Button hold delay + hold repeat rate

[asztalosdani]

I would like to set a different hold delay and a hold repeat rate for a Button, like when you hold a key on the keyboard on PC.
Currently it is not possible because the Button waits hold_time first, then fires every hold_time.

[lurch]

So I guess you're asking for e.g. a repeat_time parameter, which is different from hold_time? That'd probably need changes to HoldMixin and it might be tricky to make those changes in a backwards-compatible way.

As a "temporary hack" what happens if you directly modify the Button's .hold_time property from inside the .when_held callback? I guess you'd also need to "reset" the hold time in the .when_released callback too.

[asztalosdani]

So I guess you're asking for e.g. a repeat_time parameter, which is different from hold_time? That'd probably need changes to HoldMixin and it might be tricky to make those changes in a backwards-compatible way.

Yes. Ideally it could be represented with only two parameters, Button(pin, hold_delay, repeat_rate) where hold_delay is the time to wait until the button considers it held, and repeat_rate is the time between each hold event fires, with a default of 0 meaning it won't be repeated. This way, the hold_repeat bool can be removed. But yes, this breaks backward-compatibility.
In case this is not doable, adding a new hold_repeat_time parameter should do the trick.
If we can agree on the interface, I can whip up a PR.

As a "temporary hack" what happens if you directly modify the Button's .hold_time property from inside the .when_held callback? I guess you'd also need to "reset" the hold time in the .when_released callback too.

Thanks, it works, it will do for the time being.

from gpiozero import Button
from signal import pause

button = Button(16, pull_up=True, hold_repeat=True)


def when_pressed():
    print("pressed")


def when_held():
    print("held")
    button.hold_time = 0.1


def when_released():
    print("released")
    button.hold_time = 1


print("starting")

button.when_pressed = when_pressed
button.when_held = when_held
button.when_released = when_released

pause()

[lurch]

But yes, this breaks backward-compatibility. In case this is not doable, adding a new hold_repeat_time parameter should do the trick. If we can agree on the interface, I can whip up a PR.

I don't think we should break backwards-compatibility (especially for such a small tweak as this), as we don't want to suddenly break all of the existing user-code that's making use of GpioZero!

I've not given it much thought, but perhaps an "API" something like this works in a backwards-compatible manner?
(here I've just copied the Button's __init__ method as an example)

    def __init__(self, pin=None, *, pull_up=True, active_state=None,
                 bounce_time=None, hold_time=1, hold_repeat=False,
                 hold_repeat_time=None, pin_factory=None):
        if hold_repeat and hold_repeat_time is None:
            hold_repeat_time = hold_time
        # ...and now do everything else...

As a "temporary hack" what happens if you directly modify the Button's .hold_time property from inside the .when_held callback? I guess you'd also need to "reset" the hold time in the .when_released callback too.

Thanks, it works, it will do for the time being.

Awesome! I guess for consistency, since you're setting hold_time to 1 in when_released, you should probably explicitly pass hold_time=1 into the Button constructor too?