Retrieve data from DB as LiveData has been implemented.

owncloudApp/src/main/java/com/owncloud/android/dependecyinjection/UseCaseModule.kt

@@ -41,6 +41,7 @@ import com.owncloud.android.domain.files.usecases.CreateFolderAsyncUseCase
 import com.owncloud.android.domain.files.usecases.GetFileByIdUseCase
 import com.owncloud.android.domain.files.usecases.GetFileByRemotePathUseCase
 import com.owncloud.android.domain.files.usecases.GetFilesSharedByLinkUseCase
+import com.owncloud.android.domain.files.usecases.GetFolderContentAsLiveDataUseCase
 import com.owncloud.android.domain.files.usecases.GetFolderContentUseCase
 import com.owncloud.android.domain.files.usecases.GetFolderImagesUseCase
 import com.owncloud.android.domain.files.usecases.MoveFileUseCase
@@ -92,6 +93,7 @@ val useCaseModule = module {
     factory { GetFileByIdUseCase(get()) }
     factory { GetFileByRemotePathUseCase(get()) }
     factory { GetFolderContentUseCase(get()) }
+    factory { GetFolderContentAsLiveDataUseCase(get()) }
     factory { GetFolderImagesUseCase(get()) }
     factory { MoveFileUseCase(get()) }
     factory { RefreshFolderFromServerAsyncUseCase(get()) }

owncloudApp/src/main/java/com/owncloud/android/dependecyinjection/ViewModelModule.kt

@@ -75,5 +75,5 @@ val viewModelModule = module {
     viewModel { PreviewImageViewModel(get(), get(), get()) }
     viewModel { FileDetailsViewModel(get(), get(), get(), get(), get()) }
     viewModel { FileOperationViewModel(get(), get(), get(), get(), get(), get()) }
-    viewModel { MainFileListViewModel(get(), get()) }
+    viewModel { MainFileListViewModel(get(), get(), get()) }
 }

owncloudApp/src/main/java/com/owncloud/android/presentation/UIResult.kt

@@ -19,6 +19,8 @@
 
 package com.owncloud.android.presentation
 
+import com.owncloud.android.domain.UseCaseResult
+
 sealed class UIResult<out T> {
     data class Loading<out T>(val data: T? = null) : UIResult<T>()
     data class Success<out T>(val data: T? = null) : UIResult<T>()
@@ -41,6 +43,15 @@ sealed class UIResult<out T> {
             is Error -> error
             else -> null
         }
+
+    companion object {
+        fun <T> fromResult(result: UseCaseResult<T>): UIResult<T> =
+            if (result.isSuccess) {
+                Success(result.getDataOrNull())
+            } else {
+                Error(result.getThrowableOrNull())
+            }
+    }
 }
 
 fun <T> UIResult<T>.onLoading(action: (data: T?) -> Unit): UIResult<T> {
@@ -69,3 +80,5 @@ fun <T> UIResult<T>.fold(
         is UIResult.Error -> onFailure(error)
     }
 }
+
+fun <T> UseCaseResult<T>.toUIResult() = UIResult.fromResult(this)

owncloudApp/src/main/java/com/owncloud/android/presentation/ui/files/filelist/MainFileListFragment.kt

@@ -30,8 +30,6 @@ import com.owncloud.android.databinding.MainFileListFragmentBinding
 import com.owncloud.android.domain.files.model.OCFile
 import com.owncloud.android.domain.utils.Event
 import com.owncloud.android.presentation.adapters.filelist.FileListAdapter
-import com.owncloud.android.presentation.onError
-import com.owncloud.android.presentation.onLoading
 import com.owncloud.android.presentation.onSuccess
 import org.koin.androidx.viewmodel.ext.android.viewModel
 
@@ -69,15 +67,13 @@ class MainFileListFragment : Fragment() {
     }
 
     private fun subscribeToViewModels() {
-        //Observe the action of retrieving the list of files.
+        //Observe the action of retrieving the list of files from BBDD.
         mainFileListViewModel.getFilesListStatusLiveData.observe(viewLifecycleOwner, Event.EventObserver {
-            it.onLoading { /*TODO Manage Loading*/ }
             it.onSuccess { data ->
                 val files = data ?: emptyList()
                 fileListAdapter.updateFileList(filesToAdd = files)
                 mainFileListViewModel.manageListOfFiles(files)
             }
-            it.onError { /*TODO Manage Error*/ }
         })
 
         mainFileListViewModel.numberOfFilesPerType.observe(viewLifecycleOwner, Event.EventObserver {

owncloudApp/src/main/java/com/owncloud/android/presentation/ui/files/filelist/MainFileListViewModel.kt

@@ -25,18 +25,19 @@ import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
 import com.owncloud.android.R
-import com.owncloud.android.domain.UseCaseResult
 import com.owncloud.android.domain.files.model.OCFile
 import com.owncloud.android.domain.files.usecases.GetFolderContentUseCase
 import com.owncloud.android.domain.utils.Event
 import com.owncloud.android.presentation.UIResult
+import com.owncloud.android.presentation.toUIResult
 import com.owncloud.android.providers.ContextProvider
-import kotlinx.coroutines.Dispatchers
+import com.owncloud.android.providers.CoroutinesDispatcherProvider
 import kotlinx.coroutines.launch
 
 class MainFileListViewModel(
-    private val getFolderContentUseCase: GetFolderContentUseCase,
+    private val getFolderContentAsFlowUseCase: GetFolderContentUseCase,
     private val contextProvider: ContextProvider,
+    private val coroutinesDispatcherProvider: CoroutinesDispatcherProvider,
 ) : ViewModel() {
 
     private var file: OCFile? = null
@@ -54,13 +55,9 @@ class MainFileListViewModel(
         get() = _footerText
 
     private fun getFilesList(folderId: Long) {
-        viewModelScope.launch(Dispatchers.IO) {
-            _getFilesListStatusLiveData.postValue(Event(UIResult.Loading()))
-            getFolderContentUseCase.execute(GetFolderContentUseCase.Params(folderId = folderId)).let {
-                when (it) {
-                    is UseCaseResult.Error -> _getFilesListStatusLiveData.postValue(Event(UIResult.Error(it.getThrowableOrNull())))
-                    is UseCaseResult.Success -> _getFilesListStatusLiveData.postValue(Event(UIResult.Success(it.getDataOrNull())))
-                }
+        viewModelScope.launch(coroutinesDispatcherProvider.io) {
+            with(getFolderContentAsFlowUseCase.execute(GetFolderContentUseCase.Params(folderId = folderId)).toUIResult()) {
+                _getFilesListStatusLiveData.postValue(Event(this))
             }
         }
     }

owncloudData/src/main/java/com/owncloud/android/data/files/datasources/LocalFileDataSource.kt

@@ -20,13 +20,15 @@
 
 package com.owncloud.android.data.files.datasources
 
+import androidx.lifecycle.LiveData
 import com.owncloud.android.domain.files.model.OCFile
 
 interface LocalFileDataSource {
     fun copyFile(sourceFile: OCFile, targetFile: OCFile, finalRemotePath: String, remoteId: String)
     fun getFileById(fileId: Long): OCFile?
     fun getFileByRemotePath(remotePath: String, owner: String): OCFile?
     fun getFolderContent(folderId: Long): List<OCFile>
+    fun getFolderContentAsLiveData(folderId: Long): LiveData<List<OCFile>>
     fun getFolderImages(folderId: Long): List<OCFile>
     fun getFilesSharedByLink(owner: String): List<OCFile>
     fun moveFile(sourceFile: OCFile, targetFile: OCFile, finalRemotePath: String, finalStoragePath: String)

owncloudData/src/main/java/com/owncloud/android/data/files/datasources/implementation/OCLocalFileDataSource.kt

@@ -19,6 +19,8 @@
 package com.owncloud.android.data.files.datasources.implementation
 
 import androidx.annotation.VisibleForTesting
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.Transformations
 import com.owncloud.android.data.files.datasources.LocalFileDataSource
 import com.owncloud.android.data.files.db.FileDao
 import com.owncloud.android.data.files.db.OCFileEntity
@@ -67,6 +69,13 @@ class OCLocalFileDataSource(
             it.toModel()
         }
 
+    override fun getFolderContentAsLiveData(folderId: Long): LiveData<List<OCFile>> =
+        Transformations.map(fileDao.getFolderContentAsLiveData(folderId = folderId)) { list ->
+            list.map {
+                it.toModel()
+            }
+        }
+
     override fun getFolderImages(folderId: Long): List<OCFile> =
         fileDao.getFolderByMimeType(folderId = folderId, mimeType = MIME_PREFIX_IMAGE).map {
             it.toModel()

owncloudData/src/main/java/com/owncloud/android/data/files/db/FileDao.kt

@@ -18,6 +18,7 @@
  */
 package com.owncloud.android.data.files.db
 
+import androidx.lifecycle.LiveData
 import androidx.room.Dao
 import androidx.room.Insert
 import androidx.room.OnConflictStrategy
@@ -45,6 +46,11 @@ abstract class FileDao {
         folderId: Long
     ): List<OCFileEntity>
 
+    @Query(SELECT_FOLDER_CONTENT)
+    abstract fun getFolderContentAsLiveData(
+        folderId: Long
+    ): LiveData<List<OCFileEntity>>
+
     @Query(SELECT_FOLDER_BY_MIMETYPE)
     abstract fun getFolderByMimeType(
         folderId: Long,

owncloudData/src/main/java/com/owncloud/android/data/files/repository/OCFileRepository.kt

@@ -20,6 +20,7 @@
 
 package com.owncloud.android.data.files.repository
 
+import androidx.lifecycle.LiveData
 import com.owncloud.android.data.files.datasources.LocalFileDataSource
 import com.owncloud.android.data.files.datasources.RemoteFileDataSource
 import com.owncloud.android.data.storage.LocalStorageProvider
@@ -113,6 +114,9 @@ class OCFileRepository(
     override fun getFolderContent(folderId: Long): List<OCFile> =
         localFileDataSource.getFolderContent(folderId)
 
+    override fun getFolderContentAsLiveData(folderId: Long): LiveData<List<OCFile>> =
+        localFileDataSource.getFolderContentAsLiveData(folderId)
+
     override fun getFolderImages(folderId: Long): List<OCFile> =
         localFileDataSource.getFolderImages(folderId)
 

owncloudDomain/src/main/java/com/owncloud/android/domain/files/FileRepository.kt

@@ -20,6 +20,7 @@
 
 package com.owncloud.android.domain.files
 
+import androidx.lifecycle.LiveData
 import com.owncloud.android.domain.files.model.OCFile
 
 interface FileRepository {
@@ -28,6 +29,7 @@ interface FileRepository {
     fun getFileById(fileId: Long): OCFile?
     fun getFileByRemotePath(remotePath: String, owner: String): OCFile?
     fun getFolderContent(folderId: Long): List<OCFile>
+    fun getFolderContentAsLiveData(folderId: Long): LiveData<List<OCFile>>
     fun getFolderImages(folderId: Long): List<OCFile>
     fun getFilesSharedByLink(owner: String): List<OCFile>
     fun moveFile(listOfFilesToMove: List<OCFile>, targetFile: OCFile)

owncloudDomain/src/main/java/com/owncloud/android/domain/files/usecases/GetFolderContentAsLiveDataUseCase.kt

@@ -0,0 +1,34 @@
+/**
+ * ownCloud Android client application
+ *
+ * @author Abel García de Prada
+ * Copyright (C) 2020 ownCloud GmbH.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2,
+ * as published by the Free Software Foundation.
+ *
+ * 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 com.owncloud.android.domain.files.usecases
+
+import androidx.lifecycle.LiveData
+import com.owncloud.android.domain.BaseUseCase
+import com.owncloud.android.domain.files.FileRepository
+import com.owncloud.android.domain.files.model.OCFile
+
+class GetFolderContentAsLiveDataUseCase(
+    private val repository: FileRepository
+) : BaseUseCase<LiveData<List<OCFile>>, GetFolderContentAsLiveDataUseCase.Params>() {
+
+    override fun run(params: Params) = repository.getFolderContentAsLiveData(params.folderId)
+
+    data class Params(val folderId: Long)
+
+}