extended_text_field 0.1.2

extended official text field to quickly build special text like inline image or @somebody etc.

extended_text_field

extended official text field to quickly build special text like inline image or @somebody etc.

base on flutter version 1.5.7

limitation

1.Not support: TextDirection.rtl. Image position calculated by TextPainter is strange.

2.Not support: obscureText is true.

3.Not support: TextEditingValue is composed.

4.codes are base on flutter 1.5.7, if any one find some codes are broken, please fix them base on your flutter version, we can't maintain codes for every version.

How to use it.

1. just to extend SpecialText and define your rule.

code for @xxx

class AtText extends SpecialText {
  static const String flag = "@";
  final int start;

  /// whether show background for @somebody
  final bool showAtBackground;

  final BuilderType type;
  AtText(TextStyle textStyle, SpecialTextGestureTapCallback onTap, this.start,
      {this.showAtBackground: false, this.type})
      : super(flag, " ", textStyle, onTap: onTap);

  @override
  TextSpan finishText() {
    // TODO: implement finishText
    TextStyle textStyle = showAtBackground
        ? this.textStyle?.copyWith(
            fontSize: 16.0,
            background: Paint()..color = Colors.blue.withOpacity(0.5))
        : this.textStyle?.copyWith(color: Colors.blue, fontSize: 16.0);

    final String atText = toString();

    if (type == BuilderType.extendedText)
      return TextSpan(
          text: atText,
          style: textStyle,
          recognizer: TapGestureRecognizer()
            ..onTap = () {
              if (onTap != null) onTap(atText);
            });

    return SpecialTextSpan(
      text: atText,
      actualText: atText,
      start: start,
      deleteAll: false,
      style: textStyle,
    );
  }
}

code for image

class EmojiText extends SpecialText {
  static const String flag = "[";
  final int start;
  EmojiText(TextStyle textStyle, this.start)
      : super(EmojiText.flag, "]", textStyle);

  @override
  TextSpan finishText() {
    // TODO: implement finishText
    var key = toString();
    if (EmojiUitl.instance.emojiMap.containsKey(key)) {
      //fontsize id define image height
      //size = 30.0/26.0 * fontSize
      final double size = 20.0;

      ///fontSize 26 and text height =30.0
      //final double fontSize = 26.0;

      return ImageSpan(AssetImage(EmojiUitl.instance.emojiMap[key]),
          actualText: key,
          imageWidth: size,
          imageHeight: size,
          start: start,
          deleteAll: true,
          fit: BoxFit.fill,
          margin: EdgeInsets.only(left: 2.0, top: 2.0, right: 2.0));
    }

    return TextSpan(text: toString(), style: textStyle);
  }
}

2. create your SpecialTextSpanBuilder.

class MySpecialTextSpanBuilder extends SpecialTextSpanBuilder {
  /// whether show background for @somebody
  final bool showAtBackground;
  final BuilderType type;
  MySpecialTextSpanBuilder(
      {this.showAtBackground: false, this.type: BuilderType.extendedText});
  @override
  TextSpan build(String data, {TextStyle textStyle, onTap}) {
    // TODO: implement build
    if (data == null) return null;
    List<TextSpan> inlineList = new List<TextSpan>();
    if (data.length > 0) {
      SpecialText specialText;
      String textStack = "";
      //String text
      for (int i = 0; i < data.length; i++) {
        String char = data[i];
        if (specialText != null) {
          if (!specialText.isEnd(char)) {
            specialText.appendContent(char);
          } else {
            inlineList.add(specialText.finishText());
            specialText = null;
          }
        } else {
          textStack += char;
          specialText = createSpecialText(textStack,
              textStyle: textStyle, onTap: onTap, start: i);
          if (specialText != null) {
            if (textStack.length - specialText.startFlag.length >= 0) {
              textStack = textStack.substring(
                  0, textStack.length - specialText.startFlag.length);
              if (textStack.length > 0) {
                inlineList.add(TextSpan(text: textStack, style: textStyle));
              }
            }
            textStack = "";
          }
        }
      }

      if (specialText != null) {
        inlineList.add(TextSpan(
            text: specialText.startFlag + specialText.getContent(),
            style: textStyle));
      } else if (textStack.length > 0) {
        inlineList.add(TextSpan(text: textStack, style: textStyle));
      }
    } else {
      inlineList.add(TextSpan(text: data, style: textStyle));
    }

    // TODO: implement build
    return TextSpan(children: inlineList, style: textStyle);
  }

  @override
  SpecialText createSpecialText(String flag,
      {TextStyle textStyle, SpecialTextGestureTapCallback onTap, int start}) {
    if (flag == null || flag == "") return null;
    // TODO: implement createSpecialText

    if (isStart(flag, AtText.flag)) {
      return AtText(textStyle, onTap, start,
          showAtBackground: showAtBackground, type: type);
    } else if (isStart(flag, EmojiText.flag)) {
      return EmojiText(textStyle, start);
    } else if (isStart(flag, DollarText.flag)) {
      return DollarText(textStyle, onTap, start, type: type);
    }
    return null;
  }
}

enum BuilderType { extendedText, extendedTextField }

3.enjoy your nice text field

input text will auto change to SpecialTextSpan and show in text field

 ExtendedTextField(
            specialTextSpanBuilder: MySpecialTextSpanBuilder(
                showAtBackground: false, type: BuilderType.extendedTextField),
            controller: _textEditingController,
            maxLines: null,
            focusNode: _focusNode,
            decoration: InputDecoration(
                suffixIcon: GestureDetector(
                  onTap: () {
                    setState(() {
                      sessions.insert(0, _textEditingController.text);
                      _textEditingController.clear();
                    });
                  },
                  child: Icon(Icons.send),
                ),
                contentPadding: EdgeInsets.all(12.0)),
            //textDirection: TextDirection.rtl,
          ),

more detail