sky/sdk/lib/editing/editable_text.dart

// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:async';

import '../widgets/basic.dart';
import 'editable_string.dart';

class EditableText extends Component {

  EditableText({String key, this.value, this.focused})
      : super(key: key, stateful: true);

  // static final Style _cursorStyle = new Style('''
  //   width: 2px;
  //   height: 1.2em;
  //   vertical-align: top;
  //   background-color: ${Blue[500]};'''
  // );

  // static final Style _composingStyle = new Style('''
  //   text-decoration: underline;'''
  // );

  EditableString value;
  bool focused;

  void syncFields(EditableText source) {
    value = source.value;
    focused = source.focused;
  }

  Timer _cursorTimer;
  bool _showCursor = false;

  void _cursorTick(Timer timer) {
    setState(() {
      _showCursor = !_showCursor;
    });
  }

  void _startCursorTimer() {
    _showCursor = true;
    _cursorTimer = new Timer.periodic(
        new Duration(milliseconds: 500), _cursorTick);
  }

  void didUnmount() {
    if (_cursorTimer != null)
      _stopCursorTimer();
    super.didUnmount();
  }

  void _stopCursorTimer() {
    _cursorTimer.cancel();
    _cursorTimer = null;
    _showCursor = false;
  }

  Widget build() {
    if (focused && _cursorTimer == null)
      _startCursorTimer();
    else if (!focused && _cursorTimer != null)
      _stopCursorTimer();

    //List<Widget> children = new List<Widget>();
    String hack = "";

    if (!value.composing.isValid) {
      // children.add(new TextFragment(value.text));
      hack += value.text;
    } else {
      hack += value.textBefore(value.composing);
      hack += value.textInside(value.composing);
      hack += value.textAfter(value.composing);
      // if (!composing.isEmpty) {
      //   children.add(new TextFragment(
      //     composing,
      //     key: 'composing',
      //     style: _composingStyle
      //   ));
      // }

      // String afterComposing = value.textAfter(value.composing);
      // if (!afterComposing.isEmpty)
      //   children.add(new TextFragment(afterComposing));
    }

    // if (_showCursor)
    //   children.add(new Container(
    //     key: 'cursor',
    //     // style: _cursorStyle
    //     ));

    return new Text(hack);
  }
}