New user model

New non-nullable user model abstracts away all complexities of Nextcloud
user account and provides.

- backported java.util.Optional
- extended UserAccountManager with User getters
- deprecated CurrentAccountProvider.getCurrentAccount() method
- migrated connectivity service to new user model
- migrated UploadsStorageManager to new user model
- migrated OCFileListAdapter

Signed-off-by: Chris Narkiewicz <hello@ezaquarii.com>

src/main/java/com/nextcloud/client/account/AnonymousUser.kt

@@ -0,0 +1,57 @@
+/*
+ * Nextcloud Android client application
+ *
+ * @author Chris Narkiewicz <hello@ezaquarii.com>
+ * Copyright (C) 2019 Chris Narkiewicz
+ * Copyright (C) 2019 Nextcloud GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.nextcloud.client.account
+
+import android.accounts.Account
+import android.content.Context
+import android.net.Uri
+import com.owncloud.android.MainApp
+import com.owncloud.android.R
+import com.owncloud.android.lib.common.OwnCloudAccount
+import com.owncloud.android.lib.common.OwnCloudBasicCredentials
+import java.net.URI
+
+/**
+ * This object represents anonymous user, ie. user that did not log in the Nextcloud server.
+ * It serves as a semantically correct "empty value", allowing simplification of logic
+ * in various components requiring user data, such as DB queries.
+ */
+internal class AnonymousUser(private val accountType: String) : User {
+
+    companion object {
+        @JvmStatic
+        fun fromContext(context: Context): AnonymousUser {
+            val type = context.getString(R.string.account_type)
+            return AnonymousUser(type)
+        }
+    }
+
+    override val accountName: String = "anonymous"
+    override val server = Server(URI.create(""), MainApp.MINIMUM_SUPPORTED_SERVER_VERSION)
+
+    override fun toPlatformAccount(): Account {
+        return Account(accountName, accountType)
+    }
+
+    override fun toOwnCloudAccount(): OwnCloudAccount {
+        return OwnCloudAccount(Uri.EMPTY, OwnCloudBasicCredentials("", ""))
+    }
+}

src/main/java/com/nextcloud/client/account/CurrentAccountProvider.java

@@ -2,19 +2,31 @@ package com.nextcloud.client.account;
 
 import android.accounts.Account;
 
+import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
 /**
- * This interface provides access to currently selected user Account.
+ * This interface provides access to currently selected user.
+ *
  * @see UserAccountManager
  */
-@FunctionalInterface
 public interface CurrentAccountProvider {
     /**
-     *  Get currently active account.
+     * Get currently active account.
      *
      * @return Currently selected {@link Account} or first valid {@link Account} registered in OS or null, if not available at all.
      */
+    @Deprecated
     @Nullable
     Account getCurrentAccount();
+
+    /**
+     * Get currently active user profile. If there is no actice user, anonymous user is returned.
+     *
+     * @return User profile. Profile is never null.
+     */
+    @NonNull
+    default User getUser() {
+        return new AnonymousUser("dummy");
+    }
 }

src/main/java/com/nextcloud/client/account/RegisteredUser.kt

@@ -0,0 +1,46 @@
+/*
+ * Nextcloud Android client application
+ *
+ * @author Chris Narkiewicz <hello@ezaquarii.com>
+ * Copyright (C) 2019 Chris Narkiewicz
+ * Copyright (C) 2019 Nextcloud GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.nextcloud.client.account
+
+import android.accounts.Account
+import com.owncloud.android.lib.common.OwnCloudAccount
+
+/**
+ * This class represents normal user logged into the Nextcloud server.
+ */
+internal class RegisteredUser(
+    private val account: Account,
+    private val ownCloudAccount: OwnCloudAccount,
+    override val server: Server
+) : User {
+
+    override val accountName: String get() {
+        return account.name
+    }
+
+    override fun toPlatformAccount(): Account {
+        return account
+    }
+
+    override fun toOwnCloudAccount(): OwnCloudAccount {
+        return ownCloudAccount
+    }
+}

src/main/java/com/nextcloud/client/account/Server.kt

@@ -0,0 +1,30 @@
+/*
+ * Nextcloud Android client application
+ *
+ * @author Chris Narkiewicz <hello@ezaquarii.com>
+ * Copyright (C) 2019 Chris Narkiewicz
+ * Copyright (C) 2019 Nextcloud GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.nextcloud.client.account
+
+import com.owncloud.android.lib.resources.status.OwnCloudVersion
+import java.net.URI
+
+/**
+ * This object provides all information necessary to interact
+ * with backend server.
+ */
+data class Server(val uri: URI, val version: OwnCloudVersion)

src/main/java/com/nextcloud/client/account/User.kt

@@ -0,0 +1,53 @@
+/*
+ * Nextcloud Android client application
+ *
+ * @author Chris Narkiewicz <hello@ezaquarii.com>
+ * Copyright (C) 2019 Chris Narkiewicz
+ * Copyright (C) 2019 Nextcloud GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+package com.nextcloud.client.account
+
+import android.accounts.Account
+import com.owncloud.android.lib.common.OwnCloudAccount
+
+interface User {
+    val accountName: String
+    val server: Server
+
+    /**
+     * This is temporary helper method created to facilitate incremental refactoring.
+     * Code using legacy platform Account can be partially converted to instantiate User
+     * object and use account instance when required.
+     *
+     * This method calls will allow tracing code awaiting further refactoring.
+     *
+     * @return Account instance that is associated with this User object.
+     */
+    @Deprecated("Temporary workaround")
+    fun toPlatformAccount(): Account
+
+    /**
+     * This is temporary helper method created to facilitate incremental refactoring.
+     * Code using legacy ownCloud account can be partially converted to instantiate User
+     * object and use account instance when required.
+     *
+     * This method calls will allow tracing code awaiting further refactoring.
+     *
+     * @return OwnCloudAccount instance that is associated with this User object.
+     */
+    @Deprecated("Temporary workaround")
+    fun toOwnCloudAccount(): OwnCloudAccount
+}

src/main/java/com/nextcloud/client/account/UserAccountManager.java

@@ -21,10 +21,13 @@ package com.nextcloud.client.account;
 
 import android.accounts.Account;
 
+import com.nextcloud.java.util.Optional;
 import com.owncloud.android.datamodel.OCFile;
 import com.owncloud.android.lib.common.OwnCloudAccount;
 import com.owncloud.android.lib.resources.status.OwnCloudVersion;
 
+import java.util.List;
+
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
@@ -51,6 +54,22 @@ public interface UserAccountManager extends CurrentAccountProvider {
     @NonNull
     Account[] getAccounts();
 
+    /**
+     * Get configured nextcloud user accounts
+     * @return List of users or empty list, if users are not registered.
+     */
+    @NonNull
+    List<User> getAllUsers();
+
+    /**
+     * Get user with a specific account name.
+     *
+     * @param accountName Account name of the requested user
+     * @return User or empty optional if user does not exist.
+     */
+    @NonNull
+    Optional<User> getUser(CharSequence accountName);
+
     /**
      * Check if Nextcloud account is registered in {@link android.accounts.AccountManager}
      *

src/main/java/com/nextcloud/client/account/UserAccountManagerImpl.java

@@ -27,6 +27,7 @@ import android.content.SharedPreferences;
 import android.preference.PreferenceManager;
 import android.text.TextUtils;
 
+import com.nextcloud.java.util.Optional;
 import com.owncloud.android.MainApp;
 import com.owncloud.android.R;
 import com.owncloud.android.datamodel.ArbitraryDataProvider;
@@ -35,11 +36,18 @@ import com.owncloud.android.lib.common.OwnCloudAccount;
 import com.owncloud.android.lib.common.OwnCloudClient;
 import com.owncloud.android.lib.common.OwnCloudClientManagerFactory;
 import com.owncloud.android.lib.common.UserInfo;
+import com.owncloud.android.lib.common.accounts.AccountUtils;
 import com.owncloud.android.lib.common.operations.RemoteOperationResult;
 import com.owncloud.android.lib.common.utils.Log_OC;
 import com.owncloud.android.lib.resources.status.OwnCloudVersion;
 import com.owncloud.android.lib.resources.users.GetUserInfoRemoteOperation;
 
+import org.jetbrains.annotations.NotNull;
+
+import java.net.URI;
+import java.util.ArrayList;
+import java.util.List;
+
 import javax.inject.Inject;
 
 import androidx.annotation.NonNull;
@@ -80,6 +88,20 @@ public class UserAccountManagerImpl implements UserAccountManager {
         return accountManager.getAccountsByType(getAccountType());
     }
 
+    @Override
+    @NonNull
+    public List<User> getAllUsers() {
+        Account[] accounts = getAccounts();
+        List<User> users = new ArrayList<>(accounts.length);
+        for (Account account : accounts) {
+            User user = createUserFromAccount(account);
+            if (user != null) {
+                users.add(user);
+            }
+        }
+        return users;
+    }
+
     @Override
     public boolean exists(Account account) {
         Account[] nextcloudAccounts = getAccounts();
@@ -103,6 +125,7 @@ public class UserAccountManagerImpl implements UserAccountManager {
         return false;
     }
 
+    @Override
     @Nullable
     public Account getCurrentAccount() {
         Account[] ocAccounts = getAccounts();
@@ -139,6 +162,76 @@ public class UserAccountManagerImpl implements UserAccountManager {
         return defaultAccount;
     }
 
+    /**
+     * Temporary solution to convert platform account to user instance.
+     * It takes null and returns null on error to ease error handling
+     * in legacy code.
+     *
+     * @param account Account instance
+     * @return User instance or null, if conversion failed
+     */
+    @Nullable
+    private User createUserFromAccount(@Nullable Account account) {
+        if (account == null) {
+            return null;
+        }
+
+        OwnCloudAccount ownCloudAccount = null;
+        try {
+            ownCloudAccount = new OwnCloudAccount(account, context);
+        } catch (AccountUtils.AccountNotFoundException ex) {
+            return null;
+        }
+
+        /*
+         * Server version
+         */
+        String serverVersionStr = accountManager.getUserData(account, AccountUtils.Constants.KEY_OC_VERSION);
+        OwnCloudVersion serverVersion;
+        if (serverVersionStr != null) {
+            serverVersion = new OwnCloudVersion(serverVersionStr);
+        } else {
+            serverVersion = MainApp.MINIMUM_SUPPORTED_SERVER_VERSION;
+        }
+
+        /*
+         * Server address
+         */
+        String serverAddressStr = accountManager.getUserData(account, AccountUtils.Constants.KEY_OC_BASE_URL);
+        if (serverAddressStr == null || serverAddressStr.isEmpty()) {
+            return AnonymousUser.fromContext(context);
+        }
+        URI serverUri = URI.create(serverAddressStr); // TODO: validate
+
+        return new RegisteredUser(
+            account,
+            ownCloudAccount,
+            new Server(serverUri, serverVersion)
+        );
+    }
+
+    /**
+     * Get user. If user cannot be retrieved due to data error, anonymous user is returned instead.
+     *
+     *
+     * @return User instance
+     */
+    @NotNull
+    @Override
+    public User getUser() {
+        Account account = getCurrentAccount();
+        User user = createUserFromAccount(account);
+        return user != null ? user : AnonymousUser.fromContext(context);
+    }
+
+    @Override
+    @NonNull
+    public Optional<User> getUser(CharSequence accountName) {
+        Account account = getAccountByName(accountName.toString());
+        User user =  createUserFromAccount(account);
+        return Optional.of(user);
+    }
+
     @Override
     @Nullable
     public OwnCloudAccount getCurrentOwnCloudAccount() {
@@ -197,6 +290,7 @@ public class UserAccountManagerImpl implements UserAccountManager {
         return result;
     }
 
+    @Deprecated
     @Override
     @NonNull
     public OwnCloudVersion getServerVersion(Account account) {

src/main/java/com/nextcloud/client/network/ConnectivityServiceImpl.java

@@ -20,14 +20,13 @@
 
 package com.nextcloud.client.network;
 
-import android.accounts.Account;
 import android.net.ConnectivityManager;
 import android.net.NetworkInfo;
 
 import com.evernote.android.job.JobRequest;
+import com.nextcloud.client.account.Server;
 import com.nextcloud.client.account.UserAccountManager;
-import com.owncloud.android.lib.common.OwnCloudAccount;
-import com.owncloud.android.lib.common.utils.Log_OC;
+import com.nextcloud.client.logger.Logger;
 import com.owncloud.android.lib.resources.status.OwnCloudVersion;
 
 import org.apache.commons.httpclient.HttpClient;
@@ -44,10 +43,11 @@ class ConnectivityServiceImpl implements ConnectivityService {
 
     private final static String TAG = ConnectivityServiceImpl.class.getName();
 
-    private ConnectivityManager connectivityManager;
-    private UserAccountManager accountManager;
-    private ClientFactory clientFactory;
-    private GetRequestBuilder requestBuilder;
+    private final ConnectivityManager connectivityManager;
+    private final UserAccountManager accountManager;
+    private final ClientFactory clientFactory;
+    private final GetRequestBuilder requestBuilder;
+    private final Logger logger;
 
     static class GetRequestBuilder implements Function1<String, GetMethod> {
         @Override
@@ -59,55 +59,55 @@ class ConnectivityServiceImpl implements ConnectivityService {
     ConnectivityServiceImpl(ConnectivityManager connectivityManager,
                             UserAccountManager accountManager,
                             ClientFactory clientFactory,
-                            GetRequestBuilder requestBuilder) {
+                            GetRequestBuilder requestBuilder,
+                            Logger logger) {
         this.connectivityManager = connectivityManager;
         this.accountManager = accountManager;
         this.clientFactory = clientFactory;
         this.requestBuilder = requestBuilder;
+        this.logger = logger;
     }
 
     @Override
     public boolean isInternetWalled() {
         if (isOnlineWithWifi()) {
             try {
-                Account account = accountManager.getCurrentAccount();
-                OwnCloudAccount ocAccount = accountManager.getCurrentOwnCloudAccount();
-                if (account != null && ocAccount != null) {
-                    OwnCloudVersion serverVersion = accountManager.getServerVersion(account);
+                Server server = accountManager.getUser().getServer();
+                String baseServerAddress = server.getUri().toString();
+                if (baseServerAddress.isEmpty()) {
+                    return true;
+                }
+                String url;
+                if (server.getVersion().compareTo(OwnCloudVersion.nextcloud_13) > 0) {
+                    url = baseServerAddress + "/index.php/204";
+                } else {
+                    url = baseServerAddress + "/status.php";
+                }
 
-                    String url;
-                    if (serverVersion.compareTo(OwnCloudVersion.nextcloud_13) > 0) {
-                        url = ocAccount.getBaseUri() + "/index.php/204";
-                    } else {
-                        url = ocAccount.getBaseUri() + "/status.php";
-                    }
+                GetMethod get = requestBuilder.invoke(url);
+                HttpClient client = clientFactory.createPlainClient();
 
-                    GetMethod get = requestBuilder.invoke(url);
-                    HttpClient client = clientFactory.createPlainClient();
+                int status = client.executeMethod(get);
 
-                    int status = client.executeMethod(get);
-
-                    if (serverVersion.compareTo(OwnCloudVersion.nextcloud_13) > 0) {
-                        return !(status == HttpStatus.SC_NO_CONTENT &&
-                            (get.getResponseContentLength() == -1 || get.getResponseContentLength() == 0));
-                    } else {
-                        if (status == HttpStatus.SC_OK) {
-                            try {
-                                // try parsing json to verify response
-                                // check if json contains maintenance and it should be false
-
-                                String json = get.getResponseBodyAsString();
-                                return new JSONObject(json).getBoolean("maintenance");
-                            } catch (Exception e) {
-                                return true;
-                            }
-                        } else {
+                if (server.getVersion().compareTo(OwnCloudVersion.nextcloud_13) > 0) {
+                    return !(status == HttpStatus.SC_NO_CONTENT &&
+                        (get.getResponseContentLength() == -1 || get.getResponseContentLength() == 0));
+                } else {
+                    if (status == HttpStatus.SC_OK) {
+                        try {
+                            // try parsing json to verify response
+                            // check if json contains maintenance and it should be false
+                            String json = get.getResponseBodyAsString();
+                            return new JSONObject(json).getBoolean("maintenance");
+                        } catch (Exception e) {
                             return true;
                         }
+                    } else {
+                        return true;
                     }
                 }
             } catch (IOException e) {
-                Log_OC.e(TAG, "Error checking internet connection", e);
+                logger.e(TAG, "Error checking internet connection", e);
             }
         } else {
             return getActiveNetworkType() == JobRequest.NetworkType.ANY;

src/main/java/com/nextcloud/client/network/NetworkModule.java

@@ -24,6 +24,7 @@ import android.content.Context;
 import android.net.ConnectivityManager;
 
 import com.nextcloud.client.account.UserAccountManager;
+import com.nextcloud.client.logger.Logger;
 
 import javax.inject.Singleton;
 
@@ -36,11 +37,13 @@ public class NetworkModule {
     @Provides
     ConnectivityService connectivityService(ConnectivityManager connectivityManager,
                                             UserAccountManager accountManager,
-                                            ClientFactory clientFactory) {
+                                            ClientFactory clientFactory,
+                                            Logger logger) {
         return new ConnectivityServiceImpl(connectivityManager,
                                            accountManager,
                                            clientFactory,
-                                           new ConnectivityServiceImpl.GetRequestBuilder());
+                                           new ConnectivityServiceImpl.GetRequestBuilder(),
+                                           logger);
     }
 
     @Provides

src/main/java/com/nextcloud/java/util/Optional.java

@@ -0,0 +1,366 @@
+/*
+ * Copyright (c) 2012, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.nextcloud.java.util;
+
+import com.nextcloud.java.util.function.Predicate;
+
+import java.util.NoSuchElementException;
+
+import androidx.core.util.Consumer;
+import androidx.core.util.ObjectsCompat;
+import androidx.core.util.Supplier;
+import kotlin.jvm.functions.Function1;
+
+/**
+ * This class is backported from Java 8 to be used on older Android API levels.
+ * It uses available interfaces from Kotlin and androidx. It is semantically
+ * identical with Java 8 API, allowing smooth migration when those APIs become
+ * available.
+ *
+ * A container object which may or may not contain a non-null value.
+ * If a value is present, {@code isPresent()} will return {@code true} and
+ * {@code get()} will return the value.
+ *
+ * <p>Additional methods that depend on the presence or absence of a contained
+ * value are provided, such as {@link #orElse(java.lang.Object) orElse()}
+ * (return a default value if value not present) and
+ * {@link #ifPresent(Consumer) ifPresent()} (execute a block
+ * of code if the value is present).
+ */
+public final class Optional<T> {
+    /**
+     * Common instance for {@code empty()}.
+     */
+    private static final Optional<?> EMPTY = new Optional<>();
+
+    /**
+     * If non-null, the value; if null, indicates no value is present
+     */
+    private final T value;
+
+    /**
+     * Constructs an empty instance.
+     *
+     * @implNote Generally only one empty instance, {@link Optional#EMPTY},
+     * should exist per VM.
+     */
+    private Optional() {
+        this.value = null;
+    }
+
+    /**
+     * Returns an empty {@code Optional} instance.  No value is present for this
+     * Optional.
+     *
+     * @apiNote Though it may be tempting to do so, avoid testing if an object
+     * is empty by comparing with {@code ==} against instances returned by
+     * {@code Option.empty()}. There is no guarantee that it is a singleton.
+     * Instead, use {@link #isPresent()}.
+     *
+     * @param <T> Type of the non-existent value
+     * @return an empty {@code Optional}
+     */
+    public static<T> Optional<T> empty() {
+        @SuppressWarnings("unchecked")
+        Optional<T> t = (Optional<T>) EMPTY;
+        return t;
+    }
+
+    /**
+     * Constructs an instance with the value present.
+     *
+     * @param value the non-null value to be present
+     * @throws NullPointerException if value is null
+     */
+    private Optional(T value) {
+        if (value == null) {
+            throw new NullPointerException();
+        }
+        this.value = value;
+    }
+
+    /**
+     * Returns an {@code Optional} with the specified present non-null value.
+     *
+     * @param <T> the class of the value
+     * @param value the value to be present, which must be non-null
+     * @return an {@code Optional} with the value present
+     * @throws NullPointerException if value is null
+     */
+    public static <T> Optional<T> of(T value) {
+        return new Optional<>(value);
+    }
+
+    /**
+     * Returns an {@code Optional} describing the specified value, if non-null,
+     * otherwise returns an empty {@code Optional}.
+     *
+     * @param <T> the class of the value
+     * @param value the possibly-null value to describe
+     * @return an {@code Optional} with a present value if the specified value
+     * is non-null, otherwise an empty {@code Optional}
+     */
+    public static <T> Optional<T> ofNullable(T value) {
+        return value == null ? empty() : of(value);
+    }
+
+    /**
+     * If a value is present in this {@code Optional}, returns the value,
+     * otherwise throws {@code NoSuchElementException}.
+     *
+     * @return the non-null value held by this {@code Optional}
+     * @throws NoSuchElementException if there is no value present
+     *
+     * @see Optional#isPresent()
+     */
+    public T get() {
+        if (value == null) {
+            throw new NoSuchElementException("No value present");
+        }
+        return value;
+    }
+
+    /**
+     * Return {@code true} if there is a value present, otherwise {@code false}.
+     *
+     * @return {@code true} if there is a value present, otherwise {@code false}
+     */
+    public boolean isPresent() {
+        return value != null;
+    }
+
+    /**
+     * If a value is present, invoke the specified consumer with the value,
+     * otherwise do nothing.
+     *
+     * @param consumer block to be executed if a value is present
+     * @throws NullPointerException if value is present and {@code consumer} is
+     * null
+     */
+    public void ifPresent(Consumer<? super T> consumer) {
+        if (value != null) {
+            consumer.accept(value);
+        }
+    }
+
+    /**
+     * If a value is present, and the value matches the given predicate,
+     * return an {@code Optional} describing the value, otherwise return an
+     * empty {@code Optional}.
+     *
+     * @param predicate a predicate to apply to the value, if present
+     * @return an {@code Optional} describing the value of this {@code Optional}
+     * if a value is present and the value matches the given predicate,
+     * otherwise an empty {@code Optional}
+     * @throws NullPointerException if the predicate is null
+     */
+    public Optional<T> filter(Predicate<? super T> predicate) {
+        if (predicate == null) {
+            throw new NullPointerException();
+        }
+        if (!isPresent()) {
+            return this;
+        } else {
+            return predicate.test(value) ? this : empty();
+        }
+    }
+
+    /**
+     * If a value is present, apply the provided mapping function to it,
+     * and if the result is non-null, return an {@code Optional} describing the
+     * result.  Otherwise return an empty {@code Optional}.
+     *
+     * @apiNote This method supports post-processing on optional values, without
+     * the need to explicitly check for a return status.  For example, the
+     * following code traverses a stream of file names, selects one that has
+     * not yet been processed, and then opens that file, returning an
+     * {@code Optional<FileInputStream>}:
+     *
+     * <pre>{@code
+     *     Optional<FileInputStream> fis =
+     *         names.stream().filter(name -> !isProcessedYet(name))
+     *                       .findFirst()
+     *                       .map(name -> new FileInputStream(name));
+     * }</pre>
+     *
+     * Here, {@code findFirst} returns an {@code Optional<String>}, and then
+     * {@code map} returns an {@code Optional<FileInputStream>} for the desired
+     * file if one exists.
+     *
+     * @param <U> The type of the result of the mapping function
+     * @param mapper a mapping function to apply to the value, if present
+     * @return an {@code Optional} describing the result of applying a mapping
+     * function to the value of this {@code Optional}, if a value is present,
+     * otherwise an empty {@code Optional}
+     * @throws NullPointerException if the mapping function is null
+     */
+    public<U> Optional<U> map(Function1<? super T, ? extends U> mapper) {
+        if (mapper == null) {
+            throw new NullPointerException();
+        }
+        if (!isPresent()) {
+            return empty();
+        } else {
+            return Optional.ofNullable(mapper.invoke(value));
+        }
+    }
+
+    /**
+     * If a value is present, apply the provided {@code Optional}-bearing
+     * mapping function to it, return that result, otherwise return an empty
+     * {@code Optional}.  This method is similar to {@link #map(Function1)},
+     * but the provided mapper is one whose result is already an {@code Optional},
+     * and if invoked, {@code flatMap} does not wrap it with an additional
+     * {@code Optional}.
+     *
+     * @param <U> The type parameter to the {@code Optional} returned by
+     * @param mapper a mapping function to apply to the value, if present
+     *           the mapping function
+     * @return the result of applying an {@code Optional}-bearing mapping
+     * function to the value of this {@code Optional}, if a value is present,
+     * otherwise an empty {@code Optional}
+     * @throws NullPointerException if the mapping function is null or returns
+     * a null result
+     */
+    public<U> Optional<U> flatMap(Function1<? super T, Optional<U>> mapper) {
+        if(mapper == null) {
+            throw new NullPointerException();
+        }
+        if (!isPresent()) {
+            return empty();
+        } else {
+            Optional<U> u = mapper.invoke(value);
+            if (u == null) {
+                throw new NullPointerException();
+            }
+            return u;
+        }
+    }
+
+    /**
+     * Return the value if present, otherwise return {@code other}.
+     *
+     * @param other the value to be returned if there is no value present, may
+     * be null
+     * @return the value, if present, otherwise {@code other}
+     */
+    public T orElse(T other) {
+        return value != null ? value : other;
+    }
+
+    /**
+     * Return the value if present, otherwise invoke {@code other} and return
+     * the result of that invocation.
+     *
+     * @param other a {@code Supplier} whose result is returned if no value
+     * is present
+     * @return the value if present otherwise the result of {@code other.get()}
+     * @throws NullPointerException if value is not present and {@code other} is
+     * null
+     */
+    public T orElseGet(Supplier<? extends T> other) {
+        return value != null ? value : other.get();
+    }
+
+    /**
+     * Return the contained value, if present, otherwise throw an exception
+     * to be created by the provided supplier.
+     *
+     * @apiNote A method reference to the exception constructor with an empty
+     * argument list can be used as the supplier. For example,
+     * {@code IllegalStateException::new}
+     *
+     * @param <X> Type of the exception to be thrown
+     * @param exceptionSupplier The supplier which will return the exception to
+     * be thrown
+     * @return the present value
+     * @throws X if there is no value present
+     * @throws NullPointerException if no value is present and
+     * {@code exceptionSupplier} is null
+     */
+    public <X extends Throwable> T orElseThrow(Supplier<? extends X> exceptionSupplier) throws X {
+        if (value != null) {
+            return value;
+        } else {
+            throw exceptionSupplier.get();
+        }
+    }
+
+    /**
+     * Indicates whether some other object is "equal to" this Optional. The
+     * other object is considered equal if:
+     * <ul>
+     * <li>it is also an {@code Optional} and;
+     * <li>both instances have no value present or;
+     * <li>the present values are "equal to" each other via {@code equals()}.
+     * </ul>
+     *
+     * @param obj an object to be tested for equality
+     * @return {code true} if the other object is "equal to" this object
+     * otherwise {@code false}
+     */
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+
+        if (!(obj instanceof Optional)) {
+            return false;
+        }
+
+        Optional<?> other = (Optional<?>) obj;
+        return ObjectsCompat.equals(value, other.value);
+    }
+
+    /**
+     * Returns the hash code value of the present value, if any, or 0 (zero) if
+     * no value is present.
+     *
+     * @return hash code value of the present value or 0 if no value is present
+     */
+    @Override
+    public int hashCode() {
+        return ObjectsCompat.hashCode(value);
+    }
+
+    /**
+     * Returns a non-empty string representation of this Optional suitable for
+     * debugging. The exact presentation format is unspecified and may vary
+     * between implementations and versions.
+     *
+     * @implSpec If a value is present the result must include its string
+     * representation in the result. Empty and present Optionals must be
+     * unambiguously differentiable.
+     *
+     * @return the string representation of this instance
+     */
+    @Override
+    public String toString() {
+        return value != null
+            ? String.format("Optional[%s]", value)
+            : "Optional.empty";
+    }
+}

src/main/java/com/nextcloud/java/util/function/Predicate.java

@@ -0,0 +1,121 @@
+/*
+ * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code 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
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package com.nextcloud.java.util.function;
+
+/**
+ * This class is backported from Java 8 to be used on older Android API levels.
+ *
+ * Represents a predicate (boolean-valued function) of one argument.
+ *
+ * <p>This is a <a href="package-summary.html">functional interface</a>
+ * whose functional method is {@link #test(Object)}.
+ *
+ * @param <T> the type of the input to the predicate
+ */
+@FunctionalInterface
+public interface Predicate<T> {
+
+    /**
+     * Evaluates this predicate on the given argument.
+     *
+     * @param t the input argument
+     * @return {@code true} if the input argument matches the predicate,
+     * otherwise {@code false}
+     */
+    boolean test(T t);
+
+    /**
+     * Returns a composed predicate that represents a short-circuiting logical
+     * AND of this predicate and another.  When evaluating the composed
+     * predicate, if this predicate is {@code false}, then the {@code other}
+     * predicate is not evaluated.
+     *
+     * <p>Any exceptions thrown during evaluation of either predicate are relayed
+     * to the caller; if evaluation of this predicate throws an exception, the
+     * {@code other} predicate will not be evaluated.
+     *
+     * @param other a predicate that will be logically-ANDed with this
+     *              predicate
+     * @return a composed predicate that represents the short-circuiting logical
+     * AND of this predicate and the {@code other} predicate
+     * @throws NullPointerException if other is null
+     */
+    default Predicate<T> and(Predicate<? super T> other) {
+        if (other == null) {
+            throw new NullPointerException();
+        }
+        return (t) -> test(t) && other.test(t);
+    }
+
+    /**
+     * Returns a predicate that represents the logical negation of this
+     * predicate.
+     *
+     * @return a predicate that represents the logical negation of this
+     * predicate
+     */
+    default Predicate<T> negate() {
+        return (t) -> !test(t);
+    }
+
+    /**
+     * Returns a composed predicate that represents a short-circuiting logical
+     * OR of this predicate and another.  When evaluating the composed
+     * predicate, if this predicate is {@code true}, then the {@code other}
+     * predicate is not evaluated.
+     *
+     * <p>Any exceptions thrown during evaluation of either predicate are relayed
+     * to the caller; if evaluation of this predicate throws an exception, the
+     * {@code other} predicate will not be evaluated.
+     *
+     * @param other a predicate that will be logically-ORed with this
+     *              predicate
+     * @return a composed predicate that represents the short-circuiting logical
+     * OR of this predicate and the {@code other} predicate
+     * @throws NullPointerException if other is null
+     */
+    default Predicate<T> or(Predicate<? super T> other) {
+        if (other == null) {
+            throw new NullPointerException();
+        }
+        return (t) -> test(t) || other.test(t);
+    }
+
+    /**
+     * Returns a predicate that tests if two arguments are equal according
+     * to {@link androidx.core.util.ObjectsCompat#equals(Object, Object)}.
+     *
+     * @param <T> the type of arguments to the predicate
+     * @param targetRef the object reference with which to compare for equality,
+     *               which may be {@code null}
+     * @return a predicate that tests if two arguments are equal according
+     * to {@link androidx.core.util.ObjectsCompat#equals(Object, Object)}
+     */
+    static <T> Predicate<T> isEqual(Object targetRef) {
+        return (null == targetRef)
+            ? object -> object == null
+            : object -> targetRef.equals(object);
+    }
+}

src/main/java/com/nextcloud/java/util/package-info.java

@@ -0,0 +1,26 @@
+/*
+ * Nextcloud Android client application
+ *
+ * @author Chris Narkiewicz <hello@ezaquarii.com>
+ * Copyright (C) 2019 Chris Narkiewicz
+ * Copyright (C) 2019 Nextcloud GmbH
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/**
+ * This is a compatibility package providing some backported Java 8 classes
+ * not available in some older Android runtimes.
+ */
+package com.nextcloud.java.util;

src/main/java/com/owncloud/android/datamodel/UploadsStorageManager.java

@@ -30,6 +30,7 @@ import android.database.Cursor;
 import android.net.Uri;
 
 import com.nextcloud.client.account.CurrentAccountProvider;
+import com.nextcloud.client.account.User;
 import com.owncloud.android.db.OCUpload;
 import com.owncloud.android.db.ProviderMeta.ProviderTableMeta;
 import com.owncloud.android.db.UploadResult;
@@ -345,24 +346,19 @@ public class UploadsStorageManager extends Observable {
     }
 
     public OCUpload[] getCurrentAndPendingUploadsForCurrentAccount() {
-        Account account = currentAccountProvider.getCurrentAccount();
+        User user = currentAccountProvider.getUser();
 
-        if (account != null) {
-            return getUploads(
-                ProviderTableMeta.UPLOADS_STATUS + "==" + UploadStatus.UPLOAD_IN_PROGRESS.value +
-                            " OR " + ProviderTableMeta.UPLOADS_LAST_RESULT +
-                            "==" + UploadResult.DELAYED_FOR_WIFI.getValue() +
-                            " OR " + ProviderTableMeta.UPLOADS_LAST_RESULT +
-                            "==" + UploadResult.LOCK_FAILED.getValue() +
-                            " OR " + ProviderTableMeta.UPLOADS_LAST_RESULT +
-                            "==" + UploadResult.DELAYED_FOR_CHARGING.getValue() +
-                            " OR " + ProviderTableMeta.UPLOADS_LAST_RESULT +
-                            "==" + UploadResult.DELAYED_IN_POWER_SAVE_MODE.getValue() +
-                            " AND " + ProviderTableMeta.UPLOADS_ACCOUNT_NAME + "== ?",
-                account.name);
-        } else {
-            return new OCUpload[0];
-        }
+        return getUploads(ProviderTableMeta.UPLOADS_STATUS + "==" + UploadStatus.UPLOAD_IN_PROGRESS.value +
+                        " OR " + ProviderTableMeta.UPLOADS_LAST_RESULT +
+                        "==" + UploadResult.DELAYED_FOR_WIFI.getValue() +
+                        " OR " + ProviderTableMeta.UPLOADS_LAST_RESULT +
+                        "==" + UploadResult.LOCK_FAILED.getValue() +
+                        " OR " + ProviderTableMeta.UPLOADS_LAST_RESULT +
+                        "==" + UploadResult.DELAYED_FOR_CHARGING.getValue() +
+                        " OR " + ProviderTableMeta.UPLOADS_LAST_RESULT +
+                        "==" + UploadResult.DELAYED_IN_POWER_SAVE_MODE.getValue() +
+                        " AND " + ProviderTableMeta.UPLOADS_ACCOUNT_NAME + "== ?",
+                        user.getAccountName());
     }
 
     /**
@@ -384,14 +380,10 @@ public class UploadsStorageManager extends Observable {
     }
 
     public OCUpload[] getFinishedUploadsForCurrentAccount() {
-        Account account = currentAccountProvider.getCurrentAccount();
+        User user = currentAccountProvider.getUser();
 
-        if (account != null) {
-            return getUploads(ProviderTableMeta.UPLOADS_STATUS + "==" + UploadStatus.UPLOAD_SUCCEEDED.value + AND +
-                                  ProviderTableMeta.UPLOADS_ACCOUNT_NAME + "== ?", account.name);
-        } else {
-            return new OCUpload[0];
-        }
+        return getUploads(ProviderTableMeta.UPLOADS_STATUS + "==" + UploadStatus.UPLOAD_SUCCEEDED.value + AND +
+                              ProviderTableMeta.UPLOADS_ACCOUNT_NAME + "== ?", user.getAccountName());
     }
 
     /**
@@ -403,23 +395,19 @@ public class UploadsStorageManager extends Observable {
     }
 
     public OCUpload[] getFailedButNotDelayedUploadsForCurrentAccount() {
-        Account account = currentAccountProvider.getCurrentAccount();
+        User user = currentAccountProvider.getUser();
 
-        if (account != null) {
-            return getUploads(ProviderTableMeta.UPLOADS_STATUS + "==" + UploadStatus.UPLOAD_FAILED.value +
-                            AND + ProviderTableMeta.UPLOADS_LAST_RESULT +
-                            "<>" + UploadResult.DELAYED_FOR_WIFI.getValue() +
-                            AND + ProviderTableMeta.UPLOADS_LAST_RESULT +
-                            "<>" + UploadResult.LOCK_FAILED.getValue() +
-                            AND + ProviderTableMeta.UPLOADS_LAST_RESULT +
-                            "<>" + UploadResult.DELAYED_FOR_CHARGING.getValue() +
-                            AND + ProviderTableMeta.UPLOADS_LAST_RESULT +
-                            "<>" + UploadResult.DELAYED_IN_POWER_SAVE_MODE.getValue() +
-                            AND + ProviderTableMeta.UPLOADS_ACCOUNT_NAME + "== ?",
-                              account.name);
-        } else {
-            return new OCUpload[0];
-        }
+        return getUploads(ProviderTableMeta.UPLOADS_STATUS + "==" + UploadStatus.UPLOAD_FAILED.value +
+                        AND + ProviderTableMeta.UPLOADS_LAST_RESULT +
+                        "<>" + UploadResult.DELAYED_FOR_WIFI.getValue() +
+                        AND + ProviderTableMeta.UPLOADS_LAST_RESULT +
+                        "<>" + UploadResult.LOCK_FAILED.getValue() +
+                        AND + ProviderTableMeta.UPLOADS_LAST_RESULT +
+                        "<>" + UploadResult.DELAYED_FOR_CHARGING.getValue() +
+                        AND + ProviderTableMeta.UPLOADS_LAST_RESULT +
+                        "<>" + UploadResult.DELAYED_IN_POWER_SAVE_MODE.getValue() +
+                        AND + ProviderTableMeta.UPLOADS_ACCOUNT_NAME + "== ?",
+                        user.getAccountName());
     }
 
     /**
@@ -446,50 +434,41 @@ public class UploadsStorageManager extends Observable {
     }
 
     public long clearFailedButNotDelayedUploads() {
-        Account account = currentAccountProvider.getCurrentAccount();
-
-        long result = 0;
-        if (account != null) {
-            result = getDB().delete(
-                    ProviderTableMeta.CONTENT_URI_UPLOADS,
-                    ProviderTableMeta.UPLOADS_STATUS + "==" + UploadStatus.UPLOAD_FAILED.value +
-                            AND + ProviderTableMeta.UPLOADS_LAST_RESULT +
-                            "<>" + UploadResult.LOCK_FAILED.getValue() +
-                            AND + ProviderTableMeta.UPLOADS_LAST_RESULT +
-                            "<>" + UploadResult.DELAYED_FOR_WIFI.getValue() +
-                            AND + ProviderTableMeta.UPLOADS_LAST_RESULT +
-                            "<>" + UploadResult.DELAYED_FOR_CHARGING.getValue() +
-                            AND + ProviderTableMeta.UPLOADS_LAST_RESULT +
-                            "<>" + UploadResult.DELAYED_IN_POWER_SAVE_MODE.getValue() +
-                            AND + ProviderTableMeta.UPLOADS_ACCOUNT_NAME + "== ?",
-                    new String[]{account.name}
-            );
-        }
-
+        User user = currentAccountProvider.getUser();
+        final long deleted = getDB().delete(
+                ProviderTableMeta.CONTENT_URI_UPLOADS,
+                ProviderTableMeta.UPLOADS_STATUS + "==" + UploadStatus.UPLOAD_FAILED.value +
+                        AND + ProviderTableMeta.UPLOADS_LAST_RESULT +
+                        "<>" + UploadResult.LOCK_FAILED.getValue() +
+                        AND + ProviderTableMeta.UPLOADS_LAST_RESULT +
+                        "<>" + UploadResult.DELAYED_FOR_WIFI.getValue() +
+                        AND + ProviderTableMeta.UPLOADS_LAST_RESULT +
+                        "<>" + UploadResult.DELAYED_FOR_CHARGING.getValue() +
+                        AND + ProviderTableMeta.UPLOADS_LAST_RESULT +
+                        "<>" + UploadResult.DELAYED_IN_POWER_SAVE_MODE.getValue() +
+                        AND + ProviderTableMeta.UPLOADS_ACCOUNT_NAME + "== ?",
+                new String[]{user.getAccountName()}
+        );
         Log_OC.d(TAG, "delete all failed uploads but those delayed for Wifi");
-        if (result > 0) {
+        if (deleted > 0) {
             notifyObserversNow();
         }
-        return result;
+        return deleted;
     }
 
     public long clearSuccessfulUploads() {
-        Account account = currentAccountProvider.getCurrentAccount();
-
-        long result = 0;
-        if (account != null) {
-            result = getDB().delete(
-                    ProviderTableMeta.CONTENT_URI_UPLOADS,
-                    ProviderTableMeta.UPLOADS_STATUS + "==" + UploadStatus.UPLOAD_SUCCEEDED.value + AND +
-                            ProviderTableMeta.UPLOADS_ACCOUNT_NAME + "== ?", new String[]{account.name}
-            );
-        }
+        User user = currentAccountProvider.getUser();
+        final long deleted = getDB().delete(
+                ProviderTableMeta.CONTENT_URI_UPLOADS,
+                ProviderTableMeta.UPLOADS_STATUS + "==" + UploadStatus.UPLOAD_SUCCEEDED.value + AND +
+                        ProviderTableMeta.UPLOADS_ACCOUNT_NAME + "== ?", new String[]{user.getAccountName()}
+        );
 
         Log_OC.d(TAG, "delete all successful uploads");
-        if (result > 0) {
+        if (deleted > 0) {
             notifyObserversNow();
         }
-        return result;
+        return deleted;
     }
 
     /**

src/main/java/com/owncloud/android/ui/adapter/OCFileListAdapter.java

@@ -47,6 +47,7 @@ import android.widget.TextView;
 
 import com.bumptech.glide.Glide;
 import com.bumptech.glide.request.target.BitmapImageViewTarget;
+import com.nextcloud.client.account.User;
 import com.nextcloud.client.account.UserAccountManager;
 import com.nextcloud.client.preferences.AppPreferences;
 import com.owncloud.android.R;
@@ -117,7 +118,7 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
     private Set<OCFile> checkedFiles;
 
     private FileDataStorageManager mStorageManager;
-    private Account account;
+    private User user;
     private OCFileListFragmentInterface ocFileListFragmentInterface;
 
     private FilesFilter mFilesFilter;
@@ -135,7 +136,7 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
 
     public OCFileListAdapter(
         Context context,
-        Account account,
+        User user,
         AppPreferences preferences,
         UserAccountManager accountManager,
         ComponentsGetter transferServiceGetter,
@@ -147,16 +148,16 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
         mContext = context;
         this.preferences = preferences;
         this.accountManager = accountManager;
-        this.account = account;
+        this.user = user;
         mHideItemOptions = argHideItemOptions;
         this.gridView = gridView;
         checkedFiles = new HashSet<>();
 
         this.transferServiceGetter = transferServiceGetter;
 
-        if (account != null) {
+        if (this.user != null) {
             AccountManager platformAccountManager = AccountManager.get(mContext);
-            userId = platformAccountManager.getUserData(account,
+            userId = platformAccountManager.getUserData(this.user.toPlatformAccount(),
                                                 com.owncloud.android.lib.common.accounts.AccountUtils.Constants.KEY_USER_ID);
         } else {
             userId = "";
@@ -399,7 +400,7 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
                                 showFederatedShareAvatar(sharee.getUserId(), avatarRadius, resources, avatar);
                             } else {
                                 avatar.setTag(sharee);
-                                DisplayUtils.setAvatar(account,
+                                DisplayUtils.setAvatar(user.toPlatformAccount(),
                                                        sharee.getUserId(),
                                                        sharee.getDisplayName(),
                                                        this,
@@ -460,17 +461,17 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
             OperationsService.OperationsServiceBinder operationsServiceBinder = transferServiceGetter.getOperationsServiceBinder();
             FileDownloader.FileDownloaderBinder fileDownloaderBinder = transferServiceGetter.getFileDownloaderBinder();
             FileUploader.FileUploaderBinder fileUploaderBinder = transferServiceGetter.getFileUploaderBinder();
-            if (operationsServiceBinder != null && operationsServiceBinder.isSynchronizing(account, file)) {
+            if (operationsServiceBinder != null && operationsServiceBinder.isSynchronizing(user.toPlatformAccount(), file)) {
                 //synchronizing
                 gridViewHolder.localFileIndicator.setImageResource(R.drawable.ic_synchronizing);
                 gridViewHolder.localFileIndicator.setVisibility(View.VISIBLE);
 
-            } else if (fileDownloaderBinder != null && fileDownloaderBinder.isDownloading(account, file)) {
+            } else if (fileDownloaderBinder != null && fileDownloaderBinder.isDownloading(user.toPlatformAccount(), file)) {
                 // downloading
                 gridViewHolder.localFileIndicator.setImageResource(R.drawable.ic_synchronizing);
                 gridViewHolder.localFileIndicator.setVisibility(View.VISIBLE);
 
-            } else if (fileUploaderBinder != null && fileUploaderBinder.isUploading(account, file)) {
+            } else if (fileUploaderBinder != null && fileUploaderBinder.isUploading(user.toPlatformAccount(), file)) {
                 //uploading
                 gridViewHolder.localFileIndicator.setImageResource(R.drawable.ic_synchronizing);
                 gridViewHolder.localFileIndicator.setVisibility(View.VISIBLE);
@@ -575,13 +576,17 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
                     if (ThumbnailsCacheManager.cancelPotentialThumbnailWork(file, thumbnailView)) {
                         try {
                             final ThumbnailsCacheManager.ThumbnailGenerationTask task =
-                                new ThumbnailsCacheManager.ThumbnailGenerationTask(thumbnailView, mStorageManager,
-                                                                                   account, asyncTasks);
+                                new ThumbnailsCacheManager.ThumbnailGenerationTask(thumbnailView,
+                                                                                   mStorageManager,
+                                                                                   user.toPlatformAccount(),
+                                                                                   asyncTasks);
 
                             if (thumbnail == null) {
                                 thumbnail = BitmapUtils.drawableToBitmap(
-                                    MimeTypeUtil.getFileTypeIcon(file.getMimeType(), file.getFileName(),
-                                                                 account, mContext));
+                                    MimeTypeUtil.getFileTypeIcon(file.getMimeType(),
+                                                                 file.getFileName(),
+                                                                 user.toPlatformAccount(),
+                                                                 mContext));
                             }
                             final ThumbnailsCacheManager.AsyncThumbnailDrawable asyncDrawable =
                                 new ThumbnailsCacheManager.AsyncThumbnailDrawable(mContext.getResources(),
@@ -602,7 +607,7 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
             } else {
                 thumbnailView.setImageDrawable(MimeTypeUtil.getFileTypeIcon(file.getMimeType(),
                                                                             file.getFileName(),
-                                                                            account,
+                                                                            user.toPlatformAccount(),
                                                                             mContext));
             }
         }
@@ -685,7 +690,7 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
                 sharedIconView.setImageResource(R.drawable.ic_unshared);
                 sharedIconView.setContentDescription(mContext.getString(R.string.shared_icon_share));
             }
-            if (accountManager.accountOwnsFile(file, account)) {
+            if (accountManager.accountOwnsFile(file, user.toPlatformAccount())) {
                 sharedIconView.setOnClickListener(view -> ocFileListFragmentInterface.onShareIconClick(file));
             } else {
                 sharedIconView.setOnClickListener(view -> ocFileListFragmentInterface.showShareDetailView(file));
@@ -703,7 +708,7 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
      * @param limitToMimeType       show only files of this mimeType
      */
     public void swapDirectory(
-        Account account,
+        User account,
         OCFile directory,
         FileDataStorageManager updatedStorageManager,
         boolean onlyOnDevice, String limitToMimeType
@@ -712,8 +717,8 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
 
         if (updatedStorageManager != null && !updatedStorageManager.equals(mStorageManager)) {
             mStorageManager = updatedStorageManager;
-            showShareAvatar = mStorageManager.getCapability(account.name).getVersion().isShareesOnDavSupported();
-            this.account = account;
+            showShareAvatar = mStorageManager.getCapability(account.getAccountName()).getVersion().isShareesOnDavSupported();
+            this.user = account;
         }
         if (mStorageManager != null) {
             mFiles = mStorageManager.getFolderContent(directory, onlyOnDevice);
@@ -744,11 +749,11 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
                         FileDataStorageManager storageManager, OCFile folder, boolean clear) {
         if (storageManager != null && mStorageManager == null) {
             mStorageManager = storageManager;
-            showShareAvatar = mStorageManager.getCapability(account.name).getVersion().isShareesOnDavSupported();
+            showShareAvatar = mStorageManager.getCapability(user.getAccountName()).getVersion().isShareesOnDavSupported();
         }
 
         if (mStorageManager == null) {
-            mStorageManager = new FileDataStorageManager(account, mContext.getContentResolver());
+            mStorageManager = new FileDataStorageManager(user.toPlatformAccount(), mContext.getContentResolver());
         }
 
         if (clear) {
@@ -808,12 +813,12 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
                 shares.add(ocShare);
 
                 // get ocFile from Server to have an up-to-date copy
-                RemoteOperationResult result = new ReadFileRemoteOperation(ocShare.getPath()).execute(account,
+                RemoteOperationResult result = new ReadFileRemoteOperation(ocShare.getPath()).execute(user.toPlatformAccount(),
                                                                                                       mContext);
 
                 if (result.isSuccess()) {
                     OCFile file = FileStorageUtils.fillOCFile((RemoteFile) result.getData().get(0));
-                    FileStorageUtils.searchForLocalFileInDefaultPath(file, account);
+                    FileStorageUtils.searchForLocalFileInDefaultPath(file, user.toPlatformAccount());
                     file = mStorageManager.saveFileWithParent(file, mContext);
 
                     ShareType newShareType = ocShare.getShareType();
@@ -868,7 +873,7 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
 
         for (Object remoteFile : objects) {
             OCFile ocFile = FileStorageUtils.fillOCFile((RemoteFile) remoteFile);
-            FileStorageUtils.searchForLocalFileInDefaultPath(ocFile, account);
+            FileStorageUtils.searchForLocalFileInDefaultPath(ocFile, user.toPlatformAccount());
 
             try {
                 if (ExtendedListFragment.SearchType.PHOTO_SEARCH == searchType) {
@@ -885,9 +890,9 @@ public class OCFileListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHol
                                                                                             true,
                                                                                             false,
                                                                                             mStorageManager,
-                                                                                            account,
+                                                                                            user.toPlatformAccount(),
                                                                                             mContext);
-                        refreshFolderOperation.execute(account, mContext);
+                        refreshFolderOperation.execute(user.toPlatformAccount(), mContext);
                     }
                 }
 

src/main/java/com/owncloud/android/ui/fragment/OCFileListFragment.java

@@ -332,7 +332,7 @@ public class OCFileListFragment extends ExtendedListFragment implements
 
         mAdapter = new OCFileListAdapter(
             getActivity(),
-            accountManager.getCurrentAccount(),
+            accountManager.getUser(),
             preferences,
             accountManager,
             mContainerActivity,
@@ -1180,7 +1180,7 @@ public class OCFileListFragment extends ExtendedListFragment implements
                 }
 
                 mAdapter.swapDirectory(
-                    accountManager.getCurrentAccount(),
+                    accountManager.getUser(),
                     directory,
                     storageManager,
                     onlyOnDevice,

src/test/java/com/nextcloud/client/network/ConnectivityServiceTest.kt

@@ -19,16 +19,17 @@
  */
 package com.nextcloud.client.network
 
-import android.accounts.Account
 import android.net.ConnectivityManager
 import android.net.NetworkInfo
-import android.net.Uri
+import com.nextcloud.client.account.Server
+import com.nextcloud.client.account.User
 import com.nextcloud.client.account.UserAccountManager
+import com.nextcloud.client.logger.Logger
 import com.nhaarman.mockitokotlin2.any
 import com.nhaarman.mockitokotlin2.mock
+import com.nhaarman.mockitokotlin2.never
 import com.nhaarman.mockitokotlin2.verify
 import com.nhaarman.mockitokotlin2.whenever
-import com.owncloud.android.lib.common.OwnCloudAccount
 import com.owncloud.android.lib.resources.status.OwnCloudVersion
 import org.apache.commons.httpclient.HttpClient
 import org.apache.commons.httpclient.HttpStatus
@@ -42,6 +43,7 @@ import org.junit.runners.Suite
 import org.mockito.ArgumentCaptor
 import org.mockito.Mock
 import org.mockito.MockitoAnnotations
+import java.net.URI
 
 @RunWith(Suite::class)
 @Suite.SuiteClasses(
@@ -86,13 +88,14 @@ class ConnectivityServiceTest {
         lateinit var requestBuilder: ConnectivityServiceImpl.GetRequestBuilder
 
         @Mock
-        lateinit var platformAccount: Account
+        lateinit var logger: Logger
+
+        val baseServerUri = URI.create(SERVER_BASE_URL)
+        val newServer = Server(baseServerUri, OwnCloudVersion.nextcloud_14)
+        val legacyServer = Server(baseServerUri, OwnCloudVersion.nextcloud_13)
 
         @Mock
-        lateinit var ownCloudAccount: OwnCloudAccount
-
-        @Mock
-        lateinit var baseServerUri: Uri
+        lateinit var user: User
 
         lateinit var connectivityService: ConnectivityServiceImpl
 
@@ -103,15 +106,15 @@ class ConnectivityServiceTest {
                 platformConnectivityManager,
                 accountManager,
                 clientFactory,
-                requestBuilder
+                requestBuilder,
+                logger
             )
+
             whenever(platformConnectivityManager.activeNetworkInfo).thenReturn(networkInfo)
             whenever(requestBuilder.invoke(any())).thenReturn(getRequest)
             whenever(clientFactory.createPlainClient()).thenReturn(client)
-            whenever(accountManager.currentOwnCloudAccount).thenReturn(ownCloudAccount)
-            whenever(accountManager.currentAccount).thenReturn(platformAccount)
-            whenever(baseServerUri.toString()).thenReturn(SERVER_BASE_URL)
-            whenever(ownCloudAccount.baseUri).thenReturn(baseServerUri)
+            whenever(user.server).thenReturn(newServer)
+            whenever(accountManager.user).thenReturn(user)
         }
     }
 
@@ -158,7 +161,7 @@ class ConnectivityServiceTest {
         fun setUp() {
             whenever(networkInfo.isConnectedOrConnecting).thenReturn(true)
             whenever(networkInfo.type).thenReturn(ConnectivityManager.TYPE_WIFI)
-            whenever(accountManager.getServerVersion(any())).thenReturn(OwnCloudVersion.nextcloud_13)
+            whenever(user.server).thenReturn(legacyServer)
             assertTrue("Precondition failed", connectivityService.isOnlineWithWifi)
         }
 
@@ -207,6 +210,28 @@ class ConnectivityServiceTest {
             assertTrue("Precondition failed", connectivityService.isOnlineWithWifi)
         }
 
+        @Test
+        fun `check request is not sent when server uri is not set`() {
+            // GIVEN
+            //      network connectivity is present
+            //      user has no server URI (empty)
+            val serverWithoutUri = Server(URI(""), OwnCloudVersion.nextcloud_14)
+            whenever(user.server).thenReturn(serverWithoutUri)
+
+            // WHEN
+            //      connectivity is checked
+            val result = connectivityService.isInternetWalled
+
+            // THEN
+            //      connection is walled
+            //      request is not sent
+            assertTrue("Server should not be accessible", result)
+            verify(requestBuilder, never()).invoke(any())
+            verify(client, never()).executeMethod(any())
+            verify(client, never()).executeMethod(any(), any())
+            verify(client, never()).executeMethod(any(), any(), any())
+        }
+
         fun mockResponse(contentLength: Long = 0, status: Int = HttpStatus.SC_OK) {
             whenever(client.executeMethod(any())).thenReturn(status)
             whenever(getRequest.statusCode).thenReturn(status)