| // Copyright 2014 The Flutter 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 'package:flutter/material.dart'; |
| import 'package:string_scanner/string_scanner.dart'; |
| |
| class SyntaxHighlighterStyle { |
| SyntaxHighlighterStyle({ |
| this.baseStyle, |
| this.numberStyle, |
| this.commentStyle, |
| this.keywordStyle, |
| this.stringStyle, |
| this.punctuationStyle, |
| this.classStyle, |
| this.constantStyle, |
| }); |
| |
| static SyntaxHighlighterStyle lightThemeStyle() { |
| return SyntaxHighlighterStyle( |
| baseStyle: const TextStyle(color: Color(0xFF000000)), |
| numberStyle: const TextStyle(color: Color(0xFF1565C0)), |
| commentStyle: const TextStyle(color: Color(0xFF9E9E9E)), |
| keywordStyle: const TextStyle(color: Color(0xFF9C27B0)), |
| stringStyle: const TextStyle(color: Color(0xFF43A047)), |
| punctuationStyle: const TextStyle(color: Color(0xFF000000)), |
| classStyle: const TextStyle(color: Color(0xFF512DA8)), |
| constantStyle: const TextStyle(color: Color(0xFF795548)), |
| ); |
| } |
| |
| static SyntaxHighlighterStyle darkThemeStyle() { |
| return SyntaxHighlighterStyle( |
| baseStyle: const TextStyle(color: Color(0xFFFFFFFF)), |
| numberStyle: const TextStyle(color: Color(0xFF1565C0)), |
| commentStyle: const TextStyle(color: Color(0xFF9E9E9E)), |
| keywordStyle: const TextStyle(color: Color(0xFF80CBC4)), |
| stringStyle: const TextStyle(color: Color(0xFF009688)), |
| punctuationStyle: const TextStyle(color: Color(0xFFFFFFFF)), |
| classStyle: const TextStyle(color: Color(0xFF009688)), |
| constantStyle: const TextStyle(color: Color(0xFF795548)), |
| ); |
| } |
| |
| final TextStyle? baseStyle; |
| final TextStyle? numberStyle; |
| final TextStyle? commentStyle; |
| final TextStyle? keywordStyle; |
| final TextStyle? stringStyle; |
| final TextStyle? punctuationStyle; |
| final TextStyle? classStyle; |
| final TextStyle? constantStyle; |
| } |
| |
| abstract class SyntaxHighlighter { |
| TextSpan format(String src); |
| } |
| |
| class DartSyntaxHighlighter extends SyntaxHighlighter { |
| DartSyntaxHighlighter([this._style]) { |
| _spans = <_HighlightSpan>[]; |
| _style ??= SyntaxHighlighterStyle.darkThemeStyle(); |
| } |
| |
| SyntaxHighlighterStyle? _style; |
| |
| static const List<String> _keywords = <String>[ |
| 'abstract', 'as', 'assert', 'async', 'await', 'break', 'case', 'catch', |
| 'class', 'const', 'continue', 'default', 'deferred', 'do', 'dynamic', 'else', |
| 'enum', 'export', 'external', 'extends', 'factory', 'false', 'final', |
| 'finally', 'for', 'get', 'if', 'implements', 'import', 'in', 'is', 'library', |
| 'new', 'null', 'operator', 'part', 'rethrow', 'return', 'set', 'static', |
| 'super', 'switch', 'sync', 'this', 'throw', 'true', 'try', 'typedef', 'var', |
| 'void', 'while', 'with', 'yield', |
| ]; |
| |
| static const List<String> _builtInTypes = <String>[ |
| 'int', 'double', 'num', 'bool', |
| ]; |
| |
| String? _src; |
| late StringScanner _scanner; |
| |
| late List<_HighlightSpan> _spans; |
| |
| @override |
| TextSpan format(String? src) { |
| _src = src; |
| _scanner = StringScanner(_src!); |
| |
| if (_generateSpans()) { |
| // Successfully parsed the code |
| final List<TextSpan> formattedText = <TextSpan>[]; |
| int currentPosition = 0; |
| |
| for (final _HighlightSpan span in _spans) { |
| if (currentPosition != span.start) { |
| formattedText.add(TextSpan(text: _src!.substring(currentPosition, span.start))); |
| } |
| |
| formattedText.add(TextSpan(style: span.textStyle(_style), text: span.textForSpan(_src!))); |
| |
| currentPosition = span.end; |
| } |
| |
| if (currentPosition != _src!.length) { |
| formattedText.add(TextSpan(text: _src!.substring(currentPosition, _src!.length))); |
| } |
| |
| return TextSpan(style: _style!.baseStyle, children: formattedText); |
| } else { |
| // Parsing failed, return with only basic formatting |
| return TextSpan(style: _style!.baseStyle, text: src); |
| } |
| } |
| |
| bool _generateSpans() { |
| int lastLoopPosition = _scanner.position; |
| |
| while (!_scanner.isDone) { |
| // Skip White space |
| _scanner.scan(RegExp(r'\s+')); |
| |
| // Block comments |
| if (_scanner.scan(RegExp(r'/\*(.|\n)*\*/'))) { |
| _spans.add(_HighlightSpan( |
| _HighlightType.comment, |
| _scanner.lastMatch!.start, |
| _scanner.lastMatch!.end, |
| )); |
| continue; |
| } |
| |
| // Line comments |
| if (_scanner.scan('//')) { |
| final int startComment = _scanner.lastMatch!.start; |
| |
| bool eof = false; |
| int endComment; |
| if (_scanner.scan(RegExp(r'.*\n'))) { |
| endComment = _scanner.lastMatch!.end - 1; |
| } else { |
| eof = true; |
| endComment = _src!.length; |
| } |
| |
| _spans.add(_HighlightSpan( |
| _HighlightType.comment, |
| startComment, |
| endComment, |
| )); |
| |
| if (eof) { |
| break; |
| } |
| |
| continue; |
| } |
| |
| // Raw r"String" |
| if (_scanner.scan(RegExp(r'r".*"'))) { |
| _spans.add(_HighlightSpan( |
| _HighlightType.string, |
| _scanner.lastMatch!.start, |
| _scanner.lastMatch!.end, |
| )); |
| continue; |
| } |
| |
| // Raw r'String' |
| if (_scanner.scan(RegExp(r"r'.*'"))) { |
| _spans.add(_HighlightSpan( |
| _HighlightType.string, |
| _scanner.lastMatch!.start, |
| _scanner.lastMatch!.end, |
| )); |
| continue; |
| } |
| |
| // Multiline """String""" |
| if (_scanner.scan(RegExp(r'"""(?:[^"\\]|\\(.|\n))*"""'))) { |
| _spans.add(_HighlightSpan( |
| _HighlightType.string, |
| _scanner.lastMatch!.start, |
| _scanner.lastMatch!.end, |
| )); |
| continue; |
| } |
| |
| // Multiline '''String''' |
| if (_scanner.scan(RegExp(r"'''(?:[^'\\]|\\(.|\n))*'''"))) { |
| _spans.add(_HighlightSpan( |
| _HighlightType.string, |
| _scanner.lastMatch!.start, |
| _scanner.lastMatch!.end, |
| )); |
| continue; |
| } |
| |
| // "String" |
| if (_scanner.scan(RegExp(r'"(?:[^"\\]|\\.)*"'))) { |
| _spans.add(_HighlightSpan( |
| _HighlightType.string, |
| _scanner.lastMatch!.start, |
| _scanner.lastMatch!.end, |
| )); |
| continue; |
| } |
| |
| // 'String' |
| if (_scanner.scan(RegExp(r"'(?:[^'\\]|\\.)*'"))) { |
| _spans.add(_HighlightSpan( |
| _HighlightType.string, |
| _scanner.lastMatch!.start, |
| _scanner.lastMatch!.end, |
| )); |
| continue; |
| } |
| |
| // Double |
| if (_scanner.scan(RegExp(r'\d+\.\d+'))) { |
| _spans.add(_HighlightSpan( |
| _HighlightType.number, |
| _scanner.lastMatch!.start, |
| _scanner.lastMatch!.end, |
| )); |
| continue; |
| } |
| |
| // Integer |
| if (_scanner.scan(RegExp(r'\d+'))) { |
| _spans.add(_HighlightSpan( |
| _HighlightType.number, |
| _scanner.lastMatch!.start, |
| _scanner.lastMatch!.end) |
| ); |
| continue; |
| } |
| |
| // Punctuation |
| if (_scanner.scan(RegExp(r'[\[\]{}().!=<>&\|\?\+\-\*/%\^~;:,]'))) { |
| _spans.add(_HighlightSpan( |
| _HighlightType.punctuation, |
| _scanner.lastMatch!.start, |
| _scanner.lastMatch!.end, |
| )); |
| continue; |
| } |
| |
| // Meta data |
| if (_scanner.scan(RegExp(r'@\w+'))) { |
| _spans.add(_HighlightSpan( |
| _HighlightType.keyword, |
| _scanner.lastMatch!.start, |
| _scanner.lastMatch!.end, |
| )); |
| continue; |
| } |
| |
| // Words |
| if (_scanner.scan(RegExp(r'\w+'))) { |
| _HighlightType? type; |
| |
| String word = _scanner.lastMatch![0]!; |
| if (word.startsWith('_')) { |
| word = word.substring(1); |
| } |
| |
| if (_keywords.contains(word)) { |
| type = _HighlightType.keyword; |
| } else if (_builtInTypes.contains(word)) { |
| type = _HighlightType.keyword; |
| } else if (_firstLetterIsUpperCase(word)) { |
| type = _HighlightType.klass; |
| } else if (word.length >= 2 && word.startsWith('k') && _firstLetterIsUpperCase(word.substring(1))) { |
| type = _HighlightType.constant; |
| } |
| |
| if (type != null) { |
| _spans.add(_HighlightSpan( |
| type, |
| _scanner.lastMatch!.start, |
| _scanner.lastMatch!.end, |
| )); |
| } |
| } |
| |
| // Check if this loop did anything |
| if (lastLoopPosition == _scanner.position) { |
| // Failed to parse this file, abort gracefully |
| return false; |
| } |
| lastLoopPosition = _scanner.position; |
| } |
| |
| _simplify(); |
| return true; |
| } |
| |
| void _simplify() { |
| for (int i = _spans.length - 2; i >= 0; i -= 1) { |
| if (_spans[i].type == _spans[i + 1].type && _spans[i].end == _spans[i + 1].start) { |
| _spans[i] = _HighlightSpan( |
| _spans[i].type, |
| _spans[i].start, |
| _spans[i + 1].end, |
| ); |
| _spans.removeAt(i + 1); |
| } |
| } |
| } |
| |
| bool _firstLetterIsUpperCase(String str) { |
| if (str.isNotEmpty) { |
| final String first = str.substring(0, 1); |
| return first == first.toUpperCase(); |
| } |
| return false; |
| } |
| } |
| |
| enum _HighlightType { |
| number, |
| comment, |
| keyword, |
| string, |
| punctuation, |
| klass, |
| constant |
| } |
| |
| class _HighlightSpan { |
| _HighlightSpan(this.type, this.start, this.end); |
| final _HighlightType type; |
| final int start; |
| final int end; |
| |
| String textForSpan(String src) { |
| return src.substring(start, end); |
| } |
| |
| TextStyle? textStyle(SyntaxHighlighterStyle? style) { |
| if (type == _HighlightType.number) { |
| return style!.numberStyle; |
| } else if (type == _HighlightType.comment) { |
| return style!.commentStyle; |
| } else if (type == _HighlightType.keyword) { |
| return style!.keywordStyle; |
| } else if (type == _HighlightType.string) { |
| return style!.stringStyle; |
| } else if (type == _HighlightType.punctuation) { |
| return style!.punctuationStyle; |
| } else if (type == _HighlightType.klass) { |
| return style!.classStyle; |
| } else if (type == _HighlightType.constant) { |
| return style!.constantStyle; |
| } else { |
| return style!.baseStyle; |
| } |
| } |
| } |
