From 3ab7bdbe9ef921aa03165f391ad3e0b15bb100de Mon Sep 17 00:00:00 2001
From: Guillaume Gomez <guillaume1.gomez@gmail.com>
Date: Sun, 21 Mar 2021 22:34:48 +0100
Subject: [PATCH] Start transforming documentation toggles into pure css ones

---
 src/librustdoc/html/format.rs              |  7 ++--
 src/librustdoc/html/render/mod.rs          | 26 +++++++++----
 src/librustdoc/html/static/main.js         | 36 +++++++++++++-----
 src/librustdoc/html/static/rustdoc.css     | 43 ++++++++++++++++++++++
 src/librustdoc/html/static/themes/dark.css |  2 +-
 5 files changed, 94 insertions(+), 20 deletions(-)

diff --git a/src/librustdoc/html/format.rs b/src/librustdoc/html/format.rs
index bea0e75832c33..4b0903019312e 100644
--- a/src/librustdoc/html/format.rs
+++ b/src/librustdoc/html/format.rs
@@ -51,19 +51,20 @@ impl Print for &'_ str {
 crate struct Buffer {
     for_html: bool,
     buffer: String,
+    crate label_id_count: usize,
 }
 
 impl Buffer {
     crate fn empty_from(v: &Buffer) -> Buffer {
-        Buffer { for_html: v.for_html, buffer: String::new() }
+        Buffer { for_html: v.for_html, buffer: String::new(), label_id_count: 0 }
     }
 
     crate fn html() -> Buffer {
-        Buffer { for_html: true, buffer: String::new() }
+        Buffer { for_html: true, buffer: String::new(), label_id_count: 0 }
     }
 
     crate fn new() -> Buffer {
-        Buffer { for_html: false, buffer: String::new() }
+        Buffer { for_html: false, buffer: String::new(), label_id_count: 0 }
     }
 
     crate fn is_empty(&self) -> bool {
diff --git a/src/librustdoc/html/render/mod.rs b/src/librustdoc/html/render/mod.rs
index 66c47f14655ba..70f7896ccb749 100644
--- a/src/librustdoc/html/render/mod.rs
+++ b/src/librustdoc/html/render/mod.rs
@@ -626,9 +626,14 @@ fn render_markdown(
     is_hidden: bool,
 ) {
     let mut ids = cx.id_map.borrow_mut();
+    let label_id_count = w.label_id_count;
+    w.label_id_count += 1;
     write!(
         w,
-        "<div class=\"docblock{}\">{}{}</div>",
+        "<input id=\"{0}i\" type=checkbox class=\"toggle\"{1}><label for=\"{0}i\"></label>\
+         <div class=\"docblock{2}\">{3}{4}</div>",
+        label_id_count,
+        if is_hidden { "" } else { " checked" },
         if is_hidden { " hidden" } else { "" },
         prefix,
         Markdown(
@@ -1519,12 +1524,12 @@ fn render_impl(
             } else {
                 (true, " hidden")
             };
-        match *item.kind {
+        let need_close = match *item.kind {
             clean::MethodItem(..) | clean::TyMethodItem(_) => {
                 // Only render when the method is not static or we allow static methods
                 if render_method_item {
                     let id = cx.derive_id(format!("{}.{}", item_type, name));
-                    write!(w, "<h4 id=\"{}\" class=\"{}{}\">", id, item_type, extra_class);
+                    write!(w, "<div><h4 id=\"{}\" class=\"{}{}\">", id, item_type, extra_class);
                     w.write_str("<code>");
                     render_assoc_item(w, item, link.anchor(&id), ItemType::Impl, cx);
                     w.write_str("</code>");
@@ -1538,10 +1543,11 @@ fn render_impl(
                     write_srclink(cx, item, w);
                     w.write_str("</h4>");
                 }
+                render_method_item
             }
             clean::TypedefItem(ref tydef, _) => {
                 let id = cx.derive_id(format!("{}.{}", ItemType::AssocType, name));
-                write!(w, "<h4 id=\"{}\" class=\"{}{}\"><code>", id, item_type, extra_class);
+                write!(w, "<div><h4 id=\"{}\" class=\"{}{}\"><code>", id, item_type, extra_class);
                 assoc_type(
                     w,
                     item,
@@ -1552,10 +1558,11 @@ fn render_impl(
                     cx.cache(),
                 );
                 w.write_str("</code></h4>");
+                true
             }
             clean::AssocConstItem(ref ty, ref default) => {
                 let id = cx.derive_id(format!("{}.{}", item_type, name));
-                write!(w, "<h4 id=\"{}\" class=\"{}{}\"><code>", id, item_type, extra_class);
+                write!(w, "<div><h4 id=\"{}\" class=\"{}{}\"><code>", id, item_type, extra_class);
                 assoc_const(w, item, ty, default.as_ref(), link.anchor(&id), "", cx);
                 w.write_str("</code>");
                 render_stability_since_raw(
@@ -1567,16 +1574,18 @@ fn render_impl(
                 );
                 write_srclink(cx, item, w);
                 w.write_str("</h4>");
+                true
             }
             clean::AssocTypeItem(ref bounds, ref default) => {
                 let id = cx.derive_id(format!("{}.{}", item_type, name));
-                write!(w, "<h4 id=\"{}\" class=\"{}{}\"><code>", id, item_type, extra_class);
+                write!(w, "<div><h4 id=\"{}\" class=\"{}{}\"><code>", id, item_type, extra_class);
                 assoc_type(w, item, bounds, default.as_ref(), link.anchor(&id), "", cx.cache());
                 w.write_str("</code></h4>");
+                true
             }
             clean::StrippedItem(..) => return,
             _ => panic!("can't make docs for trait item with name {:?}", item.name),
-        }
+        };
 
         if render_method_item {
             if !is_default_item {
@@ -1614,6 +1623,9 @@ fn render_impl(
                 document_short(w, item, cx, link, "", is_hidden, Some(parent), show_def_docs);
             }
         }
+        if need_close {
+            w.write_str("</div>");
+        }
     }
 
     w.write_str("<div class=\"impl-items\">");
diff --git a/src/librustdoc/html/static/main.js b/src/librustdoc/html/static/main.js
index e7b522093c74d..4491f8317a0fa 100644
--- a/src/librustdoc/html/static/main.js
+++ b/src/librustdoc/html/static/main.js
@@ -2249,9 +2249,14 @@ function defocusSearchBar() {
             });
             innerToggle.title = "collapse all docs";
             if (fromAutoCollapse !== true) {
+                // Old toggle handling.
                 onEachLazy(document.getElementsByClassName("collapse-toggle"), function(e) {
                     collapseDocs(e, "show");
                 });
+                // New toggle handling.
+                onEachLazy(document.getElementsByClassName("toggle"), function(e) {
+                    e.checked = true;
+                });
             }
         } else {
             updateLocalStorage("rustdoc-collapse", "true");
@@ -2270,6 +2275,7 @@ function defocusSearchBar() {
             });
             innerToggle.title = "expand all docs";
             if (fromAutoCollapse !== true) {
+                // Old toggle handling.
                 onEachLazy(document.getElementsByClassName("collapse-toggle"), function(e) {
                     var parent = e.parentNode;
                     var superParent = null;
@@ -2282,6 +2288,19 @@ function defocusSearchBar() {
                         collapseDocs(e, "hide");
                     }
                 });
+                // New toggle handling.
+                onEachLazy(document.getElementsByClassName("toggle"), function(e) {
+                    var parent = e.parentNode;
+                    var superParent = null;
+
+                    if (parent) {
+                        superParent = parent.parentNode;
+                    }
+                    if (!parent || !superParent || superParent.id !== "main" ||
+                        hasClass(parent, "impl") === false) {
+                        e.checked = false;
+                    }
+                });
             }
         }
     }
@@ -2460,7 +2479,7 @@ function defocusSearchBar() {
             span.style.display = "none";
         }
         if (!otherMessage) {
-            span.innerHTML = "&nbsp;Expand&nbsp;description";
+           return null;
         } else {
             span.innerHTML = otherMessage;
         }
@@ -2506,11 +2525,9 @@ function defocusSearchBar() {
             if (!next) {
                 return;
             }
-            if (hasClass(next, "docblock")) {
-                var newToggle = toggle.cloneNode(true);
-                insertAfter(newToggle, e.childNodes[e.childNodes.length - 1]);
+            if (hasClass(next, "toggle")) {
                 if (hideMethodDocs === true && hasClass(e, "method") === true) {
-                    collapseDocs(newToggle, "hide");
+                    next.checked = true;
                 }
             }
         };
@@ -2672,14 +2689,15 @@ function defocusSearchBar() {
                     extraClass = "marg-left";
                 }
 
-                e.parentNode.insertBefore(
-                    createToggle(
+                var t = createToggle(
                         toggle,
                         otherMessage,
                         fontSize,
                         extraClass,
-                        hasClass(e, "type-decl") === false || showItemDeclarations === true),
-                    e);
+                        hasClass(e, "type-decl") === false || showItemDeclarations === true);
+                if (t) {
+                    e.parentNode.insertBefore(t, e);
+                }
                 if (hasClass(e, "type-decl") === true && showItemDeclarations === true) {
                     collapseDocs(e.previousSibling.childNodes[0], "toggle");
                 }
diff --git a/src/librustdoc/html/static/rustdoc.css b/src/librustdoc/html/static/rustdoc.css
index 4f287cde73b1b..a75d35678984d 100644
--- a/src/librustdoc/html/static/rustdoc.css
+++ b/src/librustdoc/html/static/rustdoc.css
@@ -80,6 +80,10 @@ html {
 	}
 }
 
+div {
+	position: relative;
+}
+
 /* General structure and fonts */
 
 body {
@@ -1768,3 +1772,42 @@ div.name.expand::before {
 .type-decl > pre > .docblock.attributes {
 	margin-left: 4em;
 }
+
+input.toggle {
+	display: none;
+}
+input.toggle + label {
+	position: absolute;
+	top: 0;
+	font-family: "Fira Sans", Arial, sans-serif;
+	font-weight: 300;
+	cursor: pointer;
+}
+input.toggle + label:before {
+	content: "[+]";
+}
+input.toggle:checked + label:before {
+	content: "[-]";
+}
+input.toggle:not(:checked) + label + .docblock {
+	display: none;
+}
+h4 + input.toggle + label {
+	font-size: 0.8em;
+	top: 5px;
+}
+.type-decl + input.toggle + label {
+	top: initial;
+}
+.type-decl + input.toggle:not(:checked) + label {
+	margin-bottom: .6em;
+	height: 25px;
+	position: initial;
+}
+.type-decl + input.toggle:not(:checked) + label:before {
+	content: "[+]";
+}
+.type-decl + input.toggle:not(:checked) + label:after {
+	content: "Expand description";
+	margin-left: 6px;
+}
\ No newline at end of file
diff --git a/src/librustdoc/html/static/themes/dark.css b/src/librustdoc/html/static/themes/dark.css
index 88ac3252bb4b2..f545993051676 100644
--- a/src/librustdoc/html/static/themes/dark.css
+++ b/src/librustdoc/html/static/themes/dark.css
@@ -186,7 +186,7 @@ a.test-arrow {
 	color: #dedede;
 }
 
-.collapse-toggle {
+.collapse-toggle, input.toggle + label {
 	color: #999;
 }