diff options
| author | Jacob Hoffman-Andrews <github@hoffman-andrews.com> | 2022-06-20 12:41:11 -0700 |
|---|---|---|
| committer | Jacob Hoffman-Andrews <github@hoffman-andrews.com> | 2022-06-20 15:08:02 -0700 |
| commit | b37a05bd01a4f1fdcdfda77df4a9008d04236528 (patch) | |
| tree | c721c0c224e78af8a1526ff9d26c10878781888c /src/librustdoc/html/static/js | |
| parent | bb8c2f41174caceec00c28bc6c5c20ae9f9a175c (diff) | |
| download | rust-b37a05bd01a4f1fdcdfda77df4a9008d04236528.tar.gz rust-b37a05bd01a4f1fdcdfda77df4a9008d04236528.zip | |
rustdoc: optimize loading of source sidebar
The source sidebar has a setting to remember whether it should be open or closed. Previously, this setting was handled in source-script.js, which is loaded with `defer`, meaning it is often run after the document is rendered. Since CSS renders the source sidebar as closed by default, changing this after the initial render results in a relayout. Instead, handle the setting in storage.js, which is the first script to load and is the only script that blocks render. This avoids a relayout and means navigating between files with the sidebar open is faster.
Diffstat (limited to 'src/librustdoc/html/static/js')
| -rw-r--r-- | src/librustdoc/html/static/js/source-script.js | 10 | ||||
| -rw-r--r-- | src/librustdoc/html/static/js/storage.js | 11 |
2 files changed, 13 insertions, 8 deletions
diff --git a/src/librustdoc/html/static/js/source-script.js b/src/librustdoc/html/static/js/source-script.js index 14d8a942977..45955c6dd05 100644 --- a/src/librustdoc/html/static/js/source-script.js +++ b/src/librustdoc/html/static/js/source-script.js @@ -76,14 +76,13 @@ function createDirEntry(elem, parent, fullPath, currentFile, hasFoundFile) { } function toggleSidebar() { - const sidebar = document.querySelector("nav.sidebar"); const child = this.children[0]; if (child.innerText === ">") { - sidebar.classList.add("expanded"); + addClass(document.documentElement, "source-sidebar-expanded"); child.innerText = "<"; updateLocalStorage("source-sidebar-show", "true"); } else { - sidebar.classList.remove("expanded"); + removeClass(document.documentElement, "source-sidebar-expanded"); child.innerText = ">"; updateLocalStorage("source-sidebar-show", "false"); } @@ -119,11 +118,6 @@ function createSourceSidebar() { const sidebar = document.createElement("div"); sidebar.id = "source-sidebar"; - if (getCurrentValue("source-sidebar-show") !== "true") { - container.classList.remove("expanded"); - } else { - container.classList.add("expanded"); - } const currentFile = getCurrentFilePath(); let hasFoundFile = false; diff --git a/src/librustdoc/html/static/js/storage.js b/src/librustdoc/html/static/js/storage.js index 4fcf0499234..1c4c8834488 100644 --- a/src/librustdoc/html/static/js/storage.js +++ b/src/librustdoc/html/static/js/storage.js @@ -1,3 +1,8 @@ +// storage.js is loaded in the `<head>` of all rustdoc pages and doesn't +// use `async` or `defer`. That means it blocks further parsing and rendering +// of the page: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/script. +// This makes it the correct place to act on settings that affect the display of +// the page, so we don't see major layout changes during the load of the page. "use strict"; const darkThemes = ["dark", "ayu"]; @@ -236,6 +241,12 @@ if (getSettingValue("use-system-theme") !== "false" && window.matchMedia) { switchToSavedTheme(); } +if (getSettingValue("source-sidebar-show") === "true") { + // At this point in page load, `document.body` is not available yet. + // Set a class on the `<html>` element instead. + addClass(document.documentElement, "source-sidebar-expanded"); +} + // If we navigate away (for example to a settings page), and then use the back or // forward button to get back to a page, the theme may have changed in the meantime. // But scripts may not be re-loaded in such a case due to the bfcache |