it’s possible without it, but that artifact does add a lot of “adapters” that would make your life a...

# compose

[Leland Richardson [G]]

it’s possible without it, but that artifact does add a lot of “adapters” that would make your life a lot easier

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

Cool, so I should just be able to “call” any View subclass from a composable function? Are there any requirements about which view constructors are required or anything? I’m trying to do this with a custom view and I’m only seeing the constructors I’ve defined, no versions with ref or anything.

So I’ve got a custom View that looks like this:

class WorkflowViewStub
@JvmOverloads constructor(
  context: Context,
  attributeSet: AttributeSet? = null,
  defStyle: Int = 0,
  defStyleRes: Int = 0
) : View(context, attributeSet, defStyle, defStyleRes) { … }

And I should just be able to do something like this?

@Composable fun myComponent() {
  WorkflowViewStub()
}

(https://github.com/square/workflow/pull/703/commits/6fc61720a281055ee410ad41566546a640481661#diff-f3d0030f5e5c4962c8c2e1b4d5300553R47-R54)

[Leland Richardson [G]]

Great question… A couple of things to understand here:

1. IDE support for these calls is really lacking. If it is intercepted successfully, it should not show up as red/unresolved, but you will also not (yet) be able to “command-click” to go to declaration of the call. That’s the “quick test” to figure out if it worked without doing a full compile.
2. Right now for views it targets constructors of the form (Context) -> T where T: View.
3. Properties (and getters/setters from java) will be resolvable as name = T in the argument list of the call. ALL parameters must be named in order for this to work. For example, TextView(text="hello world") works because of setText(String) and TextView(text=R.string.foo) works because of the setter overload.

[Leland Richardson [G]]

i actually haven’t checked to see if the @JvmOverloads constructor like you showed will get properly intercepted. if it’s not working, try splitting it out and creating one with just Context

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

Awesome, thanks for the tips!

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

I simplified the constructor to only take a Context, and it compiles but i’m getting a runtime crash: IllegalStateException: Could not convert WorkflowViewStub to an Emittable. ViewComposer seems to be trying to find an adapter for my view, but the adapters list is empty.

[Leland Richardson [G]]

in order to use views, you will want to start off compose using setViewContent instead of setContent

[Leland Richardson [G]]

at some point we will create ways to easily switch between the two. right now it is a bit of a pain

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

I’m using setViewContent on a FrameLayout.

[Leland Richardson [G]]

so the error above means that you’re trying to add a WorkFlowViewStub as a child to a ComponentNode

[Leland Richardson [G]]

are you trying to wrap this with other compose UI composables like `Row`/`Column?`

[Leland Richardson [G]]

because right now that won’t work

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

Ah, yes I am (a Container).

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

I’ll shelve this project for now. Thanks again for your help!

[Leland Richardson [G]]

np