Add syntax highlighting to Clojure documentation codeblocks (#52)

* Add syntax highlighting to clojure documentation

* Enhance code with suggestions

* Add CHANGELOG.md

Author: isaiasvallejos

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## [Unreleased]
 
+- Add syntax highlighting to Clojure documentation codeblocks
+
 ## 2.4.5
 
 - Only log server communication when trace-level matches.

build.gradle.kts

@@ -36,7 +36,7 @@ dependencies {
         exclude("org.clojure", "core.async")
     }
     implementation ("com.rpl:proxy-plus:0.0.9")
-    implementation ("markdown-clj:markdown-clj:1.11.4")
+    implementation ("markdown-clj:markdown-clj:1.12.1")
 }
 
 sourceSets {

deps.edn

@@ -6,7 +6,7 @@
         seesaw/seesaw {:mvn/version "1.5.0"}
         camel-snake-kebab/camel-snake-kebab {:mvn/version "0.4.3"}
         com.github.clojure-lsp/clojure-lsp {:mvn/version "2024.03.01-11.37.51"}
-        markdown-clj/markdown-clj {:mvn/version "1.11.4"}
+        markdown-clj/markdown-clj {:mvn/version "1.12.1"}
         com.rpl/proxy-plus {:mvn/version "0.0.9"}}
  :aliases {:dev {:deps {nrepl/nrepl {:mvn/version "1.0.0"}
                         com.jetbrains.intellij.platform/ide-impl {:mvn/version "213.7172.48"

src/main/clojure/com/github/clojure_lsp/intellij/extension/documentation.clj

@@ -9,10 +9,65 @@
   (:import
    [com.intellij.openapi.util.text StringUtil]
    [com.intellij.openapi.util.text HtmlBuilder]
-   [com.intellij.psi PsiDocumentManager PsiElement PsiFile]))
+   [com.intellij.psi PsiDocumentManager PsiElement PsiFile]
+   [com.intellij.openapi.fileTypes SyntaxHighlighterFactory]
+   [com.intellij.openapi.editor.colors EditorColorsManager]
+   [com.github.clojure_lsp.intellij ClojureLanguage]
+   [java.awt Color]))
 
 (set! *warn-on-reflection* true)
 
+(defn ^:private rgb-html-style [^Color color]
+  (str "rgb(" (.getRed color) ", " (.getGreen color) ", " (.getBlue color) ")"))
+
+(defn ^:private html-style [prop value]
+  (if (some? value)
+    (str prop ":" value ";")
+    ""))
+
+(defn ^:private highlight-html-text
+  [^String text {:keys [foreground-color background-color font-type]}]
+  (let [color-style       (html-style "color" (when foreground-color
+                                                (rgb-html-style foreground-color)))
+        background-style  (html-style "background-color" (when background-color
+                                                           (rgb-html-style foreground-color)))
+        font-weight-style (html-style "font-weight" (case font-type
+                                                      :bold "bold"
+                                                      :bold-italic "bold"
+                                                      "normal"))
+        font-style        (html-style "font-style" (case font-type
+                                                     :italic "italic"
+                                                     :bold-italic "italic"
+                                                     "normal"))]
+    (str "<span style=\"" color-style background-style font-weight-style font-style "\">" text "</span>")))
+
+(defn ^:private highlight-html-code [^String code]
+  (let [highlighter  (SyntaxHighlighterFactory/getSyntaxHighlighter (ClojureLanguage/INSTANCE) nil nil)
+        lexer        (.getHighlightingLexer highlighter)
+        color-scheme (.getGlobalScheme (EditorColorsManager/getInstance))]
+    (loop [highlighted-code ""]
+      (if (empty? highlighted-code)
+        (.start lexer code)
+        (.advance lexer))
+      (let [lexer-not-finished? (.getTokenType lexer)]
+        (if lexer-not-finished?
+          (let [text             (.getTokenText lexer)
+                highlight        (first (.getTokenHighlights highlighter (.getTokenType lexer)))
+                highlight-attrs  (.getAttributes color-scheme highlight)
+                foreground-color (some-> highlight-attrs .getForegroundColor)
+                background-color (some-> highlight-attrs .getBackgroundColor)
+                font-type        (some-> highlight-attrs .getFontType (#(case (int %)
+                                                                         1 :bold
+                                                                         2 :italic
+                                                                         3 :bold-italic
+                                                                         nil)))]
+            (if (some some? [foreground-color background-color font-type])
+              (recur (str highlighted-code (highlight-html-text text {:foreground-color foreground-color
+                                                                      :background-color background-color
+                                                                      :font-type        font-type})))
+              (recur (str highlighted-code text))))
+          highlighted-code)))))
+
 (defn ^:private build-doc [^PsiElement element]
   (when-let [client (db/get-in (.getProject element) [:client])]
     (when-let [psi-file ^PsiFile (.getContainingFile element)]
@@ -25,9 +80,14 @@
                                                               :position {:line (.line line-col)
                                                                          :character (.column line-col)}}])]
 
-        (when-let [raw-html (markdown/md-to-html-string (:value contents))]
+        (when-let [html (markdown/md-to-html-string (:value contents)
+                                                    :codeblock-no-escape? true
+                                                    :codeblock-callback (fn [code language]
+                                                                          (if (= language "clojure")
+                                                                            (highlight-html-code code)
+                                                                            code)))]
           (-> (HtmlBuilder.)
-              (.appendRaw raw-html)
+              (.appendRaw html)
               (.toString)))))))
 
 (defn -getCustomDocumentationElement