How to count how long a key is pressed

Processing Beginners
1

I’ve been trying to make a program that counts how long you’ve pressed a key. Is this possible in Processing Java?

Here’s my code so far:

int frames;
void keyPressed() {
frames++;
}

void keyReleased() {
println(frames);
frames = 0;
}
2

You need an active sketch, not a static one which is as simple as adding a draw function

int frames;

void draw(){
}


void keyPressed() {
   frames++;
}

void keyReleased() {
   println(frames);
   frames = 0;
}
3

Hi

Welcome to our community you need kind of timer

4

Heres a quick example, used a boolean to only detect the key pressed once, that way you get the exact seconds its held down, millis is a reference to milliseconds, hence the division in the print statement

float millis;
boolean pressed;

void draw() {
}

void keyPressed() {
  if (pressed == false) {
    millis = millis();
    pressed = true;
  }
}

void keyReleased() {
  println((millis()-millis)/1000);
  pressed = false;
}
1 Like
5

And here is other example


int d = 0;

void setup() {
  size(640, 320);
}

void draw() {
}

void keyPressed() {
  if (key == 'j') {
    d = millis();
  }
}

void keyReleased() {
  if (key == 'j') {
    d = millis() - d/1000;
    println("j key pressed " + d + " milliseconds");
  }
}
6

Or this


int d = 0;

void setup() {
  size(640, 320);
}

void draw() {
}

void keyPressed() {

  d = millis();
}

void keyReleased() {
  d = millis() - d;
  println(" key pressed " + d + " milliseconds");
}
7

That way doesnt work, was my initial try aswell, keyPressed keeps overriding the variable d, thats why i used a boolean to only set d once

1 Like
8

Hi
I didn’t test mine because I am using my tablet

1 Like
9

Its alright, my initial thought was, keyPressed would only detect once per press aswell, turns out no, it detects once per frame which is odd, a boolean always comes in handy for things like that though

1 Like
10

Yes you are true Sir

11

Maybe you can do it that way …

int d = -1;
int dd = 0;

void setup() {
  size(640, 320);
}

void draw() {
  background(0);  
  if (keyPressed) {
    if (d==-1) {
      d = millis();
    }
    else {
      dd = millis() - d;
    }  
  }
  else {
    d=-1;
  }
  fill(255);    
  text(dd + "ms",width/2,height/2);
}

Cheers
— mnse

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