commonMain.com.eygraber.vice.sources.DerivedStateSource.kt Maven / Gradle / Ivy

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package com.eygraber.vice.sources

import androidx.compose.runtime.Composable
import androidx.compose.runtime.ReadOnlyComposable
import androidx.compose.runtime.State
import androidx.compose.runtime.derivedStateOf
import androidx.compose.runtime.snapshotFlow
import com.eygraber.vice.ViceSource
import kotlinx.coroutines.flow.Flow

public abstract class DerivedStateSource : ViceSource, State {
  protected abstract fun deriveState(): T

  private val state by lazy {
    derivedStateOf(::deriveState)
  }

  public val updates: Flow get() = snapshotFlow { state.value }

  override val value: T get() = state.value

  @Composable
  @ReadOnlyComposable
  final override fun currentState(): T = state.value
}