Issues with keyPressed in Processing

Question

I’m new to Processing and I’m having some issues. I’m working on a data visualization of word frequency in a text, shown through a bar graph.

For the example code I replaced my text with a sequence of 200 random numbers: the bar graph scrolls when pressing up and down on the keyboard while the other half of the screen is supposed to show one of the 200 numbers picked randomly every time the key R is pressed or a text saying “Hello there” when H is pressed.

With some help I was able to have my numbers properly shown on screen but I’m not sure how to make this work with two different keyPressed interactions that I need to juggle between: random number and text.

I’ve tried like this but I can’t seem to make this work for the text part:


String numbers[];
String randomnumber;
String h;

//PANNING VARIABLES
float yPan = 0;
boolean panUp = false;
boolean panDown = false;

void setup() {
  fullScreen();
  smooth(2);
  concordance = new IntDict();

  String numberString = "74,34,62,41,81,11,36,76,37,14,54,57,50,57,95,35,82,100,49,67,48,18,11,97,14,41,85,53,80,72,61,91,93,67,72,73,72,20,32,45,62,9,36,70,99,47,6,98,36,26,65,32,75,8,93,71,72,55,95,7,1,36,93,9,21,100,43,22,30,58,21,4,9,4,35,12,57,26,3,90,16,65,36,11,67,4,22,14,63,89,45,10,51,60,3,32,12,41,83,37,100,91,74,76,73,69,6,22,26,100,59,16,24,30,41,77,79,91,86,37,88,26,10,49,32,95,79,50,46,49,45,58,74,22,53,44,82,61,60,61,73,31,41,5,94,38,48,5,90,77,91,6,45,11,1,16,13,23,10,52,45,8,48,16,96,24,61,25,59,40,44,6,13,51,88,42,62,43,94,8,24,47,96,71,10,30,22,68,54,87,70,45,8,78,77,81,24,7,21,7";
  String[] numbers = splitTokens(numberString, ",");

  //FREQUENCY COUNT
  for (int i = 0; i < numbers.length; i++) {
    String s=(numbers[i].toLowerCase());
    concordance.increment(s);
  }
}


void draw() {
  background(0);

  concordance.sortValuesReverse();
  String[] keys = concordance.keyArray();
  for (int i = 0; i < keys.length; i++) {
    String num = keys[i];
    int frequency = concordance.get(num);

    //DRAW GRAPH
    fill(255);
    rect(35, (((i*13)+9)+(yPan)), (frequency*2.2), 6);

    fill(255);
    textAlign(RIGHT);
    textSize(13);
    text(frequency, 30, ((i*13)+16)+(yPan));

    fill(255);
    textAlign(LEFT);
    text(num, (frequency*2.2)+40, ((i*13)+16)+(yPan));
  }
  if (randomnumber!=null) {
    fill(0);
    rect(width/2, 0, width/2, height);

    fill(255);
    textAlign(TOP);
    textSize(60);
    text (randomnumber, width/2+10, 9, width/2, height);
  }

  if (h!=null) {
    fill(0);
    rect(width/2, 0, width/2, height);

    fill(255);
    textAlign(TOP);
    textSize(60);
    text (h, width/2+30, 9, width/2, height);
  }
}

void keyPressed() {

  //SCROLL GRAPH
  if (keyCode == UP) {
    if (panUp) {
      yPan +=35;
    }
    panUp = true;
    panDown = false;
  }

  if (keyCode == DOWN) {
    if (panDown) {
      yPan -=35;
    }
    panUp=false;
    panDown = true;

    //PICK AND SHOW A RANDOM NUMBER WHEN R IS PRESSED
  } else if (key == 'R' || key == 'r') { 
    String numberString = "74,34,62,41,81,11,36,76,37,14,54,57,50,57,95,35,82,100,49,67,48,18,11,97,14,41,85,53,80,72,61,91,93,67,72,73,72,20,32,45,62,9,36,70,99,47,6,98,36,26,65,32,75,8,93,71,72,55,95,7,1,36,93,9,21,100,43,22,30,58,21,4,9,4,35,12,57,26,3,90,16,65,36,11,67,4,22,14,63,89,45,10,51,60,3,32,12,41,83,37,100,91,74,76,73,69,6,22,26,100,59,16,24,30,41,77,79,91,86,37,88,26,10,49,32,95,79,50,46,49,45,58,74,22,53,44,82,61,60,61,73,31,41,5,94,38,48,5,90,77,91,6,45,11,1,16,13,23,10,52,45,8,48,16,96,24,61,25,59,40,44,6,13,51,88,42,62,43,94,8,24,47,96,71,10,30,22,68,54,87,70,45,8,78,77,81,24,7,21,7";
    String[] numbers = splitTokens(numberString, ",");

    int index = int(random(numbers.length));
    randomnumber = numbers[index];

  } else if (key == 'H' || key == 'h') { 
    String h = "hello there";
  }
}

user_3248412 · Answer

You were very close.

First of all:

  } else if (key == 'H' || key == 'h') { 
    // String h = "hello there"; -> delete this
    h = "hello there";
  }

Before, when you were pressing the "h" key, you were creating a new String object h, which then did not get used anywhere. Delete the String infront of h.

Next, when you first pressed R and then H, and then R again, the reason you still saw the text was because value of h was not null, and therefore it overwrote the result of R. To fix this, initialize to null the value that you want to draw over whenever you press a button:

  } else if (key == 'R' || key == 'r') { 
    //initialize h string to null
    if (h != null) {
      h = null;  
    }

    String numberString = "74,34...";
    String[] numbers = splitTokens(numberString, ",");

    int index = int(random(numbers.length));
    randomnumber = numbers[index];

  } else if (key == 'H' || key == 'h') { 
    //initialize random number to null
    if (randomnumber != null) {
      randomnumber = null;  
    }

    h = "hello there";
  }

Issues with keyPressed in Processing

1 Answers