implement semantic highlighting (#49)

src/main/kotlin/com/github/brcosta/cljstuffplugin/extensions/ClojureAnnotator.kt

@@ -67,10 +67,6 @@ class ClojureAnnotator : Annotator {
         }
     }
 
-    private fun isNamespaced(element: ClKeyword) =
-        (element.text?.contains("/") == true) &&
-                (element.parentOfType<ClSexpComment>(false) == null)
-
     private fun isNsReaderMacro(element: PsiElement) =
         (element.prevSibling != null) &&
                 (element.prevSibling.text == "#:") &&
@@ -81,4 +77,11 @@ class ClojureAnnotator : Annotator {
                 (element.nextSibling is LeafPsiElement) &&
                 ((element.nextSibling as LeafPsiElement).elementType.toString() == "ns separator") &&
                 (element.parentOfType<ClSexpComment>(false) == null)
+
+    companion object {
+        fun isNamespaced(element: ClKeyword) =
+            (element.text?.contains("/") == true) &&
+                    (element.parentOfType<ClSexpComment>(false) == null)
+    }
+
 }

src/main/kotlin/com/github/brcosta/cljstuffplugin/extensions/ClojureColorsAndFontPageEx.kt

@@ -1,16 +1,19 @@
 package com.github.brcosta.cljstuffplugin.extensions
 
+import com.intellij.codeHighlighting.RainbowHighlighter
+import com.intellij.lang.Language
 import com.intellij.openapi.editor.colors.TextAttributesKey
 import com.intellij.openapi.fileTypes.SyntaxHighlighter
 import com.intellij.openapi.options.colors.AttributesDescriptor
 import com.intellij.openapi.options.colors.ColorDescriptor
-import com.intellij.openapi.options.colors.ColorSettingsPage
+import com.intellij.openapi.options.colors.RainbowColorSettingsPage
 import cursive.ClojureIcons
+import cursive.ClojureLanguage
 import cursive.highlighter.ClojureSyntaxHighlighter
 import javax.swing.Icon
 
 @Suppress("unused")
-class ClojureColorsAndFontsPageEx : ColorSettingsPage {
+class ClojureColorsAndFontsPageEx : RainbowColorSettingsPage {
 
     override fun getDisplayName(): String {
         return "Clojure Extras"
@@ -37,18 +40,28 @@ class ClojureColorsAndFontsPageEx : ColorSettingsPage {
     }
 
     override fun getAdditionalHighlightingTagToDescriptorMap(): Map<String, TextAttributesKey> {
-        val map: MutableMap<String, TextAttributesKey> = mutableMapOf()
+        val map = RainbowHighlighter.createRainbowHLM()
         map["keyword-namespace"] = KEYWORD_NAMESPACE
         map["symbol-namespace"] = SYMBOL_NAMESPACE
         map["head-symbol-namespace"] = HEAD_SYMBOL_NAMESPACE
         return map
     }
 
+    override fun isRainbowType(type: TextAttributesKey?): Boolean {
+        return type == SEMANTIC_HIGHLIGHTING
+    }
+
+    override fun getLanguage(): Language? {
+        return ClojureLanguage.getInstance()
+    }
+
     companion object {
         private val ATTRS: Array<AttributesDescriptor>
         val KEYWORD_NAMESPACE = TextAttributesKey.createTextAttributesKey("Keyword Namespace")
         val SYMBOL_NAMESPACE = TextAttributesKey.createTextAttributesKey("Symbol Namespace")
         val HEAD_SYMBOL_NAMESPACE = TextAttributesKey.createTextAttributesKey("Head Symbol Namespace")
+        val SEMANTIC_HIGHLIGHTING = TextAttributesKey.createTextAttributesKey("Semantic Highlighting")
+
         init {
             ATTRS = arrayOf(
                 AttributesDescriptor("Keyword Namespace", KEYWORD_NAMESPACE),

src/main/kotlin/com/github/brcosta/cljstuffplugin/extensions/codeInsight/daemon/ClojureRainbowVisitor.kt

@@ -0,0 +1,76 @@
+package com.github.brcosta.cljstuffplugin.extensions.codeInsight.daemon
+
+import com.github.brcosta.cljstuffplugin.extensions.ClojureAnnotator.Companion.isNamespaced
+import com.github.brcosta.cljstuffplugin.extensions.ClojureColorsAndFontsPageEx.Companion.SEMANTIC_HIGHLIGHTING
+import com.intellij.codeInsight.daemon.RainbowVisitor
+import com.intellij.codeInsight.daemon.UsedColors
+import com.intellij.codeInsight.daemon.impl.HighlightInfo
+import com.intellij.codeInsight.daemon.impl.HighlightVisitor
+import com.intellij.openapi.util.UserDataHolderEx
+import com.intellij.psi.PsiElement
+import com.intellij.psi.PsiFile
+import cursive.psi.api.ClKeyword
+import cursive.psi.api.ClojureFile
+import cursive.psi.api.symbols.ClSymbol
+
+/**
+ * Enables semantic highlighting for all symbols and keywords. Namespaces are treated as separate highlighted elements.
+ */
+class ClojureRainbowVisitor : RainbowVisitor() {
+    override fun suitableForFile(file: PsiFile): Boolean {
+        return file is ClojureFile
+    }
+
+    override fun visit(element: PsiElement) {
+        val maybeName = when (element) {
+            is ClSymbol -> element.name
+            is ClKeyword -> element.name
+            else -> null
+        }
+        maybeName?.let { elementName ->
+            element.context?.let { context ->
+                fun separateNsHighlighting(keyword: ClKeyword): List<HighlightInfo> {
+                    fun rangedInfo(name: String, start: Int, end: Int): HighlightInfo {
+                        val color =
+                            UsedColors.getOrAddColorIndex((context as UserDataHolderEx), name, highlighter.colorsCount)
+                        return highlighter.getInfo(color, start, end, SEMANTIC_HIGHLIGHTING)
+                    }
+
+                    val start = keyword.textRange.startOffset
+                    val nsEnd = start + keyword.text.indexOf('/')
+                    return listOf(
+                        rangedInfo(
+                            keyword.namespace,
+                            start,
+                            nsEnd,
+                        ),
+                        rangedInfo(
+                            elementName,
+                            nsEnd,
+                            keyword.textRange.endOffset,
+                        )
+                    )
+                }
+
+                if (element is ClKeyword && isNamespaced(element))
+                    separateNsHighlighting(element).forEach(::addInfo)
+                else
+                    // separate ns highlighting for symbols works by default
+                    addInfo(
+                        getInfo(
+                            context,
+                            element,
+                            elementName,
+                            SEMANTIC_HIGHLIGHTING
+                        )
+                    )
+
+            }
+        }
+    }
+
+    override fun clone(): HighlightVisitor {
+        return ClojureRainbowVisitor()
+    }
+
+}

src/main/resources/META-INF/plugin.xml

@@ -19,6 +19,7 @@
         <externalAnnotator language="Clojure" implementationClass="com.github.brcosta.cljstuffplugin.extensions.CljKondoAnnotator" />
 
         <colorSettingsPage implementation="com.github.brcosta.cljstuffplugin.extensions.ClojureColorsAndFontsPageEx"/>
+        <highlightVisitor implementation="com.github.brcosta.cljstuffplugin.extensions.codeInsight.daemon.ClojureRainbowVisitor"/>
 
         <additionalTextAttributes file="colors/ClojureStuffDefaultColors.xml" scheme="Default"/>
         <additionalTextAttributes file="colors/ClojureStuffDarculaColors.xml" scheme="Darcula"/>