Is there any way to throat or debounce when user click on a

Question

Is there any way to throat or debounce when user click on a button in Android to avoid multi clicks I ve found something like this ```fun lt T gt debounce delayMillis Long = 300L scope CoroutineScope action T gt Unit T gt Unit var debounceJob Job = null return param T gt if debounceJob == null debounceJob = scope launch action param delay delayMillis debounceJob = null ``` Where I can do ```fun setDebounceListener view Button onClickListener View OnClickListener val clickWithDebounce view View gt Unit = debounce scope = MainScope onClickListener onClick it view setOnClickListener clickWithDebounce ``` Does it make sense to use debounce here It s just to avoid double click on a Button

louiscad · Answer

You can also disable the button on click and re enable it only at the right time

louiscad · Answer

See this function from Splitties View Coroutines <https github com LouisCAD Splitties blob 1936c6c7e445c048077d8b4b7bb1c13b99e0ca0a modules views coroutines src androidMain kotlin splitties views coroutines VisibilityAndClicks kt L35 L51|https github com LouisCAD Splitties blob 1936c6c7e445c048077d8b4b7bb1c13b99e0ca0 idMain kotlin splitties views coroutines VisibilityAndClicks kt> If you every need to turn it into a flow it s pretty easy as well you just need an infinite loop that calls `awaitOneClick ` in the `flow ` builder

Pablo · Answer

How do I cancel it

Pablo · Answer

I ve tried your code and it says no value passed for onCancellation

louiscad · Answer

It s a suspending function you cancel it like another one

Pablo · Answer

Then do I have to create a coroutineScope to launch it right

louiscad · Answer

Yep or use the `xxxLatest` operators if called from a flow operator

Pablo · Answer

But I mean I have this continuation resume Unit and it s complaining because I have to set a new parameter for onCancellation

Pablo · Answer

How would be the debouncing with flow Because AFAIK there s a debounce method in flow right

louiscad · Answer

You d not debounce you d simply not call `awaitOneClick ` again until your app wants to allow clicks again

louiscad · Answer

Look at the imports in that file that ll help you fix the complaint of the file

louiscad · Answer

Example usage ```suspend handleStuff while true btn awaitOneClick doStuff ```

louiscad · Answer

No need for magic timers raised hands skin tone 3

Pablo · Answer

sorry I copied the wrong thing

louiscad · Answer

Given `doStuff ` is a suspending function

Pablo · Answer

```fun View clicks Flow lt Unit gt = callbackFlow setOnClickListener offer Unit awaitClose setOnClickListener null ```

louiscad · Answer

Then delete the message wink

Pablo · Answer

```button clicks debounce 1000 onEach println clicked launchIn GlobalScope ```

louiscad · Answer

The correct way to transform it to a `Flow` is the following ```fun View clicks Flow lt Unit gt = flow while true awaitOneClick emit Unit ```

louiscad · Answer

It handles backpressure so the view will stay disabled while `emit` is suspending which is when the lambda of `collect` is executing

Pablo · Answer

Ah but this is mixing your solution with flow right

Pablo · Answer

What s the difference between the code I put and using your solution

louiscad · Answer

Mine disables the view e g button when the app is busy and not ready to accept new requests from the user

Pablo · Answer

ah okok

louiscad · Answer

It all boils down to the implementation of `awaitOneClick `

Pablo · Answer

Let me try then

Pablo · Answer

And the way to call this function from the view

louiscad · Answer

You don t call it from the View istelf You call it from the code that controls the View s

louiscad · Answer

Can be a custom class or even a suspending function that can be top level

Pablo · Answer

The thing is that I have problems from a RecyclerView adapter View Holder

Pablo · Answer

So I d need to control the onClickListener there

louiscad · Answer

Linking earlier conversation <https kotlinlang slack com archives C1CFAFJSK p1620831596391700 thread ts=1620827701 380100 amp cid=C1CFAFJSK>

Pablo · Answer

Ah ok

Pablo · Answer

Uh guess it s overkill for an easy think I want

Pablo · Answer

Do all this stuff just to avoid double clicks on a button

louiscad · Answer

I don t think it s that overkill personally but I might be biased wink

Pablo · Answer

It s bad praxis if I pass the CoroutineScope to adapter and then launch button onSingleClick

louiscad · Answer

bad practice I don t think so you just need to make sure the scope is from the view lifecycle or a sub scope

louiscad · Answer

I m not convinced by the naming of your onSingleClick function though it looks like a callback

Pablo · Answer

yeye sorry bad naming

Pablo · Answer

So the issue now is in continuation resume Unit

Pablo · Answer

is waiting for a cancellation callback but you do not have that why

louiscad · Answer

I already told you to look at the imports in my original snippet

louiscad · Answer

You re missing one import

louiscad · Answer

There s an extension function Did you find it

Pablo · Answer

import kotlin coroutines resume

Pablo · Answer

So I have to pass as a parameter a lambda to do my Unit thing when onClickListener right

Pablo · Answer

imagine I had button setOnClickListener itemClicked invoke position

Pablo · Answer

I did it like ```scope launch singleClick onEach itemClicked invoke position launchIn this ```

Pablo · Answer

it s redundant I guess I m already launching it from scope so no need to add launchIn right confused

louiscad · Answer

You likely want to use `collect` instead yup Also having a flow that actually gives only one value ever is weird name wise and use wise just using `awaitOneClick ` would make more sense here

Pablo · Answer

true

Pablo · Answer

If I use awaitOneClick can I pass a lambda then Like I wrote before

Pablo · Answer

Also what I ve found is From recyclerView click gt it goes to detail can not do multi click but when going back to the list I can not click anymore and also I m doing this to do the click and not sure if it s ok scope launch awaitOneClick onItemClicked invoke

louiscad · Answer

That s why I was using a loop in my example

Pablo · Answer

This you mean ```fun View clicks Flow lt Unit gt = flow while true awaitOneClick emit Unit ```

Pablo · Answer

But then I got your point to not use flow for 1 emit and 1 collect

louiscad · Answer

Or this <https kotlinlang slack com archives C1CFAFJSK p1621410257030300 thread ts=1621352294 011700 amp cid=C1CFAFJSK>

Pablo · Answer

And I want to use just the awaitOneClick with a lambda it s an unit

Pablo · Answer

I don t get why I have to do a while true there confused

louiscad · Answer

Because the function handles only one click ever

louiscad · Answer

So you need to call it again

louiscad · Answer

But if that doesn t suit your use case don t use it shrug skin tone 3

Pablo · Answer

Well I just wanted to try to avoid double click on a button passing a lambda or something do the action just once and that s it then if I tap the button again work the same but I see that in your example don t check this timing stuff so that s why it s not working

Pablo · Answer

the problem is that my button can do a multiple click on a item and it starts 2 activities at least the same one

Pablo · Answer

So I wanted to avoid that and since I m starting with coroutines flow was looking for a cool solution of doing this

louiscad · Answer

If you are starting an activity you probably want to call `delay timeMillis = 700 ` or alike after doing it before calling `awaitOneClick ` again

Pablo · Answer

Sure but I wanted to encapsulate this everything to an extensionFunction so I don t have to do the while true delay etc on every button

louiscad · Answer

You can if you want

Pablo · Answer

Neither create a SuspendButton View and change all the buttons at least from now

Pablo · Answer

Creating an extension function of coroutineScope

Pablo · Answer

Or in the same extensionFunction awaitOneClick

louiscad · Answer

Probably more an extension on `View` that takes a `CoroutineScope`

Pablo · Answer

And then the while true and everything inside the suspendcancelable

louiscad · Answer

No

louiscad · Answer

That extension would use `awaitOneClick ` `suspendCancellable` is an implementation detail of `awaitOneClick`

Pablo · Answer

From now I have this ```suspend fun View awaitOneClick disableAfterClick Boolean = true hideAfterClick Boolean = false onClick View gt Unit = try if disableAfterClick isEnabled = true if hideAfterClick isVisible = true suspendCancellableCoroutine lt Unit gt continuation gt setOnClickListener onClick invoke it continuation resume Unit finally setOnClickListener null if disableAfterClick isEnabled = false if hideAfterClick isVisible = false ```

louiscad · Answer

Yes I know that code I wrote it stuck out tongue

Pablo · Answer

I ve pased the lambda so I can call this function as ```awaitOneClick do something ```

louiscad · Answer

You can leave it like that and use it intor your own function that takes whatever lambda you want

louiscad · Answer

And please with a different name I trademarked `awaitOneClick ` kidding about the TM but you can find a clearer name to the function that d use `awaitOneClick `

Pablo · Answer

And now if I pass coroutineScope via parameter then I don t know where to but what I was doing in the ViewHolder ```scope launch while true delay 700 awaitOnClick onClick invoke position ```

louiscad · Answer

You see the code you want to pass in the non existing lambda of `awaitOneClick ` Just put if after calling `awaitOneClick `

louiscad · Answer

Also the `delay` should be after that code not before

louiscad · Answer

Otherwise you re just slowing your app down and annoying all your users

louiscad · Answer

I spent too much time on this now I hope I was helpful slightly smiling face

Pablo · Answer

So to add it in the extensionFunction shall I create a new one And then use yours it s unclear where to put this while true How would be the pseudo Not the real code

Pablo · Answer

gt You see the code you want to pass in the non existing lambda of `awaitOneClick ` I add it in your code when I said I have this from now

Pablo · Answer

louiscad · Answer

Oh sorry you should not edit that and use the one I linked

louiscad · Answer

I didn t notice that onClick extra parameter

louiscad · Answer

What you want to do boils down to extracting that <https github com LouisCAD Splitties blob 1936c6c7e445c048077d8b4b7bb1c13b99e0ca0a samples android app src androidMain kotlin com example splitties main MainActivity kt L83 L87|https github com LouisCAD Splitties blob 1936c6c7e445c048077d8b4b7bb1c13b99e0ca0 c androidMain kotlin com example splitties main MainActivity kt>

louiscad · Answer

into an extension function

louiscad · Answer

`launchLoop` is `launch` on a scope + `while isActive `

Pablo · Answer

Cool I think I got it ignoring the naming this should be like a good option ```fun View handleSingleClick scope CoroutineScope block gt Unit scope launch while true awaitOneClick block delay 700 ```

louiscad · Answer

Ignoring the naming yes

Pablo · Answer

any difference my while true with your launchLoop extension Mine could cause leaks

louiscad · Answer

They are the same but if you want to be sure there s zero leaks you need the right scope AND to use suspend bind that I linked before from another conversation

louiscad · Answer

That s why I was suggesting to use that for RecyclerView from the beginning slightly smiling face