */
public class TextField extends Actor
{
    private boolean active = false;
    private boolean cursorActive = false;
    private boolean displayKeyNames;
    private boolean enabled = true;
    
    private static int activeTextField = 1;
    
    private int textFieldNumber;
    private int textFontSize;
    private int cursorPosition = 0;
    
    private long cursorTime = System.currentTimeMillis();
    
    private String input = "";
    private String text = "";
    private String temp = "";
    
    private Color bgColor = Color.white;
    private Color textColor = Color.black;
    
    /**
     * Creates a new TextField of a default size of 250 x 50 with black letters on white background.
     */
    public TextField() {
        this(250, 50, false, true, Color.white, Color.black, "");
    }
    
    /**
     * Creates a new TextField with a default size of 250 x 50 with black letters on white background and a starting text.
     * 
     * @param text
     *      The text that is shown directly.
     */
    public TextField(String text) {
        this(250, 50, false, true, Color.white, Color.black, text);
    }
    
    /**
     * Creates a new TextField with a default size of 250 x 50 with black letters on white background and a starting text.
     * 
     * @param text
     *      The text that is shown directly.
     * 
     * @param enabled
     *      If you want the textfield to be enabled (able to write in it) this boolean has to be true.
     */
    public TextField(String text, boolean enabled) {
        this(250, 50, false, enabled, Color.white, Color.black, text);
    }
    
    /**
     * Creates a new TextField of the given size with black letters on white background.
     * 
     * @param width
     *      The TextFields width (which has to be greater than 50).
     * 
     * @param height
     *      The TextFields height (which has to be greater than 20).
     */
    public TextField(int width, int height) throws IllegalArgumentException {
        this(width, height, false, true, Color.white, Color.black, "");
    }
    
    /**
     * Creates a new TextField of the given size with black letters on white background.
     * 
     * @param width
     *      The TextFields width (which has to be greater than 50).
     * 
     * @param height
     *      The TextFields height (which has to be greater than 20).
     * 
     * @param enabled
     *      If you want the textfield to be enabled (able to write in it) this boolean has to be true.
     */
    public TextField(int width, int height, boolean enabled) throws IllegalArgumentException {
        this(width, height, false, enabled, Color.white, Color.black, "");
    }
    
    /**
     * Creates a new TextField of the given size with black letters on white background and a starting text.
     * 
     * @param width
     *      The TextFields width (which has to be greater than 50).
     * 
     * @param height
     *      The TextFields height (which has to be greater than 20).
     * 
     * @param text
     *      The text that is shown directly.
     */
    public TextField(int width, int height, String text) throws IllegalArgumentException {
        this(width, height, false, true, Color.white, Color.black, text);
    }
    
    /**
     * Creates a new TextField of the given size with black letters on white background and a starting text.
     * 
     * @param width
     *      The TextFields width (which has to be greater than 50).
     * 
     * @param height
     *      The TextFields height (which has to be greater than 20).
     * 
     * @param displayKeyNames
     *      If you want to use the textfield for only one key this parameter has to be true.
     * 
     * @param text
     *      The text that is shown directly.
     */
    public TextField(int width, int height, boolean displayKeyNames, String text) throws IllegalArgumentException {
        this(width, height, displayKeyNames, true, Color.white, Color.black, text);
    }
    
    /**
     * Creates a new TextField of the given size and the given colors.
     * 
     * @param width
     *      The TextFields width (which has to be greater than 50).
     * 
     * @param height
     *      The TextFields height (which has to be greater than 20).
     * 
     * @param bgColor
     *      The color of the TextFields background.
     * 
     * @param textColor
     *      The color of the text.
     */
    public TextField(int width, int height, Color bgColor, Color textColor) throws IllegalArgumentException {
        this(width, height, false, true, bgColor, textColor, "");
    }
    
    /**
     * Creates a new TextField of the given size and the given colors.
     * 
     * @param width
     *      The TextFields width (which has to be greater than 50).
     * 
     * @param height
     *      The TextFields height (which has to be greater than 20).
     * 
     * @param displayKeyNames
     *      If you want to use the textfield for only one key this parameter has to be true.
     * 
     * @param bgColor
     *      The color of the TextFields background.
     * 
     * @param textColor
     *      The color of the text.
     */
    public TextField(int width, int height, boolean displayKeyNames, Color bgColor, Color textColor) throws IllegalArgumentException {
        this(width, height, false, true, bgColor, textColor, "");
    }
    
    /**
     * Creates a new TextField of the given size, the given colors and a starting text.
     * 
     * @param width
     *      The TextFields width (which has to be greater than 50).
     * 
     * @param height
     *      The TextFields height (which has to be greater than 20).
     * 
     * @param bgColor
     *      The color of the TextFields background.
     * 
     * @param textColor
     *      The color of the text.
     */
    public TextField(int width, int height, Color bgColor, Color textColor, String text) throws IllegalArgumentException {
        this(width, height, false, true, bgColor, textColor, text);
    }
    
    /**
     * Creates a new TextField of the given size, the given colors and a starting text.
     * 
     * @param width
     *      The TextFields width (which has to be greater than 50).
     * 
     * @param height
     *      The TextFields height (which has to be greater than 20).
     * 
     * @param displayKeyNames
     *      If you want to use the textfield for only one key this parameter has to be true.
     * 
     * @param bgColor
     *      The color of the TextFields background.
     * 
     * @param textColor
     *      The color of the text.
     */
    public TextField(int width, int height, boolean displayKeyNames, Color bgColor, Color textColor, String text) throws IllegalArgumentException {
        this(width, height, displayKeyNames, true, bgColor, textColor, text);
    }
    
    /**
     * Creates a new TextField of the given size, the given colors and a starting text.
     * 
     * @param width
     *      The TextFields width (which has to be greater than 50).
     * 
     * @param height
     *      The TextFields height (which has to be greater than 20).
     * 
     * @param displayKeyNames
     *      If you want to use the textfield for only one key this parameter has to be true.
     * 
     * @param enabled
     *      If you want the textfield to be enabled (able to write in it) this boolean has to be true.
     * 
     * @param bgColor
     *      The color of the TextFields background.
     * 
     * @param textColor
     *      The color of the text.
     */
    public TextField(int width, int height, boolean displayKeyNames, boolean enabled, Color bgColor, Color textColor, String text) throws IllegalArgumentException {
        if (width < 50) {
            throw new IllegalArgumentException("The width of the text field has to be greater or equal 50");
        }
        else if (height < 20) {
            throw new IllegalArgumentException("The height of the text field has to be greater or equal 20");
        }
        this.bgColor = bgColor;
        this.textColor = textColor;
        this.text = text;
        this.displayKeyNames = displayKeyNames;
        this.enabled = enabled;
        cursorPosition = text.length();
        getImage().clear();
        getImage().scale(width, height);
        textFontSize = height - 10;
        resetImage();
        displayText();
    }
    
    /**
     * Assigns this field a number.
     * This method is called when the object is added to the world.
     */
    public void addedToWorld(World world) {
        textFieldNumber = getWorld().getObjects(TextField.class).size();
    }
    
    /**
     * Control the TextFields action.
     */
    public void act() {
        if (Greenfoot.mouseClicked(this)) {
            activeTextField = textFieldNumber;
            active = true;
        }
        if (active) {
            if (activeTextField != textFieldNumber) {
                active = false;
                cursorActive = false;
                displayText();
                return;
            }
            if (System.currentTimeMillis() - cursorTime > 750) {
                cursorTime = System.currentTimeMillis();
                cursorActive = !cursorActive;
            }
            input = Greenfoot.getKey();
            if (enabled) {
                if (displayKeyNames) {
                    if (input != null && input != "") {
                        text = input;
                    }
                }
                else {
                    if (input == "backspace" && text.length() != 0 && cursorPosition != 0) {
                        if (cursorPosition == text.length()) {
                            text = text.substring(0, text.length()-1);
                        }
                        else {
                            temp = text.substring(0, cursorPosition - 1);
                            temp += text.substring(cursorPosition, text.length()-1);
                            text = temp;
                            temp = "";
                        }
                        cursorPosition--;
                    }
                    else if (input == "enter") {
                        setActiveTextField();
                    }
                    else if (input == "space") {
                        if (cursorPosition == text.length()) {
                            text += " ";
                        }
                        else {
                            temp = text.substring(0, cursorPosition);
                            temp += " ";
                            temp += text.substring(cursorPosition, text.length() - 1);
                            text = temp;
                            temp = "";
                        }
                        cursorPosition++;
                    }
                    else if (input == "left") {
                        if (cursorPosition > 0) {
                            cursorPosition--;
                            cursorTime = System.currentTimeMillis();
                            cursorActive = true;
                        }
                    }
                    else if (input == "right") {
                        if (cursorPosition < text.length()) {
                            cursorPosition++;
                            cursorTime = System.currentTimeMillis();
                            cursorActive = true;
                        }
                    }
                    else if (input != null && input.length() == 1) {
                        if (cursorPosition == text.length()) {
                            text += input;
                        }
                        else {
                            temp = text.substring(0, cursorPosition);
                            temp += input;
                            temp += text.substring(cursorPosition, text.length() - 1);
                            text = temp;
                            temp = "";
                        }
                        cursorPosition++;
                    }
                }
            }
            else if (input == "enter") {
                setActiveTextField();
            }
            displayText();
        }
        else {
            if (activeTextField == textFieldNumber) {
                active = true;
            }
        }
    }
    
    /**
     * Display the text onto the TextField.
     */
    private void displayText() {
        GreenfootImage textImage = new GreenfootImage(text, textFontSize, textColor, new Color(0, 0, 0, 0));
        GreenfootImage textBeforeCursor = new GreenfootImage(text.substring(0, cursorPosition), textFontSize, textColor, new Color(0, 0, 0, 0));
        resetImage();
        getImage().drawImage(textImage, (textImage.getWidth() > getImage().getWidth() - 10 ? -(textImage.getWidth() - getImage().getWidth()) - 10 : 5), (getImage().getHeight() / 2 - textImage.getHeight() / 2));
        getImage().setColor(textColor);
        if (cursorActive) {
            getImage().fillRect((textBeforeCursor.getWidth() > getImage().getWidth() - 10 ? getImage().getWidth() - 8 : textBeforeCursor.getWidth() + 7), getImage().getHeight() / 2 - textFontSize / 2, 2, textFontSize);
        }
        getImage().setColor(bgColor);
        getImage().fillRect(0, 0, 3, getImage().getHeight()-2);
    }
    
    /**
     * Clears the image of the TextField so that it is empty again.
     */
    private void resetImage() {
        getImage().setColor(bgColor);
        getImage().fill();
        getImage().setColor(Color.black);
        getImage().fillRect(0, getImage().getHeight()-2, getImage().getWidth(), 3);
        getImage().fillRect(getImage().getWidth()-2, 0, 3, getImage().getHeight());
    }
    
    /**
     * Set the active TextField to the given number.
     * 
     * @param activeTextField
     *      The number of the TextField that is activated.
     */
    public void setActiveTextField(int activeTextField) {
        this.activeTextField = activeTextField;
    }
    /**
     * Set the active TextField to the next textfield.
     */
    public void setActiveTextField() {
        activeTextField++;
        if (activeTextField > getWorld().getObjects(TextField.class).size()) {
            activeTextField = 1;
        }
    }
    
    /**
     * Check whether this textfield is enabled (if you can change the text in it).
     * 
     * @return
     *      Returns true if the text field is enabled.
     */
    public boolean isEnabled() {
        return enabled;
    }
    /**
     * Enable or disenable the textfield.
     * 
     * @param enabled
     *      If you want the textfield to be enabled (able to write in it) this boolean has to be true.
     */
    public void setEnabled(boolean enabled) {
        this.enabled = enabled;
    }
    
    /**
     * Returns the text of this textfield.
     * 
     * @return
     *      The text that is currently displayed in the textfield.
     */
    public String getText() {
        return text;
    }
    /**
     * Set the text of this textfield.
     * 
     * @param text
     *      The text that should be displayed in the textfield.
     */
    public void setText(String text) {
        this.text = text;
        cursorPosition = text.length();
    }
    
    /**
     * Returns the backgroundcolor of this TextField.
     * 
     * @return
     *      The backgroundcolor of this TextField.
     */
    public Color getBackgroundColor() {
        return bgColor;
    }
    /**
     * Set the backgroundcolor to the given color.
     * 
     * @param bgColor
     *      The new backgroundcolor.
     */
    public void setBackgroundColor(Color bgColor) {
        this.bgColor = bgColor;
    }
    
    /**
     * Returns the textcolor of this TextField.
     * 
     * @return
     *      The textcolor of this TextField.
     */
    public Color getTextColor() {
        return textColor;
    }
    /**
     * Set the textcolor to the given color.
     * 
     * @param textColor
     *      The new textcolor.
     */
    public void setTextColor(Color textColor) {
        this.textColor = textColor;
    }
}
coder04 coder04

2015/2/17

#
help please?
erdelf erdelf

2015/2/17

#
I am not quite sure where you want to add it in this code, but the basics of a caesar cipher is simple, but you have to do it character by character. 
char decoded = 'd'; // the character you want to encode
int caesar = 3; // the parameter used for the caesar cipher
char encoded = decoded-('a'+caesar%24)+'a'; // the encoded character
(this should work)
danpost danpost

2015/2/17

#
First, you will need a field to hold the "key" to the cipher. It can be an int field that holds a value between 1 and 25, inclusive. This is the offset value between the real character and the coded character. Then you will need a methods to code/decode the characters. Something like this: 
public char convertChar(char c, int offset)  // offset is key value to code and negative key value to decode
{
    if (char<=64 || (char>90 && char<=96) || char>122) return c; // not an alpha character
    return (char)(32*((int)c)/32)+1+(((int)c-1)%32+offset+26)%26); // converted character
}
I did not test the method, but it should be close (if not accurate).
coder04 coder04

2015/2/17

#
I dont get how i would make this work with text if i put it into this code it will not compile have you got any example for Caesar cipher or a different way i could use?
coder04 coder04

2015/2/17

#
I have got two of the text fields one needs to be where i type and the other needs to change automatically so where do i put this? 
public char convertChar(char c, int offset)  // offset is key value to code and negative key value to decode
{
    if (char<=64 || (char>90 && char<=96) || char>122) return c; // not an alpha character
    return (char)(32*((int)c)/32)+1+(((int)c-1)%32+offset+26)%26); // converted character
danpost danpost

2015/2/17

#
You could add another method: 
public String convertString(String str, int offset)
{
    String converted = "";
    for (int i=0; i<str.length(); i++) converted += convertChar(str.charAt(i), offset);
    return converted;
}
coder04 coder04

2015/2/17

#
Its says .class is expected 
  if (char<=64 || (char>90 && char<=96) || char>122) return c; // not an alpha character
danpost danpost

2015/2/17

#
Actually, these methods are not particular to any world or actor. You should be able to call them from anywhere at anytime. Adding a static 'Cipher' class might be the way to go: 
public static class Cipher
{
    public static char convertChar(char c, int offset)
    {
        if (c<=64 || (c>90 && c<=96) || c>122) return c;
        return (char)(32*((int)c)/32)+1+(((int)c-1)%32+offset+26)%26);
    }

    public static String convertString(String str, int offset)
    {
        String converted = "";
        for (int i=0; i<str.length(); i++) converted += convertChar(str.charAt(i), offset);
        return converted;
    }
}
Then to convert a string, use; 
String codedString = Cipher.converString("any text or string expression", key);
// or
String decodedString = Cipher.convertString(codedString, -key);
You can also use the 'convertChar' method to code/decode individual characters.
danpost danpost

2015/2/17

#
coder04 wrote...
Its says .class is expected 
  if (char<=64 || (char>90 && char<=96) || char>122) return c; // not an alpha character
Oops. 'char' should be 'c'. See my last post.
coder04 coder04

2015/2/17

# 
return (char)(32*((int)c)/32)+1+(((int)c-1)%32+offset+26)%26);
Apparently when i add it to the textfield class on the code you showed me above the one above this bit needs ; expected
danpost danpost

2015/2/17

#
coder04 wrote...
return (char)(32*((int)c)/32)+1+(((int)c-1)%32+offset+26)%26);
Apparently when i add it to the textfield class on the code you showed me above the one above this bit needs ; expected
Looking into it.
danpost danpost

2015/2/17

#
Alright, the final class code follows: 
public abstract class Cipher
{
    public static char convertChar(char c, int offset)
    {
        if (c<=64 || (c>90 && c<=96) || c>122) return c;
        int base = 32*((c-1)/32);
        return (char)(base+1+((((c-base-1)%26)+26+offset)%26));
    }
 
    public static String convertString(String str, int offset)
    {
        String converted = "";
        for (int i=0; i<str.length(); i++) converted += convertChar(str.charAt(i), offset);
        return converted;
    }
}
coder04 coder04

2015/2/17

#
so i put it it into a separate class and delete the act and type this correct?
coder04 coder04

2015/2/17

#
cool it has now compiled i have two of the textfields 1 and 2 which i have added to the world. I want to type in one and the other on to change. What do I add to the textfield for it to work
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