Some extension methods to use ActivityResult API in a callback way.

ActivityResultExtensions.kt

package com.kpstv.xclipper.extensions

import android.content.Intent
import androidx.activity.ComponentActivity
import androidx.activity.result.ActivityResult
import androidx.activity.result.ActivityResultLauncher
import androidx.activity.result.contract.ActivityResultContract
import androidx.activity.result.contract.ActivityResultContracts
import androidx.fragment.app.Fragment
import java.util.*

/**
 * Start an activity for result where the result will be called on the [onActivityResult] lambda.
 *
 * Instead of calling result on `onActivityResult(...)`, they will be invoked on [onActivityResult].
 */
fun ComponentActivity.startActivityWithResult(
    input: Intent,
    onActivityResult: (ActivityResult) -> Unit
) : Unit = launchContractWithResult(input, ActivityResultContracts.StartActivityForResult(), onActivityResult)

/**
 * Start an activity for result where the result will be called on the [onActivityResult] lambda.
 *
 * Instead of calling result on `onActivityResult(...)`, they will be invoked on [onActivityResult].
 */
fun Fragment.startActivityWithResult(
    input: Intent,
    onActivityResult: (ActivityResult) -> Unit
) : Unit = requireActivity().startActivityWithResult(input, onActivityResult)

/**
 * Execute [input] through a given [contract] where the result will be called on the [onResult] lambda.
 */
fun <I, O> ComponentActivity.launchContractWithResult(
    input: I,
    contract: ActivityResultContract<I, O>,
    onResult: (O) -> Unit
) {
    register
    val contractKey = "contract_${UUID.randomUUID()}"
    var launcher: ActivityResultLauncher<I?>? = null
    launcher = activityResultRegistry.register(contractKey, contract) { result ->
        launcher?.unregister()
        onResult(result)
    }
    launcher.launch(input)
}

/**
 * Execute [input] through a given [contract] where the result will be called on the [onResult] lambda.
 */
fun <I, O> Fragment.launchContractWithResult(
    input: I,
    contract: ActivityResultContract<I, O>,
    onResult: (O) -> Unit
) {
    requireActivity().launchContractWithResult(
        input = input,
        contract = contract,
        onResult = onResult
    )
}