Setting a timeout on a keyPressed

Programming Questions

speltrong

Setting a timeout on a keyPressed

in Programming Questions • 1 year ago

I'm coding a game where I'd like there to be a limit on how long you can hold a key down. If you press it for any more than say 1 second, you lose a point and it goes back to the "off" state until you release the key and press it again. Any suggestions on how to do this? I'd really rather not use keyReleased(); because it would screw up the timing of the user input (it's a rhythm-based game).

I found this code by rbrauer that cleverly gets around the repeat rate issue, but I can't get my head around how I'd work a timer into it

boolean state, pstate;
void setup() {}
void draw() {
state = false;
state = keyPressed;
if(state != pstate) println(state); //only react if there's been a change
pstate = state; //flip it so the starting state is the current state
}

Thanks!

Replies(9)

tfguy44

Re: Setting a timeout on a keyPressed

1 year ago

boolean state, pstate;
int time = -1;
void setup(){
pstate = false;
}
void draw() {
state = keyPressed;
if( millis() > time && time != -1 ){
state = false;
println( "BAD HOLD!" );
}
if(state != pstate){
println(state); //only react if there's been a change
if( state ){
time = millis() + 1000;
} else {
time = -1;
}
}
pstate = state; // Update previous state for next loop.
}

speltrong

Re: Setting a timeout on a keyPressed

1 year ago

Thanks for the reply, TFGuy. I went down a similar path, but it flips back over to true if you keep holding the key. I think I need to put a third state in there called "limbo" or something that activates after a second and waits for a keyReleased() event to reset it so that keyPressed() stops triggering anything after a second. I'll have time later today to muck with it.

speltrong

Re: Setting a timeout on a keyPressed

1 year ago

I figured out a workaround by making a fake timer. I'd love to figure out how to incorporate a real one, because this way is going to vary depending on the refresh rate, but at least it does exactly what I want:

int fakeTimer;
int maxTime;
boolean hit;
void setup(){
fakeTimer = 0;
maxTime = 30;
hit = false;
}
void draw(){
//key events
if(keyPressed){
fakeTimer++;
} else {
fakeTimer = 0;
}
//boolean controls
if(fakeTimer >= maxTime){
hit = false;
} else if(fakeTimer > 0 && fakeTimer <= maxTime){
hit = true;
} else if(fakeTimer == 0){
hit = false;
}
println(hit);
}

PhiLho

Re: Setting a timeout on a keyPressed

1 year ago

Use millis() to be independent of frame rate.

speltrong

Re: Re: Setting a timeout on a keyPressed

1 year ago

I did already figure out how to make a millis() timer work, but what I'm still having trouble with is getting it to activate once and only once when you press a key. My line of thinking now is that I can still use the fake timer to increment the variable when a key is pressed and then start the timer only when that variable only equals 1 (but no more or less), then reset the fake timer on keyRelease (or !=keyPressed). I really wish there was just a "noRepeat" option for the keyPressed... that would make life so much easier!

Can you think of a more elegant solution?

Sergio Pa..

Re: Setting a timeout on a keyPressed

1 year ago

Try this:

int whenPressed;
void setup() {
whenPressed = 0;
}
void draw() { }
void keyPressed() {
if (whenPressed == 0) {
whenPressed = millis();
} else if (millis() - whenPressed <= 1000) {
println("pressing key: " + keyCode + " , millis: " + millis());
}
}
void keyReleased() {
whenPressed = 0;
}

speltrong

Re: Setting a timeout on a keyPressed

1 year ago

*Edit* - Never mind, that was me being stupid

. It looks like your code does do exactly what I asked for originally: holds the keypress for one second. Thanks so much - I'll implement that in my game and see how it works!

Thanks for the response, Sergio. Unfortunately, that still ends up registering several keypresses per action on my laptop at least (Win7 x64, Intel Centrino Duo). In order to make this game work, it really needs to register one and only one keypress per action. I think in order to guarantee that, the keypress really needs to increment a variable which would then only trigger when that variable==1. I'll give that a shot a bit later.

Sergio Pa..

Re: Setting a timeout on a keyPressed

1 year ago

In that case, I suggest you make the action on keyReleased() instead, as it will only trigger once per key press no matter how long the player keeps it pressed.

Edit: If you are using Linux, the keyReleased() will also send multiple results.

speltrong

Re: Re: Setting a timeout on a keyPressed

1 year ago

It's a timing-based game, so keyReleased() wouldn't work. You need to hit the key exactly when a target is over your reticle, so a keyReleased() action isn't intuitive here, unfortunately. It's kind of annoying that mousePressed() actually works the way I wish keyPressed() would - when you click the mouse and hold, it only activates an action once. There really ought to be a noRepeat option for keyPressed.

I managed to use a combination of your keyPressed() timer and a fake incrementing timer so that the click only registers once. Still a few more bugs in my code, but I think I can figure that out (or else I'll be back here when I get frustrated :)

Thanks for your help.

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