Add alt text validation option to user preferences (supersedes #913) (#914)

* Add alt text validation option to user preferences

* Fix typos/linting issues

* Update accessibility setting to match styles

* Update the required alt text reminder to go away once it's added

---------

Co-authored-by: Emma Fuller <emma@emmafuller.dev>

src/state/models/media/gallery.ts

@@ -23,6 +23,10 @@ export class GalleryModel {
     return this.images.length
   }
 
+  get needsAltText() {
+    return this.images.some(image => image.altText.trim() === '')
+  }
+
   async add(image_: Omit<RNImage, 'size'>) {
     if (this.size >= 4) {
       return

src/state/models/ui/preferences.ts

@@ -53,6 +53,7 @@ export class PreferencesModel {
   homeFeedRepliesThreshold: number = 2
   homeFeedRepostsEnabled: boolean = true
   homeFeedQuotePostsEnabled: boolean = true
+  requireAltTextEnabled: boolean = false
 
   // used to linearize async modifications to state
   lock = new AwaitLock()
@@ -72,6 +73,7 @@ export class PreferencesModel {
       homeFeedRepliesThreshold: this.homeFeedRepliesThreshold,
       homeFeedRepostsEnabled: this.homeFeedRepostsEnabled,
       homeFeedQuotePostsEnabled: this.homeFeedQuotePostsEnabled,
+      requireAltTextEnabled: this.requireAltTextEnabled,
     }
   }
 
@@ -152,6 +154,13 @@ export class PreferencesModel {
       ) {
         this.homeFeedQuotePostsEnabled = v.homeFeedQuotePostsEnabled
       }
+      // check if requiring alt text is enabled in preferences, then hydrate
+      if (
+        hasProp(v, 'requireAltTextEnabled') &&
+        typeof v.requireAltTextEnabled === 'boolean'
+      ) {
+        this.requireAltTextEnabled = v.requireAltTextEnabled
+      }
     }
   }
 
@@ -467,4 +476,8 @@ export class PreferencesModel {
   toggleHomeFeedQuotePostsEnabled() {
     this.homeFeedQuotePostsEnabled = !this.homeFeedQuotePostsEnabled
   }
+
+  toggleRequireAltTextEnabled() {
+    this.requireAltTextEnabled = !this.requireAltTextEnabled
+  }
 }