feat(theming): allow to disable standalone windows

Co-authored-by: Ferdinand Thiessen <opensource@fthiessen.de>

Signed-off-by: Simon L. <szaimen@e.mail.de>

Author: szaimen

apps/theming/lib/Controller/ThemingController.php

@@ -436,7 +436,7 @@ public function getManifest($app) {
 						'sizes' => '16x16'
 					]
 				],
-			'display' => 'standalone'
+			'display' => $this->config->getSystemValueBool('theming.standalone_window.enabled', true) ? 'standalone' : 'browser'
 		];
 		$response = new Http\JSONResponse($responseJS);
 		$response->cacheFor(3600);

apps/theming/tests/Controller/ThemingControllerTest.php

@@ -772,7 +772,7 @@ public function testGetManifest() {
 						'sizes' => '16x16'
 					]
 				],
-			'display' => 'standalone',
+			'display' => $standalone ? 'standalone' : 'browser',
 			'short_name' => 'Nextcloud',
 			'theme_color' => null,
 			'background_color' => null,

config/config.sample.php

@@ -1946,6 +1946,14 @@
  */
 'enforce_theme' => '',
 
+
+/**
+ * This setting allows to disable the PWA functionality that allows browsers to open web applications in dedicated windows.
+ *
+ * Defaults to ``true``
+ */
+'theming.standalone_window.enabled' => true,
+
 /**
  * The default cipher for encrypting files. Currently supported are:
  *  - AES-256-CTR