OpenContacts/lib/string_formatter.dart
2023-05-12 18:31:05 +02:00

221 lines
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7.4 KiB
Dart

import 'package:color/color.dart' as cc;
import 'package:flutter/material.dart';
class FormatNode {
String text;
final FormatData format;
final List<FormatNode> children;
FormatNode({required this.text, required this.format, required this.children});
bool get isUnformatted => format.isUnformatted && children.isEmpty;
bool get isEmpty => text.isEmpty && children.isEmpty;
factory FormatNode.unformatted(String? text) {
return FormatNode(text: text ?? "", format: FormatData.unformatted(), children: const []);
}
factory FormatNode.fromText(String? text) {
if (text == null) return FormatNode.unformatted(text);
var tags = FormatTag.parseTags(text);
if (tags.isEmpty) return FormatNode.unformatted(text);
final root = FormatNode(
format: FormatData.unformatted(),
text: text.substring(0, tags.first.startIndex),
children: [],
);
final activeTags = <FormatData>[];
for (int i = 0; i < tags.length; i++) {
final tag = tags[i];
final substr = text.substring(tag.endIndex, (i + 1 < tags.length) ? tags[i + 1].startIndex : null);
if (tag.format.isAdditive) {
activeTags.add(tag.format);
} else {
final idx = activeTags.lastIndexWhere((element) => element.name == tag.format.name);
if (idx != -1) {
activeTags.removeAt(idx);
}
}
if (substr.isNotEmpty) {
root.children.add(
FormatNode.buildFromStyles(activeTags, substr)
);
}
}
return root;
}
TextSpan toTextSpan({required TextStyle baseStyle}) {
final spanTree = TextSpan(
text: text,
style: format.isUnformatted ? baseStyle : format.style(),
children: children.map((e) => e.toTextSpan(baseStyle: baseStyle)).toList()
);
return spanTree;
}
static FormatNode buildFromStyles(List<FormatData> styles, String text) {
if (styles.isEmpty) return FormatNode(format: FormatData.unformatted(), children: [], text: text);
final root = FormatNode(text: "", format: styles.first, children: []);
var current = root;
for (final style in styles.sublist(1)) {
final next = FormatNode(text: "", format: style, children: []);
current.children.add(next);
current = next;
}
current.text = text;
return root;
}
}
class FormatTag {
final int startIndex;
final int endIndex;
final FormatData format;
const FormatTag({
required this.startIndex,
required this.endIndex,
required this.format,
});
static List<FormatTag> parseTags(String text) {
final startMatches = RegExp(r"<(.+?)>").allMatches(text);
final spans = <FormatTag>[];
for (final startMatch in startMatches) {
final fullTag = startMatch.group(1);
if (fullTag == null) continue;
final tag = FormatData.parse(fullTag);
spans.add(
FormatTag(
startIndex: startMatch.start,
endIndex: startMatch.end,
format: tag,
)
);
}
return spans;
}
}
class FormatAction {
final String Function(String input, String parameter)? transform;
final TextStyle Function(String? parameter, TextStyle baseStyle)? style;
FormatAction({this.transform, this.style});
}
class FormatData {
static Color? tryParseColor(String? text) {
if (text == null) return null;
var color = cc.RgbColor.namedColors[text];
if (color != null) {
return Color.fromARGB(255, color.r.round(), color.g.round(), color.b.round());
}
try {
color = cc.HexColor(text);
return Color.fromARGB(255, color.r.round(), color.g.round(), color.b.round());
} catch (_) {
return null;
}
}
static final Map<String, FormatAction> _richTextTags = {
"align": FormatAction(),
"alpha": FormatAction(style: (param, baseStyle) {
if (param == null || !param.startsWith("#")) return baseStyle;
final alpha = int.tryParse(param.substring(1), radix: 16);
if (alpha == null) return baseStyle;
return baseStyle.copyWith(color: baseStyle.color?.withAlpha(alpha));
}),
"color": FormatAction(style: (param, baseStyle) {
if (param == null) return baseStyle;
final color = tryParseColor(param);
if (color == null) return baseStyle;
return baseStyle.copyWith(color: color);
}),
"b": FormatAction(style: (param, baseStyle) => baseStyle.copyWith(fontWeight: FontWeight.bold)),
"br": FormatAction(transform: (text, param) => "\n$text"),
"i": FormatAction(style: (param, baseStyle) => baseStyle.copyWith(fontStyle: FontStyle.italic)),
"cspace": FormatAction(),
"font": FormatAction(),
"indent": FormatAction(),
"line-height": FormatAction(),
"line-indent": FormatAction(),
"link": FormatAction(),
"lowercase": FormatAction(transform: (input, parameter) => input.toLowerCase(),),
"uppercase": FormatAction(transform: (input, parameter) => input.toUpperCase(),),
"smallcaps": FormatAction(),
"margin": FormatAction(),
"mark": FormatAction(style: (param, baseStyle) {
if (param == null) return baseStyle;
final color = tryParseColor(param);
if (color == null) return baseStyle;
return baseStyle.copyWith(backgroundColor: color);
}),
"mspace": FormatAction(),
"noparse": FormatAction(),
"nobr": FormatAction(),
"page": FormatAction(),
"pos": FormatAction(),
"size": FormatAction(
style: (param, baseStyle) {
if (param == null) return baseStyle;
if (param.endsWith("%")) {
final percentage = int.tryParse(param.replaceAll("%", ""));
if (percentage == null || percentage <= 0) return baseStyle;
final baseSize = baseStyle.fontSize ?? 12;
return baseStyle.copyWith(fontSize: baseSize * (percentage / 100));
} else {
final size = num.tryParse(param);
if (size == null || size <= 0) return baseStyle;
return baseStyle.copyWith(fontSize: size.toDouble());
}
}
),
"space": FormatAction(),
"sprite": FormatAction(),
"s": FormatAction(style: (param, baseStyle) => baseStyle.copyWith(decoration: TextDecoration.lineThrough)),
"u": FormatAction(style: (param, baseStyle) => baseStyle.copyWith(decoration: TextDecoration.underline)),
"style": FormatAction(),
"sub": FormatAction(),
"sup": FormatAction(),
"voffset": FormatAction(),
"width": FormatAction(),
};
final String name;
final String parameter;
final bool isAdditive;
const FormatData({required this.name, required this.parameter, required this.isAdditive});
factory FormatData.parse(String text) {
if (text.contains("/")) return FormatData(name: text.replaceAll("/", ""), parameter: "", isAdditive: false);
final sepIdx = text.indexOf("=");
if (sepIdx == -1) {
return FormatData(name: text, parameter: "", isAdditive: true);
} else {
return FormatData(
name: text.substring(0, sepIdx).trim().toLowerCase(),
parameter: text.substring(sepIdx + 1, text.length).trim().toLowerCase(),
isAdditive: true,
);
}
}
factory FormatData.unformatted() => const FormatData(name: "", parameter: "", isAdditive: false);
bool get isUnformatted => name.isEmpty && parameter.isEmpty && !isAdditive;
bool get isValid => _richTextTags.containsKey(name);
String? apply(String? text) => text == null ? null : _richTextTags[name]?.transform?.call(text, parameter);
TextStyle style() => _richTextTags[name]?.style?.call(parameter, const TextStyle()) ?? const TextStyle();
}