[Editor] Create working Java editor

editor/build.gradle

@@ -40,6 +40,7 @@ dependencies {
     implementation platform("org.kordamp.ikonli:ikonli-bom:${ikonliVersion}")
     implementation 'org.kordamp.ikonli:ikonli-javafx'
     implementation 'org.kordamp.ikonli:ikonli-fontawesome-pack'
+    implementation "org.fxmisc.richtext:richtextfx:${richtextfxVersion}"
 
     // Spring
     implementation 'org.springframework.boot:spring-boot-starter'

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/code/component/CodeEditor.kt

@@ -0,0 +1,61 @@
+package com.bartlomiejpluta.base.editor.code.component
+
+import com.bartlomiejpluta.base.editor.code.highlighting.JavaSyntaxHighlighter
+import com.bartlomiejpluta.base.editor.code.stylesheet.HighlightingStylesheet
+import javafx.beans.property.Property
+import javafx.concurrent.Task
+import javafx.scene.layout.StackPane
+import org.fxmisc.flowless.VirtualizedScrollPane
+import org.fxmisc.richtext.CodeArea
+import org.fxmisc.richtext.LineNumberFactory
+import org.fxmisc.richtext.model.StyleSpans
+import java.time.Duration
+import java.util.*
+import java.util.concurrent.Executors
+
+
+class CodeEditor(val codeProperty: Property<String>) : StackPane() {
+   private val editor = CodeArea()
+   private val executor = Executors.newSingleThreadExecutor()
+   private val cleanupWhenDone = editor.multiPlainChanges()
+
+   private val highlighting = JavaSyntaxHighlighter()
+
+   init {
+      editor.paragraphGraphicFactory = LineNumberFactory.get(editor)
+      editor.replaceText(0, 0, codeProperty.value)
+      applyHighlighting(highlighting.highlight(editor.text))
+
+      cleanupWhenDone
+         .successionEnds(Duration.ofMillis(500))
+         .supplyTask(this::computeHighlightingAsync)
+         .awaitLatest(editor.multiPlainChanges())
+         .filterMap {
+            when {
+               it.isSuccess -> Optional.of(it.get())
+               else -> Optional.empty()
+            }
+         }
+         .subscribe(this::applyHighlighting)
+
+
+      children += VirtualizedScrollPane(editor)
+   }
+
+   private fun computeHighlightingAsync(): Task<StyleSpans<Collection<String>>> {
+      val code = editor.text
+
+      val task = object : Task<StyleSpans<Collection<String>>>() {
+         override fun call() = highlighting.highlight(code)
+      }
+
+      executor.execute(task)
+      return task
+   }
+
+   private fun applyHighlighting(highlighting: StyleSpans<Collection<String>>) {
+      editor.setStyleSpans(0, highlighting)
+   }
+
+   override fun getUserAgentStylesheet() = HighlightingStylesheet().base64URL.toExternalForm()
+}

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/code/highlighting/JavaSyntaxHighlighter.kt

@@ -0,0 +1,66 @@
+package com.bartlomiejpluta.base.editor.code.highlighting
+
+import org.fxmisc.richtext.model.StyleSpans
+import org.fxmisc.richtext.model.StyleSpansBuilder
+
+class JavaSyntaxHighlighter : SyntaxHighlighter {
+   override fun highlight(code: String): StyleSpans<Collection<String>> = StyleSpansBuilder<Collection<String>>().let {
+      val lastKeywordEnd = PATTERN.findAll(code).fold(0) { lastKeywordEnd, result ->
+         val styleClass = when {
+            result.groups["KEYWORD"] != null -> "keyword"
+            result.groups["PAREN"] != null -> "paren"
+            result.groups["BRACE"] != null -> "brace"
+            result.groups["BRACKET"] != null -> "bracket"
+            result.groups["SEMICOLON"] != null -> "semicolon"
+            result.groups["STRING"] != null -> "string"
+            result.groups["COMMENT"] != null -> "comment"
+            else -> throw IllegalStateException("Unsupported regex group")
+         }
+
+         it.add(emptyList(), result.range.first - lastKeywordEnd)
+         it.add(listOf(styleClass), result.range.last - result.range.first + 1)
+
+         result.range.last + 1
+      }
+
+      it.add(emptyList(), code.length - lastKeywordEnd)
+
+      it.create()
+   }
+
+   companion object {
+      private val KEYWORDS = arrayOf(
+         "abstract", "assert", "boolean", "break", "byte",
+         "case", "catch", "char", "class", "const",
+         "continue", "default", "do", "double", "else",
+         "enum", "extends", "final", "finally", "float",
+         "for", "goto", "if", "implements", "import",
+         "instanceof", "int", "interface", "long", "native",
+         "new", "package", "private", "protected", "public",
+         "return", "short", "static", "strictfp", "super",
+         "switch", "synchronized", "this", "throw", "throws",
+         "transient", "try", "void", "volatile", "while"
+      )
+
+      private val KEYWORD_PATTERN = "\\b(" + KEYWORDS.joinToString("|") + ")\\b"
+      private val PAREN_PATTERN = "\\(|\\)"
+      private val BRACE_PATTERN = "\\{|\\}"
+      private val BRACKET_PATTERN = "\\[|\\]"
+      private val SEMICOLON_PATTERN = "\\;"
+      private val STRING_PATTERN = "\"([^\"\\\\]|\\\\.)*\""
+      private val COMMENT_PATTERN = """
+      //[^
+      ]*|/\*(.|\R)*?\*/
+      """.trimIndent()
+
+      private val PATTERN = (
+            "(?<KEYWORD>" + KEYWORD_PATTERN + ")"
+                  + "|(?<PAREN>" + PAREN_PATTERN + ")"
+                  + "|(?<BRACE>" + BRACE_PATTERN + ")"
+                  + "|(?<BRACKET>" + BRACKET_PATTERN + ")"
+                  + "|(?<SEMICOLON>" + SEMICOLON_PATTERN + ")"
+                  + "|(?<STRING>" + STRING_PATTERN + ")"
+                  + "|(?<COMMENT>" + COMMENT_PATTERN + ")"
+            ).toRegex()
+   }
+}

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/code/highlighting/SyntaxHighlighter.kt

@@ -0,0 +1,7 @@
+package com.bartlomiejpluta.base.editor.code.highlighting
+
+import org.fxmisc.richtext.model.StyleSpans
+
+interface SyntaxHighlighter {
+   fun highlight(code: String): StyleSpans<Collection<String>>
+}

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/code/stylesheet/HighlightingStylesheet.kt

@@ -0,0 +1,56 @@
+package com.bartlomiejpluta.base.editor.code.stylesheet
+
+import javafx.scene.text.FontWeight
+import tornadofx.*
+
+class HighlightingStylesheet : Stylesheet() {
+   companion object {
+      val keyword by cssclass()
+      val semicolon by cssclass()
+      val paren by cssclass()
+      val bracket by cssclass()
+      val brace by cssclass()
+      val string by cssclass()
+      val comment by cssclass()
+      val paragraphBox by cssclass()
+      val hasCaret by csspseudoclass()
+   }
+
+   init {
+      keyword {
+         fill = c("purple")
+         fontWeight = FontWeight.BOLD
+      }
+
+      semicolon {
+         fontWeight = FontWeight.BOLD
+      }
+
+      paren {
+         fill = c("firebrick")
+         fontWeight = FontWeight.BOLD
+      }
+
+      bracket {
+         fill = c("darkgreen")
+         fontWeight = FontWeight.BOLD
+      }
+
+      brace {
+         fill = c("teal")
+         fontWeight = FontWeight.BOLD
+      }
+
+      string {
+         fill = c("blue")
+      }
+
+      comment {
+         fill = c("cadetblue")
+      }
+
+      paragraphBox and hasCaret {
+         backgroundColor = multi(c("#f2f9fc"))
+      }
+   }
+}

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/code/view/CodeEditorFragment.kt

@@ -1,9 +1,9 @@
 package com.bartlomiejpluta.base.editor.code.view
 
 import tornadofx.Fragment
-import tornadofx.hbox
 
 class CodeEditorFragment : Fragment() {
+   private val editorView = find<CodeEditorView>()
 
-   override val root = hbox {}
+   override val root = editorView.root
 }

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/code/view/CodeEditorView.kt

@@ -1,9 +1,15 @@
 package com.bartlomiejpluta.base.editor.code.view
 
+import com.bartlomiejpluta.base.editor.code.component.CodeEditor
+import com.bartlomiejpluta.base.editor.code.viewmodel.CodeVM
 import tornadofx.View
-import tornadofx.hbox
+import tornadofx.borderpane
 
 class CodeEditorView : View() {
+   private val codeVM = find<CodeVM>()
+   private val editor = CodeEditor(codeVM.codeProperty)
 
-   override val root = hbox {}
+   override val root = borderpane {
+      center = editor
+   }
 }

gradle.properties

@@ -7,3 +7,4 @@ tornadoFxVersion=2.0.0-SNAPSHOT
 ikonliVersion=12.2.0
 protobufPluginVersion=0.8.14
 protobufVersion=3.14.0
+richtextfxVersion=0.10.5