MOBILE-3635 settings: Improve color scheme preference detection

src/core/features/settings/lang.json

@@ -6,7 +6,8 @@
     "cannotsyncoffline": "Cannot synchronise offline.",
     "cannotsyncwithoutwifi": "Cannot synchronise because the current settings only allow to synchronise when connected to Wi-Fi. Please connect to a Wi-Fi network.",
     "colorscheme": "Color Scheme",
-    "colorscheme-auto": "Auto (based on system settings)",
+    "colorscheme-system": "System default",
+    "colorscheme-system-notice": "System default mode will depend on your device support.",
     "colorscheme-dark": "Dark",
     "colorscheme-light": "Light",
     "compilationinfo": "Compilation info",

src/core/features/settings/pages/general/general.html

@@ -32,7 +32,8 @@
             </ion-segment-button>
         </ion-segment>
     </ion-item>
-    <ion-item class="ion-text-wrap core-settings-general-color-scheme" *ngIf="colorSchemes.length > 0">
+    <ion-item class="ion-text-wrap core-settings-general-color-scheme" *ngIf="colorSchemes.length > 0"
+        [lines]="selectedScheme=='system' && isAndroid ? 'none' : 'inset'">
         <ion-label>
             <h2>{{ 'core.settings.colorscheme' | translate }}</h2>
             <p *ngIf="colorSchemeDisabled" class="text-danger">{{ 'core.settings.forcedsetting' | translate }}</p>
@@ -43,6 +44,9 @@
                 {{ 'core.settings.colorscheme-' + scheme | translate }}</ion-select-option>
         </ion-select>
     </ion-item>
+    <ion-item text-wrap *ngIf="colorSchemes.length > 0 && selectedScheme=='system' && isAndroid">
+        <ion-label><p>{{ 'core.settings.colorscheme-system-notice' | translate }}</p></ion-label>
+    </ion-item>
     <ion-item class="ion-text-wrap">
         <ion-label>
             <h2>{{ 'core.settings.enablerichtexteditor' | translate }}</h2>

src/core/features/settings/pages/general/general.ts

@@ -20,6 +20,7 @@ import { CoreLang } from '@services/lang';
 import { CoreDomUtils } from '@services/utils/dom';
 import { CorePushNotifications } from '@features/pushnotifications/services/pushnotifications';
 import { CoreSettingsHelper, CoreColorScheme, CoreZoomLevel } from '../../services/settings-helper';
+import { CoreApp } from '@services/app';
 
 /**
  * Page that displays the general settings.
@@ -42,6 +43,7 @@ export class CoreSettingsGeneralPage {
     colorSchemes: CoreColorScheme[] = [];
     selectedScheme: CoreColorScheme = CoreColorScheme.LIGHT;
     colorSchemeDisabled = false;
+    isAndroid = false;
 
     constructor() {
         this.asyncInit();
@@ -72,14 +74,8 @@ export class CoreSettingsGeneralPage {
                 this.colorSchemes.push(CoreColorScheme.LIGHT);
                 this.selectedScheme = this.colorSchemes[0];
             } else {
-                this.colorSchemes.push(CoreColorScheme.LIGHT);
-                this.colorSchemes.push(CoreColorScheme.DARK);
-
-                if (window.matchMedia('(prefers-color-scheme: dark)').matches ||
-                                    window.matchMedia('(prefers-color-scheme: light)').matches) {
-                    this.colorSchemes.push(CoreColorScheme.AUTO);
-                }
-
+                this.isAndroid = CoreApp.isAndroid();
+                this.colorSchemes = CoreSettingsHelper.getAllowedColorSchemes();
                 this.selectedScheme = await CoreConfig.get(CoreConstants.SETTINGS_COLOR_SCHEME, CoreColorScheme.LIGHT);
             }
         }

src/core/features/settings/services/settings-helper.ts

@@ -43,7 +43,7 @@ export interface CoreSiteSpaceUsage {
  * Constants to define color schemes.
  */
 export const enum CoreColorScheme {
-    AUTO = 'auto',
+    SYSTEM = 'system',
     LIGHT = 'light',
     DARK = 'dark',
 }
@@ -65,6 +65,7 @@ export class CoreSettingsHelperProvider {
 
     protected syncPromises: { [s: string]: Promise<void> } = {};
     protected prefersDark?: MediaQueryList;
+    protected colorSchemes: CoreColorScheme[] = [];
 
     constructor() {
         if (!CoreConstants.CONFIG.forceColorScheme) {
@@ -404,13 +405,37 @@ export class CoreSettingsHelperProvider {
         document.documentElement.style.zoom = zoom + '%';
     }
 
+    /**
+     * Get system allowed color schemes.
+     *
+     * @return Allowed color schemes.
+     */
+    getAllowedColorSchemes(): CoreColorScheme[] {
+        if (this.colorSchemes.length > 0) {
+            return this.colorSchemes;
+        }
+
+        if (!CoreConstants.CONFIG.forceColorScheme) {
+            this.colorSchemes.push(CoreColorScheme.LIGHT);
+            this.colorSchemes.push(CoreColorScheme.DARK);
+
+            if (this.canIUsePrefersColorScheme()) {
+                this.colorSchemes.push(CoreColorScheme.SYSTEM);
+            }
+        } else {
+            this.colorSchemes = [CoreConstants.CONFIG.forceColorScheme];
+        }
+
+        return this.colorSchemes;
+    }
+
     /**
      * Set body color scheme.
      *
      * @param colorScheme Name of the color scheme.
      */
     setColorScheme(colorScheme: CoreColorScheme): void {
-        if (colorScheme == CoreColorScheme.AUTO && this.prefersDark) {
+        if (colorScheme == CoreColorScheme.SYSTEM && this.prefersDark) {
             // Listen for changes to the prefers-color-scheme media query.
             this.prefersDark.addEventListener('change', this.toggleDarkModeListener);
 
@@ -423,6 +448,18 @@ export class CoreSettingsHelperProvider {
         }
     }
 
+    /**
+     * Check if device can detect color scheme system preference.
+     * https://caniuse.com/prefers-color-scheme
+     *
+     * @returns if the color scheme system preference is avalaible.
+     */
+    canIUsePrefersColorScheme(): boolean {
+        // The following check will check browser support but system may differ from that.
+        // @todo Detect SO support to watch media query.
+        return window.matchMedia('(prefers-color-scheme)').media !== 'not all';
+    }
+
     /**
      * Listener function to toggle dark mode.
      *

src/theme/theme.base.scss

@@ -52,6 +52,15 @@ ion-item.ion-text-wrap ion-label {
     }
 }
 
+@each $color-name, $value in $colors {
+    $value: map-get($colors, $color-name);
+    $base: map-get($value, base);
+
+    .text-#{$color-name},
+    p.text-#{$color-name} {
+        color: $base;
+    }
+}
 
 // Ionic toolbar.
 ion-toolbar ion-back-button,
@@ -466,3 +475,8 @@ ion-button.core-button-select {
         display: none !important;
     }
 }
+
+// Hide virtual utilities.
+.core-browser-copy-area {
+    display: none;
+}