#1253 readd action mode for sharing and deleting zim files on disk

app/objectbox-models/default.json.bak

@@ -218,7 +218,7 @@
         },
         {
           "id": "2:6862771806221961183",
-          "name": "zimID"
+          "name": "zimId"
         },
         {
           "id": "3:4312769031500860715",

app/src/main/java/org/kiwix/kiwixmobile/di/components/ActivityComponent.kt

@@ -23,6 +23,7 @@ import dagger.Subcomponent
 import org.kiwix.kiwixmobile.di.modules.ActivityModule
 import org.kiwix.kiwixmobile.downloader.DownloadFragment
 import org.kiwix.kiwixmobile.zim_manager.fileselect_view.ZimFileSelectFragment
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.effects.DeleteFiles
 import org.kiwix.kiwixmobile.zim_manager.library_view.LibraryFragment
 
 @Subcomponent(modules = [ActivityModule::class])
@@ -33,6 +34,8 @@ interface ActivityComponent {
 
   fun inject(zimFileSelectFragment: ZimFileSelectFragment)
 
+  fun inject(deleteFiles: DeleteFiles)
+
   @Subcomponent.Builder
   interface Builder {
 

app/src/main/java/org/kiwix/kiwixmobile/extensions/ActivityExtensions.kt

@@ -0,0 +1,43 @@
+package org.kiwix.kiwixmobile.extensions
+
+import android.app.Activity
+import android.view.ActionMode
+import android.view.ActionMode.Callback
+import android.view.Menu
+import android.view.MenuItem
+
+fun Activity.startActionMode(
+  menuId: Int,
+  idsToClickActions: Map<Int, () -> Any>,
+  onDestroyAction: () -> Unit
+): ActionMode? {
+  return startActionMode(object : Callback {
+    override fun onActionItemClicked(
+      mode: ActionMode,
+      item: MenuItem
+    ) = idsToClickActions[item.itemId]?.let {
+      it()
+      mode.finish()
+      true
+    } ?: false
+
+    override fun onCreateActionMode(
+      mode: ActionMode,
+      menu: Menu?
+    ): Boolean {
+      mode.getMenuInflater()
+          .inflate(menuId, menu)
+      return true
+    }
+
+    override fun onPrepareActionMode(
+      mode: ActionMode?,
+      menu: Menu?
+    ) = false
+
+    override fun onDestroyActionMode(mode: ActionMode?) {
+      onDestroyAction()
+    }
+
+  })
+}

app/src/main/java/org/kiwix/kiwixmobile/main/MainActivity.java

@@ -37,7 +37,6 @@ import android.net.Uri;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.CountDownTimer;
-import android.os.Environment;
 import android.os.Handler;
 import android.provider.Settings;
 import android.text.SpannableString;
@@ -100,11 +99,9 @@ import org.kiwix.kiwixmobile.base.BaseActivity;
 import org.kiwix.kiwixmobile.bookmark.BookmarkItem;
 import org.kiwix.kiwixmobile.bookmark.BookmarksActivity;
 import org.kiwix.kiwixmobile.data.ZimContentProvider;
-import org.kiwix.kiwixmobile.data.local.entity.Bookmark;
 import org.kiwix.kiwixmobile.help.HelpActivity;
 import org.kiwix.kiwixmobile.history.HistoryActivity;
 import org.kiwix.kiwixmobile.history.HistoryListItem;
-import org.kiwix.kiwixmobile.library.entity.LibraryNetworkEntity;
 import org.kiwix.kiwixmobile.search.SearchActivity;
 import org.kiwix.kiwixmobile.settings.KiwixSettingsActivity;
 import org.kiwix.kiwixmobile.utils.DimenUtils;
@@ -377,6 +374,7 @@ public class MainActivity extends BaseActivity implements WebViewCallback,
              open(bookOnDiskItem);
              return Unit.INSTANCE;
            },
+           null,
            null),
         BookOnDiskDelegate.LanguageDelegate.INSTANCE
     );
@@ -2105,7 +2103,7 @@ public class MainActivity extends BaseActivity implements WebViewCallback,
 
   @Override
   public void addBooks(List<BooksOnDiskListItem> books) {
-    booksAdapter.setItemList(books);
+    booksAdapter.setItems(books);
   }
 
   private void searchFiles() {

app/src/main/java/org/kiwix/kiwixmobile/zim_manager/ZimManageViewModel.kt

@@ -52,9 +52,24 @@ import org.kiwix.kiwixmobile.zim_manager.Fat32Checker.FileSystemState.CanWrite4G
 import org.kiwix.kiwixmobile.zim_manager.Fat32Checker.FileSystemState.CannotWrite4GbFile
 import org.kiwix.kiwixmobile.zim_manager.Fat32Checker.FileSystemState.NotEnoughSpaceFor4GbFile
 import org.kiwix.kiwixmobile.zim_manager.NetworkState.CONNECTED
+import org.kiwix.kiwixmobile.zim_manager.ZimManageViewModel.FileSelectActions.MultiModeFinished
+import org.kiwix.kiwixmobile.zim_manager.ZimManageViewModel.FileSelectActions.RequestDeleteMultiSelection
+import org.kiwix.kiwixmobile.zim_manager.ZimManageViewModel.FileSelectActions.RequestMultiSelection
+import org.kiwix.kiwixmobile.zim_manager.ZimManageViewModel.FileSelectActions.RequestOpen
+import org.kiwix.kiwixmobile.zim_manager.ZimManageViewModel.FileSelectActions.RequestSelect
+import org.kiwix.kiwixmobile.zim_manager.ZimManageViewModel.FileSelectActions.RequestShareMultiSelection
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.FileSelectListState
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.SelectionMode.MULTI
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.SelectionMode.NORMAL
 import org.kiwix.kiwixmobile.zim_manager.fileselect_view.StorageObserver
 import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BooksOnDiskListItem
 import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BooksOnDiskListItem.BookOnDisk
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.effects.DeleteFiles
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.effects.None
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.effects.OpenFile
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.effects.ShareFiles
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.effects.SideEffect
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.effects.StartMultiSelection
 import org.kiwix.kiwixmobile.zim_manager.library_view.adapter.LibraryListItem
 import org.kiwix.kiwixmobile.zim_manager.library_view.adapter.LibraryListItem.BookItem
 import org.kiwix.kiwixmobile.zim_manager.library_view.adapter.LibraryListItem.DividerItem
@@ -79,16 +94,26 @@ class ZimManageViewModel @Inject constructor(
   private val defaultLanguageProvider: DefaultLanguageProvider,
   private val dataSource: DataSource
 ) : ViewModel() {
+  sealed class FileSelectActions {
+    data class RequestOpen(val bookOnDisk: BookOnDisk) : FileSelectActions()
+    data class RequestSelect(val bookOnDisk: BookOnDisk) : FileSelectActions()
+    data class RequestMultiSelection(val bookOnDisk: BookOnDisk) : FileSelectActions()
+    object RequestDeleteMultiSelection : FileSelectActions()
+    object RequestShareMultiSelection : FileSelectActions()
+    object MultiModeFinished : FileSelectActions()
+  }
 
+  val sideEffects = PublishProcessor.create<SideEffect<out Any?>>()
   val libraryItems: MutableLiveData<List<LibraryListItem>> = MutableLiveData()
   val downloadItems: MutableLiveData<List<DownloadItem>> = MutableLiveData()
-  val bookItems: MutableLiveData<List<BooksOnDiskListItem>> = MutableLiveData()
+  val fileSelectListStates: MutableLiveData<FileSelectListState> = MutableLiveData()
   val deviceListIsRefreshing = MutableLiveData<Boolean>()
   val libraryListIsRefreshing = MutableLiveData<Boolean>()
   val networkStates = MutableLiveData<NetworkState>()
   val languageItems = MutableLiveData<List<Language>>()
 
   val requestFileSystemCheck = PublishProcessor.create<Unit>()
+  val fileSelectActions = PublishProcessor.create<FileSelectActions>()
   val requestDownloadLibrary = BehaviorProcessor.createDefault<Unit>(Unit)
   val requestFiltering = BehaviorProcessor.createDefault<String>("")
   val requestLanguagesDialog = PublishProcessor.create<Unit>()
@@ -127,10 +152,74 @@ class ZimManageViewModel @Inject constructor(
         updateLanguagesInDao(networkLibrary, languages),
         updateNetworkStates(),
         updateLanguageItemsForDialog(languages),
-        requestsAndConnectivtyChangesToLibraryRequests(networkLibrary)
+        requestsAndConnectivtyChangesToLibraryRequests(networkLibrary),
+        fileSelectActions()
     )
   }
 
+  private fun fileSelectActions() = fileSelectActions.subscribe({
+    sideEffects.offer(
+        when (it) {
+          is RequestOpen -> OpenFile(it.bookOnDisk)
+          is RequestMultiSelection -> startMultiSelectionAndSelectBook(it.bookOnDisk)
+          RequestDeleteMultiSelection -> DeleteFiles(selectionsFromState())
+          RequestShareMultiSelection -> ShareFiles(selectionsFromState())
+          MultiModeFinished -> noSideEffectAndClearSelectionState()
+          is RequestSelect -> noSideEffectSelectBook(it.bookOnDisk)
+        }
+    )
+  }, Throwable::printStackTrace)
+
+  private fun startMultiSelectionAndSelectBook(
+    bookOnDisk: BookOnDisk
+  ): StartMultiSelection {
+    fileSelectListStates.value?.let {
+      fileSelectListStates.postValue(
+          it.copy(
+              bookOnDiskListItems = selectBook(it, bookOnDisk),
+              selectionMode = MULTI
+          )
+      )
+    }
+    return StartMultiSelection(bookOnDisk, fileSelectActions)
+  }
+
+  private fun selectBook(
+    it: FileSelectListState,
+    bookOnDisk: BookOnDisk
+  ): List<BooksOnDiskListItem> {
+    return it.bookOnDiskListItems.map { listItem ->
+      if (listItem.id == bookOnDisk.id) listItem.apply { isSelected = !isSelected }
+      else listItem
+    }
+  }
+
+  private fun noSideEffectSelectBook(bookOnDisk: BookOnDisk): SideEffect<Unit> {
+    fileSelectListStates.value?.let {
+      fileSelectListStates.postValue(
+          it.copy(bookOnDiskListItems = it.bookOnDiskListItems.map { listItem ->
+            if (listItem.id == bookOnDisk.id) listItem.apply { isSelected = !isSelected }
+            else listItem
+          })
+      )
+    }
+    return None
+  }
+
+  private fun selectionsFromState() = fileSelectListStates.value?.selectedBooks ?: emptyList()
+
+  private fun noSideEffectAndClearSelectionState(): SideEffect<Unit> {
+    fileSelectListStates.value?.let {
+      fileSelectListStates.postValue(
+          it.copy(
+              bookOnDiskListItems = it.bookOnDiskListItems.map { it.apply { isSelected = false } },
+              selectionMode = NORMAL
+          )
+      )
+    }
+    return None
+  }
+
   private fun requestsAndConnectivtyChangesToLibraryRequests(library: PublishProcessor<LibraryNetworkEntity>) =
     Flowable.combineLatest(
         requestDownloadLibrary,
@@ -411,10 +500,27 @@ class ZimManageViewModel @Inject constructor(
   private fun updateBookItems() =
     dataSource.booksOnDiskAsListItems()
         .subscribe(
-            bookItems::postValue,
+            { newList ->
+              fileSelectListStates.postValue(
+                  fileSelectListStates.value?.let { inheritSelections(it, newList) }
+                      ?: FileSelectListState(newList)
+              )
+            },
             Throwable::printStackTrace
         )
 
+  private fun inheritSelections(
+    oldState: FileSelectListState,
+    newList: MutableList<BooksOnDiskListItem>
+  ): FileSelectListState {
+    return oldState.copy(
+        bookOnDiskListItems = newList.map { newBookOnDisk ->
+          val firstOrNull =
+            oldState.bookOnDiskListItems.firstOrNull { oldBookOnDisk -> oldBookOnDisk.id == newBookOnDisk.id }
+          newBookOnDisk.apply { isSelected = firstOrNull?.isSelected ?: false }
+        })
+  }
+
   private fun removeCompletedDownloadsFromDb(downloadStatuses: Flowable<List<DownloadStatus>>) =
     downloadStatuses
         .observeOn(Schedulers.io())

app/src/main/java/org/kiwix/kiwixmobile/zim_manager/fileselect_view/FileSelectListState.kt

@@ -0,0 +1,37 @@
+/*
+ * Kiwix Android
+ * Copyright (C) 2018  Kiwix <android.kiwix.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.kiwix.kiwixmobile.zim_manager.fileselect_view
+
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.SelectionMode.NORMAL
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BooksOnDiskListItem
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BooksOnDiskListItem.BookOnDisk
+
+data class FileSelectListState(
+  val bookOnDiskListItems: List<BooksOnDiskListItem>,
+  val selectionMode: SelectionMode = NORMAL
+) {
+  val selectedBooks by lazy {
+    bookOnDiskListItems.filter { it.isSelected }.filterIsInstance(BookOnDisk::class.java)
+  }
+
+}
+
+enum class SelectionMode {
+  NORMAL,
+  MULTI
+}

app/src/main/java/org/kiwix/kiwixmobile/zim_manager/fileselect_view/ZimFileSelectFragment.kt

@@ -21,8 +21,8 @@ package org.kiwix.kiwixmobile.zim_manager.fileselect_view
 
 import android.Manifest
 import android.content.pm.PackageManager
-import android.os.Build
 import android.os.Bundle
+import android.view.ActionMode
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
@@ -32,49 +32,49 @@ import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.ViewModelProviders
 import androidx.recyclerview.widget.LinearLayoutManager
 import androidx.recyclerview.widget.RecyclerView
+import io.reactivex.disposables.CompositeDisposable
 import kotlinx.android.synthetic.main.zim_list.file_management_no_files
 import kotlinx.android.synthetic.main.zim_list.zim_swiperefresh
 import kotlinx.android.synthetic.main.zim_list.zimfilelist
 import org.kiwix.kiwixmobile.R
-import org.kiwix.kiwixmobile.R.string
 import org.kiwix.kiwixmobile.base.BaseFragment
-import org.kiwix.kiwixmobile.data.ZimContentProvider
-import org.kiwix.kiwixmobile.database.newdb.dao.NewBookDao
 import org.kiwix.kiwixmobile.di.components.ActivityComponent
 import org.kiwix.kiwixmobile.extensions.toast
-import org.kiwix.kiwixmobile.utils.BookUtils
 import org.kiwix.kiwixmobile.utils.Constants.REQUEST_STORAGE_PERMISSION
-import org.kiwix.kiwixmobile.utils.DialogShower
-import org.kiwix.kiwixmobile.utils.KiwixDialog.DeleteZim
 import org.kiwix.kiwixmobile.utils.LanguageUtils
 import org.kiwix.kiwixmobile.utils.SharedPreferenceUtil
-import org.kiwix.kiwixmobile.utils.files.FileUtils
-import org.kiwix.kiwixmobile.zim_manager.ZimManageActivity
 import org.kiwix.kiwixmobile.zim_manager.ZimManageViewModel
+import org.kiwix.kiwixmobile.zim_manager.ZimManageViewModel.FileSelectActions
+import org.kiwix.kiwixmobile.zim_manager.ZimManageViewModel.FileSelectActions.RequestMultiSelection
+import org.kiwix.kiwixmobile.zim_manager.ZimManageViewModel.FileSelectActions.RequestOpen
+import org.kiwix.kiwixmobile.zim_manager.ZimManageViewModel.FileSelectActions.RequestSelect
 import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BookOnDiskDelegate.BookDelegate
 import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BookOnDiskDelegate.LanguageDelegate
 import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BooksOnDiskAdapter
-import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BooksOnDiskListItem.BookOnDisk
 import javax.inject.Inject
 
 class ZimFileSelectFragment : BaseFragment() {
 
   @Inject lateinit var sharedPreferenceUtil: SharedPreferenceUtil
-  @Inject lateinit var bookDao: NewBookDao
-  @Inject lateinit var dialogShower: DialogShower
   @Inject lateinit var viewModelFactory: ViewModelProvider.Factory
-  @Inject lateinit var bookUtils: BookUtils
+
+  private var actionMode: ActionMode? = null
+  val disposable = CompositeDisposable()
 
   private val zimManageViewModel: ZimManageViewModel by lazy {
     ViewModelProviders.of(activity!!, viewModelFactory)
         .get(ZimManageViewModel::class.java)
   }
 
+  private val bookDelegate: BookDelegate by lazy {
+    BookDelegate(sharedPreferenceUtil,
+        { offerAction(RequestOpen(it)) },
+        { offerAction(RequestMultiSelection(it)) },
+        { offerAction(RequestSelect(it)) })
+  }
+
   private val booksOnDiskAdapter: BooksOnDiskAdapter by lazy {
-    BooksOnDiskAdapter(
-        BookDelegate(sharedPreferenceUtil, this::openOnClick, this::deleteOnLongClick),
-        LanguageDelegate
-    )
+    BooksOnDiskAdapter(bookDelegate, LanguageDelegate)
   }
 
   override fun inject(activityComponent: ActivityComponent) {
@@ -101,31 +101,51 @@ class ZimFileSelectFragment : BaseFragment() {
       layoutManager = LinearLayoutManager(context, RecyclerView.VERTICAL, false)
       setHasFixedSize(true)
     }
-    zimManageViewModel.bookItems.observe(this, Observer {
-      booksOnDiskAdapter.itemList = it!!
-      checkEmpty(it)
-    })
+    zimManageViewModel.fileSelectListStates.observe(this, Observer { render(it) })
+    disposable.add(sideEffects())
     zimManageViewModel.deviceListIsRefreshing.observe(this, Observer {
       zim_swiperefresh.isRefreshing = it!!
     })
   }
 
+  private fun sideEffects() = zimManageViewModel.sideEffects.subscribe(
+      {
+        val effectResult = it.invokeWith(activity!!)
+        if (effectResult is ActionMode) {
+          actionMode = effectResult
+        }
+      }, Throwable::printStackTrace
+  )
+
+  private fun render(state: FileSelectListState) {
+    val items = state.bookOnDiskListItems
+    bookDelegate.selectionMode = state.selectionMode
+    booksOnDiskAdapter.items = items
+    actionMode?.title = String.format("%d", state.selectedBooks.size)
+    file_management_no_files.visibility = if (items.isEmpty()) View.VISIBLE else View.GONE
+  }
+
   override fun onResume() {
     super.onResume()
     checkPermissions()
   }
 
-  private fun checkEmpty(books: List<Any>) {
-    file_management_no_files.visibility =
-      if (books.isEmpty()) View.VISIBLE
-      else View.GONE
+  override fun onDestroy() {
+    super.onDestroy()
+    disposable.clear()
+  }
+
+  private fun offerAction(
+    action: FileSelectActions
+  ) {
+    zimManageViewModel.fileSelectActions.offer(action)
   }
 
   private fun checkPermissions() {
     if (ContextCompat.checkSelfPermission(
             activity!!,
             Manifest.permission.WRITE_EXTERNAL_STORAGE
-        ) != PackageManager.PERMISSION_GRANTED && Build.VERSION.SDK_INT > 18
+        ) != PackageManager.PERMISSION_GRANTED
     ) {
       context.toast(R.string.request_storage)
       requestPermissions(
@@ -140,34 +160,4 @@ class ZimFileSelectFragment : BaseFragment() {
   private fun requestFileSystemCheck() {
     zimManageViewModel.requestFileSystemCheck.onNext(Unit)
   }
-
-  private fun openOnClick(it: BookOnDisk) {
-    val file = it.file
-    ZimContentProvider.canIterate = false
-    if (!file.canRead()) {
-      context.toast(string.error_filenotfound)
-    } else {
-      (activity as ZimManageActivity).finishResult(file.path)
-    }
-  }
-
-  private fun deleteOnLongClick(it: BookOnDisk) {
-    dialogShower.show(DeleteZim, {
-      if (deleteSpecificZimFile(it)) {
-        context.toast(string.delete_specific_zim_toast)
-      } else {
-        context.toast(string.delete_zim_failed)
-      }
-    })
-  }
-
-  private fun deleteSpecificZimFile(book: BookOnDisk): Boolean {
-    val file = book.file
-    FileUtils.deleteZimFile(file.path)
-    if (file.exists()) {
-      return false
-    }
-    bookDao.delete(book.databaseId!!)
-    return true
-  }
 }

app/src/main/java/org/kiwix/kiwixmobile/zim_manager/fileselect_view/adapter/BookOnDiskDelegate.kt

@@ -18,11 +18,13 @@
 package org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter
 
 import android.view.ViewGroup
+import androidx.recyclerview.widget.RecyclerView.ViewHolder
 import org.kiwix.kiwixmobile.R
 import org.kiwix.kiwixmobile.extensions.inflate
 import org.kiwix.kiwixmobile.utils.SharedPreferenceUtil
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.SelectionMode
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.SelectionMode.NORMAL
 import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BookOnDiskViewHolder.BookViewHolder
-import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BookOnDiskViewHolder.LanguageItemViewHolder
 import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BooksOnDiskListItem.BookOnDisk
 import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BooksOnDiskListItem.LanguageItem
 import org.kiwix.kiwixmobile.zim_manager.library_view.adapter.base.AbsDelegateAdapter
@@ -33,17 +35,28 @@ sealed class BookOnDiskDelegate<I : BooksOnDiskListItem, VH : BookOnDiskViewHold
   class BookDelegate(
     val sharedPreferenceUtil: SharedPreferenceUtil,
     val clickAction: (BookOnDisk) -> Unit,
-    val longClickAction: ((BookOnDisk) -> Unit)? = null
+    val longClickAction: ((BookOnDisk) -> Unit)? = null,
+    val multiSelectAction: ((BookOnDisk) -> Unit)? = null
   ) : BookOnDiskDelegate<BookOnDisk, BookViewHolder>() {
 
     override val itemClass = BookOnDisk::class.java
 
+    var selectionMode: SelectionMode = NORMAL
+
+    override fun bind(
+      viewHolder: ViewHolder,
+      itemToBind: BooksOnDiskListItem
+    ) {
+      (viewHolder as BookOnDiskViewHolder.BookViewHolder).bind((itemToBind as BookOnDisk), selectionMode)
+    }
+
     override fun createViewHolder(parent: ViewGroup) =
       BookViewHolder(
           parent.inflate(R.layout.item_book, false),
           sharedPreferenceUtil,
           clickAction,
-          longClickAction
+          longClickAction,
+          multiSelectAction
       )
   }
 

app/src/main/java/org/kiwix/kiwixmobile/zim_manager/fileselect_view/adapter/BooksOnDiskAdapter.kt

@@ -1,7 +1,6 @@
 package org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter
 
 import org.kiwix.kiwixmobile.zim_manager.library_view.adapter.base.AdapterDelegate
-import org.kiwix.kiwixmobile.zim_manager.library_view.adapter.base.AdapterDelegateManager
 import org.kiwix.kiwixmobile.zim_manager.library_view.adapter.base.BaseDelegateAdapter
 
 class BooksOnDiskAdapter(

app/src/main/java/org/kiwix/kiwixmobile/zim_manager/fileselect_view/adapter/BooksOnDiskListItem.kt

@@ -6,6 +6,7 @@ import java.io.File
 import java.util.Locale
 
 sealed class BooksOnDiskListItem {
+  var isSelected: Boolean = false
   abstract val id: Long
 
   data class LanguageItem constructor(

app/src/main/java/org/kiwix/kiwixmobile/zim_manager/fileselect_view/adapter/BooksOnDiskViewHolder.kt

@@ -3,6 +3,7 @@ package org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter
 import android.graphics.ColorMatrixColorFilter
 import android.view.View
 import kotlinx.android.synthetic.main.header_language.header_language
+import kotlinx.android.synthetic.main.item_book.itemBookCheckbox
 import kotlinx.android.synthetic.main.item_book.item_book_article_count
 import kotlinx.android.synthetic.main.item_book.item_book_date
 import kotlinx.android.synthetic.main.item_book.item_book_description
@@ -17,6 +18,9 @@ import org.kiwix.kiwixmobile.main.KiwixWebView
 import org.kiwix.kiwixmobile.utils.SharedPreferenceUtil
 import org.kiwix.kiwixmobile.zim_manager.KiloByte
 import org.kiwix.kiwixmobile.zim_manager.fileselect_view.ArticleCount
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.SelectionMode
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.SelectionMode.MULTI
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.SelectionMode.NORMAL
 import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BooksOnDiskListItem.BookOnDisk
 import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BooksOnDiskListItem.LanguageItem
 import org.kiwix.kiwixmobile.zim_manager.library_view.adapter.base.BaseViewHolder
@@ -28,10 +32,17 @@ sealed class BookOnDiskViewHolder<T : BooksOnDiskListItem>(containerView: View)
     containerView: View,
     private val sharedPreferenceUtil: SharedPreferenceUtil,
     private val clickAction: (BookOnDisk) -> Unit,
-    private val longClickAction: ((BookOnDisk) -> Unit)?
+    private val longClickAction: ((BookOnDisk) -> Unit)?,
+    private val multiSelectAction: ((BookOnDisk) -> Unit)?
   ) : BookOnDiskViewHolder<BookOnDisk>(containerView) {
 
     override fun bind(item: BookOnDisk) {
+    }
+
+    fun bind(
+      item: BookOnDisk,
+      selectionMode: SelectionMode
+    ) {
       val book = item.book
       item_book_title.text = book.getTitle()
       item_book_date.text = book.getDate()
@@ -59,24 +70,29 @@ sealed class BookOnDiskViewHolder<T : BooksOnDiskListItem>(containerView: View)
         item_book_label_video.visibility = View.GONE
       }
 
-      containerView.setOnClickListener {
-        clickAction.invoke(item)
-      }
-      containerView.setOnLongClickListener {
-        longClickAction?.invoke(item)
-        return@setOnLongClickListener true
+      when (selectionMode) {
+        MULTI -> {
+          itemBookCheckbox.visibility = View.VISIBLE
+          containerView.setOnClickListener { multiSelectAction?.invoke(item) }
+          containerView.setOnLongClickListener(null)
+        }
+        NORMAL -> {
+          itemBookCheckbox.visibility = View.GONE
+          containerView.setOnClickListener { clickAction.invoke(item) }
+          containerView.setOnLongClickListener {
+            longClickAction?.invoke(item)
+            return@setOnLongClickListener true
+          }
+        }
       }
     }
   }
-
-  class LanguageItemViewHolder(containerView: View) :
-      BookOnDiskViewHolder<LanguageItem>(containerView) {
-
-    override fun bind(item: LanguageItem) {
-      header_language.text = item.text
-    }
-  }
-
 }
 
+class LanguageItemViewHolder(containerView: View) :
+    BookOnDiskViewHolder<LanguageItem>(containerView) {
 
+  override fun bind(item: LanguageItem) {
+    header_language.text = item.text
+  }
+}

app/src/main/java/org/kiwix/kiwixmobile/zim_manager/fileselect_view/effects/DeleteFiles.kt

@@ -0,0 +1,42 @@
+package org.kiwix.kiwixmobile.zim_manager.fileselect_view.effects
+
+import android.app.Activity
+import org.kiwix.kiwixmobile.R.string
+import org.kiwix.kiwixmobile.database.newdb.dao.NewBookDao
+import org.kiwix.kiwixmobile.extensions.toast
+import org.kiwix.kiwixmobile.utils.DialogShower
+import org.kiwix.kiwixmobile.utils.KiwixDialog.DeleteZim
+import org.kiwix.kiwixmobile.utils.files.FileUtils
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BooksOnDiskListItem.BookOnDisk
+import javax.inject.Inject
+
+class DeleteFiles(val booksOnDiskListItem: List<BookOnDisk>) :
+    SideEffect<Unit> {
+
+  @Inject lateinit var dialogShower: DialogShower
+  @Inject lateinit var newBookDao: NewBookDao
+
+  override fun invokeWith(activity: Activity) {
+    activityComponent(activity).inject(this)
+    booksOnDiskListItem.forEach {
+      dialogShower.show(DeleteZim, {
+        if (deleteSpecificZimFile(it)) {
+          activity.toast(string.delete_specific_zim_toast)
+        } else {
+          activity.toast(string.delete_zim_failed)
+        }
+      })
+    }
+  }
+
+  private fun deleteSpecificZimFile(book: BookOnDisk): Boolean {
+    val file = book.file
+    FileUtils.deleteZimFile(file.path)
+    if (file.exists()) {
+      return false
+    }
+    newBookDao.delete(book.databaseId!!)
+    return true
+  }
+
+}

app/src/main/java/org/kiwix/kiwixmobile/zim_manager/fileselect_view/effects/None.kt

@@ -0,0 +1,8 @@
+package org.kiwix.kiwixmobile.zim_manager.fileselect_view.effects
+
+import android.app.Activity
+
+object None : SideEffect<Unit> {
+  override fun invokeWith(activity: Activity) {
+  }
+}

app/src/main/java/org/kiwix/kiwixmobile/zim_manager/fileselect_view/effects/OpenFile.kt

@@ -0,0 +1,38 @@
+/*
+ * Kiwix Android
+ * Copyright (C) 2018  Kiwix <android.kiwix.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.kiwix.kiwixmobile.zim_manager.fileselect_view.effects
+
+import android.app.Activity
+import org.kiwix.kiwixmobile.R
+import org.kiwix.kiwixmobile.data.ZimContentProvider
+import org.kiwix.kiwixmobile.extensions.toast
+import org.kiwix.kiwixmobile.zim_manager.ZimManageActivity
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BooksOnDiskListItem.BookOnDisk
+
+class OpenFile(val bookOnDisk: BookOnDisk): SideEffect<Unit> {
+
+  override fun invokeWith(activity: Activity) {
+    val file = bookOnDisk.file
+    ZimContentProvider.canIterate = false
+    if (!file.canRead()) {
+      activity.toast(R.string.error_filenotfound)
+    } else {
+      (activity as ZimManageActivity).finishResult(file.path)
+    }
+  }
+}

app/src/main/java/org/kiwix/kiwixmobile/zim_manager/fileselect_view/effects/ShareFiles.kt

@@ -0,0 +1,42 @@
+package org.kiwix.kiwixmobile.zim_manager.fileselect_view.effects
+
+import android.app.Activity
+import android.content.Intent
+import android.net.Uri
+import android.os.Build
+import androidx.core.content.FileProvider
+import org.kiwix.kiwixmobile.BuildConfig
+import org.kiwix.kiwixmobile.R
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BooksOnDiskListItem.BookOnDisk
+
+class ShareFiles(val selectedBooks: List<BookOnDisk>) : SideEffect<Unit> {
+  override fun invokeWith(activity: Activity) {
+    val selectedFileShareIntent = Intent()
+    selectedFileShareIntent.action = Intent.ACTION_SEND_MULTIPLE
+    selectedFileShareIntent.type = "application/octet-stream"
+    val selectedFileContentURIs = selectedBooks.mapNotNull {
+      if (Build.VERSION.SDK_INT >= 24) {
+        FileProvider.getUriForFile(
+            activity,
+            BuildConfig.APPLICATION_ID + ".fileprovider",
+            it.file
+        )
+      } else {
+        Uri.fromFile(it.file)
+      }
+    }
+    selectedFileShareIntent.putParcelableArrayListExtra(
+        Intent.EXTRA_STREAM,
+        ArrayList(selectedFileContentURIs)
+    )
+    selectedFileShareIntent.flags = Intent.FLAG_GRANT_READ_URI_PERMISSION
+    val shareChooserIntent = Intent.createChooser(
+        selectedFileShareIntent,
+        activity.getString(R.string.selected_file_cab_app_chooser_title)
+    )
+    if (shareChooserIntent.resolveActivity(activity.getPackageManager()) != null) {
+      activity.startActivity(shareChooserIntent)  // Open the app chooser dialog
+    }
+  }
+
+}

app/src/main/java/org/kiwix/kiwixmobile/zim_manager/fileselect_view/effects/SideEffect.kt

@@ -0,0 +1,28 @@
+/*
+ * Kiwix Android
+ * Copyright (C) 2018  Kiwix <android.kiwix.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.kiwix.kiwixmobile.zim_manager.fileselect_view.effects
+
+import android.app.Activity
+import org.kiwix.kiwixmobile.KiwixApplication
+
+interface SideEffect<T:Any?> {
+  fun invokeWith(activity: Activity):T
+  fun activityComponent(activity: Activity) =
+    KiwixApplication.getApplicationComponent().activityComponent().activity(activity).build()
+}
+

app/src/main/java/org/kiwix/kiwixmobile/zim_manager/fileselect_view/effects/StartMultiSelection.kt

@@ -0,0 +1,27 @@
+package org.kiwix.kiwixmobile.zim_manager.fileselect_view.effects
+
+import android.app.Activity
+import android.view.ActionMode
+import io.reactivex.processors.PublishProcessor
+import org.kiwix.kiwixmobile.R
+import org.kiwix.kiwixmobile.extensions.startActionMode
+import org.kiwix.kiwixmobile.zim_manager.ZimManageViewModel.FileSelectActions
+import org.kiwix.kiwixmobile.zim_manager.ZimManageViewModel.FileSelectActions.RequestDeleteMultiSelection
+import org.kiwix.kiwixmobile.zim_manager.ZimManageViewModel.FileSelectActions.RequestShareMultiSelection
+import org.kiwix.kiwixmobile.zim_manager.fileselect_view.adapter.BooksOnDiskListItem
+
+data class StartMultiSelection(
+  val bookOnDisk: BooksOnDiskListItem.BookOnDisk,
+  val fileSelectActions: PublishProcessor<FileSelectActions>
+) : SideEffect<ActionMode?> {
+  override fun invokeWith(activity: Activity) =
+    activity.startActionMode(
+        R.menu.menu_zim_files_contextual,
+        mapOf(
+            R.id.zim_file_delete_item to { fileSelectActions.offer(RequestDeleteMultiSelection) },
+            R.id.zim_file_share_item to { fileSelectActions.offer(RequestShareMultiSelection) }
+        ),
+        { fileSelectActions.offer(FileSelectActions.MultiModeFinished) }
+    )
+
+}

app/src/main/java/org/kiwix/kiwixmobile/zim_manager/library_view/LibraryFragment.kt

@@ -140,7 +140,7 @@ class LibraryFragment : BaseFragment() {
   }
 
   private fun onLibraryItemsChange(it: List<LibraryListItem>?) {
-    libraryAdapter.itemList = it!!
+    libraryAdapter.items = it!!
     if (it.isEmpty()) {
       libraryErrorText.setText(
           if (isNotConnected) R.string.no_network_connection

app/src/main/java/org/kiwix/kiwixmobile/zim_manager/library_view/adapter/base/BaseDelegateAdapter.kt

@@ -30,7 +30,7 @@ abstract class BaseDelegateAdapter<ITEM>(
     setHasStableIds(true)
   }
 
-  var itemList: List<ITEM> = mutableListOf()
+  var items: List<ITEM> = mutableListOf()
     set(value) {
       field = value
       notifyDataSetChanged()
@@ -41,19 +41,19 @@ abstract class BaseDelegateAdapter<ITEM>(
     viewType: Int
   ) = delegateManager.createViewHolder(parent, viewType)
 
-  override fun getItemCount() = itemList.size
+  override fun getItemCount() = items.size
   override fun onBindViewHolder(
     holder: ViewHolder,
     position: Int
   ) {
-    delegateManager.onBindViewHolder(itemList[position], holder)
+    delegateManager.onBindViewHolder(items[position], holder)
   }
 
   override fun getItemViewType(position: Int) =
-    delegateManager.getViewTypeFor(itemList[position])
+    delegateManager.getViewTypeFor(items[position])
 
   override fun getItemId(position: Int): Long {
-    return getIdFor(itemList[position])
+    return getIdFor(items[position])
   }
 
   abstract fun getIdFor(item:ITEM):Long

app/src/main/res/layout/item_book.xml

@@ -4,7 +4,7 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
-    android:background="?attr/selectableItemBackground"
+    android:background="?android:attr/selectableItemBackground"
     android:paddingEnd="0dp"
     android:paddingLeft="0dp"
     android:paddingRight="0dp"
@@ -12,13 +12,25 @@
     android:paddingTop="@dimen/activity_vertical_margin"
     >
 
+  <CheckBox
+      android:id="@+id/itemBookCheckbox"
+      android:layout_width="wrap_content"
+      android:layout_height="wrap_content"
+      android:visibility="gone"
+      android:paddingRight="10dp"
+      android:paddingEnd="10dp"
+      app:layout_constraintBottom_toBottomOf="parent"
+      app:layout_constraintStart_toStartOf="parent"
+      app:layout_constraintTop_toTopOf="parent"
+      />
+
   <ImageView
       android:id="@+id/item_book_icon"
       android:layout_width="40dp"
       android:layout_height="40dp"
       android:contentDescription="@string/favicon"
       app:layout_constraintBottom_toBottomOf="parent"
-      app:layout_constraintStart_toStartOf="parent"
+      app:layout_constraintStart_toEndOf="@id/itemBookCheckbox"
       app:layout_constraintTop_toTopOf="parent"
       tools:src="@mipmap/kiwix_icon_round"
       />

app/src/test/java/org/kiwix/kiwixmobile/zim_manager/ZimManageViewModelTest.kt

@@ -235,7 +235,7 @@ class ZimManageViewModelTest {
       val expectedList = listOf(bookOnDisk())
       booksOnDiskListItems.onNext(expectedList)
       testScheduler.triggerActions()
-      viewModel.bookItems.test()
+      viewModel.fileSelectListStates.test()
           .assertValue(expectedList)
     }