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@ActivityScope
class SearchViewDelegate @Inject constructor(
  private val presenter: SearchTweetPresenter,
  @Named("CoroutineUIScope") private val scope: CoroutineScope
) {
  // ...
  fun getStateFlow(): StateFlow<TweetsUIState> = presenter.stateFlow
}

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@ActivityScope
public class SearchTweetPresenter {
  @Inject
  public SearchTweetPresenter(@NotNull SearchTweetUseCase tweetSearchUseCase) {
    this.tweetSearchUseCase = tweetSearchUseCase;
  }
  // ...
  @NotNull
  public StateFlow<TweetsUIState> getStateFlow() {
    return tweetSearchUseCase.getStateFlow();

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/**
 * Use case for State Flow defines a unit of execution
 */
interface UseCaseStateFlow<T> {
    fun execute(param: String)
    fun cancel()
    fun getStateFlow(): StateFlow<T>
}

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/**
 * Search tweets Use case implementation of [UseCaseStateFlow]
 */
@RetainedScope
class SearchTweetUseCase @Inject constructor(
   private val repository: TweetsRepository,
   @Named("CoroutineScopeTransfer") val coroutineScope: CoroutineScope
) : UseCaseStateFlow<TweetsUIState> {
        
   private val tweetsUIStateFlow = MutableStateFlow<TweetsUIState>(TweetsUIState.InitialIdleUIState)

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/**
 * Output UI States defined for StateFlow & Compose in the workflow
 */
sealed class TweetsUIState {
    data class ListResultsUIState(val tweets: List<Tweet>): TweetsUIState()
    data class ErrorUIState(val msg: String): TweetsUIState()
    data class EmptyUIState(val query: String): TweetsUIState()
    object InitialIdleUIState: TweetsUIState()
    object LoadingUIState: TweetsUIState()
}

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/*
 * Copyright (C) 2020 Raul Hernandez Lopez
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software

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/*
 * Copyright (C) 2020 Raul Hernandez Lopez
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software

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public class TweetsListUI extends ViewUI {
  @Inject
  SearchViewDelegate viewDelegate;

  @Inject
  StateFlowHandler stateFlowHandler;

  // ...
  @Override
  public void onDestroy() {

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@ActivityScope
class StateFlowHandler @Inject constructor(taskThreading: TaskThreading) {

  private val scope = CoroutineScope(taskThreading.ui() + SupervisorJob())
  private var tweetsListUI: TweetsListUI? = null

  // ...
  fun cancel() {
     scope.cancel()
     tweetsListUI = null

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fun TweetsListUI.handleStates(stateFlow: TweetsUIState?) {
  when (stateFlow) {
    is TweetsUIState.LoadingUIState -> {
      showLoading()
    }
    is TweetsUIState.ListResultsUIState -> {
      showResults(stateFlow)
    }
    is TweetsUIState.EmptyUIState -> {
      showEmptyState()