Merge pull request #41395 from nextcloud/hello-emf

feat: add preview provider for emf files based on office

2 files changed, 68 insertions, 25 deletions

diff --git a/lib/private/Preview/EMF.php b/lib/private/Preview/EMF.php
new file mode 100644
index 00000000000..2b5f40e66af
--- /dev/null
+++ b/lib/private/Preview/EMF.php
@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * @copyright 2023 Daniel Kesselberg <mail@danielkesselberg.de>
+ *
+ * @author Daniel Kesselberg <mail@danielkesselberg.de>
+ *
+ * @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\Preview;
+
+class EMF extends Office {
+	public function getMimeType(): string {
+		return '/image\/emf/';
+	}
+}
diff --git a/lib/private/Preview/Office.php b/lib/private/Preview/Office.php
index 3ba7c5a21a0..68499a6fea6 100644
--- a/lib/private/Preview/Office.php
+++ b/lib/private/Preview/Office.php
@@ -31,7 +31,8 @@ namespace OC\Preview;
 use OCP\Files\File;
 use OCP\Files\FileInfo;
 use OCP\IImage;
-use Psr\Log\LoggerInterface;
+use OCP\ITempManager;
+use OCP\Server;
 
 abstract class Office extends ProviderV2 {
 	/**
@@ -49,51 +50,60 @@ abstract class Office extends ProviderV2 {
 			return null;
 		}
 
-		$absPath = $this->getLocalFile($file);
-
-		$tmpDir = \OC::$server->getTempManager()->getTempBaseDir();
+		$tempManager = Server::get(ITempManager::class);
 
-		$defaultParameters = ' -env:UserInstallation=file://' . escapeshellarg($tmpDir . '/owncloud-' . \OC_Util::getInstanceId() . '/') . ' --headless --nologo --nofirststartwizard --invisible --norestore --convert-to png --outdir ';
-		$clParameters = \OC::$server->getConfig()->getSystemValue('preview_office_cl_parameters', $defaultParameters);
+		// The file to generate the preview for.
+		$absPath = $this->getLocalFile($file);
 
-		$cmd = $this->options['officeBinary'] . $clParameters . escapeshellarg($tmpDir) . ' ' . escapeshellarg($absPath);
+		// The destination for the LibreOffice user profile.
+		// LibreOffice can rune once per user profile and therefore instance id and file id are included.
+		$profile = $tempManager->getTemporaryFolder(
+			'nextcloud-office-profile-' . \OC_Util::getInstanceId() . '-' . $file->getId()
+		);
 
-		exec($cmd, $output, $returnCode);
+		// The destination for the LibreOffice convert result.
+		$outdir = $tempManager->getTemporaryFolder(
+			'nextcloud-office-preview-' . \OC_Util::getInstanceId() . '-' . $file->getId()
+		);
 
-		if ($returnCode !== 0) {
+		if ($profile === false || $outdir === false) {
 			$this->cleanTmpFiles();
 			return null;
 		}
 
-		//create imagick object from png
-		$pngPreview = null;
-		try {
-			[$dirname, , , $filename] = array_values(pathinfo($absPath));
-			$pngPreview = $tmpDir . '/' . $filename . '.png';
+		$parameters = [
+			$this->options['officeBinary'],
+			'-env:UserInstallation=file://' . escapeshellarg($profile),
+			'--headless',
+			'--nologo',
+			'--nofirststartwizard',
+			'--invisible',
+			'--norestore',
+			'--convert-to png',
+			'--outdir ' . escapeshellarg($outdir),
+			escapeshellarg($absPath),
+		];
 
-			$png = new \Imagick($pngPreview . '[0]');
-			$png->setImageFormat('jpg');
-		} catch (\Exception $e) {
+		$cmd = implode(' ', $parameters);
+		exec($cmd, $output, $returnCode);
+
+		if ($returnCode !== 0) {
 			$this->cleanTmpFiles();
-			unlink($pngPreview);
-			\OC::$server->get(LoggerInterface::class)->error($e->getMessage(), [
-				'exception' => $e,
-				'app' => 'core',
-			]);
 			return null;
 		}
 
+		$preview = $outdir . pathinfo($absPath, PATHINFO_FILENAME) . '.png';
+
 		$image = new \OCP\Image();
-		$image->loadFromData((string) $png);
+		$image->loadFromFile($preview);
 
 		$this->cleanTmpFiles();
-		unlink($pngPreview);
 
 		if ($image->valid()) {
 			$image->scaleDownToFit($maxX, $maxY);
-
 			return $image;
 		}
+
 		return null;
 	}
 }