From e34c46c89306e30a953acce8487b0a8f5fb83c64 Mon Sep 17 00:00:00 2001
From: David Baker <dave@matrix.org>
Date: Wed, 20 Nov 2019 15:42:15 +0000
Subject: [PATCH] Dedup theming code

Following on from https://github.com/matrix-org/matrix-react-sdk/pull/3637
this removes the code dealing with themes in vector/index.js and uses the
code from react-sdk. The two did almost exactly the same thing but in
subtley different ways.

This code can be incredibly subtle though, so doing this a separate
PR.
---
 src/vector/index.js | 51 ++-------------------------------------------
 1 file changed, 2 insertions(+), 49 deletions(-)

diff --git a/src/vector/index.js b/src/vector/index.js
index 402587bc7a..2a88fed54f 100644
--- a/src/vector/index.js
+++ b/src/vector/index.js
@@ -57,7 +57,7 @@ import WebPlatform from './platform/WebPlatform';
 import MatrixClientPeg from 'matrix-react-sdk/lib/MatrixClientPeg';
 import SettingsStore from "matrix-react-sdk/lib/settings/SettingsStore";
 import SdkConfig from "matrix-react-sdk/lib/SdkConfig";
-import {getBaseTheme, setTheme, ThemeWatcher} from "matrix-react-sdk/lib/theme";
+import {setTheme} from "matrix-react-sdk/lib/theme";
 
 import Olm from 'olm';
 
@@ -255,54 +255,7 @@ async function loadApp() {
     }
 
     // as quickly as we possibly can, set a default theme...
-    // we do this by checking to see if the theme's "base" has loaded first so we can
-    // safely rely on the assets.
-    let a;
-    const themeWatcher = new ThemeWatcher();
-    const theme = themeWatcher.getEffectiveTheme();
-    const baseTheme = getBaseTheme(theme);
-    for (let i = 0; (a = document.getElementsByTagName("link")[i]); i++) {
-        const href = a.getAttribute("href");
-        if (!href) continue;
-        // shouldn't we be using the 'title' tag rather than the href?
-        const match = href.match(/^bundles\/.*\/theme-(.*)\.css$/);
-        if (match) {
-            if (match[1] === baseTheme) {
-                // remove the disabled flag off the stylesheet
-
-                // Firefox requires setting the attribute to false, so do
-                // that instead of removing it. Related:
-                // https://bugzilla.mozilla.org/show_bug.cgi?id=1281135
-                a.disabled = false;
-
-                // in case the Tinter.tint() in MatrixChat fires before the
-                // CSS has actually loaded (which in practice happens)...
-
-                // This if fixes setTheme to not fire on Firefox
-                // in case it is the first time loading Riot.
-                // `InstallTrigger` is a Object which only exists on Firefox
-                // (it is used for their Plugins) and can be used as a
-                // feature check.
-                // Firefox loads css always before js. This is why we dont use
-                // onload or it's EventListener as those will never trigger.
-                if (typeof InstallTrigger !== 'undefined') {
-                    setTheme(theme);
-                } else {
-                    // FIXME: we should probably block loading the app or even
-                    // showing a spinner until the theme is loaded, to avoid
-                    // flashes of unstyled content.
-                    a.onload = () => {
-                        setTheme(theme);
-                    };
-                }
-            } else {
-                // Firefox requires this to not be done via `setAttribute`
-                // or via HTML.
-                // https://bugzilla.mozilla.org/show_bug.cgi?id=1281135
-                a.disabled = true;
-            }
-        }
-    }
+    await setTheme();
 
     // Now that we've loaded the theme (CSS), display the config syntax error if needed.
     if (configSyntaxError) {