Key Just Pressed?

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Deobfuscate

November 02, 2023 16:32

I don't want to reveal what I'm working on, so here is a basic example to understand my problem.

In this example, I have a simple counter that goes up when you press a key.

var counter = 0;

function setup() {
    textSize(40);
}

keyPressed = function() {
    counter += 1;
    background(255,255,255);
    fill(255, 0, 0);
    text(counter, 0, 50);
};

When you paste this code in a Khan Academy project, the counter will go up at the same speed as holding down a letter. It's tied to the users OS key delay rate.

When you paste this code in the official ProcessingJS editor, it will only press once, and you have to RELEASE and PRESS the key AGAIN to make the counter go up.

I want to achieve what the ProcessingJS editor does: call the action as soon as the key has just been pressed, and don't call it repeatedly.

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2 comments

HM Wogglebug TE

November 02, 2023 22:46

Edited
1

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Hi, Deobfuscate!

Sadly, Khan Academy's version of Processing is outdated. If you want to only detect when a key is pressed (but not held), then you could create an extra variable to remember presses. Here's an example:
```
// Remembers when a key is held
var pressing = false;

var count = 0;

// A key is pressed; update the variable after
// counting once.
keyPressed = function () {
  if (!pressing) {
    count ++;
  }
  
  pressing = true;
};

// Forget the last key press when a key is released
keyReleased = function () {
  pressing = false;
};
```
I hope this answers your question

- The Wogglebug
Deobfuscate

November 06, 2023 22:08
1

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Thank you, Wogglebug! This really does help with my solution! I was able to tweak this code to fit perfectly with my project, and it would have been unusable without this. If anybody else is looking for a solution as well, I will try to follow up with my own example.

Thanks again, Wogglebug.

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