rollup merge of rust-lang#20092: barosl/rustdoc-line-number-clickable

While talking on IRC, someone wanted to post a link to the Rust source code, but while the lines of the rendered source code do have anchors (`<span id="[line number]">`), there is no convenient way to make links as they are not clickable. This PR makes them clickable.

Also, a minor fix of the FAQ is included.

Author: alexcrichton

src/doc/complement-lang-faq.md

@@ -17,7 +17,7 @@ Some examples that demonstrate different aspects of the language:
 * [sprocketnes], an NES emulator with no GC, using modern Rust conventions
 * The language's general-purpose [hash] function, SipHash-2-4. Bit twiddling, OO, macros
 * The standard library's [HashMap], a sendable hash map in an OO style
-* The extra library's [json] module. Enums and pattern matching
+* The standard library's [json] module. Enums and pattern matching
 
 [sprocketnes]: https://github.com/pcwalton/sprocketnes
 [hash]: https://github.com/rust-lang/rust/blob/master/src/libstd/hash/mod.rs

src/librustdoc/html/render.rs

@@ -2253,9 +2253,9 @@ impl<'a> fmt::Show for Source<'a> {
             cols += 1;
             tmp /= 10;
         }
-        try!(write!(fmt, "<pre class='line-numbers'>"));
+        try!(write!(fmt, "<pre class=\"line-numbers\">"));
         for i in range(1, lines + 1) {
-            try!(write!(fmt, "<span id='{0}'>{0:1$}</span>\n", i, cols));
+            try!(write!(fmt, "<span id=\"{0}\">{0:1$}</span>\n", i, cols));
         }
         try!(write!(fmt, "</pre>"));
         try!(write!(fmt, "{}", highlight::highlight(s.as_slice(), None, None)));

src/librustdoc/html/static/main.css

@@ -157,6 +157,7 @@ nav.sub {
     left: 0;
     top: 0;
     min-height: 100%;
+    z-index: -1;
 }
 
 .content, nav { max-width: 960px; }
@@ -217,10 +218,18 @@ nav.sub {
     overflow: auto;
     padding-left: 0;
 }
-.content pre.line-numbers { float: left; border: none; }
-.line-numbers span { color: #c67e2d; }
+.content pre.line-numbers {
+    float: left;
+    border: none;
+
+    -webkit-user-select: none;
+    -moz-user-select: none;
+    -ms-user-select: none;
+    user-select: none;
+}
+.line-numbers span { color: #c67e2d; cursor: pointer; }
 .line-numbers .line-highlighted {
-    background-color: #f6fdb0;
+    background-color: #f6fdb0 !important;
 }
 
 .content .highlighted {
@@ -470,6 +479,7 @@ h1 .stability {
 .summary.Unmarked { background-color: #BBBBBB; }
 
 :target { background: #FDFFD3; }
+.line-numbers :target { background-color: transparent; }
 
 /* Code highlighting */
 pre.rust .kw { color: #8959A8; }

src/librustdoc/html/static/main.js

@@ -50,7 +50,7 @@
     resizeShortBlocks();
     $(window).on('resize', resizeShortBlocks);
 
-    function highlightSourceLines() {
+    function highlightSourceLines(ev) {
         var i, from, to, match = window.location.hash.match(/^#?(\d+)(?:-(\d+))?$/);
         if (match) {
             from = parseInt(match[1], 10);
@@ -59,14 +59,14 @@
             if ($('#' + from).length === 0) {
                 return;
             }
-            $('#' + from)[0].scrollIntoView();
+            if (ev === null) $('#' + from)[0].scrollIntoView();
             $('.line-numbers span').removeClass('line-highlighted');
             for (i = from; i <= to; ++i) {
                 $('#' + i).addClass('line-highlighted');
             }
         }
     }
-    highlightSourceLines();
+    highlightSourceLines(null);
     $(window).on('hashchange', highlightSourceLines);
 
     $(document).on('keyup', function(e) {
@@ -778,4 +778,35 @@
         $("#main > .docblock").before(wrapper);
     });
 
+    $('pre.line-numbers').on('click', 'span', function() {
+        var prev_id = 0;
+
+        function set_fragment(name) {
+            if (history.replaceState) {
+                history.replaceState(null, null, '#' + name);
+                $(window).trigger('hashchange');
+            } else {
+                location.replace('#' + name);
+            }
+        }
+
+        return function(ev) {
+            var cur_id = parseInt(ev.target.id);
+
+            if (ev.shiftKey && prev_id) {
+                if (prev_id > cur_id) {
+                    var tmp = prev_id;
+                    prev_id = cur_id;
+                    cur_id = tmp;
+                }
+
+                set_fragment(prev_id + '-' + cur_id);
+            } else {
+                prev_id = cur_id;
+
+                set_fragment(cur_id);
+            }
+        };
+    }());
+
 }());