Lifecycle Effect Once API (#425)

Author: DevSrSouza

samples/android/src/main/java/cafe/adriel/voyager/sample/basicNavigation/BasicNavigationScreen.kt

@@ -18,6 +18,7 @@ import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.unit.dp
 import cafe.adriel.voyager.core.lifecycle.LifecycleEffect
+import cafe.adriel.voyager.core.lifecycle.LifecycleEffectOnce
 import cafe.adriel.voyager.core.screen.Screen
 import cafe.adriel.voyager.core.screen.uniqueScreenKey
 import cafe.adriel.voyager.navigator.LocalNavigator
@@ -36,6 +37,9 @@ data class BasicNavigationScreen(
             onStarted = { Log.d("Navigator", "Start screen #$index") },
             onDisposed = { Log.d("Navigator", "Dispose screen #$index") }
         )
+        LifecycleEffectOnce {
+            Log.d("Navigator", "On screen first appear #$index")
+        }
 
         val navigator = LocalNavigator.currentOrThrow
 

voyager-core/src/commonMain/kotlin/cafe/adriel/voyager/core/lifecycle/LifecycleEffectStore.kt

@@ -0,0 +1,22 @@
+package cafe.adriel.voyager.core.lifecycle
+
+import cafe.adriel.voyager.core.concurrent.ThreadSafeMap
+import cafe.adriel.voyager.core.concurrent.ThreadSafeSet
+import cafe.adriel.voyager.core.screen.Screen
+import cafe.adriel.voyager.core.screen.ScreenKey
+
+internal object LifecycleEffectStore : ScreenDisposable {
+    private val executedLifecycles = ThreadSafeMap<ScreenKey, ThreadSafeSet<String>>()
+
+    fun store(screen: Screen, effectKey: String) {
+        val set = executedLifecycles.getOrPut(screen.key) { ThreadSafeSet() }
+        set.add(effectKey)
+    }
+
+    fun hasExecuted(screen: Screen, effectKey: String): Boolean =
+        executedLifecycles.get(screen.key)?.contains(effectKey) == true
+
+    override fun onDispose(screen: Screen) {
+        executedLifecycles.remove(screen.key)
+    }
+}

voyager-core/src/commonMain/kotlin/cafe/adriel/voyager/core/lifecycle/ScreenLifecycle.kt

@@ -2,9 +2,16 @@ package cafe.adriel.voyager.core.lifecycle
 
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.DisposableEffect
+import androidx.compose.runtime.LaunchedEffect
 import androidx.compose.runtime.remember
+import androidx.compose.runtime.saveable.rememberSaveable
+import cafe.adriel.voyager.core.annotation.ExperimentalVoyagerApi
 import cafe.adriel.voyager.core.screen.Screen
+import cafe.adriel.voyager.core.screen.randomUuid
 
+@Deprecated(
+    message = "This API is a wrap on top on DisposableEffect, will be removed in 1.1.0, replace with DisposableEffect"
+)
 @Composable
 public fun Screen.LifecycleEffect(
     onStarted: () -> Unit = {},
@@ -16,6 +23,23 @@ public fun Screen.LifecycleEffect(
     }
 }
 
+@ExperimentalVoyagerApi
+@Composable
+public fun Screen.LifecycleEffectOnce(onFirstAppear: () -> Unit) {
+    val uniqueCompositionKey = rememberSaveable { randomUuid() }
+
+    val lifecycleEffectStore = remember {
+        ScreenLifecycleStore.get(this) { LifecycleEffectStore }
+    }
+
+    LaunchedEffect(Unit) {
+        if (lifecycleEffectStore.hasExecuted(this@LifecycleEffectOnce, uniqueCompositionKey).not()) {
+            lifecycleEffectStore.store(this@LifecycleEffectOnce, uniqueCompositionKey)
+            onFirstAppear()
+        }
+    }
+}
+
 @Composable
 public fun rememberScreenLifecycleOwner(
     screen: Screen