using System; using System.Globalization; using System.Text; namespace Nikse.SubtitleEdit.Core { public static class StringExtensions { public static bool LineStartsWithHtmlTag(this string text, bool threeLengthTag, bool includeFont = false) { if (text == null || (!threeLengthTag && !includeFont)) return false; return StartsWithHtmlTag(text, threeLengthTag, includeFont); } public static bool LineEndsWithHtmlTag(this string text, bool threeLengthTag, bool includeFont = false) { if (text == null) return false; var len = text.Length; if (len < 6 || text[len - 1] != '>') return false; // if (threeLengthTag && len > 3 && text[len - 4] == '<' && text[len - 3] == '/') return true; if (includeFont && len > 8 && text[len - 7] == '<' && text[len - 6] == '/') return true; return false; } public static bool LineBreakStartsWithHtmlTag(this string text, bool threeLengthTag, bool includeFont = false) { if (text == null || (!threeLengthTag && !includeFont)) return false; var newLineIdx = text.IndexOf(Environment.NewLine, StringComparison.Ordinal); if (newLineIdx < 0 || text.Length < newLineIdx + 5) return false; text = text.Substring(newLineIdx + 2); return StartsWithHtmlTag(text, threeLengthTag, includeFont); } private static bool StartsWithHtmlTag(string text, bool threeLengthTag, bool includeFont) { if (threeLengthTag && text.Length >= 3 && text[0] == '<' && text[2] == '>' && (text[1] == 'i' || text[1] == 'I' || text[1] == 'u' || text[1] == 'U' || text[1] == 'b' || text[1] == 'B')) return true; if (includeFont && text.Length > 5 && text.StartsWith("', 5) >= 5; // or return false; } public static bool StartsWith(this string s, char c) { return s.Length > 0 && s[0] == c; } public static bool StartsWith(this StringBuilder sb, char c) { return sb.Length > 0 && sb[0] == c; } public static bool EndsWith(this string s, char c) { return s.Length > 0 && s[s.Length - 1] == c; } public static bool EndsWith(this StringBuilder sb, char c) { return sb.Length > 0 && sb[sb.Length - 1] == c; } public static bool Contains(this string source, char value) { return source.IndexOf(value) >= 0; } public static bool Contains(this string source, char[] value) { return source.IndexOfAny(value) >= 0; } public static bool Contains(this string source, string value, StringComparison comparisonType) { return source.IndexOf(value, comparisonType) >= 0; } public static string[] SplitToLines(this string source) { return source.Replace("\r\n", "\n").Replace('\r', '\n').Replace('\u2028', '\n').Split('\n'); } // http://www.codeproject.com/Articles/43726/Optimizing-string-operations-in-C public static int FastIndexOf(this string source, string pattern) { if (pattern == null) throw new ArgumentNullException(); if (pattern.Length == 0) return 0; if (pattern.Length == 1) return source.IndexOf(pattern[0]); int limit = source.Length - pattern.Length + 1; if (limit < 1) return -1; // Store the first 2 characters of "pattern" char c0 = pattern[0]; char c1 = pattern[1]; // Find the first occurrence of the first character int first = source.IndexOf(c0, 0, limit); while (first != -1) { // Check if the following character is the same like // the 2nd character of "pattern" if (source[first + 1] != c1) { first = source.IndexOf(c0, ++first, limit - first); continue; } // Check the rest of "pattern" (starting with the 3rd character) bool found = true; for (var j = 2; j < pattern.Length; j++) if (source[first + j] != pattern[j]) { found = false; break; } // If the whole word was found, return its index, otherwise try again if (found) return first; first = source.IndexOf(c0, ++first, limit - first); } return -1; } public static int IndexOfAny(this string s, string[] words, StringComparison comparionType) { if (words == null || string.IsNullOrEmpty(s)) return -1; for (int i = 0; i < words.Length; i++) { var idx = s.IndexOf(words[i], comparionType); if (idx >= 0) return idx; } return -1; } public static string FixExtraSpaces(this string s) { if (string.IsNullOrEmpty(s)) return s; while (s.Contains(" ")) s = s.Replace(" ", " "); s = s.Replace(" " + Environment.NewLine, Environment.NewLine); return s.Replace(Environment.NewLine + " ", Environment.NewLine); } public static bool ContainsLetter(this string s) { if (string.IsNullOrWhiteSpace(s)) return false; foreach (var c in s) { if (char.IsLetter(c)) return true; } return false; } public static string RemoveControlCharacters(this string s) { var sb = new StringBuilder(s.Length); foreach (var ch in s) { if (!Char.IsControl(ch)) sb.Append(ch); } return sb.ToString(); } public static string RemoveControlCharactersButWhiteSpace(this string s) { var sb = new StringBuilder(s.Length); foreach (var ch in s) { if (!Char.IsControl(ch) || ch == '\u000d' || ch == '\u000a' || ch == '\u0009') sb.Append(ch); } return sb.ToString(); } public static string CapitalizeFirstLetter(this string s, CultureInfo ci = null) { var si = new StringInfo(s); if (ci == null) ci = CultureInfo.CurrentCulture; if (si.LengthInTextElements > 0) s = si.SubstringByTextElements(0, 1).ToUpper(ci); if (si.LengthInTextElements > 1) s += si.SubstringByTextElements(1); return s; } } }