class NUMBER_INPUT {
  
  //Initalize variables
  int x, y;
  float boxLength, boxHeight;
  int numberOfDigits, maxDigits;
  String highestValue, lowestValue;
  int [] digitsArray;
  boolean acceptKeyboard;
  color mouseOut, mouseOver, mouseClick;
  String units, heading;
  
  //Attributes
  NUMBER_INPUT(int xTEMP, int yTEMP, String headingTEMP, String unitsTEMP, int initialValueTEMP, int lowestValueTEMP, int highestValueTEMP){
    
    //Assign attributes
    x = xTEMP;
    y = yTEMP;
    units = unitsTEMP;
    heading = headingTEMP;
    lowestValue = str(lowestValueTEMP);
    highestValue = str(highestValueTEMP);
    maxDigits = highestValue.length();
    
    boxLength = 10+textWidth(highestValue);
    boxHeight = textAscent()+textDescent()+6;
    
    //Assign other variables
    numberOfDigits = 0;
    acceptKeyboard = false;
    digitsArray = new int [maxDigits];
    
    //append initial value
    String initialValue = str(initialValueTEMP);
    for (int i=0; i<initialValue.length(); i++){
      digitsArray[i] = int(initialValue.substring(i,i+1));
    }
    numberOfDigits = initialValue.length();
    
    //Translate the coordinates so that x and y are the coordinates for the number input box
    x+=textWidth(heading);
  }
  
  //Methods
  
  //Draws the boxes
  void display(){
    
    //Colour the box...
    //when the box is clicked
    if (acceptKeyboard==true){
      fill(Attention);
    }
    
    //when the mouse is over the box
    else if ((mouseX>x)&&(mouseX<x+boxLength)&&(mouseY>y)&&(mouseY<y+boxHeight)){
      fill(Hover);
    }
    
    //when the mouse is outside the box
    else {
      fill(Foreground);
    }
    
    //Draw the box
    rect(x,y,boxLength,boxHeight);
    
    //Collect the digits
    String numberToPrint = "";
    for (int i=0; i<numberOfDigits; i++){
      numberToPrint += digitsArray [i];
    }
    
    //Print the digits
    fill(Outline);
    text(numberToPrint,x+5,y+textDescent()+textAscent());
    
    //Prints the units of measurements
    text(units,x+boxLength+5,y+textDescent()+textAscent());
    
    //Print the heading
    text(heading, x-textWidth(heading),y+textDescent()+textAscent());
  }
  
  //Set boxes to or not to accept keyboard inputs ONCE the mouse is pressed
  void activate_keyboardInput(){
    if ((mouseX>x)&&(mouseX<x+boxLength)&&(mouseY>y)&&(mouseY<y+boxHeight)){
      acceptKeyboard = true;
    }
    else {
      acceptKeyboard = false;
    }
  }
  
  //Inserts or deletes a digit according to the keypressed pressed
  void keyboard_input(){
    String digit;
    if (acceptKeyboard == true){
      if (numberOfDigits != maxDigits){
        if (key=='1'){
          this.append_digit("1");
        }
        else if (key=='2'){
          this.append_digit("2");
        }
        else if (key=='3'){
          this.append_digit("3");
        }
        else if (key=='4'){
          this.append_digit("4");
        }
        else if (key=='5'){
          this.append_digit("5");
        }
        else if (key=='6'){
          this.append_digit("6");
        }
        else if (key=='7'){
          this.append_digit("7");
        }
        else if (key=='8'){
          this.append_digit("8");
        }
        else if (key=='9'){
          this.append_digit("9");
        }
        else if (key=='0'){
          this.append_digit("0");
        }
      }
      if (key == BACKSPACE){
        if (numberOfDigits != 0){
          numberOfDigits--;
        }
      }
      if ((key == RETURN)||(key == ENTER)){
        acceptKeyboard = false;
      }
    }
  }
  
  //To add a digit to the array
  void append_digit(String digit){
    digitsArray[numberOfDigits] = int(digit);
    numberOfDigits++;
  }
  
  //To replace the array of digits completely
  void replace_array(String number){
    numberOfDigits = 0;
    for (int i=0; i<number.length(); i++){
      this.append_digit(number.substring(i,i+1));
    }
  }
  
  //Returns a value
  int return_value(){
    
    //if there are no user input return the lowest possible value
    if (numberOfDigits == 0){
      this.replace_array(lowestValue);
      return int(lowestValue);
    }
    
    //convert the array of digits to a single string
    String numberToConvert = "";
    for (int i=0; i<numberOfDigits; i++){
      numberToConvert += digitsArray [i];
    }
    
    //if the user input is smaller then the smallest possible value...
    //...change the input value to the smallest possible value and return it
    if (int(numberToConvert)<int(lowestValue)){
      this.replace_array(lowestValue);
      return int(lowestValue);
    }
    
    //if the user input is bigger then the highest possible value...
    //...change the input value to the highest possible value and return it
    else if (int(numberToConvert)>int(highestValue)){
      this.replace_array(highestValue);
      return int(highestValue);
    }
    
    return int(numberToConvert);
  }
}