Added PlaceholderAvatar with own cached images

When avatar scope is private, the PlaceholderAvatar is used to deliver a
placeholder avatar based on the user's initials.

This was implemented as a separate class for now to avoid messing with
the existing UserAvatar implementation and its generated vs
non-generated logic.

Signed-off-by: Vincent Petry <vincent@nextcloud.com>

lib/private/Avatar/AvatarManager.php

@@ -122,7 +122,11 @@ class AvatarManager implements IAvatarManager {
 			$requestingUser = $this->userSession->getUser();
 		}
 
-		$canShowRealAvatar = true;
+		try {
+			$folder = $this->appData->getFolder($userId);
+		} catch (NotFoundException $e) {
+			$folder = $this->appData->newFolder($userId);
+		}
 
 		// requesting in public page
 		if ($requestingUser === null) {
@@ -132,18 +136,11 @@ class AvatarManager implements IAvatarManager {
 
 			// v2-private scope hides the avatar from public access
 			if ($avatarScope === IAccountManager::SCOPE_PRIVATE) {
-				// FIXME: guest avatar is re-generated every time, use a cache instead
+				// use a placeholder avatar which caches the generated images
-				// see how UserAvatar caches the generated one
+				return new PlaceholderAvatar($folder, $user, $this->logger);
-				return $this->getGuestAvatar($userId);
 			}
 		}
 
-		try {
-			$folder = $this->appData->getFolder($userId);
-		} catch (NotFoundException $e) {
-			$folder = $this->appData->newFolder($userId);
-		}
-
 		return new UserAvatar($folder, $this->l, $user, $this->logger, $this->config);
 	}
 

lib/private/Avatar/PlaceholderAvatar.php

@@ -0,0 +1,183 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright Copyright (c) 2018, Michael Weimann <mail@michael-weimann.eu>
+ *
+ * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
+ * @author Christoph Wurst <christoph@winzerhof-wurst.at>
+ * @author Joas Schilling <coding@schilljs.com>
+ * @author Michael Weimann <mail@michael-weimann.eu>
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace OC\Avatar;
+
+use OC\NotSquareException;
+use OC\User\User;
+use OCP\Files\NotFoundException;
+use OCP\Files\NotPermittedException;
+use OCP\Files\SimpleFS\ISimpleFile;
+use OCP\Files\SimpleFS\ISimpleFolder;
+use OCP\IConfig;
+use OCP\IImage;
+use OCP\IL10N;
+use OCP\ILogger;
+
+/**
+ * This class represents a registered user's placeholder avatar.
+ *
+ * It generates an image based on the user's initials and caches it on storage
+ * for faster retrieval, unlike the GuestAvatar.
+ */
+class PlaceholderAvatar extends Avatar {
+	/** @var ISimpleFolder */
+	private $folder;
+
+	/** @var User */
+	private $user;
+
+	/**
+	 * UserAvatar constructor.
+	 *
+	 * @param IConfig $config The configuration
+	 * @param ISimpleFolder $folder The avatar files folder
+	 * @param IL10N $l The localization helper
+	 * @param User $user The user this class manages the avatar for
+	 * @param ILogger $logger The logger
+	 */
+	public function __construct(
+		ISimpleFolder $folder,
+		$user,
+		ILogger $logger) {
+		parent::__construct($logger);
+
+		$this->folder = $folder;
+		$this->user = $user;
+	}
+
+	/**
+	 * Check if an avatar exists for the user
+	 *
+	 * @return bool
+	 */
+	public function exists() {
+		return true;
+	}
+
+	/**
+	 * Sets the users avatar.
+	 *
+	 * @param IImage|resource|string $data An image object, imagedata or path to set a new avatar
+	 * @throws \Exception if the provided file is not a jpg or png image
+	 * @throws \Exception if the provided image is not valid
+	 * @throws NotSquareException if the image is not square
+	 * @return void
+	 */
+	public function set($data) {
+		// unimplemented for placeholder avatars
+	}
+
+	/**
+	 * Removes the users avatar.
+	 */
+	public function remove(bool $silent = false) {
+		$avatars = $this->folder->getDirectoryListing();
+
+		foreach ($avatars as $avatar) {
+			$avatar->delete();
+		}
+	}
+
+	/**
+	 * Returns the avatar for an user.
+	 *
+	 * If there is no avatar file yet, one is generated.
+	 *
+	 * @param int $size
+	 * @return ISimpleFile
+	 * @throws NotFoundException
+	 * @throws \OCP\Files\NotPermittedException
+	 * @throws \OCP\PreConditionNotMetException
+	 */
+	public function getFile($size) {
+		$size = (int) $size;
+
+		$ext = 'png';
+
+		if ($size === -1) {
+			$path = 'avatar-placeholder.' . $ext;
+		} else {
+			$path = 'avatar-placeholder.' . $size . '.' . $ext;
+		}
+
+		try {
+			$file = $this->folder->getFile($path);
+		} catch (NotFoundException $e) {
+			if ($size <= 0) {
+				throw new NotFoundException;
+			}
+
+			if (!$data = $this->generateAvatarFromSvg($size)) {
+				$data = $this->generateAvatar($this->getDisplayName(), $size);
+			}
+
+			try {
+				$file = $this->folder->newFile($path);
+				$file->putContent($data);
+			} catch (NotPermittedException $e) {
+				$this->logger->error('Failed to save avatar placeholder for ' . $this->user->getUID());
+				throw new NotFoundException();
+			}
+		}
+
+		return $file;
+	}
+
+	/**
+	 * Returns the user display name.
+	 *
+	 * @return string
+	 */
+	public function getDisplayName(): string {
+		return $this->user->getDisplayName();
+	}
+
+	/**
+	 * Handles user changes.
+	 *
+	 * @param string $feature The changed feature
+	 * @param mixed $oldValue The previous value
+	 * @param mixed $newValue The new value
+	 * @throws NotPermittedException
+	 * @throws \OCP\PreConditionNotMetException
+	 */
+	public function userChanged($feature, $oldValue, $newValue) {
+		$this->remove();
+	}
+
+	/**
+	 * Check if the avatar of a user is a custom uploaded one
+	 *
+	 * @return bool
+	 */
+	public function isCustomAvatar(): bool {
+		return false;
+	}
+}

lib/private/Avatar/UserAvatar.php

@@ -270,6 +270,7 @@ class UserAvatar extends Avatar {
 				throw new NotFoundException;
 			}
 
+			// TODO: rework to integrate with the PlaceholderAvatar in a compatible way
 			if ($this->folder->fileExists('generated')) {
 				if (!$data = $this->generateAvatarFromSvg($size)) {
 					$data = $this->generateAvatar($this->getDisplayName(), $size);

tests/lib/Avatar/AvatarManagerTest.php

@@ -25,7 +25,7 @@
 namespace Test\Avatar;
 
 use OC\Avatar\AvatarManager;
-use OC\Avatar\GuestAvatar;
+use OC\Avatar\PlaceholderAvatar;
 use OC\Avatar\UserAvatar;
 use OC\User\Manager;
 use OCP\Accounts\IAccount;
@@ -159,10 +159,13 @@ class AvatarManagerTest extends \Test\TestCase {
 			->method('get')
 			->with('valid-user')
 			->willReturn($user);
+
 		$folder = $this->createMock(ISimpleFolder::class);
 		$this->appData
-			->expects($this->never())
+			->expects($this->once())
-			->method('getFolder');
+			->method('getFolder')
+			->with('valid-user')
+			->willReturn($folder);
 
 		$account = $this->createMock(IAccount::class);
 		$this->accountManager->expects($this->once())
@@ -180,7 +183,7 @@ class AvatarManagerTest extends \Test\TestCase {
 			->method('getScope')
 			->willReturn(IAccountManager::SCOPE_PRIVATE);
 
-		$expected = new GuestAvatar('valid-user', $this->createMock(ILogger::class));
+		$expected = new PlaceholderAvatar($folder, $user, $this->createMock(ILogger::class));
 		$this->assertEquals($expected, $this->avatarManager->getAvatar('valid-user'));
 	}
 }