#2119 re-re-write of History activity

core/src/main/java/org/kiwix/kiwixmobile/core/data/Repository.kt

@@ -67,10 +67,9 @@ class Repository @Inject internal constructor(
   override fun booksOnDiskAsListItems(): Flowable<List<BooksOnDiskListItem>> = bookDao.books()
     .map { it.sortedBy { bookOnDisk -> bookOnDisk.book.language + bookOnDisk.book.title } }
     .map {
-      HeaderizableList(it as List<BooksOnDiskListItem>).foldOverAddingHeaders(
-        { bookOnDisk -> LanguageItem((bookOnDisk as BookOnDisk).locale) },
-        { current, next ->
-          (current as BookOnDisk).locale.displayName != (next as BookOnDisk).locale.displayName })
+      HeaderizableList<BooksOnDiskListItem, BookOnDisk, LanguageItem>(it).foldOverAddingHeaders(
+        { bookOnDisk -> LanguageItem(bookOnDisk.locale) },
+        { current, next -> current.locale.displayName != next.locale.displayName })
     }
     .map { it.toList() }
 
@@ -93,11 +92,12 @@ class Repository @Inject internal constructor(
         zimReaderContainer.zimCanonicalPath
       )
     ).map {
-        HeaderizableList(it as List<HistoryListItem>).foldOverAddingHeaders(
-          { historyItem -> DateItem((historyItem as HistoryItem).dateString) },
-          { current, next ->
-            (current as HistoryItem).dateString != (next as HistoryItem).dateString })
-      }
+      HeaderizableList<HistoryListItem, HistoryItem, DateItem>(it).foldOverAddingHeaders(
+        { historyItem -> DateItem(historyItem.dateString) },
+        { current, next ->
+          current.dateString != next.dateString
+        })
+    }
       .subscribeOn(io)
       .observeOn(mainThread)
 

core/src/main/java/org/kiwix/kiwixmobile/core/extensions/HeaderizableList.kt

@@ -1,6 +1,6 @@
 package org.kiwix.kiwixmobile.core.extensions
 
-inline class HeaderizableList<SUPERTYPE, ITEM : SUPERTYPE, HEADER : SUPERTYPE>(
+inline class HeaderizableList<SUPERTYPE, out ITEM : SUPERTYPE, in HEADER : SUPERTYPE>(
   val list: List<ITEM>
 ) {
   fun foldOverAddingHeaders(
@@ -13,7 +13,7 @@ inline class HeaderizableList<SUPERTYPE, ITEM : SUPERTYPE, HEADER : SUPERTYPE>(
       }
       acc.add(currentItem)
       if (index < list.size - 1) {
-        val nextItem = list.get(index + 1)
+        val nextItem = list[index + 1]
         if (criteriaToAddHeader.invoke(currentItem, nextItem)) {
           acc.add(headerConstructor.invoke(nextItem))
         }

core/src/main/java/org/kiwix/kiwixmobile/core/history/HistoryActivity.kt

@@ -18,7 +18,6 @@ import kotlinx.android.synthetic.main.activity_history.no_history
 import kotlinx.android.synthetic.main.activity_history.recycler_view
 import kotlinx.android.synthetic.main.layout_toolbar.toolbar
 import org.kiwix.kiwixmobile.core.R
-import org.kiwix.kiwixmobile.core.R.id
 import org.kiwix.kiwixmobile.core.R.string
 import org.kiwix.kiwixmobile.core.base.BaseActivity
 import org.kiwix.kiwixmobile.core.di.components.CoreComponent
@@ -33,12 +32,11 @@ import org.kiwix.kiwixmobile.core.history.viewmodel.Action
 import org.kiwix.kiwixmobile.core.history.viewmodel.Action.ExitHistory
 import org.kiwix.kiwixmobile.core.history.viewmodel.Action.Filter
 import org.kiwix.kiwixmobile.core.history.viewmodel.Action.OnItemLongClick
-import org.kiwix.kiwixmobile.core.history.viewmodel.Action.RequestDeleteAllHistoryItems
-import org.kiwix.kiwixmobile.core.history.viewmodel.Action.RequestDeleteSelectedHistoryItems
 import org.kiwix.kiwixmobile.core.history.viewmodel.Action.ToggleShowHistoryFromAllBooks
+import org.kiwix.kiwixmobile.core.history.viewmodel.Action.UserClickedDeleteButton
+import org.kiwix.kiwixmobile.core.history.viewmodel.Action.UserClickedDeleteSelectedHistoryItems
 import org.kiwix.kiwixmobile.core.history.viewmodel.HistoryViewModel
 import org.kiwix.kiwixmobile.core.history.viewmodel.State
-import org.kiwix.kiwixmobile.core.history.viewmodel.State.NoResults
 import org.kiwix.kiwixmobile.core.history.viewmodel.State.Results
 import org.kiwix.kiwixmobile.core.history.viewmodel.State.SelectionResults
 import org.kiwix.kiwixmobile.core.utils.SimpleTextListener
@@ -60,13 +58,11 @@ class HistoryActivity : OnItemClickListener, BaseActivity() {
         return true
       }
 
-      override fun onPrepareActionMode(mode: ActionMode, menu: Menu): Boolean {
-        return false
-      }
+      override fun onPrepareActionMode(mode: ActionMode, menu: Menu): Boolean = false
 
       override fun onActionItemClicked(mode: ActionMode, item: MenuItem): Boolean {
         if (item.itemId == R.id.menu_context_delete) {
-          historyViewModel.actions.offer(RequestDeleteSelectedHistoryItems)
+          historyViewModel.actions.offer(UserClickedDeleteSelectedHistoryItems)
           return true
         }
         historyViewModel.actions.offer(Action.ExitActionModeMenu)
@@ -101,7 +97,7 @@ class HistoryActivity : OnItemClickListener, BaseActivity() {
     history_switch.setOnCheckedChangeListener { _, isChecked ->
       historyViewModel.actions.offer(ToggleShowHistoryFromAllBooks(isChecked))
     }
-    history_switch.isChecked = !sharedPreferenceUtil.showHistoryCurrentBook
+    history_switch.isChecked = !sharedPreferenceUtil.showHistoryAllBooks
 
     compositeDisposable.add(historyViewModel.effects.subscribe { it.invokeWith(this) })
   }
@@ -127,7 +123,7 @@ class HistoryActivity : OnItemClickListener, BaseActivity() {
       historyViewModel.actions.offer(ExitHistory)
     }
     if (item.itemId == R.id.menu_history_clear) {
-      historyViewModel.actions.offer(RequestDeleteAllHistoryItems)
+      historyViewModel.actions.offer(UserClickedDeleteButton)
     }
     return super.onOptionsItemSelected(item)
   }
@@ -136,23 +132,18 @@ class HistoryActivity : OnItemClickListener, BaseActivity() {
     when (state) {
       is Results -> {
         actionMode?.finish()
-        state.historyItems?.let { historyAdapter.items = it }
+        state.historyListItems.let { historyAdapter.items = it }
         history_switch.isEnabled = true
         no_history.visibility = View.GONE
       }
       is SelectionResults -> {
-        if (state.historyItems?.filterIsInstance<HistoryItem>()?.any { it.isSelected } == true &&
-          actionMode == null) {
+        if (state.historyItems.any(HistoryItem::isSelected) && actionMode == null) {
           actionMode = startSupportActionMode(actionModeCallback)
         }
-        state.historyItems?.let { historyAdapter.items = it }
+        state.historyListItems.let { historyAdapter.items = it }
         history_switch.isEnabled = false
         no_history.visibility = View.GONE
       }
-      is NoResults -> {
-        state.historyItems?.let { historyAdapter.items = it }
-        no_history.visibility = View.VISIBLE
-      }
     }
 
   override fun onItemClick(favicon: ImageView, history: HistoryItem) {

core/src/main/java/org/kiwix/kiwixmobile/core/history/viewmodel/Action.kt

@@ -18,18 +18,19 @@
 
 package org.kiwix.kiwixmobile.core.history.viewmodel
 
-import org.kiwix.kiwixmobile.core.history.adapter.HistoryListItem
 import org.kiwix.kiwixmobile.core.history.adapter.HistoryListItem.HistoryItem
 
 sealed class Action {
   object ExitHistory : Action()
   object ExitActionModeMenu : Action()
-  object DeleteHistoryItems : Action()
-  object RequestDeleteAllHistoryItems : Action()
-  object RequestDeleteSelectedHistoryItems : Action()
+  object UserClickedDelete : Action()
+  object UserClickedDeleteButton : Action()
+  object UserClickedDeleteSelectedHistoryItems : Action()
 
-  data class OnItemClick(val historyListItem: HistoryListItem) : Action()
+  data class OnItemClick(val historyItem: HistoryItem) : Action()
   data class OnItemLongClick(val historyItem: HistoryItem) : Action()
   data class ToggleShowHistoryFromAllBooks(val isChecked: Boolean) : Action()
+  data class AllHistoryPreferenceChanged(val showAll: Boolean) : Action()
   data class Filter(val searchTerm: String) : Action()
+  data class UpdateHistory(val history: List<HistoryItem>) : Action()
 }

core/src/main/java/org/kiwix/kiwixmobile/core/history/viewmodel/HistoryViewModel.kt

@@ -1,41 +1,31 @@
 package org.kiwix.kiwixmobile.core.history.viewmodel
 
-import DeleteSelectedOrAllHistoryItems
 import OpenHistoryItem
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
-import io.reactivex.Flowable
 import io.reactivex.disposables.CompositeDisposable
-import io.reactivex.functions.Function3
-import io.reactivex.processors.BehaviorProcessor
 import io.reactivex.processors.PublishProcessor
 import org.kiwix.kiwixmobile.core.base.SideEffect
 import org.kiwix.kiwixmobile.core.dao.HistoryDao
-import org.kiwix.kiwixmobile.core.extensions.HeaderizableList
-import org.kiwix.kiwixmobile.core.history.adapter.HistoryListItem
-import org.kiwix.kiwixmobile.core.history.adapter.HistoryListItem.DateItem
-import org.kiwix.kiwixmobile.core.history.adapter.HistoryListItem.HistoryItem
-import org.kiwix.kiwixmobile.core.history.viewmodel.Action.DeleteHistoryItems
+import org.kiwix.kiwixmobile.core.history.viewmodel.Action.AllHistoryPreferenceChanged
 import org.kiwix.kiwixmobile.core.history.viewmodel.Action.ExitActionModeMenu
 import org.kiwix.kiwixmobile.core.history.viewmodel.Action.ExitHistory
 import org.kiwix.kiwixmobile.core.history.viewmodel.Action.Filter
 import org.kiwix.kiwixmobile.core.history.viewmodel.Action.OnItemClick
 import org.kiwix.kiwixmobile.core.history.viewmodel.Action.OnItemLongClick
-import org.kiwix.kiwixmobile.core.history.viewmodel.Action.RequestDeleteAllHistoryItems
-import org.kiwix.kiwixmobile.core.history.viewmodel.Action.RequestDeleteSelectedHistoryItems
 import org.kiwix.kiwixmobile.core.history.viewmodel.Action.ToggleShowHistoryFromAllBooks
-import org.kiwix.kiwixmobile.core.history.viewmodel.State.NoResults
+import org.kiwix.kiwixmobile.core.history.viewmodel.Action.UpdateHistory
+import org.kiwix.kiwixmobile.core.history.viewmodel.Action.UserClickedDelete
+import org.kiwix.kiwixmobile.core.history.viewmodel.Action.UserClickedDeleteButton
+import org.kiwix.kiwixmobile.core.history.viewmodel.Action.UserClickedDeleteSelectedHistoryItems
 import org.kiwix.kiwixmobile.core.history.viewmodel.State.Results
 import org.kiwix.kiwixmobile.core.history.viewmodel.State.SelectionResults
+import org.kiwix.kiwixmobile.core.history.viewmodel.effects.DeleteHistoryItems
 import org.kiwix.kiwixmobile.core.history.viewmodel.effects.ShowDeleteHistoryDialog
-import org.kiwix.kiwixmobile.core.history.viewmodel.effects.ToggleShowAllHistorySwitchAndSaveItsStateToPrefs
+import org.kiwix.kiwixmobile.core.history.viewmodel.effects.UpdateAllHistoryPreference
 import org.kiwix.kiwixmobile.core.reader.ZimReaderContainer
 import org.kiwix.kiwixmobile.core.search.viewmodel.effects.Finish
-import org.kiwix.kiwixmobile.core.utils.KiwixDialog.DeleteAllHistory
-import org.kiwix.kiwixmobile.core.utils.KiwixDialog.DeleteSelectedHistory
 import org.kiwix.kiwixmobile.core.utils.SharedPreferenceUtil
-import java.text.SimpleDateFormat
-import java.util.Locale
 import javax.inject.Inject
 
 class HistoryViewModel @Inject constructor(
@@ -43,133 +33,142 @@ class HistoryViewModel @Inject constructor(
   private val zimReaderContainer: ZimReaderContainer,
   private val sharedPreferenceUtil: SharedPreferenceUtil
 ) : ViewModel() {
-  val state = MutableLiveData<State>().apply { value = NoResults(emptyList()) }
+  val state = MutableLiveData<State>().apply {
+    value = Results(emptyList(), sharedPreferenceUtil.showHistoryAllBooks)
+  }
   val effects = PublishProcessor.create<SideEffect<*>>()
   val actions = PublishProcessor.create<Action>()
-  private val filter = BehaviorProcessor.createDefault("")
   private val compositeDisposable = CompositeDisposable()
-  val showAllSwitchToggle =
-    BehaviorProcessor.createDefault(!sharedPreferenceUtil.showHistoryCurrentBook)
-  private val dateFormatter = SimpleDateFormat("d MMM yyyy", Locale.getDefault())
-  private val deselectAllItems = BehaviorProcessor.createDefault(false)
 
   init {
     compositeDisposable.addAll(
-      viewStateReducer(),
-      actionMapper(),
-      deselectAllItems()
+      historyDao.history().subscribe { actions.offer(UpdateHistory(it)) },
+      sharedPreferenceUtil.showAllHistoryToggleSwitch.subscribe {
+        actions.offer(AllHistoryPreferenceChanged(it))
+      },
+      viewStateReducer()
     )
   }
 
-  private fun deselectAllItems() = deselectAllItems.subscribe {
-    state.value?.historyItems?.filterIsInstance<HistoryItem>()?.forEach { it.isSelected = false }
-  }
-
   private fun viewStateReducer() =
-    Flowable.combineLatest(
-      filter,
-      showAllSwitchToggle,
-      historyDao.history(),
-      Function3(::searchResults)
-    ).subscribe { state.postValue(updateResultsState(it)) }
+    actions.map { reduce(it, state.value!!) }.subscribe(state::postValue)
 
-  private fun updateResultsState(
-    historyListWithDateItems: List<HistoryListItem>
+  private fun reduce(action: Action, state: State): State =
+    when (action) {
+      ExitHistory -> finishHistoryActivity(state)
+      ExitActionModeMenu -> deselectAllHistoryItems(state)
+      UserClickedDelete -> offerDeletionOfItems(state)
+      UserClickedDeleteButton -> offerShowDeleteDialog(state)
+      is OnItemClick -> handleItemClick(state, action)
+      is OnItemLongClick -> handleItemLongClick(state, action)
+      is ToggleShowHistoryFromAllBooks -> offerUpdateToShowAllToggle(action, state)
+      is Filter -> updateHistoryItemsBasedOnFilter(state, action)
+      is UpdateHistory -> updateHistoryList(state, action)
+      UserClickedDeleteSelectedHistoryItems -> offerShowDeleteDialog(state)
+      is AllHistoryPreferenceChanged -> changeShowHistoryToggle(state, action)
+    }
+
+  private fun updateHistoryItemsBasedOnFilter(state: State, action: Filter) =
+    when (state) {
+      is Results -> state.copy(searchTerm = action.searchTerm)
+      is SelectionResults -> state.copy(searchTerm = action.searchTerm)
+    }
+
+  private fun changeShowHistoryToggle(
+    state: State,
+    action: AllHistoryPreferenceChanged
   ): State {
-    return when {
-      historyListWithDateItems.isEmpty() -> NoResults(historyListWithDateItems)
-      historyListWithDateItems.filterIsInstance<HistoryItem>()
-        .any { it.isSelected } -> SelectionResults(
-          historyListWithDateItems
-      )
-      else -> Results(historyListWithDateItems)
+    return when (state) {
+      is SelectionResults -> state
+      is Results -> state.copy(showAll = action.showAll)
     }
   }
 
-  private fun searchResults(
-    searchString: String,
-    showAllToggle: Boolean,
-    historyList: List<HistoryListItem>
-  ): List<HistoryListItem> = HeaderizableList(historyList
-      .filterIsInstance<HistoryItem>()
-      .filter { h ->
-        h.historyTitle.contains(searchString, true) &&
-          (h.zimName == zimReaderContainer.name || showAllToggle)
+  private fun updateHistoryList(
+    state: State,
+    action: UpdateHistory
+  ): State {
+    return when (state) {
+      is Results -> state.copy(historyItems = action.history)
+      is SelectionResults -> {
+        val selectedItems = state.selectedItems
+        state.copy(historyItems = action.history.map {
+          if (selectedItems.contains(it)) it.copy(isSelected = true) else it
+        })
       }
-      .sortedByDescending { dateFormatter.parse(it.dateString) } as List<HistoryListItem>)
-      .foldOverAddingHeaders(
-        { historyItem -> DateItem((historyItem as HistoryItem).dateString) },
-        { current, next -> (current as HistoryItem).dateString != (next as HistoryItem).dateString }
+    }
+  }
+
+  private fun offerUpdateToShowAllToggle(
+    action: ToggleShowHistoryFromAllBooks,
+    state: State
+  ): State {
+    effects.offer(
+      UpdateAllHistoryPreference(
+        sharedPreferenceUtil,
+        action.isChecked
       )
+    )
+    return state
+  }
+
+  private fun handleItemLongClick(
+    state: State,
+    action: OnItemLongClick
+  ): State {
+    return when (state) {
+      is Results -> state.toggleSelectionOfItem(action.historyItem)
+      else -> state
+    }
+  }
+
+  private fun handleItemClick(
+    state: State,
+    action: OnItemClick
+  ): State {
+    return when (state) {
+      is Results -> {
+        effects.offer(OpenHistoryItem(action.historyItem, zimReaderContainer))
+        state
+      }
+      is SelectionResults -> state.toggleSelectionOfItem(action.historyItem)
+    }
+  }
+
+  private fun offerShowDeleteDialog(state: State): State {
+    effects.offer(ShowDeleteHistoryDialog(actions))
+    return state
+  }
+
+  private fun offerDeletionOfItems(state: State): State {
+    return when (state) {
+      is Results -> {
+        effects.offer(DeleteHistoryItems(state.historyItems, historyDao))
+        state
+      }
+      is SelectionResults -> {
+        effects.offer(DeleteHistoryItems(state.selectedItems, historyDao))
+        state
+      }
+    }
+  }
+
+  private fun deselectAllHistoryItems(state: State): State {
+    return when (state) {
+      is SelectionResults -> {
+        state.copy(historyItems = state.historyItems.map { it.copy(isSelected = false) })
+      }
+      else -> state
+    }
+  }
+
+  private fun finishHistoryActivity(state: State): State {
+    effects.offer(Finish)
+    return state
+  }
 
   override fun onCleared() {
     compositeDisposable.clear()
     super.onCleared()
   }
-
-  private fun toggleSelectionOfItem(historyItem: HistoryItem): State =
-    when (state.value) {
-      is Results -> SelectionResults(toggleGivenItemAndReturnListOfResultingItems(historyItem))
-      is SelectionResults -> {
-        if (toggleGivenItemAndReturnListOfResultingItems(historyItem)
-            ?.filterIsInstance<HistoryItem>()
-            ?.any { it.isSelected } == true) {
-          SelectionResults(toggleGivenItemAndReturnListOfResultingItems(historyItem))
-        } else {
-          Results(toggleGivenItemAndReturnListOfResultingItems(historyItem))
-        }
-      }
-      is NoResults -> NoResults(emptyList())
-      null -> NoResults(emptyList())
-    }
-
-  private fun toggleGivenItemAndReturnListOfResultingItems(historyItem: HistoryItem):
-    List<HistoryListItem>? {
-    return state.value
-      ?.historyItems
-      ?.map {
-        if (it.id == historyItem.id && it is HistoryItem)
-          it.copy(isSelected = !it.isSelected) else it
-      }
-  }
-
-  private fun actionMapper() = actions.map {
-    when (it) {
-      ExitHistory -> effects.offer(Finish)
-      is Filter -> filter.offer(it.searchTerm)
-      is ToggleShowHistoryFromAllBooks ->
-        toggleShowAllHistorySwitchAndSaveItsStateToPrefs(it.isChecked)
-      is OnItemLongClick -> state.postValue(toggleSelectionOfItem(it.historyItem))
-      is OnItemClick -> appendItemToSelectionOrOpenIt(it)
-      is RequestDeleteAllHistoryItems ->
-        effects.offer(ShowDeleteHistoryDialog(actions, DeleteAllHistory))
-      is RequestDeleteSelectedHistoryItems ->
-        effects.offer(ShowDeleteHistoryDialog(actions, DeleteSelectedHistory))
-      ExitActionModeMenu -> state.postValue(Results(
-        state.value
-          ?.historyItems
-          ?.map { item -> if (item is HistoryItem) item.copy(isSelected = false) else item })
-      )
-      DeleteHistoryItems -> effects.offer(DeleteSelectedOrAllHistoryItems(state, historyDao))
-    }
-  }.subscribe({}, Throwable::printStackTrace)
-
-  private fun toggleShowAllHistorySwitchAndSaveItsStateToPrefs(isChecked: Boolean) {
-    effects.offer(
-      ToggleShowAllHistorySwitchAndSaveItsStateToPrefs(
-        showAllSwitchToggle,
-        sharedPreferenceUtil,
-        isChecked
-      )
-    )
-  }
-
-  private fun appendItemToSelectionOrOpenIt(onItemClick: OnItemClick) {
-    val historyItem = onItemClick.historyListItem as HistoryItem
-    if (state.value?.containsSelectedItems() == true) {
-      state.postValue(toggleSelectionOfItem(historyItem))
-    } else {
-      effects.offer(OpenHistoryItem(historyItem, zimReaderContainer))
-    }
-  }
 }

core/src/main/java/org/kiwix/kiwixmobile/core/history/viewmodel/State.kt

@@ -18,26 +18,64 @@
 
 package org.kiwix.kiwixmobile.core.history.viewmodel
 
+import org.kiwix.kiwixmobile.core.extensions.HeaderizableList
 import org.kiwix.kiwixmobile.core.history.adapter.HistoryListItem
+import org.kiwix.kiwixmobile.core.history.adapter.HistoryListItem.DateItem
 import org.kiwix.kiwixmobile.core.history.adapter.HistoryListItem.HistoryItem
+import java.text.SimpleDateFormat
+import java.util.Locale
 
 sealed class State(
-  open val historyItems: List<HistoryListItem>?
+  open val historyItems: List<HistoryItem>,
+  open val showAll: Boolean,
+  open val searchTerm: String = ""
 ) {
 
-  fun containsSelectedItems(): Boolean {
-    return historyItems?.filterIsInstance<HistoryItem>()?.any { it.isSelected } == true
+  private val dateFormatter = SimpleDateFormat("d MMM yyyy", Locale.getDefault())
+
+  val historyListItems: List<HistoryListItem> by lazy {
+    HeaderizableList<HistoryListItem, HistoryItem, DateItem>(historyItems
+      .filter { it.historyTitle.contains(searchTerm, true) }
+      .sortedByDescending { dateFormatter.parse(it.dateString) })
+      .foldOverAddingHeaders(
+        { historyItem -> DateItem(historyItem.dateString) },
+        { current, next -> current.dateString != next.dateString }
+      )
   }
 
-  data class Results(
-    override val historyItems: List<HistoryListItem>?
-  ) : State(historyItems)
+  fun toggleSelectionOfItem(historyListItem: HistoryItem): State {
+    val newList = historyItems.map {
+      if (it.id == historyListItem.id) it.apply {
+        isSelected = !isSelected
+      } else it
+    }
+    if (newList.isEmpty()) {
+      return Results(newList, showAll)
+    }
+    return SelectionResults(newList, showAll, searchTerm)
+  }
 
-  data class NoResults(
-    override val historyItems: List<HistoryListItem>?
-  ) : State(historyItems)
+  // fun filterBasedOnSearchTerm(searchTerm: String): State =
+  //   copy(historyListItems = historyItems.filter {
+  //     it.historyTitle.contains(
+  //       searchTerm,
+  //       true
+  //     )
+  //   })
+
+  data class Results(
+    override val historyItems: List<HistoryItem>,
+    override val showAll: Boolean,
+    override val searchTerm: String = ""
+  ) : State(historyItems, showAll, searchTerm)
 
   data class SelectionResults(
-    override val historyItems: List<HistoryListItem>?
-  ) : State(historyItems)
+    override val historyItems: List<HistoryItem>,
+    override val showAll: Boolean,
+    override val searchTerm: String
+  ) : State(historyItems, showAll, searchTerm) {
+
+    val selectedItems: List<HistoryItem> =
+      historyListItems.filterIsInstance<HistoryItem>().filter(HistoryItem::isSelected)
+  }
 }

core/src/main/java/org/kiwix/kiwixmobile/core/history/viewmodel/effects/DeleteHistoryItems.kt

@@ -1,3 +1,5 @@
+package org.kiwix.kiwixmobile.core.history.viewmodel.effects
+
 /*
  * Kiwix Android
  * Copyright (c) 2020 Kiwix <android.kiwix.org>
@@ -17,22 +19,15 @@
  */
 
 import androidx.appcompat.app.AppCompatActivity
-import androidx.lifecycle.MutableLiveData
 import org.kiwix.kiwixmobile.core.base.SideEffect
 import org.kiwix.kiwixmobile.core.dao.HistoryDao
 import org.kiwix.kiwixmobile.core.history.adapter.HistoryListItem.HistoryItem
-import org.kiwix.kiwixmobile.core.history.viewmodel.State
 
-data class DeleteSelectedOrAllHistoryItems(
-  private val state: MutableLiveData<State>,
+data class DeleteHistoryItems(
+  private val itemsToDelete: List<HistoryItem>,
   private val historyDao: HistoryDao
 ) : SideEffect<Unit> {
   override fun invokeWith(activity: AppCompatActivity) {
-    val historyItems = state.value?.historyItems?.filterIsInstance<HistoryItem>()
-    if (historyItems?.any { it.isSelected } == true) {
-      historyDao.deleteHistory(historyItems.filter { it.isSelected })
-    } else if (historyItems != null) {
-      historyDao.deleteHistory(historyItems)
-    }
+    historyDao.deleteHistory(itemsToDelete)
   }
 }

core/src/main/java/org/kiwix/kiwixmobile/core/history/viewmodel/effects/ShowDeleteHistoryDialog.kt

@@ -23,20 +23,19 @@ import io.reactivex.processors.PublishProcessor
 import org.kiwix.kiwixmobile.core.base.SideEffect
 import org.kiwix.kiwixmobile.core.history.HistoryActivity
 import org.kiwix.kiwixmobile.core.history.viewmodel.Action
-import org.kiwix.kiwixmobile.core.history.viewmodel.Action.DeleteHistoryItems
+import org.kiwix.kiwixmobile.core.history.viewmodel.Action.UserClickedDelete
 import org.kiwix.kiwixmobile.core.utils.DialogShower
-import org.kiwix.kiwixmobile.core.utils.KiwixDialog
+import org.kiwix.kiwixmobile.core.utils.KiwixDialog.DeleteAllHistory
 import javax.inject.Inject
 
 data class ShowDeleteHistoryDialog(
-  private val actions: PublishProcessor<Action>,
-  private val dialogType: KiwixDialog
+  private val actions: PublishProcessor<Action>
 ) : SideEffect<Unit> {
   @Inject lateinit var dialogShower: DialogShower
   override fun invokeWith(activity: AppCompatActivity) {
     (activity as HistoryActivity).activityComponent.inject(this)
-    dialogShower.show(dialogType, {
-      actions.offer(DeleteHistoryItems)
+    dialogShower.show(DeleteAllHistory, {
+      actions.offer(UserClickedDelete)
     })
   }
 }

core/src/main/java/org/kiwix/kiwixmobile/core/history/viewmodel/effects/UpdateAllHistoryPreference.kt

@@ -1,17 +1,14 @@
 package org.kiwix.kiwixmobile.core.history.viewmodel.effects
 
 import androidx.appcompat.app.AppCompatActivity
-import io.reactivex.processors.BehaviorProcessor
 import org.kiwix.kiwixmobile.core.base.SideEffect
 import org.kiwix.kiwixmobile.core.utils.SharedPreferenceUtil
 
-data class ToggleShowAllHistorySwitchAndSaveItsStateToPrefs(
-  private val showAllSwitchToggle: BehaviorProcessor<Boolean>,
+data class UpdateAllHistoryPreference(
   private val sharedPreferenceUtil: SharedPreferenceUtil,
   private val isChecked: Boolean
 ) : SideEffect<Unit> {
   override fun invokeWith(activity: AppCompatActivity) {
-    showAllSwitchToggle.offer(isChecked)
-    sharedPreferenceUtil.showHistoryCurrentBook = !isChecked
+    sharedPreferenceUtil.showHistoryAllBooks = !isChecked
   }
 }

core/src/main/java/org/kiwix/kiwixmobile/core/utils/SharedPreferenceUtil.java

@@ -55,11 +55,12 @@ public class SharedPreferenceUtil {
   private static final String PREF_EXTERNAL_LINK_POPUP = "pref_external_link_popup";
   private static final String PREF_IS_FIRST_RUN = "isFirstRun";
   private static final String PREF_SHOW_BOOKMARKS_CURRENT_BOOK = "show_bookmarks_current_book";
-  private static final String PREF_SHOW_HISTORY_CURRENT_BOOK = "show_history_current_book";
+  private static final String PREF_SHOW_HISTORY_ALL_BOOKS = "show_history_current_book";
   private static final String PREF_HOSTED_BOOKS = "hosted_books";
   public static final String PREF_NIGHT_MODE = "pref_night_mode";
   private SharedPreferences sharedPreferences;
   private final PublishProcessor<String> prefStorages = PublishProcessor.create();
+  public final PublishProcessor<Boolean> showAllHistoryToggleSwitch = PublishProcessor.create();
   private final PublishProcessor<NightModeConfig.Mode> nightModes = PublishProcessor.create();
 
   @Inject
@@ -152,6 +153,10 @@ public class SharedPreferenceUtil {
     return prefStorages.startWith(getPrefStorage());
   }
 
+  public Flowable<Boolean> getShowAllHistoryToggleSwitches() {
+    return showAllHistoryToggleSwitch.startWith(getShowHistoryAllBooks());
+  }
+
   public void putPrefFullScreen(boolean fullScreen) {
     sharedPreferences.edit().putBoolean(PREF_FULLSCREEN, fullScreen).apply();
   }
@@ -168,14 +173,15 @@ public class SharedPreferenceUtil {
     sharedPreferences.edit().putBoolean(PREF_SHOW_INTRO, false).apply();
   }
 
-  public boolean getShowHistoryCurrentBook() {
-    return sharedPreferences.getBoolean(PREF_SHOW_HISTORY_CURRENT_BOOK, true);
+  public boolean getShowHistoryAllBooks() {
+    return sharedPreferences.getBoolean(PREF_SHOW_HISTORY_ALL_BOOKS, true);
   }
 
-  public void setShowHistoryCurrentBook(boolean prefShowHistoryCurrentBook) {
+  public void setShowHistoryAllBooks(boolean prefShowHistoryAllBooks) {
     sharedPreferences.edit()
-      .putBoolean(PREF_SHOW_HISTORY_CURRENT_BOOK, prefShowHistoryCurrentBook)
+      .putBoolean(PREF_SHOW_HISTORY_ALL_BOOKS, prefShowHistoryAllBooks)
       .apply();
+    showAllHistoryToggleSwitch.offer(prefShowHistoryAllBooks);
   }
 
   public boolean getShowBookmarksCurrentBook() {

core/src/test/java/org/kiwix/kiwixmobile/core/history/viewmodel/HistoryViewModelTest.kt

@@ -1,6 +1,5 @@
 package org.kiwix.kiwixmobile.core.history.viewmodel
 
-import DeleteSelectedOrAllHistoryItems
 import OpenHistoryItem
 import com.jraska.livedata.test
 import io.mockk.clearAllMocks
@@ -18,24 +17,22 @@ import org.kiwix.kiwixmobile.core.base.SideEffect
 import org.kiwix.kiwixmobile.core.dao.HistoryDao
 import org.kiwix.kiwixmobile.core.history.adapter.HistoryListItem.DateItem
 import org.kiwix.kiwixmobile.core.history.adapter.HistoryListItem.HistoryItem
-import org.kiwix.kiwixmobile.core.history.viewmodel.Action.DeleteHistoryItems
 import org.kiwix.kiwixmobile.core.history.viewmodel.Action.ExitActionModeMenu
 import org.kiwix.kiwixmobile.core.history.viewmodel.Action.ExitHistory
-import org.kiwix.kiwixmobile.core.reader.ZimReaderContainer
-import org.kiwix.kiwixmobile.core.history.viewmodel.State.NoResults
-import org.kiwix.kiwixmobile.core.history.viewmodel.State.Results
 import org.kiwix.kiwixmobile.core.history.viewmodel.Action.Filter
 import org.kiwix.kiwixmobile.core.history.viewmodel.Action.OnItemClick
 import org.kiwix.kiwixmobile.core.history.viewmodel.Action.OnItemLongClick
-import org.kiwix.kiwixmobile.core.history.viewmodel.Action.RequestDeleteAllHistoryItems
-import org.kiwix.kiwixmobile.core.history.viewmodel.Action.RequestDeleteSelectedHistoryItems
 import org.kiwix.kiwixmobile.core.history.viewmodel.Action.ToggleShowHistoryFromAllBooks
+import org.kiwix.kiwixmobile.core.history.viewmodel.Action.UserClickedDelete
+import org.kiwix.kiwixmobile.core.history.viewmodel.Action.UserClickedDeleteButton
+import org.kiwix.kiwixmobile.core.history.viewmodel.Action.UserClickedDeleteSelectedHistoryItems
+import org.kiwix.kiwixmobile.core.history.viewmodel.State.Results
 import org.kiwix.kiwixmobile.core.history.viewmodel.State.SelectionResults
+import org.kiwix.kiwixmobile.core.history.viewmodel.effects.DeleteHistoryItems
 import org.kiwix.kiwixmobile.core.history.viewmodel.effects.ShowDeleteHistoryDialog
-import org.kiwix.kiwixmobile.core.history.viewmodel.effects.ToggleShowAllHistorySwitchAndSaveItsStateToPrefs
+import org.kiwix.kiwixmobile.core.history.viewmodel.effects.UpdateAllHistoryPreference
+import org.kiwix.kiwixmobile.core.reader.ZimReaderContainer
 import org.kiwix.kiwixmobile.core.search.viewmodel.effects.Finish
-import org.kiwix.kiwixmobile.core.utils.KiwixDialog.DeleteAllHistory
-import org.kiwix.kiwixmobile.core.utils.KiwixDialog.DeleteSelectedHistory
 import org.kiwix.kiwixmobile.core.utils.SharedPreferenceUtil
 import org.kiwix.sharedFunctions.InstantExecutorExtension
 import org.kiwix.sharedFunctions.setScheduler
@@ -62,7 +59,7 @@ internal class HistoryViewModelTest {
     clearAllMocks()
     every { zimReaderContainer.id } returns "id"
     every { zimReaderContainer.name } returns "zimName"
-    every { sharedPreferenceUtil.showHistoryCurrentBook } returns true
+    every { sharedPreferenceUtil.showHistoryAllBooks } returns true
     every { historyDao.history() } returns itemsFromDb.distinctUntilChanged()
     viewModel = HistoryViewModel(historyDao, zimReaderContainer, sharedPreferenceUtil)
   }
@@ -86,7 +83,7 @@ internal class HistoryViewModelTest {
 
     @Test
     fun `initial state is Initialising`() {
-      viewModel.state.test().assertValue(NoResults(listOf()))
+      viewModel.state.test().assertValue(Results(listOf(), true))
     }
 
     @Test
@@ -101,7 +98,7 @@ internal class HistoryViewModelTest {
         searchTerm = searchTerm,
         databaseResults = listOf(item)
       )
-      resultsIn(Results((listOf(date, item))))
+      resultsIn(Results(listOf(item), true))
     }
 
     @Test
@@ -114,7 +111,7 @@ internal class HistoryViewModelTest {
           )
         )
       )
-      resultsIn(NoResults(emptyList()))
+      resultsIn(Results(emptyList(), true))
     }
 
     @Test
@@ -126,7 +123,7 @@ internal class HistoryViewModelTest {
         searchTerm = "",
         databaseResults = listOf(item)
       )
-      resultsIn(Results(listOf(date, item)))
+      resultsIn(Results(listOf(item), true))
     }
 
     @Test
@@ -135,7 +132,7 @@ internal class HistoryViewModelTest {
         searchTerm = "",
         databaseResults = emptyList()
       )
-      resultsIn(NoResults(emptyList()))
+      resultsIn(Results(emptyList(), true))
     }
 
     @Test
@@ -150,7 +147,7 @@ internal class HistoryViewModelTest {
         databaseResults = listOf(item)
       )
       viewModel.actions.offer(Filter(searchString2))
-      resultsIn(Results(listOf(date, item)))
+      resultsIn(Results(listOf(item), true))
     }
 
     @Test
@@ -166,7 +163,7 @@ internal class HistoryViewModelTest {
         searchTerm = "b",
         databaseResults = listOf(item)
       )
-      resultsIn(Results(listOf(date, item)))
+      resultsIn(Results(listOf(item), true))
     }
 
     @Test
@@ -184,7 +181,7 @@ internal class HistoryViewModelTest {
         searchTerm = "b",
         databaseResults = listOf(item)
       )
-      resultsIn(SelectionResults(listOf(date, item)))
+      resultsIn(SelectionResults(listOf(item), true))
     }
 
     @Test
@@ -208,7 +205,7 @@ internal class HistoryViewModelTest {
         searchTerm = "",
         databaseResults = listOf(item2, item3, item1)
       )
-      resultsIn(Results(listOf(date3, item3, date1, item1, date2, item2)))
+      resultsIn(Results(listOf(item3, item1, item2), true))
     }
 
     @Test
@@ -231,7 +228,7 @@ internal class HistoryViewModelTest {
         searchTerm = "",
         databaseResults = listOf(item2, item3, item1)
       )
-      resultsIn(Results(listOf(date1, item2, item1, date3, item3)))
+      resultsIn(Results(listOf(item2, item1, item3), true))
     }
 
     @Test
@@ -247,7 +244,7 @@ internal class HistoryViewModelTest {
       )
       viewModel.actions.offer(OnItemLongClick(item1))
       item1.isSelected = true
-      resultsIn(SelectionResults(listOf(date, item1)))
+      resultsIn(SelectionResults(listOf(item1), true))
     }
 
     @Test
@@ -267,8 +264,9 @@ internal class HistoryViewModelTest {
       )
       viewModel.actions.offer(OnItemLongClick(item1))
       viewModel.actions.offer(OnItemClick(item1))
-      resultsIn(Results(listOf(date, item1, item2)))
+      resultsIn(Results(listOf(item1, item2), true))
     }
+
     @Test
     fun `Deselection via OnItemLongClick exits selection state if last item is deselected`() {
       val item1 =
@@ -286,7 +284,7 @@ internal class HistoryViewModelTest {
       )
       viewModel.actions.offer(OnItemLongClick(item1))
       viewModel.actions.offer(OnItemLongClick(item1))
-      resultsIn(Results(listOf(date, item1, item2)))
+      resultsIn(Results(listOf(item1, item2), true))
     }
 
     @Test
@@ -307,7 +305,7 @@ internal class HistoryViewModelTest {
       viewModel.actions.offer(ExitActionModeMenu)
       item1.isSelected = false
       item2.isSelected = false
-      resultsIn(Results(listOf(date, item1, item2)))
+      resultsIn(Results(listOf(item1, item2), true))
     }
   }
 
@@ -368,12 +366,17 @@ internal class HistoryViewModelTest {
 
     private fun assertItemIsSelected(item: HistoryItem) {
       assertTrue(
-        (viewModel.state.value?.historyItems?.find { it.id == item.id } as HistoryItem).isSelected
+        (viewModel.state.value?.historyListItems?.find {
+          it.id == item.id
+        } as HistoryItem).isSelected
       )
     }
+
     private fun assertItemIsDeselected(item: HistoryItem) {
       assertFalse(
-        (viewModel.state.value?.historyItems?.find { it.id == item.id } as HistoryItem).isSelected
+        (viewModel.state.value?.historyListItems?.find {
+          it.id == item.id
+        } as HistoryItem).isSelected
       )
     }
 
@@ -429,31 +432,35 @@ internal class HistoryViewModelTest {
     fun `ToggleShowHistoryFromAllBooks switches show all books toggle`() {
       actionResultsInEffects(
         ToggleShowHistoryFromAllBooks(true),
-        ToggleShowAllHistorySwitchAndSaveItsStateToPrefs(
-          viewModel.showAllSwitchToggle,
+        UpdateAllHistoryPreference(
           sharedPreferenceUtil,
-          true))
+          true
+        )
+      )
     }
 
     @Test
     fun `RequestDeleteAllHistoryItems opens dialog to request deletion`() {
       actionResultsInEffects(
-        RequestDeleteAllHistoryItems,
-        ShowDeleteHistoryDialog(viewModel.actions, DeleteAllHistory))
+        UserClickedDeleteButton,
+        ShowDeleteHistoryDialog(viewModel.actions)
+      )
     }
 
     @Test
     fun `RequestDeleteSelectedHistoryItems opens dialog to request deletion`() {
       actionResultsInEffects(
-        RequestDeleteSelectedHistoryItems,
-        ShowDeleteHistoryDialog(viewModel.actions, DeleteSelectedHistory))
+        UserClickedDeleteSelectedHistoryItems,
+        ShowDeleteHistoryDialog(viewModel.actions)
+      )
     }
 
     @Test
     fun `DeleteHistoryItems calls DeleteSelectedOrAllHistoryItems side effect`() {
       actionResultsInEffects(
-        DeleteHistoryItems,
-        DeleteSelectedOrAllHistoryItems(viewModel.state, historyDao))
+        UserClickedDelete,
+        DeleteHistoryItems(viewModel.state.value!!.historyItems, historyDao)
+      )
     }
 
     private fun actionResultsInEffects(

core/src/test/java/org/kiwix/kiwixmobile/core/history/viewmodel/effects/DeleteSelectedOrAllHistoryItemsTest.kt

@@ -1,6 +1,5 @@
 package org.kiwix.kiwixmobile.core.history.viewmodel.effects
 
-import DeleteSelectedOrAllHistoryItems
 import androidx.appcompat.app.AppCompatActivity
 import androidx.lifecycle.MutableLiveData
 import io.mockk.every
@@ -22,7 +21,7 @@ internal class DeleteSelectedOrAllHistoryItemsTest {
     every { state.value } returns SelectionResults(listOf(item1, item2))
     val historyDao: HistoryDao = mockk()
     val activity: AppCompatActivity = mockk()
-    DeleteSelectedOrAllHistoryItems(state, historyDao).invokeWith(activity)
+    DeleteHistoryItems(state, historyDao).invokeWith(activity)
     verify { historyDao.deleteHistory(listOf(item1)) }
   }
 
@@ -34,7 +33,7 @@ internal class DeleteSelectedOrAllHistoryItemsTest {
     every { state.value } returns SelectionResults(listOf(item1, item2))
     val historyDao: HistoryDao = mockk()
     val activity: AppCompatActivity = mockk()
-    DeleteSelectedOrAllHistoryItems(state, historyDao).invokeWith(activity)
+    DeleteHistoryItems(state, historyDao).invokeWith(activity)
     verify { historyDao.deleteHistory(listOf(item1, item2)) }
   }
 }

core/src/test/java/org/kiwix/kiwixmobile/core/history/viewmodel/effects/ShowDeleteHistoryDialogTest.kt

@@ -8,7 +8,7 @@ import io.reactivex.processors.PublishProcessor
 import org.junit.jupiter.api.Test
 import org.kiwix.kiwixmobile.core.history.HistoryActivity
 import org.kiwix.kiwixmobile.core.history.viewmodel.Action
-import org.kiwix.kiwixmobile.core.history.viewmodel.Action.DeleteHistoryItems
+import org.kiwix.kiwixmobile.core.history.viewmodel.Action.UserClickedDelete
 import org.kiwix.kiwixmobile.core.utils.DialogShower
 import org.kiwix.kiwixmobile.core.utils.KiwixDialog.DeleteSelectedHistory
 
@@ -30,6 +30,6 @@ internal class ShowDeleteHistoryDialogTest {
       dialogShower.show(DeleteSelectedHistory, capture(lambdaSlot))
     }
     lambdaSlot.captured.invoke()
-    verify { actions.offer(DeleteHistoryItems) }
+    verify { actions.offer(UserClickedDelete) }
   }
 }

core/src/test/java/org/kiwix/kiwixmobile/core/history/viewmodel/effects/ToggleShowAllHistorySwitchAndSaveItsStateToPrefsTest.kt

@@ -15,14 +15,14 @@ internal class ToggleShowAllHistorySwitchAndSaveItsStateToPrefsTest {
     every { toggleSwitch.offer(true) } returns true
     val sharedPreferenceUtil: SharedPreferenceUtil = mockk()
     val activity: AppCompatActivity = mockk()
-    ToggleShowAllHistorySwitchAndSaveItsStateToPrefs(
+    UpdateAllHistoryPreference(
       toggleSwitch,
       sharedPreferenceUtil,
       true
     ).invokeWith(activity)
     verify {
       toggleSwitch.offer(true)
-      sharedPreferenceUtil.showHistoryCurrentBook = false
+      sharedPreferenceUtil.showHistoryAllBooks = false
     }
   }
 }