Add AccessibilityController class, which dynamically registers (#2024)

and unregisters the google-docs.js content script

5 files changed, 103 insertions, 12 deletions

diff --git a/ext/background.html b/ext/background.html
index 44027a48..84e64c9c 100644
--- a/ext/background.html
+++ b/ext/background.html
@@ -23,6 +23,7 @@
 
 <script src="/js/yomichan.js"></script>
 
+<script src="/js/accessibility/accessibility-controller.js"></script>
 <script src="/js/background/backend.js"></script>
 <script src="/js/background/environment.js"></script>
 <script src="/js/background/profile-conditions-util.js"></script>
diff --git a/ext/js/accessibility/accessibility-controller.js b/ext/js/accessibility/accessibility-controller.js
new file mode 100644
index 00000000..a995d5d0
--- /dev/null
+++ b/ext/js/accessibility/accessibility-controller.js
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2021  Yomichan Authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/**
+ * This class controls the registration of accessibility handlers.
+ */
+class AccessibilityController {
+    /**
+     * Creates a new instance.
+     * @param {ScriptManager} scriptManager An instance of the `ScriptManager` class.
+     */
+    constructor(scriptManager) {
+        this._scriptManager = scriptManager;
+        this._updateGoogleDocsAccessibilityToken = null;
+        this._updateGoogleDocsAccessibilityPromise = null;
+        this._forceGoogleDocsHtmlRenderingAny = false;
+    }
+
+    /**
+     * Updates the accessibility handlers.
+     * @param {object} fullOptions The full options object from the `Backend` instance.
+     *   The value is treated as read-only and is not modified.
+     */
+    async update(fullOptions) {
+        let forceGoogleDocsHtmlRenderingAny = false;
+        for (const {options} of fullOptions.profiles) {
+            if (options.accessibility.forceGoogleDocsHtmlRendering) {
+                forceGoogleDocsHtmlRenderingAny = true;
+                break;
+            }
+        }
+
+        await this._updateGoogleDocsAccessibility(forceGoogleDocsHtmlRenderingAny);
+    }
+
+    // Private
+
+    async _updateGoogleDocsAccessibility(forceGoogleDocsHtmlRenderingAny) {
+        // Reentrant token
+        const token = {};
+        this._updateGoogleDocsAccessibilityToken = token;
+
+        // Wait for previous
+        let promise = this._updateGoogleDocsAccessibilityPromise;
+        if (promise !== null) { await promise; }
+
+        // Reentrant check
+        if (this._updateGoogleDocsAccessibilityToken !== token) { return; }
+
+        // Update
+        promise = this._updateGoogleDocsAccessibilityInner(forceGoogleDocsHtmlRenderingAny);
+        this._updateGoogleDocsAccessibilityPromise = promise;
+        await promise;
+        this._updateGoogleDocsAccessibilityPromise = null;
+    }
+
+    async _updateGoogleDocsAccessibilityInner(forceGoogleDocsHtmlRenderingAny) {
+        if (this._forceGoogleDocsHtmlRenderingAny === forceGoogleDocsHtmlRenderingAny) { return; }
+
+        this._forceGoogleDocsHtmlRenderingAny = forceGoogleDocsHtmlRenderingAny;
+
+        const id = 'googleDocsAccessibility';
+        try {
+            if (forceGoogleDocsHtmlRenderingAny) {
+                if (await this._scriptManager.isContentScriptRegistered(id)) { return; }
+                const details = {
+                    allFrames: true,
+                    matchAboutBlank: true,
+                    matches: ['*://docs.google.com/*'],
+                    urlMatches: '^[^:]*://docs.google.com/[\\w\\W]*$',
+                    runAt: 'document_start',
+                    js: ['js/accessibility/google-docs.js']
+                };
+                await this._scriptManager.registerContentScript(id, details);
+            } else {
+                await this._scriptManager.unregisterContentScript(id);
+            }
+        } catch (e) {
+            log.error(e);
+        }
+    }
+}
+
diff --git a/ext/js/background/backend.js b/ext/js/background/backend.js
index 4e86a23c..f8424e80 100644
--- a/ext/js/background/backend.js
+++ b/ext/js/background/backend.js
@@ -16,6 +16,7 @@
  */
 
 /* global
+ * AccessibilityController
  * AnkiConnect
  * AnkiUtil
  * AudioDownloader
@@ -69,6 +70,7 @@ class Backend {
         });
         this._optionsUtil = new OptionsUtil();
         this._scriptManager = new ScriptManager();
+        this._accessibilityController = new AccessibilityController(this._scriptManager);
 
         this._searchPopupTabId = null;
         this._searchPopupTabCreatePromise = null;
@@ -988,6 +990,8 @@ class Backend {
             this._clipboardMonitor.stop();
         }
 
+        this._accessibilityController.update(this._getOptionsFull(false));
+
         this._sendMessageAllTabsIgnoreResponse('Yomichan.optionsUpdated', {source});
     }
 
diff --git a/ext/manifest.json b/ext/manifest.json
index 422d296e..33d1ed1d 100644
--- a/ext/manifest.json
+++ b/ext/manifest.json
@@ -62,18 +62,6 @@
                 "js/script/dynamic-loader.js",
                 "js/app/content-script-main.js"
             ]
-        },
-        {
-            "run_at": "document_start",
-            "matches": [
-                "http://docs.google.com/*",
-                "https://docs.google.com/*"
-            ],
-            "match_about_blank": true,
-            "all_frames": true,
-            "js": [
-                "js/accessibility/google-docs.js"
-            ]
         }
     ],
     "minimum_chrome_version": "57.0.0.0",
diff --git a/ext/sw.js b/ext/sw.js
index 2624a04d..af6c9a43 100644
--- a/ext/sw.js
+++ b/ext/sw.js
@@ -20,6 +20,7 @@ self.importScripts(
     '/lib/wanakana.min.js',
     '/js/core.js',
     '/js/yomichan.js',
+    '/js/accessibility/accessibility-controller.js',
     '/js/background/backend.js',
     '/js/background/environment.js',
     '/js/background/profile-conditions-util.js',