rustdoc: redesign toolbar and disclosure widgets

This adds labels to the icons and moves them away from the search box.

These changes are made together, because they work together, but are based on
several complaints:

* The [+/-] thing are a Reddit-ism. They don't look like buttons, but look
  like syntax
  <https://rust-lang.zulipchat.com/#narrow/stream/266220-t-rustdoc/topic/More.20visual.20difference.20for.20the.20.2B.2F-.20.20Icons>,
  <https://github.com/rust-lang/rust/issues/59851>
  (some of these are laundry lists with more suggestions, but they all
  mention [+/-] looking wrong)

* The settings, help, and summary buttons are also too hard to recognize
  <https://lwn.net/Articles/987070/>,
  <https://github.com/rust-lang/rust/issues/90310>,
  <https://github.com/rust-lang/rust/issues/14475#issuecomment-274241997>,
  <https://internals.rust-lang.org/t/improve-rustdoc-design/12758>
  ("Not all functionality is self-explanatory, for example the [+] button in
  the top right corner, the theme picker or the settings button.")

The toggle-all and toggle-individual buttons both need done at once, since we
want them to look like they go together. This changes them from both being
[+/-] to both being arrows.

Settings and Help are also migrated, so that the whole group can benefit from
being described using actual words.

Additionally, the Help button is only shown on SERPs, not all the time.
This is done for two major reasons:

* Most of what's in there is search-related. The things that aren't are
  keyboard commands, and the search box tells you about that anyway.
  Pressing <kbd>?</kbd> will temporarily show the button and its popover.
* I'm trading it off by showing the help button, even on mobile.
  It's useful since you can use the search engine suggestions there.
* The three buttons were causing line wrapping on too many desktop layouts.

2 files changed, 164 insertions, 62 deletions

diff --git a/src/librustdoc/html/static/css/noscript.css b/src/librustdoc/html/static/css/noscript.css
index e62b16267f1..477a79d63e9 100644
--- a/src/librustdoc/html/static/css/noscript.css
+++ b/src/librustdoc/html/static/css/noscript.css
@@ -61,6 +61,8 @@ nav.sub {
 	--copy-path-img-hover-filter: invert(35%);
 	--code-example-button-color: #7f7f7f;
 	--code-example-button-hover-color: #595959;
+	--settings-menu-filter: invert(50%);
+	--settings-menu-hover-filter: invert(35%);
 	--codeblock-error-hover-color: rgb(255, 0, 0);
 	--codeblock-error-color: rgba(255, 0, 0, .5);
 	--codeblock-ignore-hover-color: rgb(255, 142, 0);
@@ -87,7 +89,6 @@ nav.sub {
 	--search-tab-button-not-selected-background: #e6e6e6;
 	--search-tab-button-selected-border-top-color: #0089ff;
 	--search-tab-button-selected-background: #fff;
-	--settings-menu-filter: none;
 	--stab-background-color: #fff5d6;
 	--stab-code-color: #000;
 	--code-highlight-kw-color: #8959a8;
@@ -192,6 +193,8 @@ nav.sub {
 		--search-tab-button-not-selected-background: #252525;
 		--search-tab-button-selected-border-top-color: #0089ff;
 		--search-tab-button-selected-background: #353535;
+		--settings-menu-filter: invert(50%);
+		--settings-menu-hover-filter: invert(65%);
 		--stab-background-color: #314559;
 		--stab-code-color: #e6e1cf;
 		--code-highlight-kw-color: #ab8ac1;
diff --git a/src/librustdoc/html/static/css/rustdoc.css b/src/librustdoc/html/static/css/rustdoc.css
index 38154dee3e2..2a9b4c95883 100644
--- a/src/librustdoc/html/static/css/rustdoc.css
+++ b/src/librustdoc/html/static/css/rustdoc.css
@@ -165,7 +165,7 @@ h1, h2, h3, h4 {
 .main-heading h1 {
 	margin: 0;
 	padding: 0;
-	flex-grow: 1;
+	grid-area: main-heading-h1;
 	/* We use overflow-wrap: break-word for Safari, which doesn't recognize
 	   `anywhere`: https://developer.mozilla.org/en-US/docs/Web/CSS/overflow-wrap */
 	overflow-wrap: break-word;
@@ -174,8 +174,12 @@ h1, h2, h3, h4 {
 	overflow-wrap: anywhere;
 }
 .main-heading {
-	display: flex;
-	flex-wrap: wrap;
+	position: relative;
+	display: grid;
+	grid-template-areas:
+		"main-heading-h1 main-heading-toolbar"
+		"main-heading-sub-heading main-heading-toolbar";
+	grid-template-columns: 1fr max-content;
 	padding-bottom: 6px;
 	margin-bottom: 15px;
 }
@@ -218,9 +222,10 @@ h1, h2, h3, h4, h5, h6,
 .search-results .result-name,
 .item-name > a,
 .out-of-band,
+.sub-heading,
 span.since,
 a.src,
-#help-button > a,
+rustdoc-toolbar,
 summary.hideme,
 .scraped-example-list,
 /* This selector is for the items listed in the "all items" page. */
@@ -884,9 +889,19 @@ both the code example and the line numbers, so we need to remove the radius in t
 	overflow-x: auto;
 }
 
-.out-of-band {
+.sub-heading {
 	flex-grow: 0;
 	font-size: 1.125rem;
+	grid-area: main-heading-sub-heading;
+}
+
+.main-heading rustdoc-toolbar, .main-heading .out-of-band {
+	grid-area: main-heading-toolbar;
+}
+rustdoc-toolbar {
+	display: flex;
+	flex-direction: row;
+	flex-wrap: nowrap;
 }
 
 .docblock code, .docblock-short code,
@@ -1282,10 +1297,16 @@ so that we can apply CSS-filters to change the arrow color in themes */
 	border-color: var(--settings-input-color) !important;
 }
 
+#settings.popover {
+	--popover-arrow-offset: 118px;
+	top: 26px;
+}
+
 /* use larger max-width for help popover, but not for help.html */
 #help.popover {
 	max-width: 600px;
-	--popover-arrow-offset: 48px;
+	--popover-arrow-offset: 36px;
+	top: 26px;
 }
 
 #help dt {
@@ -1293,10 +1314,15 @@ so that we can apply CSS-filters to change the arrow color in themes */
 	clear: left;
 	margin-right: 0.5rem;
 }
+#help dd {
+	margin-bottom: 0.5rem;
+}
 #help span.top, #help span.bottom {
 	text-align: center;
 	display: block;
 	font-size: 1.125rem;
+	padding: 0 0.5rem;
+	text-wrap-style: balance;
 }
 #help span.top {
 	margin: 10px 0;
@@ -1308,10 +1334,13 @@ so that we can apply CSS-filters to change the arrow color in themes */
 	clear: both;
 	border-top: 1px solid var(--border-color);
 }
+.side-by-side {
+	display: flex;
+	margin-bottom: 20px;
+}
 .side-by-side > div {
 	width: 50%;
-	float: left;
-	padding: 0 20px 20px 17px;
+	padding: 0 20px 0 17px;
 }
 
 .item-info .stab {
@@ -1374,7 +1403,9 @@ so that we can apply CSS-filters to change the arrow color in themes */
 }
 
 .rightside:not(a),
-.out-of-band {
+.out-of-band,
+.sub-heading,
+rustdoc-toolbar {
 	color: var(--right-side-color);
 }
 
@@ -1588,8 +1619,8 @@ instead, we check that it's not a "finger" cursor.
 	display: block;
 }
 
-.out-of-band > span.since {
-	font-size: 1.25rem;
+.main-heading span.since::before {
+	content: "Since ";
 }
 
 .sub-variant h4 {
@@ -1691,6 +1722,8 @@ a.tooltip:hover::after {
 }
 
 #search-tabs {
+	grid-area: main-heading-sub-heading;
+	margin-top: 0.25rem;
 	display: flex;
 	flex-direction: row;
 	gap: 1px;
@@ -1752,9 +1785,10 @@ a.tooltip:hover::after {
 	border-bottom: 1px solid var(--border-color);
 }
 
-#settings-menu, #help-button {
+#settings-menu, #help-button, button#toggle-all-docs {
 	margin-left: var(--button-left-margin);
 	display: flex;
+	line-height: initial;
 }
 #sidebar-button {
 	display: none;
@@ -1778,33 +1812,35 @@ a.tooltip:hover::after {
 .hide-sidebar .src #sidebar-button {
 	position: static;
 }
-#settings-menu > a, #help-button > a, #sidebar-button > a {
+#settings-menu > a, #help-button > a, #sidebar-button > a, button#toggle-all-docs {
 	display: flex;
 	align-items: center;
 	justify-content: center;
-	background-color: var(--button-background-color);
-	border: 1px solid var(--border-color);
+	flex-direction: column;
+	border: 1px solid transparent;
 	border-radius: var(--button-border-radius);
-	color: var(--settings-button-color);
-	/* Rare exception to specifying font sizes in rem. Since this is acting
-	   as an icon, it's okay to specify their sizes in pixels. */
-	font-size: 20px;
+	color: var(--main-color);
+}
+#settings-menu > a, #help-button > a, button#toggle-all-docs {
+	width: 80px;
+}
+#sidebar-button > a {
+	background-color: var(--button-background-color);
+	border-color: var(--border-color);
 	width: 33px;
 }
 
-#settings-menu > a:hover, #settings-menu > a:focus,
-#help-button > a:hover, #help-button > a:focus,
-#sidebar-button > a:hover, #sidebar-button > a:focus {
+#settings-menu > a:hover, #settings-menu > a:focus-visible,
+#help-button > a:hover, #help-button > a:focus-visible,
+#sidebar-button > a:hover, #sidebar-button > a:focus-visible,
+button#toggle-all-docs:hover, button#toggle-all-docs:focus-visible {
 	border-color: var(--settings-button-border-focus);
+	text-decoration: none;
 }
 
-#settings-menu > a {
-	line-height: 0;
-	font-size: 0;
-}
 #settings-menu > a:before {
 	/* Wheel <https://www.svgrepo.com/svg/384069/settings-cog-gear> */
-	content: url('data:image/svg+xml,<svg width="22" height="22" viewBox="0 0 12 12" \
+	content: url('data:image/svg+xml,<svg width="18" height="18" viewBox="0 0 12 12" \
 	enable-background="new 0 0 12 12" xmlns="http://www.w3.org/2000/svg">\
 	<path d="M10.25,6c0-0.1243286-0.0261841-0.241333-0.0366211-0.362915l1.6077881-1.5545654l\
 	-1.25-2.1650391  c0,0-1.2674561,0.3625488-2.1323853,0.6099854c-0.2034912-0.1431885-0.421875\
@@ -1817,16 +1853,59 @@ a.tooltip:hover::after {
 	-0.3701782l2.1323853,0.6099854l1.25-2.1650391L10.2133789,6.362915  C10.2238159,6.241333,\
 	10.25,6.1243286,10.25,6z M6,7.5C5.1715698,7.5,4.5,6.8284302,4.5,6S5.1715698,4.5,6,4.5S7.5\
 	,5.1715698,7.5,6  S6.8284302,7.5,6,7.5z" fill="black"/></svg>');
-	width: 22px;
-	height: 22px;
+	width: 18px;
+	height: 18px;
 	filter: var(--settings-menu-filter);
 }
 
+button#toggle-all-docs:before {
+	/* Custom arrow icon */
+	content: url('data:image/svg+xml,<svg width="18" height="18" viewBox="0 0 12 12" \
+	enable-background="new 0 0 12 12" xmlns="http://www.w3.org/2000/svg">\
+	<path d="M2,2l4,4l4,-4M2,6l4,4l4,-4" stroke="black" fill="none" stroke-width="2px"/></svg>');
+	width: 18px;
+	height: 18px;
+	filter: var(--settings-menu-filter);
+}
+
+#help-button > a:before {
+	/* Question mark with circle */
+	content: url('data:image/svg+xml,<svg width="18" height="18" viewBox="0 0 12 12" \
+	enable-background="new 0 0 12 12" xmlns="http://www.w3.org/2000/svg" fill="none">\
+	<circle r="5.25" cx="6" cy="6" stroke-width="1.25" stroke="black"/>\
+	<text x="4.25" y="9" style="font:8px sans-serif;font-weight:1000" fill="black">?</text></svg>');
+	width: 18px;
+	height: 18px;
+	filter: var(--settings-menu-filter);
+}
+
+button#toggle-all-docs:before,
+#help-button > a:before,
+#settings-menu > a:before {
+	filter: var(--settings-menu-filter);
+	margin: 8px;
+}
+
+@media not (pointer: coarse) {
+	button#toggle-all-docs:hover:before,
+	#help-button > a:hover:before,
+	#settings-menu > a:hover:before {
+		filter: var(--settings-menu-hover-filter);
+	}
+}
+
+rustdoc-toolbar span.label {
+	font-size: initial;
+	font-variant-caps: small-caps;
+	text-transform: lowercase;
+	flex-grow: 1;
+}
+
 #sidebar-button > a:before {
 	/* sidebar resizer image */
 	content: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 22 22" \
 		fill="none" stroke="black">\
-		<rect x="1" y="1" width="20" height="20" ry="1.5" stroke-width="1.5"/>\
+		<rect x="1" y="1" width="20" height="20" ry="1.5" stroke-width="1.5" stroke="%23777"/>\
 		<circle cx="4.375" cy="4.375" r="1" stroke-width=".75"/>\
 		<path d="m7.6121 3v16 M5.375 7.625h-2 m2 3h-2 m2 3h-2" stroke-width="1.25"/></svg>');
 	width: 22px;
@@ -1941,10 +2020,10 @@ details.toggle > summary.hideme > span {
 }
 
 details.toggle > summary::before {
-	/* toggle plus */
-	background: url('data:image/svg+xml,<svg width="17" height="17" \
-shape-rendering="crispEdges" stroke="black" fill="none" xmlns="http://www.w3.org/2000/svg"><path \
-d="M5 2.5H2.5v12H5m7-12h2.5v12H12M5 8.5h7M8.5 12V8.625v0V5"/></svg>') no-repeat top left;
+	/* arrow pointing left */
+	background: url('data:image/svg+xml,<svg width="16" height="16" viewBox="0 0 12 12" \
+	enable-background="new 0 0 12 12" xmlns="http://www.w3.org/2000/svg">\
+	<path d="M4,2l4,4l-4,4" stroke="black" fill="none" stroke-width="1px"/></svg>');
 	content: "";
 	cursor: pointer;
 	width: 16px;
@@ -2027,10 +2106,10 @@ details.toggle[open] > summary.hideme > span {
 }
 
 details.toggle[open] > summary::before {
-	/* toggle minus */
-	background: url('data:image/svg+xml,<svg width="17" height="17" \
-shape-rendering="crispEdges" stroke="black" fill="none" xmlns="http://www.w3.org/2000/svg"><path \
-d="M5 2.5H2.5v12H5m7-12h2.5v12H12M5 8.5h7"/></svg>') no-repeat top left;
+	/* arrow pointing down */
+	background: url('data:image/svg+xml,<svg width="16" height="16" viewBox="0 0 12 12" \
+	enable-background="new 0 0 12 12" xmlns="http://www.w3.org/2000/svg">\
+	<path d="M2,4l4,4l4,-4" stroke="black" fill="none" stroke-width="1px"/></svg>');
 }
 
 details.toggle[open] > summary::after {
@@ -2076,6 +2155,15 @@ However, it's not needed with smaller screen width because the doc/code block is
 	opacity: 0.75;
 }
 
+/* help button is mostly for search */
+#help-button:not(.help-open),
+#alternative-display #toggle-all-docs {
+	display: none;
+}
+#alternative-display #help-button {
+	display: flex;
+}
+
 /* Media Queries */
 
 /* Make sure all the buttons line wrap at the same time */
@@ -2083,6 +2171,12 @@ However, it's not needed with smaller screen width because the doc/code block is
 	#search-tabs .count {
 		display: block;
 	}
+	.side-by-side {
+		flex-direction: column-reverse;
+	}
+	.side-by-side > div {
+		width: auto;
+	}
 }
 
 /*
@@ -2099,6 +2193,27 @@ in src-script.js and main.js
 		scroll-margin-top: 45px;
 	}
 
+	/* We don't display this button on mobile devices. */
+	#copy-path {
+		display: none;
+	}
+
+	/* Text label takes up too much space at this size. */
+	rustdoc-toolbar span.label {
+		display: none;
+	}
+	#settings-menu > a, #help-button > a, button#toggle-all-docs {
+		width: 33px;
+	}
+	#settings.popover {
+		--popover-arrow-offset: 48px;
+		top: calc(100% - 8px);
+	}
+	#help.popover {
+		--popover-arrow-offset: 12px;
+		top: calc(100% - 8px);
+	}
+
 	.rustdoc {
 		/* Sidebar should overlay main content, rather than pushing main content to the right.
 		   Turn off `display: flex` on the body element. */
@@ -2110,20 +2225,6 @@ in src-script.js and main.js
 		padding-top: 0px;
 	}
 
-	.main-heading {
-		flex-direction: column;
-	}
-
-	.out-of-band {
-		text-align: left;
-		margin-left: initial;
-		padding: initial;
-	}
-
-	.out-of-band .since::before {
-		content: "Since ";
-	}
-
 	/* Hide the logo and item name from the sidebar. Those are displayed
 	   in the mobile-topbar instead. */
 	.sidebar .logo-container,
@@ -2227,16 +2328,11 @@ in src-script.js and main.js
 		left: -11px;
 	}
 
-	/* We don't display these buttons on mobile devices. */
-	#copy-path, #help-button {
-		display: none;
-	}
-
 	/* sidebar button becomes topbar button */
 	#sidebar-button > a:before {
 		content: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" \
 			viewBox="0 0 22 22" fill="none" stroke="black">\
-			<rect x="1" y="1" width="20" height="20" ry="1.5" stroke-width="1.5"/>\
+			<rect x="1" y="1" width="20" height="20" ry="1.5" stroke-width="1.5" stroke="%23777"/>\
 			<circle cx="4.375" cy="4.375" r="1" stroke-width=".75"/>\
 			<path d="m3 7.375h16m0-3h-4" stroke-width="1.25"/></svg>');
 		width: 22px;
@@ -2536,6 +2632,8 @@ by default.
 	--copy-path-img-hover-filter: invert(35%);
 	--code-example-button-color: #7f7f7f;
 	--code-example-button-hover-color: #595959;
+	--settings-menu-filter: invert(50%);
+	--settings-menu-hover-filter: invert(35%);
 	--codeblock-error-hover-color: rgb(255, 0, 0);
 	--codeblock-error-color: rgba(255, 0, 0, .5);
 	--codeblock-ignore-hover-color: rgb(255, 142, 0);
@@ -2562,7 +2660,6 @@ by default.
 	--search-tab-button-not-selected-background: #e6e6e6;
 	--search-tab-button-selected-border-top-color: #0089ff;
 	--search-tab-button-selected-background: #fff;
-	--settings-menu-filter: none;
 	--stab-background-color: #fff5d6;
 	--stab-code-color: #000;
 	--code-highlight-kw-color: #8959a8;
@@ -2666,7 +2763,8 @@ by default.
 	--search-tab-button-not-selected-background: #252525;
 	--search-tab-button-selected-border-top-color: #0089ff;
 	--search-tab-button-selected-background: #353535;
-	--settings-menu-filter: none;
+	--settings-menu-filter: invert(50%);
+	--settings-menu-hover-filter: invert(65%);
 	--stab-background-color: #314559;
 	--stab-code-color: #e6e1cf;
 	--code-highlight-kw-color: #ab8ac1;
@@ -2777,7 +2875,8 @@ Original by Dempfi (https://github.com/dempfi/ayu)
 	--search-tab-button-not-selected-background: transparent !important;
 	--search-tab-button-selected-border-top-color: none;
 	--search-tab-button-selected-background: #141920 !important;
-	--settings-menu-filter: invert(100%);
+	--settings-menu-filter: invert(70%);
+	--settings-menu-hover-filter: invert(100%);
 	--stab-background-color: #314559;
 	--stab-code-color: #e6e1cf;
 	--code-highlight-kw-color: #ff7733;