Resep LocalLifecycleOwner

Resep ini menunjukkan cara menggunakan LifecycleResumeEffect dalam entri Navigation 3 untuk menjeda dan melanjutkan pekerjaan berdasarkan status siklus proses entri.

Cara kerjanya

Di Navigation 3, secara default setiap NavEntry memiliki LifecycleOwner-nya sendiri melalui LocalLifecycleOwner.current. Artinya, setiap komponen yang mendukung siklus proses di dalam entri akan otomatis di-scope ke NavEntry.

LifecycleResumeEffect dengan Adegan Dialog

  1. RouteA (Layar):

    • Menggunakan LifecycleResumeEffect(Unit) yang dicakup ke LocalLifecycleOwner.current NavEntry untuk memajukanLinearProgressIndicator saat dalam status RESUMED.
    • Secara otomatis mereset progressValue kembali ke 0f setiap kali mencapai 1f.
  2. RouteB (Dialog):

    • Dikonfigurasi sebagai dialog menggunakan DialogSceneStrategy.dialog().
    • Saat pengguna membuka dialog RouteB, RouteA tetap terlihat di belakang dialog dalam status STARTED (meninggalkan RESUMED).
    • LifecycleResumeEffect memanggil onPauseOrDispose, menjeda indikator progres.
    • Saat dialog ditutup, RouteA akan kembali ke RESUMED, dan LifecycleResumeEffect akan melanjutkan indikator progres secara otomatis.
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 * Copyright 2026 The Android Open Source Project
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 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
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 *
 *     http://www.apache.org/licenses/LICENSE-2.0
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package com.example.nav3recipes.lifecycleowner

import android.os.Bundle
import android.util.Log
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.animation.core.LinearEasing
import androidx.compose.animation.core.animateFloatAsState
import androidx.compose.animation.core.snap
import androidx.compose.animation.core.tween
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Spacer
import androidx.compose.foundation.layout.height
import androidx.compose.foundation.layout.padding
import androidx.compose.material3.AlertDialog
import androidx.compose.material3.Button
import androidx.compose.material3.LinearProgressIndicator
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.runtime.getValue
import androidx.compose.runtime.mutableFloatStateOf
import androidx.compose.runtime.remember
import androidx.compose.runtime.rememberCoroutineScope
import androidx.compose.runtime.setValue
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.unit.dp
import androidx.lifecycle.Lifecycle
import androidx.lifecycle.compose.LifecycleEventEffect
import androidx.lifecycle.compose.LifecycleResumeEffect
import androidx.lifecycle.compose.dropUnlessResumed
import androidx.navigation3.runtime.NavKey
import androidx.navigation3.runtime.entryProvider
import androidx.navigation3.runtime.rememberNavBackStack
import androidx.navigation3.scene.DialogSceneStrategy
import androidx.navigation3.ui.NavDisplay
import com.example.nav3recipes.content.ContentGreen
import com.example.nav3recipes.ui.setEdgeToEdgeConfig
import kotlinx.coroutines.delay
import kotlinx.coroutines.launch
import kotlinx.serialization.Serializable
import kotlin.time.Duration.Companion.milliseconds

@Serializable
private data object RouteA : NavKey

@Serializable
private data object RouteB : NavKey

class LifecycleOwnerActivity : ComponentActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        setEdgeToEdgeConfig()
        super.onCreate(savedInstanceState)
        setContent {
            val backStack = rememberNavBackStack(RouteA)
            val dialogStrategy = remember { DialogSceneStrategy<NavKey>() }

            NavDisplay(
                backStack = backStack,
                onBack = backStack::removeLastOrNull,
                sceneStrategies = listOf(dialogStrategy),
                entryProvider = entryProvider {
                    entry<RouteA> {
                        LogLifecycleEffect("ScreenA")
                        ContentGreen("Screen A") {
                            var progressValue by remember { mutableFloatStateOf(0f) }
                            val coroutineScope = rememberCoroutineScope()

                            val animatedProgress by animateFloatAsState(
                                targetValue = progressValue,
                                animationSpec = if (progressValue == 0f) snap() else tween(durationMillis = 100, easing = LinearEasing),
                                label = "ProgressAnimation"
                            )

                            // LifecycleResumeEffect runs only while ScreenA is in the RESUMED state.
                            // When the dialog opens, ScreenA transitions to PAUSED, which calls onPauseOrDispose.
                            LifecycleResumeEffect(Unit) {
                                val job = coroutineScope.launch {
                                    while (true) {
                                        delay(100.milliseconds)
                                        progressValue += 0.01f
                                        if (progressValue >= 1f) {
                                            progressValue = 0f
                                        }
                                    }
                                }
                                onPauseOrDispose {
                                    job.cancel()
                                }
                            }

                            Column(
                                horizontalAlignment = Alignment.CenterHorizontally,
                                modifier = Modifier.padding(16.dp)
                            ) {
                                LinearProgressIndicator(progress = { animatedProgress })
                                Spacer(modifier = Modifier.height(16.dp))
                                Button(onClick = dropUnlessResumed { backStack.add(RouteB) }) {
                                    Text("Open Dialog")
                                }
                            }
                        }
                    }
                    entry<RouteB>(metadata = DialogSceneStrategy.dialog()) {
                        LogLifecycleEffect("Dialog")
                        AlertDialog(
                            onDismissRequest = backStack::removeLastOrNull,
                            title = { Text("Dialog") },
                            text = {
                                Text("Screen A is no longer in resumed state, pausing the progress indicator.")
                            },
                            confirmButton = {
                                Button(onClick = dropUnlessResumed { backStack.removeLastOrNull() }) {
                                    Text("Dismiss Dialog")
                                }
                            }
                        )
                    }
                }
            )
        }
    }
}

@Composable
private fun LogLifecycleEffect(screenName: String) {
    LifecycleEventEffect(Lifecycle.Event.ON_CREATE) {
        Log.d("LifecycleOwner", "$screenName: ON_CREATE")
    }
    LifecycleEventEffect(Lifecycle.Event.ON_START) {
        Log.d("LifecycleOwner", "$screenName: ON_START")
    }
    LifecycleEventEffect(Lifecycle.Event.ON_RESUME) {
        Log.d("LifecycleOwner", "$screenName: ON_RESUME")
    }
    LifecycleEventEffect(Lifecycle.Event.ON_PAUSE) {
        Log.d("LifecycleOwner", "$screenName: ON_PAUSE")
    }
    LifecycleEventEffect(Lifecycle.Event.ON_STOP) {
        Log.d("LifecycleOwner", "$screenName: ON_STOP")
    }
    // Note that ON_DESTROY event is not observable from composables.
}