rustdoc: fix janky behavior on iPadOS

Author: notriddle

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

@@ -407,6 +407,7 @@ img {
 }
 
 .sidebar-resizer {
+	touch-action: none;
 	width: 9px;
 	cursor: col-resize;
 	z-index: 10;
@@ -417,12 +418,14 @@ img {
 }
 
 .rustdoc.src .sidebar-resizer {
-	/* when closed, place resizer glow on top of the normal src sidebar border (no need to worry about sidebar) */
+	/* when closed, place resizer glow on top of the normal src sidebar border (no need to worry
+	   about sidebar) */
 	left: 49px;
 }
 
 .src-sidebar-expanded .rustdoc.src .sidebar-resizer {
-	/* for src sidebar, gap is already provided by 1px border on sidebar itself, so place resizer to right of it */
+	/* for src sidebar, gap is already provided by 1px border on sidebar itself, so place resizer
+	   to right of it */
 	left: var(--src-sidebar-width, 300px);
 }
 
@@ -443,7 +446,8 @@ img {
 .sidebar-resizer.active {
 	width: 10px;
 	margin: 0;
-	/* when active or hovered, place resizer glow on top of the sidebar (right next to, or even on top of, the scrollbar) */
+	/* when active or hovered, place resizer glow on top of the sidebar (right next to, or even
+	   on top of, the scrollbar) */
 	left: var(--desktop-sidebar-width, 200px);
 	border-left: solid 1px var(--sidebar-resizer-hover);
 }
@@ -456,8 +460,18 @@ img {
 	left: calc(var(--src-sidebar-width, 300px) - 1px);
 }
 
+@media (pointer: coarse) {
+	.sidebar-resizer,
+	.sidebar-resizer:hover,
+	.sidebar-resizer:active,
+	.sidebar-resizer:focus {
+		width: 15px;
+	}
+}
+
 .sidebar-resizer.active {
-	/* make the resize tool bigger when actually resizing, to avoid :hover styles on other stuff while resizing */
+	/* make the resize tool bigger when actually resizing, to avoid :hover styles on other stuff
+	   while resizing */
 	padding: 0 140px;
 	width: 2px;
 	margin-left: -140px;

src/librustdoc/html/static/js/main.js

@@ -1239,6 +1239,7 @@ href="https://doc.rust-lang.org/${channel}/rustdoc/how-to-read-rustdoc.html\
             e.preventDefault();
         });
     }
+    let currentPointerId = null;
     const resizer = document.getElementsByClassName("sidebar-resizer")[0];
     const sidebar = document.getElementsByClassName("sidebar")[0];
     if (!resizer || !sidebar) {
@@ -1280,6 +1281,10 @@ href="https://doc.rust-lang.org/${channel}/rustdoc/how-to-read-rustdoc.html\
             hasClass(document.documentElement, "hide-sidebar");
     };
     const resize = e => {
+        if (currentPointerId === null || currentPointerId !== e.pointerId) {
+            return;
+        }
+        e.preventDefault();
         const pos = e.clientX - sidebar.offsetLeft - 3;
         if (pos < 50) {
             hideSidebar();
@@ -1292,22 +1297,42 @@ href="https://doc.rust-lang.org/${channel}/rustdoc/how-to-read-rustdoc.html\
             changeSidebarSize(Math.min(pos, window.innerWidth - 100));
         }
     };
-    const stopResize = () => {
+    const stopResize = e => {
+        if (currentPointerId === null) {
+            return;
+        }
+        e.preventDefault();
         removeClass(resizer, "active");
-        window.removeEventListener("mousemove", resize, false);
-        window.removeEventListener("mouseup", stopResize, false);
+        window.removeEventListener("pointermove", resize, false);
+        window.removeEventListener("pointerup", stopResize, false);
         removeClass(document.documentElement, "sidebar-resizing");
+        if (resizer.releasePointerCapture) {
+            resizer.releasePointerCapture(currentPointerId);
+            currentPointerId = null;
+        }
     };
     const initResize = e => {
-        if (e.altKey || e.ctrlKey || e.metaKey || e.button !== 0) {
+        if (currentPointerId !== null || e.altKey || e.ctrlKey || e.metaKey || e.button !== 0) {
             return;
         }
-        window.addEventListener("mousemove", resize, false);
-        window.addEventListener("mouseup", stopResize, false);
+        if (resizer.setPointerCapture) {
+            resizer.setPointerCapture(e.pointerId);
+            if (!resizer.hasPointerCapture(e.pointerId)) {
+                // unable to capture pointer; something else has it
+                // on iOS, this usually means you long-clicked a link instead
+                resizer.releasePointerCapture(e.pointerId);
+                return;
+            }
+            currentPointerId = e.pointerId;
+        }
+        e.preventDefault();
+        window.addEventListener("pointermove", resize, false);
+        window.addEventListener("pointercancel", stopResize, false);
+        window.addEventListener("pointerup", stopResize, false);
         addClass(resizer, "active");
         addClass(document.documentElement, "sidebar-resizing");
     };
-    resizer.addEventListener("mousedown", initResize, false);
+    resizer.addEventListener("pointerdown", initResize, false);
 }());
 
 (function() {

src/librustdoc/html/static/js/storage.js

@@ -196,14 +196,14 @@ if (getSettingValue("hide-sidebar") === "true") {
 
 function updateSidebarWidth() {
     const desktopSidebarWidth = getSettingValue("desktop-sidebar-width");
-    if (desktopSidebarWidth) {
+    if (desktopSidebarWidth && desktopSidebarWidth !== "null") {
         document.documentElement.style.setProperty(
             "--desktop-sidebar-width",
             desktopSidebarWidth + "px"
         );
     }
     const srcSidebarWidth = getSettingValue("src-sidebar-width");
-    if (srcSidebarWidth) {
+    if (srcSidebarWidth && srcSidebarWidth !== "null") {
         document.documentElement.style.setProperty(
             "--src-sidebar-width",
             srcSidebarWidth + "px"