What should I do if displaying a few items in a `LazyColumnItems` lags the screen for like 0.5 secon...

# compose

[Fudge]

What should I do if displaying a few items in a LazyColumnItems lags the screen for like 0.5 seconds when displayed? Is this perhaps because this is a preview, or do I have some way of profiling where the device spends its time?

[Timo Drick]

It should not lag in any way. Maybe you are displaying very big images?

[Fudge]

not images, just some text with some draggable modifiers

[Timo Drick]

I think we need more information to help you. Can you provide some code?

[Fudge]

there is quite a bit of stuff

[Fudge]

I'll try to solve a problem I have now where remember{} doesn't remember at all and then try to simplify it

[Fudge]

This is a very frustrating thing i've found about compose, because it doesn't use normal OOP semantics but instead hidden magics it's unclear when how or why something is saved in remember{} and the likes

[Timo Drick]

for me val variable by state { } works most of the time better

[Timo Drick]

And it will be deleted wenn the Composable is removed from the view

[Fudge]

Is there a way to keep the state even when the composable is removed from the view? so that the state remains when you navigate back and forth

[Timo Drick]

Yes just define the variable not inside of the view.

var state by mutableStateOf(initialState)

[Fudge]

I guess that's one way

[Fudge]

Isn't savedInstanceState supposed to work too? If it survives process death it should survive switching views too

[Timo Drick]

yes you are right. I did not used it yet because in the past it had many problems.

[Timo Drick]

But now it should work as expceted

[Fudge]

I tried savedInstanceState, seems like it doesn't work at all

[Fudge]

Doesn't survive process death or switching views

[Halil Ozercan]

remember is confusing because it feels like it's supposed to remember a variable but it actually remembers the result of a calculation. So if your composable gets recomposed because of a dependency change, remember will trigger again but won't invoke the callback function. So if you've made changes to the local variable that was initialized by remember, it will get re-set by initially remembered value