expandable_text.dart

import 'package:flutter/material.dart';

import 'package:flutter_markdown/flutter_markdown.dart';

import 'package:omi/utils/l10n_extensions.dart';

class ExpandableTextWidget extends StatefulWidget {
  final String text;
  final bool isExpanded;
  final Function toggleExpand;
  final TextStyle style;
  final int maxLines;
  final String? expandText;
  final String? collapseText;
  final Color linkColor;

  const ExpandableTextWidget({
    super.key,
    required this.text,
    required this.style,
    this.maxLines = 3,
    this.expandText,
    this.collapseText,
    this.linkColor = Colors.deepPurple,
    required this.isExpanded,
    required this.toggleExpand,
  });

  @override
  _ExpandableTextWidgetState createState() => _ExpandableTextWidgetState();
}

class _ExpandableTextWidgetState extends State<ExpandableTextWidget> {
  @override
  Widget build(BuildContext context) {
    final expandLabel = widget.expandText ?? context.l10n.showMore;
    final collapseLabel = widget.collapseText ?? context.l10n.showLess;

    final span = TextSpan(text: widget.text, style: widget.style);
    final tp = TextPainter(text: span, maxLines: widget.maxLines, textDirection: TextDirection.ltr);
    var width = MediaQuery.of(context).size.width;
    tp.layout(maxWidth: width);
    final isOverflowing = tp.didExceedMaxLines;
    final maxChars = tp.getPositionForOffset(Offset(width, 0)).offset * widget.maxLines;

    return SelectionArea(
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          MarkdownBody(
            shrinkWrap: true,
            styleSheet: MarkdownStyleSheet.fromTheme(Theme.of(context)).copyWith(
              a: widget.style,
              p: widget.style,
              blockquote: widget.style.copyWith(backgroundColor: Colors.transparent, color: Colors.black),
              blockquoteDecoration:
                  BoxDecoration(color: const Color(0xFF35343B), borderRadius: BorderRadius.circular(4)),
              code: widget.style.copyWith(
                backgroundColor: Colors.transparent,
                decoration: TextDecoration.none,
                color: Colors.white,
                fontWeight: FontWeight.w500,
              ),
            ),
            data: widget.isExpanded
                ? widget.text
                : widget.text.length > maxChars
                    ? widget.text.substring(0, maxChars)
                    : widget.text,
          ),
          // Text(
          //   widget.text,
          //   style: widget.style,
          //   maxLines: widget.isExpanded ? 10000 : widget.maxLines,
          //   overflow: TextOverflow.ellipsis,
          // ),
          if (isOverflowing)
            InkWell(
              onTap: () => widget.toggleExpand(),
              child: Padding(
                padding: const EdgeInsets.only(top: 4.0),
                child: Text(
                  widget.isExpanded ? collapseLabel : expandLabel,
                  style: TextStyle(
                    color: Colors.deepPurple,
                    fontWeight: FontWeight.w500,
                    fontSize: widget.style.fontSize,
                  ),
                ),
              ),
            ),
        ],
      ),
    );
  }
}