Mapping colors to categories (proof-of-concept)

src/_locales/en/messages.json

@@ -165,7 +165,7 @@
   },
 
   "settings.warning": {
-    "message": "These settings are will allow you to make use of email scheduling via Google Calendar, but there have also been reports about extraneous notification emails being sent. Please test with a small meeting first."
+    "message": "The settings below allow you to make use of email scheduling via Google Calendar, but there have also been reports about extraneous notification emails being sent. Please test with a small meeting first."
   },
 
   "settings.enableEmailInvitations": {
@@ -180,6 +180,9 @@
   "settings.forcePlainText": {
     "message": "Force use of plain text in event descriptions"
   },
+  "settings.enableColors": {
+    "message": "Enable support for event colors (experimental; enabling/disabling reloads all calendars)"
+  },
 
   "eventdialog.conferenceLabel": {
     "message": "Conference:"

src/legacy/modules/gdataUI.jsm

@@ -7,6 +7,9 @@ var EXPORTED_SYMBOLS = ["register", "unregister", "recordModule", "recordWindow"
 
 var { ExtensionSupport } = ChromeUtils.import("resource:///modules/ExtensionSupport.jsm");
 
+const Services =
+  globalThis.Services || ChromeUtils.import("resource://gre/modules/Services.jsm").Services; // Thunderbird 103 compat
+
 var unregisterIds = [];
 var unregisterModules = new Set();
 var closeWindows = new Set();
@@ -67,9 +70,39 @@ function register() {
       checkMigrateCalendars(window);
     },
   });
+
+  let { doEnableColors, doDisableColors, flushCache, getMessenger } = ChromeUtils.import(
+    "resource://gdata-provider/legacy/modules/gdataUtils.jsm"
+  );
+
+  let messenger = getMessenger();
+  messenger.storage.onChanged.addListener((settings, _target) => {
+    if ("settings.enableColors" in settings) {
+      // check for true and false explicitly, since `undefined` can also happen
+      if (settings["settings.enableColors"].newValue === true) {
+        doEnableColors();
+      } else if (settings["settings.enableColors"].newValue === false) {
+        doDisableColors();
+      }
+      // We must delete the cache and reload all calendars from the source in order
+      // to add/remove the color categories. Restarting Thunderbird is insufficient
+      // because the locally cached calendar entries lack the color information.
+      flushCache();
+    }
+  });
+
+  let enableColors = messenger.gdataSyncPrefs.get("settings.enableColors", false);
+  if (enableColors) {
+    doEnableColors();
+  }
 }
 
 function unregister() {
+  let { doDisableColors } = ChromeUtils.import(
+    "resource://gdata-provider/legacy/modules/gdataUtils.jsm"
+  );
+  doDisableColors();
+
   for (let id of unregisterIds) {
     ExtensionSupport.unregisterWindowListener(id);
     Cu.unload(`resource://gdata-provider/legacy/modules/ui/${id}.jsm`);

src/legacy/modules/gdataUtils.jsm

@@ -53,6 +53,9 @@ var EXPORTED_SYMBOLS = [
   "JSONToDate",
   "monkeyPatch",
   "spinEventLoop",
+  "doEnableColors",
+  "doDisableColors",
+  "flushCache",
   "getMessenger",
 ];
 
@@ -380,9 +383,21 @@ function EventToJSON(aItem, aOfflineStorage, aIsImport) {
   }
   setIf(itemData, "status", status);
 
+  let categoryList = aItem.getCategories({});
+  let enableColors = getMessenger().gdataSyncPrefs.get("settings.enableColors", false);
+  if (enableColors) {
+    // Take the first category of the form "Google Color dd" for 1 <= dd <= 11 and turn it into a colorId.
+    // Right now, the rest are treated like all other categories.
+    // TODO would it make sense / be possible to issue some sort of warning / error here or elsewhere?
+    let colorCat = categoryList.findIndex((category) => /^Google Color (0[1-9]|1[01])$/.test(category));
+    if (colorCat > -1) {
+        itemData.colorId = parseInt(categoryList[colorCat].match(/^Google Color (0[1-9]|1[01])$/)[1]);
+        categoryList.splice(colorCat, 1);
+    }
+  }
   // Google does not support categories natively, but allows us to store data
   // as an "extendedProperty", so we do here
-  let categories = cal.category.arrayToString(aItem.getCategories({}));
+  let categories = cal.category.arrayToString(categoryList);
   addExtendedProperty("X-MOZ-CATEGORIES", categories);
 
   // Only parse attendees if they are enabled, due to bug 407961
@@ -893,10 +908,17 @@ function JSONToEvent(aEntry, aCalendar, aDefaultReminders, aReferenceItem, aMeta
       }
     }
 
+    let categories = cal.category.stringToArray(sharedProps["X-MOZ-CATEGORIES"]);
+    let enableColors = getMessenger().gdataSyncPrefs.get("settings.enableColors", false);
+    if (enableColors) {
+      if (aEntry.colorId) {
+        // Add color category at the beginning
+        categories.unshift("Google Color " + aEntry.colorId.toString().padStart(2,'0'));
+      }
+    }
     // Google does not support categories natively, but allows us to store
     // data as an "extendedProperty", and here it's going to be retrieved
     // again
-    let categories = cal.category.stringToArray(sharedProps["X-MOZ-CATEGORIES"]);
     item.setCategories(categories);
 
     // Conference data
@@ -1479,6 +1501,43 @@ function getWXAPI(extension, name, sync = false) {
   }
 }
 
+function doEnableColors() {
+  const GOOGLE_COLORS = ["#000", "#7986CB", "#33B679", "#8E24AA", "#E67C73", "#F6BF26",
+  "#F4511E", "#039BE5", "#616161", "#3F51B5", "#0B8043", "#D50000"];
+  let calendarCategories = Services.prefs.getStringPref("calendar.categories.names");
+  for (let i=1; i<=11; i++) {
+    let paddedIndex = i.toString().padStart(2,'0');
+    let catName = "Google Color " + paddedIndex;
+    if (!calendarCategories.includes(catName)) {
+      calendarCategories += "," + catName;
+      Services.prefs.setStringPref("calendar.category.color.google_color_" + paddedIndex, GOOGLE_COLORS[i]);
+    }
+  }
+  Services.prefs.setStringPref("calendar.categories.names", calendarCategories);
+}
+
+function doDisableColors() {
+  for (let i=1; i<=11; i++) {
+    let padded_index = i.toString().padStart(2,'0');
+    Services.prefs.clearUserPref("calendar.category.color.google_color_" + padded_index);
+  }
+  let calendarCategories = Services.prefs.getStringPref("calendar.categories.names");
+  calendarCategories = calendarCategories.replaceAll(/,Google\sColor\s\d\d/g, "")
+  Services.prefs.setStringPref("calendar.categories.names", calendarCategories);
+}
+
+/**
+ * Deletes the local Google calendar cache and reloads all Google calendars from the source.
+ */
+function flushCache() {
+  let cals = cal.manager.wrappedJSObject.getCalendars();
+  for (let calendar of cals) {
+    if (calendar.type == "gdata") {
+      calendar.mUncachedCalendar.resetLog();
+    }
+  }
+}
+
 class SyncPrefs {
   prefs = {};
 

src/options/options.html

@@ -4,6 +4,18 @@
     <meta charset="utf-8">
   </head>
   <body>
+    <div class="browser-style">
+      <input type="checkbox" id="enableAttendees"/>
+      <label for="enableAttendees" data-l10n-id="settings.enableAttendees"/>
+    </div>
+    <div class="browser-style">
+      <input type="checkbox" id="forcePlainText"/>
+      <label for="forcePlainText" data-l10n-id="settings.forcePlainText"/>
+    </div>
+    <div class="browser-style">
+      <input type="checkbox" id="enableColors"/>
+      <label for="enableColors" data-l10n-id="settings.enableColors"/>
+    </div>
     <p data-l10n-id="settings.warning"></p>
     <div class="browser-style">
       <input type="checkbox" id="enableEmailInvitations"/>
@@ -13,14 +25,6 @@
       <input type="checkbox" id="sendEventNotifications"/>
       <label for="sendEventNotifications" data-l10n-id="settings.sendEventNotifications"/>
     </div>
-    <div class="browser-style">
-      <input type="checkbox" id="enableAttendees"/>
-      <label for="enableAttendees" data-l10n-id="settings.enableAttendees"/>
-    </div>
-    <div class="browser-style">
-      <input type="checkbox" id="forcePlainText"/>
-      <label for="forcePlainText" data-l10n-id="settings.forcePlainText"/>
-    </div>
     <script src="options.js"></script>
   </body>
 </html>

src/options/options.js

@@ -17,6 +17,7 @@ for (let node of document.querySelectorAll("[data-l10n-id]")) {
     "settings.sendEventNotifications": false,
     "settings.enableAttendees": false,
     "settings.forcePlainText": false,
+    "settings.enableColors": false,
   });
 
   for (let [id, value] of Object.entries(prefs)) {