AnkiTemplateRendererContentManager (#2088)

* Make function private

* Update comments

* Refactor the content manager that is provided to StructuredContentGenerator in AnkiTemplateRenderer

* Update function to not be async, for API parity

1 files changed, 45 insertions, 12 deletions

diff --git a/ext/js/display/display-content-manager.js b/ext/js/display/display-content-manager.js
index a0dd7dd6..0818f915 100644
--- a/ext/js/display/display-content-manager.js
+++ b/ext/js/display/display-content-manager.js
@@ -19,26 +19,46 @@
  * StringUtil
  */
 
+/**
+ * A callback used when a media file has been loaded.
+ * @callback DisplayContentManager.OnLoadCallback
+ * @param {string} url The URL of the media that was loaded.
+ */
+
+/**
+ * A callback used when a media file should be unloaded.
+ * @callback DisplayContentManager.OnUnloadCallback
+ * @param {boolean} fullyLoaded Whether or not the media was fully loaded.
+ */
+
+/**
+ * The content manager which is used when generating HTML display content.
+ */
 class DisplayContentManager {
+    /**
+     * Creates a new instance of the class.
+     */
     constructor() {
         this._token = {};
         this._mediaCache = new Map();
         this._loadMediaData = [];
     }
 
-    async loadMedia(path, dictionary, onLoad, onUnload) {
-        const token = this._token;
-        const data = {onUnload, loaded: false};
-
-        this._loadMediaData.push(data);
-
-        const media = await this.getMedia(path, dictionary);
-        if (token !== this._token) { return; }
-
-        onLoad(media.url);
-        data.loaded = true;
+    /**
+     * Attempts to load the media file from a given dictionary.
+     * @param {string} path The path to the media file in the dictionary.
+     * @param {string} dictionary The name of the dictionary.
+     * @param {DisplayContentManager.OnLoadCallback} onLoad The callback that is executed if the media was loaded successfully.
+     *   No assumptions should be made about the synchronicity of this callback.
+     * @param {DisplayContentManager.OnUnloadCallback} onUnload The callback that is executed when the media should be unloaded.
+     */
+    loadMedia(path, dictionary, onLoad, onUnload) {
+        this._loadMedia(path, dictionary, onLoad, onUnload);
     }
 
+    /**
+     * Unloads all media that has been loaded.
+     */
     unloadAll() {
         for (const {onUnload, loaded} of this._loadMediaData) {
             if (typeof onUnload === 'function') {
@@ -59,7 +79,20 @@ class DisplayContentManager {
         this._token = {};
     }
 
-    async getMedia(path, dictionary) {
+    async _loadMedia(path, dictionary, onLoad, onUnload) {
+        const token = this._token;
+        const data = {onUnload, loaded: false};
+
+        this._loadMediaData.push(data);
+
+        const media = await this._getMedia(path, dictionary);
+        if (token !== this._token) { return; }
+
+        onLoad(media.url);
+        data.loaded = true;
+    }
+
+    async _getMedia(path, dictionary) {
         let cachedData;
         let dictionaryCache = this._mediaCache.get(dictionary);
         if (typeof dictionaryCache !== 'undefined') {