Use AndroidView

Required dependencies

This page is standalone. AndroidView is provided by viewcompose-host-android; no separate interop artifact is required:

build.gradle.kts

repositories { mavenCentral() }

dependencies {
    implementation("com.viewcompose:viewcompose-material3-android:0.1.0-alpha01")
    implementation("androidx.activity:activity:1.12.4")
    implementation("com.google.android.material:material:1.13.0")
}

Embed and update a TextView

Create AndroidViewTutorialActivity.kt:

package com.viewcompose.samples.tutorials

import android.os.Bundle
import android.widget.TextView
import androidx.activity.ComponentActivity
import com.viewcompose.host.android.AndroidView
import com.viewcompose.material3.android.setMaterial3UiContent
import com.viewcompose.runtime.mutableStateOf
import com.viewcompose.ui.modifier.Modifier
import com.viewcompose.ui.modifier.fillMaxSize
import com.viewcompose.ui.modifier.fillMaxWidth
import com.viewcompose.ui.modifier.padding
import com.viewcompose.ui.unit.dp
import com.viewcompose.ui.foundation.Button
import com.viewcompose.ui.foundation.Column
import com.viewcompose.ui.foundation.remember

class AndroidViewTutorialActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setMaterial3UiContent {
            val count = remember { mutableStateOf(0) }

            Column(
                spacing = 12.dp,
                modifier = Modifier.fillMaxSize().padding(24.dp),
            ) {
                AndroidView(
                    factory = { context -> TextView(context) },
                    update = { view ->
                        (view as TextView).text = "Native TextView count: ${count.value}"
                    },
                    modifier = Modifier.fillMaxWidth(),
                )
                Button("Increment", onClick = { count.value += 1 })
            }
        }
    }
}

factory creates the native View only when reconciliation needs a new node. update applies the latest observable state to a retained View and must be safe to run again during rollback or rebind. Keep external one-shot work out of update. This callback form is the concise low-level escape hatch.

Extract a reusable typed adapter

Use AndroidViewAdapter<V, S> when the integration is reused or owns lifecycle callbacks. The View type and complete state snapshot remain checked across every callback:

fun typedAndroidViewAdapterSample(builder: UiTreeBuilder) {
    builder.AndroidView(
        adapter = NativeLabelAdapter,
        state = "Typed native label",
        key = "label",
        constructionKey = "default-text-appearance",
        modifier = Modifier.nativeView(key = "enabled") { view ->
            view.isEnabled = true
        },
    )
}

private object NativeLabelAdapter : AndroidViewAdapter<TextView, String> {
    override val reusePolicy: AndroidViewReusePolicy = AndroidViewReusePolicy.Resettable

    override fun create(scope: AndroidViewCreateScope): TextView = TextView(scope.context)

    override fun update(scope: AndroidViewUpdateScope<TextView>, state: String) {
        scope.view.text = state
    }

    override fun onReset(
        scope: AndroidViewResetScope<TextView>,
        reason: AndroidViewResetReason,
    ) {
        scope.view.text = null
    }
}

key identifies the logical item. The adapter implementation class plus constructionKey identifies constructor-sensitive View state. A changed state reuses the View and calls only update; a changed construction identity creates and binds a candidate, then replaces the old View only if the complete transaction succeeds. onReset is reserved for integrations that opt into cross-key mounted-tree reuse with AndroidViewReusePolicy.Resettable.

Verify the result

Press Increment and confirm that the mounted native TextView changes. Compile with:

./gradlew :samples:tutorials:assembleDebug

See Hosts, lifecycle, and Android interop for ownership and cleanup rules.