Add arabic language

WtProgram/ManagerViewService/Views/AppGroupingRulesView.fs

@@ -160,7 +160,7 @@ type GroupingApplicationMenu() as this =
             if index>=0 && index<shown.Length then picked.Trigger(shown.[index])
             elif index=shown.Length then
                 use dialog = new OpenFileDialog(Title=tr Strings.AppRules.application,
-                                               Filter=tr Strings.AppRules.applicationFiles,CheckFileExists=true)
+                                               Filter=Localization.plain Strings.AppRules.applicationFiles,CheckFileExists=true)
                 if dialog.ShowDialog(owner)=DialogResult.OK then picked.Trigger(dialog.FileName))
         choice <- Some next
         dropDown <- next.CreateDropDown() |> Option.map(fun window ->
@@ -449,7 +449,7 @@ type AppGroupingRulesView() as this =
                 tree.Focus() |> ignore)
         addGroup.Click.Add(fun _ ->
             // Short and numbered from the start: Group 1, Group 2, the first number not taken.
-            let named number = tr (Strings.AppRules.newGroup number)
+            let named number = Localization.plain (Strings.AppRules.newGroup number)
             let taken number = groups |> List.exists(fun group -> String.Equals(group.name,named number,StringComparison.OrdinalIgnoreCase))
             let target = Seq.initInfinite ((+) 1) |> Seq.find(taken >> not) |> named
             let group : AppGroupingTarget = {id=Guid.NewGuid().ToString("N");name=target}

WtProgram/Shared/Localization.fs

@@ -3,13 +3,13 @@ open System.Globalization
 
 /// One piece of user-visible text in every supported language. Every field is required, so a
 /// missing translation is a compile error. All instances live in Strings.
-type LocalizedText = { en:string; zh:string; ja:string }
+type LocalizedText = { en:string; zh:string; ja:string; ar:string }
 
 /// All user-visible text is compiled into the single WindowTabs.exe. (Satellite resource
 /// assemblies cannot be statically linked, so a .resx translation would not ship.)
 module Localization =
     /// Supported languages: code, name shown in the language menu, compact label.
-    let languages = [| "en","English","EN"; "zh","中文","中"; "ja","日本語","日" |]
+    let languages = [| "en","English","EN"; "zh","中文","中"; "ja","日本語","日"; "ar","العربية","ع" |]
     /// Values of the language setting: "system" follows the Windows display language.
     let preferences = "system" :: [for code,_,_ in languages -> code]
     let mutable private preference = "system"
@@ -18,13 +18,21 @@ module Localization =
     let current() =
         let code = if preference="system" then CultureInfo.CurrentUICulture.TwoLetterISOLanguageName else preference
         if languages |> Array.exists (fun (c,_,_) -> c=code) then code else "en"
-    let tr (text:LocalizedText) =
+    /// The text in the current language as written, for values that are parsed or saved.
+    let plain (text:LocalizedText) =
         match current() with
         | "zh" -> text.zh
         | "ja" -> text.ja
+        | "ar" -> text.ar
         | _ -> text.en
+    /// GDI and the standard controls read text left to right unless told otherwise, which puts the
+    /// words of an Arabic sentence around a Latin word, and its final full stop, in the wrong order.
+    /// A right-to-left embedding keeps each text in reading order without mirroring the layout.
+    let tr (text:LocalizedText) =
+        let value = plain text
+        if current()="ar" && value<>"" then "\u202B"+value+"\u202C" else value
     /// Every translation of a text, for search.
-    let all (text:LocalizedText) = [text.en; text.zh; text.ja]
+    let all (text:LocalizedText) = [text.en; text.zh; text.ja; text.ar]
 
 [<AutoOpen>]
 module LocalizationOperators =