Feature. Romanisation tool

docs/features/romanize.md

@@ -0,0 +1,30 @@
+# Romanize
+
+Trqnform non-latin letter languages to their roman equivalent
+
+- **Menu:** Tools → Romanize...
+- **Shortcut:** Configurable
+
+<!-- Screenshot: Romanize window -->
+![Romanize](../screenshots/romanize.png)
+
+## How to Use
+
+1. Open **Tools → Romanize...**.
+2. Check the languages which you would like to romanize
+3. Click **OK**.
+
+Subtitle Edit rewrites the text in in latin-letter equivalence. Timing, text, formatting, and comments are not changed.
+
+## Options
+
+- **Merge** — Merges source for single line result
+- **Position** — The position of the romanized text in reference to the original text
+
+## Keyboard Shortcuts
+
+| Key | Action |
+|-----|--------|
+| Enter | Apply |
+| Escape | Close / Cancel |
+| F1 | Open help |

src/libse/Romanize/IRomanizer.cs

@@ -0,0 +1,63 @@
+using System.Collections.Generic;
+using System.Globalization;
+using System.Linq;
+
+namespace Nikse.SubtitleEdit.Core.Romanize
+{
+    public interface IRomanizer
+    {
+        private static readonly JapaneseRomanizer _Japanese = new JapaneseRomanizer();
+        private static readonly KoreanRomanizer _Korean = new KoreanRomanizer();
+        private static readonly RussianRomanizer _Russian = new RussianRomanizer();
+
+        private static IRomanizer GetRomanizerForChar(char ch)
+        {
+            if (_Japanese.IsValid(ch)) return _Japanese;
+            if (_Korean.IsValid(ch)) return _Korean;
+            if (_Russian.IsValid(ch)) return _Russian;
+
+            return null;
+        }
+
+        CultureInfo Culture { get; }
+
+        bool IsValid(char chr);
+        bool IsValid(string text);
+        string Romanize(string text);
+
+        public static string RomanizeText(string text, params CultureInfo[] exclude)
+        {
+            return RomanizeText(text, exclude as IEnumerable<CultureInfo>);
+        }
+        public static string RomanizeText(string text, IEnumerable<CultureInfo> exclude)
+        {
+            if (string.IsNullOrEmpty(text))
+            {
+                return string.Empty;
+            }
+
+            var sb = new System.Text.StringBuilder(text.Length);
+            var i = 0;
+            while (i < text.Length)
+            {
+                var romanizer = GetRomanizerForChar(text[i]);
+                if (romanizer == null || exclude.Contains(romanizer.Culture) is false)
+                {
+                    sb.Append(text[i]);
+                    i++;
+                    continue;
+                }
+
+                var start = i;
+                while (i < text.Length && GetRomanizerForChar(text[i]) == romanizer)
+                {
+                    i++;
+                }
+
+                sb.Append(romanizer.Romanize(text.Substring(start, i - start)));
+            }
+
+            return sb.ToString();
+        }
+    }
+}