fix: use png as preview right away

The initial office preview implementation converted an office document with LibreOffice to PDF, used ImageMagick to extract the first page as JPEG, and passed it OC_Image.

https://github.com/nextcloud/server/pull/10198 changed the implementation to use PNG rather than PDF. OC_Image can use a PNG as a preview right away, so the ImageMagick step is unnecessary.

The registration code was updated to not ask ImageMagick if PDF is supported, as PDFs are no longer used to create office document previews.

Signed-off-by: Daniel Kesselberg <mail@danielkesselberg.de>

2 files changed, 43 insertions, 37 deletions

diff --git a/lib/private/Preview/Office.php b/lib/private/Preview/Office.php
index bc0c554a192..68499a6fea6 100644
--- a/lib/private/Preview/Office.php
+++ b/lib/private/Preview/Office.php
@@ -33,7 +33,6 @@ use OCP\Files\FileInfo;
 use OCP\IImage;
 use OCP\ITempManager;
 use OCP\Server;
-use Psr\Log\LoggerInterface;
 
 abstract class Office extends ProviderV2 {
 	/**
@@ -93,30 +92,18 @@ abstract class Office extends ProviderV2 {
 			return null;
 		}
 
-		try {
-			$filename = $outdir . pathinfo($absPath, PATHINFO_FILENAME) . '.png';
-
-			$png = new \Imagick($filename . '[0]');
-			$png->setImageFormat('jpg');
-		} catch (\Exception $e) {
-			$this->cleanTmpFiles();
-			\OC::$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();
 
 		if ($image->valid()) {
 			$image->scaleDownToFit($maxX, $maxY);
-
 			return $image;
 		}
+
 		return null;
 	}
 }
diff --git a/lib/private/PreviewManager.php b/lib/private/PreviewManager.php
index 8e41662262d..aedcbbce335 100644
--- a/lib/private/PreviewManager.php
+++ b/lib/private/PreviewManager.php
@@ -366,7 +366,7 @@ class PreviewManager implements IPreview {
 		$this->registerCoreProvider(Preview\OpenDocument::class, '/application\/vnd.oasis.opendocument.*/');
 		$this->registerCoreProvider(Preview\Imaginary::class, Preview\Imaginary::supportedMimeTypes());
 
-		// SVG, Office and Bitmap require imagick
+		// SVG and Bitmap require imagick
 		if ($this->imagickSupport->hasExtension()) {
 			$imagickProviders = [
 				'SVG' => ['mimetype' => '/image\/svg\+xml/', 'class' => Preview\SVG::class],
@@ -391,28 +391,10 @@ class PreviewManager implements IPreview {
 					$this->registerCoreProvider($class, $provider['mimetype']);
 				}
 			}
-
-			if ($this->imagickSupport->supportsFormat('PDF')) {
-				// Office requires openoffice or libreoffice
-				$officeBinary = $this->config->getSystemValue('preview_libreoffice_path', null);
-				if (!is_string($officeBinary)) {
-					$officeBinary = $this->binaryFinder->findBinaryPath('libreoffice');
-				}
-				if (!is_string($officeBinary)) {
-					$officeBinary = $this->binaryFinder->findBinaryPath('openoffice');
-				}
-
-				if (is_string($officeBinary)) {
-					$this->registerCoreProvider(Preview\MSOfficeDoc::class, '/application\/msword/', ["officeBinary" => $officeBinary]);
-					$this->registerCoreProvider(Preview\MSOffice2003::class, '/application\/vnd.ms-.*/', ["officeBinary" => $officeBinary]);
-					$this->registerCoreProvider(Preview\MSOffice2007::class, '/application\/vnd.openxmlformats-officedocument.*/', ["officeBinary" => $officeBinary]);
-					$this->registerCoreProvider(Preview\OpenDocument::class, '/application\/vnd.oasis.opendocument.*/', ["officeBinary" => $officeBinary]);
-					$this->registerCoreProvider(Preview\StarOffice::class, '/application\/vnd.sun.xml.*/', ["officeBinary" => $officeBinary]);
-					$this->registerCoreProvider(Preview\EMF::class, '/image\/emf/', ['officeBinary' => $officeBinary]);
-				}
-			}
 		}
 
+		$this->registerCoreProvidersOffice();
+
 		// Video requires avconv or ffmpeg
 		if (in_array(Preview\Movie::class, $this->getEnabledDefaultProvider())) {
 			$movieBinary = $this->config->getSystemValue('preview_ffmpeg_path', null);
@@ -430,6 +412,43 @@ class PreviewManager implements IPreview {
 		}
 	}
 
+	private function registerCoreProvidersOffice(): void {
+		$officeProviders = [
+			['mimetype' => '/application\/msword/', 'class' => Preview\MSOfficeDoc::class],
+			['mimetype' => '/application\/vnd.ms-.*/', 'class' => Preview\MSOffice2003::class],
+			['mimetype' => '/application\/vnd.openxmlformats-officedocument.*/', 'class' => Preview\MSOffice2007::class],
+			['mimetype' => '/application\/vnd.oasis.opendocument.*/', 'class' => Preview\OpenDocument::class],
+			['mimetype' => '/application\/vnd.sun.xml.*/', 'class' => Preview\StarOffice::class],
+			['mimetype' => '/image\/emf/', 'class' => Preview\EMF::class],
+		];
+
+		$findBinary = true;
+		$officeBinary = false;
+
+		foreach ($officeProviders as $provider) {
+			$class = $provider['class'];
+			if (!in_array(trim($class, '\\'), $this->getEnabledDefaultProvider())) {
+				continue;
+			}
+
+			if ($findBinary) {
+				// Office requires openoffice or libreoffice
+				$officeBinary = $this->config->getSystemValue('preview_libreoffice_path', false);
+				if ($officeBinary === false) {
+					$officeBinary = $this->binaryFinder->findBinaryPath('libreoffice');
+				}
+				if ($officeBinary === false) {
+					$officeBinary = $this->binaryFinder->findBinaryPath('openoffice');
+				}
+				$findBinary = false;
+			}
+
+			if ($officeBinary) {
+				$this->registerCoreProvider($class, $provider['mimetype'], ['officeBinary' => $officeBinary]);
+			}
+		}
+	}
+
 	private function registerBootstrapProviders(): void {
 		$context = $this->bootstrapCoordinator->getRegistrationContext();