Add linked platform labels ("clj", "cljs") to var docs

Author: @ptaoussanis

Note that this commit introduces new classes to `default.css` used (only)
by "cross-platform" projects.

This means:

  - NO behavioural changes are intended for non-cross-platform projects.
  - Cross-platform projects WILL require a theme that includes the
    new CSS classes.

codox/resources/codox/theme/default/css/default.css

@@ -347,7 +347,8 @@ h5.license {
 h4.type,
 h4.dynamic,
 h4.added,
-h4.deprecated {
+h4.deprecated,
+h4.lang {
     float: left;
     margin: 3px 10px 15px 0;
     font-size: 15px;
@@ -358,15 +359,17 @@ h4.deprecated {
 .public h4.type,
 .public h4.dynamic,
 .public h4.added,
-.public h4.deprecated {
+.public h4.deprecated,
+.public h4.lang {
     font-size: 13px;
     font-weight: bold;
     margin: 3px 0 0 10px;
 }
 
 .members h4.type,
 .members h4.added,
-.members h4.deprecated {
+.members h4.deprecated,
+.members h4.lang {
     margin-top: 1px;
 }
 
@@ -386,6 +389,16 @@ h4.deprecated {
     color: #880000;
 }
 
+.public h4.lang, .public h4.lang a {
+    font-weight: normal;
+    font-variant: normal;
+    color: #717171;
+}
+
+.public h4.lang.current {
+    color: #a33;
+}
+
 .namespace {
     margin-bottom: 30px;
 }

codox/src/codox/main.clj

@@ -98,6 +98,33 @@
           (add-source-paths root-path source-paths)
           (add-ns-defaults metadata)))))
 
+(defn- get-var-langs
+  "Returns {<ns> {<var> <set-of-languages>}} for given namespaces."
+  ([language namespaces var-langs]
+   (reduce
+     (fn [var-langs ns]
+       (reduce
+         (fn [var-langs public-var]
+           (update-in var-langs [(:name ns) (:name public-var)]
+             #(conj (or % #{}) language)))
+         var-langs
+         (:publics ns)))
+     var-langs
+     namespaces))
+
+  ([options namespaces]
+   (if-not (:cross-platform? options)
+     (get-var-langs (:language options) namespaces {})
+     (reduce
+       (fn [var-langs language]
+         (get-var-langs language (get namespaces language) var-langs))
+       {}
+       (:languages options)))))
+
+(comment (get-var-langs {:languages #{:clojure :clojurescript}}
+           '({:name codox.main :publics ({:name defaults} {:name bar})}
+             {:name codox.foo  :publics ({:name bar})})))
+
 (defn- read-documents [{:keys [doc-paths doc-files] :or {doc-files :all}}]
   (cond
     (not= doc-files :all) (map text/read-file doc-files)
@@ -145,7 +172,9 @@
      (let [options    (-> (merge defaults options) cross-platform-options)
            write-fn   (writer options)
            namespaces (read-namespaces options)
-           documents  (read-documents options)]
+           documents  (read-documents options)
+           var-langs  (get-var-langs options namespaces)]
        (write-fn (assoc options
                         :namespaces namespaces
-                        :documents  documents)))))
+                        :documents  documents
+                        :var-langs  var-langs)))))

codox/src/codox/writer/html.clj

@@ -483,6 +483,18 @@
      [:h4.type (name (:type var))])
    (if (:dynamic var)
      [:h4.dynamic "dynamic"])
+
+   (if (:cross-platform? project)
+     (let [var-langs (get-in project [:var-langs (:name namespace) (:name var)])
+           {:keys [language languages]} project]
+
+       (for [language* languages]
+         (when (contains? var-langs language*)
+           (if (= language language*)
+             [:h4.lang (link-to (var-uri (assoc namespace :language language*) var)
+                         (:ext (language-info language*)))]
+             [:h4.lang.current (:ext (language-info language*))])))))
+
    (added-and-deprecated-docs var)
    (if (:type-sig var)
      [:div.type-sig