Is there a way to hide show a composable in the hierarchy wi

Question

Is there a way to hide show a composable in the hierarchy without making it recompose I m hiding showing an `AndroidView` with a `WebView` inside and every time it becomes visible again it will recompose and therefore reload the website Any ideas how to get around this

Colton Idle · Answer

You could maybe use alpha to make it invisible instead

Zach Klippenstein (he/him) [MOD] · Answer

A composable can be invoked recomposed any number of times if something relies on a specific number of recompositions something is wrong It sounds like there s either a bug in `AndroidView` or `WebView` here or you re triggering a reload in the composable directly instead of using an effect

julioromano · Answer

This is how the composable looks like more or less it is more complex than that though but the gist is that the `factory` param is stateless whilst the stuff that changes goes in the `update` lambda Am I doing it wrong ``` Composable fun MyWebView url String AndroidView factory = WebView it it loadUrl url ```

julioromano · Answer

I understand that if `url` changes it will recompose but in my case it s not changing

Zach Klippenstein (he/him) [MOD] · Answer

`loadUrl` that lambda you re calling `it loadUrl` from i believe is the update function It should effectively be idempotent and should typically only set state on your view `loadUrl` is from what you described a side effect It s not just setting some state it s actually triggering an action That s the problem Instead you should save the `WebView` instance somewhere e g a `MutableState` in your composable then use a `DisposableEffect` or something to trigger the load E g ``` Composable fun MyWebView url String var webView by remember mutableStateOf lt WebView gt null AndroidView context gt WebView context also webView = it DisposableEffect webView url webView loadUrl url onDispose webView cancelLoading ```

julioromano · Answer

gt `loadUrl` that lambda you re calling `it loadUrl` from i believe is the update function It should effectively be idempotent and should typically only set state on your view Yes `loadUrl ` is a method of the `WebView` class I thought that calling it was actually setting state on my view isn t the currently shown url an internal state of the WebView gt It s not just setting some state it s actually triggering an action That s the problem I think I m not getting it What is the triggered action I really thought it was setting state on the webview gt Instead you should save the WebView instance somewhere e g a MutableState in your composable then use a DisposableEffect or something to trigger the load Sounds like a plan I ll try that thanks a lot

Zach Klippenstein (he/him) [MOD] · Answer

The javadoc on `loadUrl` is pretty much useless Loads the given URL No duh But from the behavior you re describing it sounds like calling `loadUrl` triggers the web view to load the page from scratch every time even if it s the same URL as the view is currently showing That s why I m thinking it s actually a side effect and not an idempotent state setter

Zach Klippenstein (he/him) [MOD] · Answer

If `loadUrl` actually were idempotent and nooped if the same value was sent twice it should probably be called `setUrl` and then your code would be correct

julioromano · Answer

gt That s why I m thinking it s actually a side effect and not an idempotent state setter Very clear thanks for the explanation Now I got the nuance

julioromano · Answer

I ve tried your approach Zach though the WebView still reloads Thing is that `MyWebView` is conditionally called inside another composable it s a tabbed screen depending on the active tab the code will either call `MyWebView ` or another composable instead My compose mental model is not accurate enough but I have the feeling that when the other tab is active the `MyWebView` composable is removed from the composition therefore when switching tabs again it is ~re~composed from scratch and therefore it reloads the website

julioromano · Answer

What I meant to say is that not only `loadUrl` is called again but also the `factory` lambda is

julioromano · Answer

I managed to make it working by hoisting the `var webView by remember mutableStateOf lt WebView gt null ` up to the outer composable This way the webview keeps its state even the web page scroll position unfortunately when switching tabs there s still a visual artifact the webview flashes once it appears then briefly disappears and then reappears

Zach Klippenstein (he/him) [MOD] · Answer

gt I have the feeling that when the other tab is active the `MyWebView` composable is removed from the composition Ah yea that sounds right