diff --git a/flutter_highlight/lib/flutter_highlight.dart b/flutter_highlight/lib/flutter_highlight.dart
index 43b7fa1..518dec3 100644
--- a/flutter_highlight/lib/flutter_highlight.dart
+++ b/flutter_highlight/lib/flutter_highlight.dart
@@ -36,38 +36,6 @@ class HighlightView extends StatelessWidget {
     int tabSize = 8, // TODO: https://github.com/flutter/flutter/issues/50087
   }) : source = input.replaceAll('\t', ' ' * tabSize);
 
-  List<TextSpan> _convert(List<Node> nodes) {
-    List<TextSpan> spans = [];
-    var currentSpans = spans;
-    List<List<TextSpan>> stack = [];
-
-    _traverse(Node node) {
-      if (node.value != null) {
-        currentSpans.add(node.className == null
-            ? TextSpan(text: node.value)
-            : TextSpan(text: node.value, style: theme[node.className]));
-      } else if (node.children != null) {
-        List<TextSpan> tmp = [];
-        currentSpans.add(TextSpan(children: tmp, style: theme[node.className]));
-        stack.add(currentSpans);
-        currentSpans = tmp;
-
-        node.children.forEach((n) {
-          _traverse(n);
-          if (n == node.children.last) {
-            currentSpans = stack.isEmpty ? spans : stack.removeLast();
-          }
-        });
-      }
-    }
-
-    for (var node in nodes) {
-      _traverse(node);
-    }
-
-    return spans;
-  }
-
   static const _rootKey = 'root';
   static const _defaultFontColor = Color(0xff000000);
   static const _defaultBackgroundColor = Color(0xffffffff);
@@ -93,9 +61,105 @@ class HighlightView extends StatelessWidget {
       child: RichText(
         text: TextSpan(
           style: _textStyle,
-          children: _convert(highlight.parse(source, language: language).nodes),
+          children: getHighlightTextSpan(source, language, theme),
         ),
       ),
     );
   }
 }
+
+List<TextSpan> getHighlightTextSpan( source, language, theme) {
+  return _convert(highlight.parse(source, language: language).nodes, theme);
+}
+
+class HighlightEditingController extends TextEditingController {
+  String language;
+  Map<String, TextStyle> theme;
+
+  HighlightEditingController(this.language, this.theme);
+
+  @override
+  TextSpan buildTextSpan({TextStyle style, bool withComposing}) {
+    final result = highlight.parse(value.text, language: language);
+    final spans =
+    TextSpan(style: style, children: _convert(result.nodes, theme));
+    if (value.composing.isValid && withComposing) {
+      underlineComposing(spans);
+    }
+    return spans;
+  }
+
+  underlineComposing(TextSpan nodes) {
+    var pos = 0;
+    final TextStyle composingStyle =
+    TextStyle(decoration: TextDecoration.underline);
+
+    TextSpan _traverse(TextSpan node) {
+      if (node.text != null && pos <= value.composing.start &&
+          value.composing.end <= pos + node.text.length) {
+        var relativeComposing = TextRange(
+          start: value.composing.start - pos,
+          end: value.composing.end - pos,
+        );
+        return TextSpan(
+          children: [
+            TextSpan(text: relativeComposing.textBefore(node.text)),
+            TextSpan(
+              style: composingStyle,
+              text: relativeComposing.textInside(node.text),
+            ),
+            TextSpan(text: relativeComposing.textAfter(node.text)),
+          ],
+        );
+      }
+
+      pos += node.text?.length ?? 0;
+      if (node.children != null) {
+        for (var i = 0;
+        i < node.children.length && pos <= value.composing.start;
+        i++) {
+          var update = _traverse(node.children[i]);
+          if (update != null) {
+            node.children[i] = update;
+            return null;
+          }
+        }
+      }
+      return null;
+    }
+
+    _traverse(nodes);
+  }
+}
+
+List<TextSpan> _convert(List<Node> nodes, theme) {
+  List<TextSpan> spans = [];
+  var currentSpans = spans;
+  List<List<TextSpan>> stack = [];
+
+  _traverse(Node node) {
+    if (node.value != null) {
+      currentSpans.add(node.className == null
+          ? TextSpan(text: node.value)
+          : TextSpan(text: node.value, style: theme[node.className]));
+    } else if (node.children != null) {
+      List<TextSpan> tmp = [];
+      currentSpans.add(TextSpan(children: tmp, style: theme[node.className]));
+      stack.add(currentSpans);
+      currentSpans = tmp;
+
+      node.children.forEach((n) {
+        _traverse(n);
+        if (n == node.children.last) {
+          currentSpans = stack.isEmpty ? spans : stack.removeLast();
+        }
+      });
+    }
+  }
+
+  for (var node in nodes) {
+    _traverse(node);
+  }
+
+  return spans;
+}