Calling a compose UI function (displaying snackbar) from a normal activity that is not extending ComposeActivity

Question

I am trying to launch a compose function that I have in an Object class and trying to call in Normal activity rather than compose activity
I am actually trying to build a VDS (UI library) in compose but I am trying to use it in normal activity. Things like popping SnackBar etc.

MainActivity1.kt

class MainActivity1 : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main1)

        TestingCall()
    }
}

TestingObject.kt

object TestingObject {
    @Composable
    public fun TestingCall() {
       // Some UI that pops up 
    }
}

Error::

@Composable invocations can only happen from the context of a @Composable function

You can Only call `Composable` from a another `Composable` function thats what the error says. you should call it like `setContent { TestingCall() }` if u want to use Compose . — ADM, Mar 08 '22 at 05:01
@ADM ... I posted above sample to simplify .... I am actually trying to build a VDS (UI library) in copose but ... I am trying to use it in normal activity .... Things like popping snackbar etc .... — Devrath, Mar 08 '22 at 05:06
In order to do that you have to have a Composable scope to call your Compose method. I don't think Directly calling method will work . Check https://developer.android.com/jetpack/compose/interop/interop-apis it might help . And Edit your question with little bit with what u are trying to achieve with this . i will try to Reopen it . — ADM, Mar 08 '22 at 05:11
@ADM ... I have edited question title and body for clarity .... please check if it can be reopened — Devrath, Mar 08 '22 at 05:22

score 0 · Answer 1 · answered Dec 15 '22 at 12:14

To call a composable function inside an activity, you have to call setContent first inside your onCreate:

class MainActivity1 : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        //setContentView(R.layout.activity_main1) //

        setContent {
            TestingCall()
        }
    }
}

Since you're using Jetpack Compose for the UI, there is no need to assign a layout. So you can remove the setContentView(R.layout.activity_main1).

Hey Devrath. Have you checked my solution above? – Alex Mamo Dec 30 '22 at 08:02 — Alex Mamo, Dec 30 '22 at 08:02

Calling a compose UI function (displaying snackbar) from a normal activity that is not extending ComposeActivity

1 Answers1