форматирование сообщений

2026-07-03 13:45:49 +07:00
parent 3a3d692a58
commit af8ba6b526
11 changed files with 1028 additions and 36 deletions
@@ -0,0 +1,204 @@
+import 'package:flutter/material.dart';
+
+enum TextFormat {
+  strong,
+  emphasized,
+  underline,
+  strikethrough,
+  monospaced,
+  quote,
+  link,
+}
+
+const Map<TextFormat, String> _formatToServer = {
+  TextFormat.strong: 'STRONG',
+  TextFormat.emphasized: 'EMPHASIZED',
+  TextFormat.underline: 'UNDERLINE',
+  TextFormat.strikethrough: 'STRIKETHROUGH',
+  TextFormat.monospaced: 'MONOSPACED',
+  TextFormat.quote: 'QUOTE',
+  TextFormat.link: 'LINK',
+};
+
+final Map<String, TextFormat> _serverToFormat = {
+  for (final e in _formatToServer.entries) e.value: e.key,
+};
+
+String textFormatToServer(TextFormat format) => _formatToServer[format]!;
+
+TextFormat? textFormatFromServer(String? raw) =>
+    raw == null ? null : _serverToFormat[raw];
+
+class FormatRange {
+  final TextFormat format;
+  final int start;
+  final int length;
+  final Map<String, dynamic>? attributes;
+
+  const FormatRange({
+    required this.format,
+    required this.start,
+    required this.length,
+    this.attributes,
+  });
+
+  int get end => start + length;
+
+  String? get url {
+    final value = attributes?['url'];
+    return value is String ? value : null;
+  }
+
+  Map<String, dynamic> toServer() => {
+    'type': textFormatToServer(format),
+    'from': start,
+    'length': length,
+    if (attributes != null) 'attributes': attributes,
+  };
+}
+
+List<FormatRange> parseFormatElements(dynamic raw) {
+  if (raw is! List) return const [];
+  final result = <FormatRange>[];
+  for (final item in raw) {
+    if (item is! Map) continue;
+    final format = textFormatFromServer(item['type']?.toString());
+    if (format == null) continue;
+    final from = _asInt(item['from']);
+    final length = _asInt(item['length']);
+    if (length <= 0) continue;
+    final attrsRaw = item['attributes'];
+    final attributes = attrsRaw is Map
+        ? Map<String, dynamic>.from(attrsRaw)
+        : null;
+    result.add(
+      FormatRange(
+        format: format,
+        start: from,
+        length: length,
+        attributes: attributes,
+      ),
+    );
+  }
+  return result;
+}
+
+List<Map<String, dynamic>> serializeFormatElements(
+  Iterable<FormatRange> ranges,
+) => [for (final range in ranges) range.toServer()];
+
+int _asInt(dynamic value) {
+  if (value is int) return value;
+  if (value is String) return int.tryParse(value) ?? 0;
+  return 0;
+}
+
+class FormatSegment {
+  final int start;
+  final int end;
+  final Set<TextFormat> formats;
+  final String? url;
+
+  const FormatSegment({
+    required this.start,
+    required this.end,
+    required this.formats,
+    this.url,
+  });
+}
+
+List<FormatSegment> segmentizeFormats(String text, List<FormatRange> ranges) {
+  if (text.isEmpty) return const [];
+  final length = text.length;
+  final clamped = <FormatRange>[];
+  for (final range in ranges) {
+    final start = range.start.clamp(0, length);
+    final end = range.end.clamp(0, length);
+    if (end <= start) continue;
+    clamped.add(
+      FormatRange(
+        format: range.format,
+        start: start,
+        length: end - start,
+        attributes: range.attributes,
+      ),
+    );
+  }
+  if (clamped.isEmpty) {
+    return [FormatSegment(start: 0, end: length, formats: const {})];
+  }
+
+  final boundaries = <int>{0, length};
+  for (final range in clamped) {
+    boundaries.add(range.start);
+    boundaries.add(range.end);
+  }
+  final points = boundaries.toList()..sort();
+
+  final segments = <FormatSegment>[];
+  for (var i = 0; i < points.length - 1; i++) {
+    final start = points[i];
+    final end = points[i + 1];
+    if (end <= start) continue;
+    final formats = <TextFormat>{};
+    String? url;
+    for (final range in clamped) {
+      if (range.start <= start && range.end >= end) {
+        formats.add(range.format);
+        if (range.format == TextFormat.link) url ??= range.url;
+      }
+    }
+    segments.add(
+      FormatSegment(start: start, end: end, formats: formats, url: url),
+    );
+  }
+  return segments;
+}
+
+TextStyle applyTextFormats(
+  TextStyle base,
+  Set<TextFormat> formats, {
+  Color? linkColor,
+  Color? quoteColor,
+  Color? monoColor,
+}) {
+  if (formats.isEmpty) return base;
+  var style = base;
+  final decorations = <TextDecoration>[];
+
+  if (formats.contains(TextFormat.strong)) {
+    style = style.merge(const TextStyle(fontWeight: FontWeight.w700));
+  }
+  if (formats.contains(TextFormat.emphasized) ||
+      formats.contains(TextFormat.quote)) {
+    style = style.merge(const TextStyle(fontStyle: FontStyle.italic));
+  }
+  if (formats.contains(TextFormat.monospaced)) {
+    style = style.merge(
+      TextStyle(
+        fontFamily: 'monospace',
+        color: monoColor ?? style.color,
+      ),
+    );
+  }
+  if (formats.contains(TextFormat.quote) && quoteColor != null) {
+    style = style.merge(TextStyle(color: quoteColor));
+  }
+  if (formats.contains(TextFormat.underline)) {
+    decorations.add(TextDecoration.underline);
+  }
+  if (formats.contains(TextFormat.strikethrough)) {
+    decorations.add(TextDecoration.lineThrough);
+  }
+  if (formats.contains(TextFormat.link)) {
+    decorations.add(TextDecoration.underline);
+    if (linkColor != null) style = style.merge(TextStyle(color: linkColor));
+  }
+
+  if (decorations.isNotEmpty) {
+    style = style.merge(
+      TextStyle(decoration: TextDecoration.combine(decorations)),
+    );
+  }
+  return style;
+}