how would you pause a `timer` type flow? it’s not ...

# coroutines

[ursus]

how would you pause a timer type flow? it’s not really idiomatic, is it? or maybe akin to backpressure, i.e. downstream telling upstream to stop?

[Richard Gomez]

What are you trying to accomplish? It seems like you'd be mixing coroutines and Java concurrency, which could be a bit awkward.

It might be easier to cancel the timer and create a new one instead.

[ursus]

Instagram stories ui .. the timer which auto-advances and can be paused via tap-n-hold

[Nick Allen]

Do you mean something like?:

timerEnabled.transformLatest { if (it) emitAll(timer) }

[ursus]

@Nick Allen can you do a bit more? I see youre only allowing timer if timerEnabled, but that would mean its filtering, not pausing right? i.e. 1 2 3 …. 10 11 12?

[Nick Allen]

It's not filtering, it's re-subscribing everytime it turns true. If timer is "hot" then it's basically a filter. If "cold", then it's more like 1,2 3 ... paused ... 1, 2, 3 (resubscribing restarts the flow)

Perhaps you want to subscribe once and not skip values but just wait for timer to become unpaused again?

timer.onEach { timerEnabled.first { it } }

Don't use instagram so I know nothing of what's implied by that. Does your timer emit an index? Should pausing not skip values? If you tap mid-interval do you need resuming the timer to wait for the remaining part of the interval?

[ursus]

@Nick Allen yes pause and resume, and yes Id ideally want a stream of floats 0..1

here is a video, watch the progress bar at the top

btw when it pauses its me holding the screen (google removed taps from screenrecording ughh), and resumes when I release

screen-20220329-230932.mp4