fix(theming): enforce theme should still provide dark as fallback

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

apps/theming/lib/Service/ThemesService.php

@@ -28,7 +28,7 @@ public function __construct(
 		private LoggerInterface $logger,
 		private DefaultTheme $defaultTheme,
 		LightTheme $lightTheme,
-		DarkTheme $darkTheme,
+		private DarkTheme $darkTheme,
 		HighContrastTheme $highContrastTheme,
 		DarkHighContrastTheme $darkHighContrastTheme,
 		DyslexiaFont $dyslexiaFont) {
@@ -59,9 +59,15 @@ public function getThemes(): array {
 			}
 
 			$defaultTheme = $this->themesProviders[$this->defaultTheme->getId()];
+			$darkTheme = $this->themesProviders[$this->darkTheme->getId()];
 			$theme = $this->themesProviders[$enforcedTheme];
 			return [
+				// Leave the default theme as a fallback
 				$defaultTheme->getId() => $defaultTheme,
+				// Make sure we also have the dark theme to allow apps
+				// to scope sections of their UI to the dark theme
+				$darkTheme->getId() => $darkTheme,
+				// Finally, the enforced theme
 				$theme->getId() => $theme,
 			];
 		}

apps/theming/src/components/ItemPreview.vue

@@ -13,7 +13,10 @@
 			<span v-if="enforced" class="theming__preview-warning" role="note">
 				{{ t('theming', 'Theme selection is enforced') }}
 			</span>
-			<NcCheckboxRadioSwitch class="theming__preview-toggle"
+
+			<!-- Only show checkbox if we can change themes -->
+			<NcCheckboxRadioSwitch v-show="!enforced"
+				class="theming__preview-toggle"
 				:checked.sync="checked"
 				:disabled="enforced"
 				:name="name"
@@ -73,6 +76,10 @@ export default {
 				return this.selected
 			},
 			set(checked) {
+				if (this.enforced) {
+					return
+				}
+
 				console.debug('Changed theme', this.theme.id, checked)
 
 				// If this is a radio, we can only enable
@@ -89,6 +96,10 @@ export default {
 
 	methods: {
 		onToggle() {
+			if (this.enforced) {
+				return
+			}
+
 			if (this.switchType === 'radio') {
 				this.checked = true
 				return