Invert header if primary is bright and background disabled

Signed-off-by: John Molakvoæ <skjnldsv@protonmail.com>

2 files changed, 17 insertions, 10 deletions

diff --git a/apps/theming/lib/Controller/UserThemeController.php b/apps/theming/lib/Controller/UserThemeController.php
index a227e72d998..6a58366c4f6 100644
--- a/apps/theming/lib/Controller/UserThemeController.php
+++ b/apps/theming/lib/Controller/UserThemeController.php
@@ -50,16 +50,14 @@ use OCP\PreConditionNotMetException;
 
 class UserThemeController extends OCSController {
 
-	protected string $userId;
+	protected ?string $userId = null;
+	
 	private IConfig $config;
 	private IUserSession $userSession;
 	private ThemesService $themesService;
 	private ThemingDefaults $themingDefaults;
 	private BackgroundService $backgroundService;
 
-	/**
-	 * Config constructor.
-	 */
 	public function __construct(string $appName,
 								IRequest $request,
 								IConfig $config,
@@ -73,7 +71,11 @@ class UserThemeController extends OCSController {
 		$this->themesService = $themesService;
 		$this->themingDefaults = $themingDefaults;
 		$this->backgroundService = $backgroundService;
-		$this->userId = $userSession->getUser()->getUID();
+
+		$user = $userSession->getUser();
+		if ($user !== null) {
+			$this->userId = $user->getUID();
+		}
 	}
 
 	/**
diff --git a/apps/theming/lib/Themes/CommonThemeTrait.php b/apps/theming/lib/Themes/CommonThemeTrait.php
index 0305a95b3d5..17591c232bb 100644
--- a/apps/theming/lib/Themes/CommonThemeTrait.php
+++ b/apps/theming/lib/Themes/CommonThemeTrait.php
@@ -24,10 +24,10 @@ declare(strict_types=1);
  */
 namespace OCA\Theming\Themes;
 
-use OCA\Theming\AppInfo\Application;
+use OCA\Theming\Util;
 use OCA\Theming\ImageManager;
+use OCA\Theming\AppInfo\Application;
 use OCA\Theming\Service\BackgroundService;
-use OCA\Theming\Util;
 
 trait CommonThemeTrait {
 	public Util $util;
@@ -82,9 +82,9 @@ trait CommonThemeTrait {
 	 * Generate admin theming background-related variables
 	 */
 	protected function generateGlobalBackgroundVariables(): array {
-		$user = $this->userSession->getUser();
 		$backgroundDeleted = $this->config->getAppValue(Application::APP_ID, 'backgroundMime', '') === 'backgroundColor';
 		$hasCustomLogoHeader = $this->util->isLogoThemed();
+		$isDefaultPrimaryBright = $this->util->invertTextColor($this->defaultPrimaryColor);
 
 		$variables = [];
 
@@ -95,8 +95,10 @@ trait CommonThemeTrait {
 		// If primary as background has been request or if we have a custom primary colour
 		// let's not define the background image
 		if ($backgroundDeleted) {
-			$variables['--color-background-plain'] = $this->themingDefaults->getColorPrimary();
+			$variables['--color-background-plain'] = $this->defaultPrimaryColor;
 			$variables['--image-background-plain'] = 'yes';
+			// If no background image is set, we need to check against the shown primary colour
+			$variables['--background-image-invert-if-bright'] = $isDefaultPrimaryBright ? 'invert(100%)' : 'no';
 		}
 
 		// Register image variables only if custom-defined
@@ -125,12 +127,15 @@ trait CommonThemeTrait {
 			&& $this->appManager->isEnabledForUser(Application::APP_ID)) {
 			$backgroundImage = $this->config->getUserValue($user->getUID(), Application::APP_ID, 'background_image', BackgroundService::BACKGROUND_DEFAULT);
 			$currentVersion = (int)$this->config->getUserValue($user->getUID(), Application::APP_ID, 'userCacheBuster', '0');
+			$isPrimaryBright = $this->util->invertTextColor($this->primaryColor);
 
 			// The user removed the background
 			if ($backgroundImage === BackgroundService::BACKGROUND_DISABLED) {
 				return [
 					'--image-background' => 'no',
-					'--color-background-plain' => $this->themingDefaults->getColorPrimary(),
+					'--color-background-plain' => $this->primaryColor,
+					// If no background image is set, we need to check against the shown primary colour
+					'--background-image-invert-if-bright' => $isPrimaryBright ? 'invert(100%)' : 'no',
 				];
 			}