rustdoc-search: put throbber at bottom of search results instead

Author: notriddle

src/librustdoc/html/static/css/rustdoc.css

@@ -339,6 +339,7 @@ summary.hideme,
 .scraped-example-list,
 .rustdoc-breadcrumbs,
 .search-switcher,
+.search-throbber,
 /* This selector is for the items listed in the "all items" page. */
 ul.all-items {
 	font-family: "Fira Sans", Arial, NanumBarunGothic, sans-serif;
@@ -2006,6 +2007,57 @@ a.tooltip:hover::after {
 	color: transparent;
 }
 
+.search-throbber {
+	position: relative;
+	height: 34px;
+}
+
+.search-throbber::before,
+.search-form.loading::before
+{
+	width: 16px;
+	height: 16px;
+	border-radius: 16px;
+	background: radial-gradient(
+		var(--button-background-color) 0 50%,
+		transparent 50% 100%
+	), conic-gradient(
+		var(--code-highlight-kw-color) 0deg 30deg,
+		var(--code-highlight-prelude-color) 30deg 60deg,
+		var(--code-highlight-number-color) 90deg 120deg,
+		var(--code-highlight-lifetime-color ) 120deg 150deg,
+		var(--code-highlight-comment-color) 150deg 180deg,
+		var(--code-highlight-self-color) 180deg 210deg,
+		var(--code-highlight-attribute-color) 210deg 240deg,
+		var(--code-highlight-literal-color) 210deg 240deg,
+		var(--code-highlight-macro-color) 240deg 270deg,
+		var(--code-highlight-question-mark-color) 270deg 300deg,
+		var(--code-highlight-prelude-val-color) 300deg 330deg,
+		var(--code-highlight-doc-comment-color) 330deg 360deg
+	);
+	content: "";
+	position: absolute;
+	right: 9px;
+	top: 8px;
+	animation: rotating 1.25s linear infinite;
+}
+.search-throbber::after,
+.search-form.loading::after
+{
+	width: 18px;
+	height: 18px;
+	border-radius: 18px;
+	background: conic-gradient(
+		var(--button-background-color) 0deg 180deg,
+		transparent 270deg 360deg
+	);
+	content: "";
+	position: absolute;
+	right: 8px;
+	top: 8px;
+	animation: rotating 0.66s linear infinite;
+}
+
 #search .error code {
 	border-radius: 3px;
 	background-color: var(--search-error-code-background-color);

src/librustdoc/html/static/js/search.js

@@ -4701,6 +4701,11 @@ async function addTab(results, query, display, finishedCallback, isTypeSearch) {
     let output = document.createElement("ul");
     output.className = "search-results " + extraClass;
 
+    const throbber = document.createElement("div");
+    throbber.className = "search-throbber";
+    throbber.innerHTML = "Loading...";
+    output.appendChild(throbber);
+
     let count = 0;
 
     /** @type {Promise<string|null>[]} */
@@ -4807,7 +4812,7 @@ ${obj.displayPath}<span class="${type}">${name}</span>\
         }
 
         link.appendChild(description);
-        output.appendChild(link);
+        output.insertBefore(link, throbber);
 
         results.next().then(async nextResult => {
             if (nextResult.value) {
@@ -4816,7 +4821,10 @@ ${obj.displayPath}<span class="${type}">${name}</span>\
                 await Promise.all(descList);
                 // need to make sure the element is shown before
                 // running this callback
-                yieldToBrowser().then(() => finishedCallback(count, output));
+                yieldToBrowser().then(() => {
+                    finishedCallback(count, output);
+                    throbber.remove();
+                });
             }
         });
     };
@@ -5012,9 +5020,14 @@ async function showResults(docSearch, results, goToFirst, filterCrates) {
     resultsElem.id = "results";
 
     search.innerHTML = "";
-    for (const [tab, output] of tabs) {
+    for (const [tabNb, [tab, output]] of tabs.entries()) {
         tabsElem.appendChild(tab);
+        const isCurrentTab = window.searchState.currentTab === tabNb;
         const placeholder = document.createElement("div");
+        placeholder.className = isCurrentTab ?
+            "search-throbber search-results active" :
+            "search-throbber search-results";
+        placeholder.innerHTML = "Loading...";
         output.then(output => {
             if (placeholder.parentElement) {
                 placeholder.parentElement.replaceChild(output, placeholder);