add language selection page in installer

CHANGELOG

@@ -4,7 +4,8 @@
     for WinXP+ (all) and Vista+ 64-bit respectively,
     reducing the sizes of installers significantly
     while adding the SarasaGothicFixed TTF font and
-    existing language translations. (Wengier)
+    a language selection page for choosing existing
+    language translations. (Wengier)
   - DOSBox-X will now search for more paths (such as
     user config directory and "languages" subfolder)
     for loading language files before fail. (Wengier)

contrib/windows/installer/DOSBox-X-setup.iss

@@ -1,4 +1,4 @@
-#define MyAppName "DOSBox-X"
+#define MyAppName "DOSBox-X"
 #define MyAppVersion "0.83.16"
 #define MyAppBit "(32-bit)"
 #define MyAppPublisher "joncampbell123 [DOSBox-X Team]"
@@ -174,7 +174,7 @@ var
   msg: string;
   build64: Boolean;    
   HelpButton: TNewButton;
-  PageBuild, PageOutput, PageVer: TInputOptionWizardPage;
+  PageBuild, PageLang, PageOutput, PageVer: TInputOptionWizardPage;
 function IsVerySilent(): Boolean;
 var
   k: Integer;
@@ -251,8 +251,16 @@ begin
     PageOutput.Add('OpenGL with pixel-perfect scaling');
     PageOutput.Add('TrueType font (TTF) / Direct3D output');
     PageOutput.Values[2] := True;
+    msg:='DOSBox-X supports language files to display messages in different languages.' #13#13 'By default the user interface is English, but you may want to select a different language for its user interface.' #13#13 'This setting can be later modified in the DOSBox-X''s configuration file (dosbox-x.conf).';
+    PageLang:=CreateInputOptionPage(101, 'User interface language', 'Select the language for DOSBox-X''s user interface', msg, True, False);
+    PageLang.Add('Default (English)');
+    PageLang.Add('Japanese (日本語)');
+    PageLang.Add('Simplified Chinese (简体中文)');
+    PageLang.Add('Spanish (Español)');
+    PageLang.Add('Traditional Chinese (繁體/正體中文)');
+    PageLang.Values[0] := True;
     msg:='You can specify a default DOS version for DOSBox-X to report to itself and DOS programs. This can sometimes change the feature sets of DOSBox-X. For example, selecting 7.10 as the reported DOS version will enable support for Windows-style long filenames (LFN) and FAT32 disk images (>2GB disk images) by default.' #13#13 'If you are not sure about which DOS version to report, you can also leave this unselected, then a preset DOS version will be reported (usually 5.00).' #13#13 'This setting can be later modified in the DOSBox-X''s configuration file (dosbox-x.conf).';
-    PageVer:=CreateInputOptionPage(101, 'Reported DOS version', 'Specify the default DOS version to report', msg, True, False);
+    PageVer:=CreateInputOptionPage(102, 'Reported DOS version', 'Specify the default DOS version to report', msg, True, False);
     PageVer.Add('DOS version 3.30');
     PageVer.Add('DOS version 5.00 (reported by default)');
     PageVer.Add('DOS version 6.22');
@@ -260,7 +268,7 @@ begin
 end;
 function ShouldSkipPage(PageID: Integer): Boolean;
 begin
-  Result := ((PageID = 101) or (PageID = 102)) and FileExists(ExpandConstant('{app}\dosbox-x.conf'));
+  Result := ((PageID = 101) or (PageID = 102) or (PageID = 103)) and FileExists(ExpandConstant('{app}\dosbox-x.conf')) or ((PageID = 102) and not PageOutput.Values[2]);
 end;
 procedure CurPageChanged(CurPageID: Integer);
 begin
@@ -319,6 +327,21 @@ begin
           msg:='TrueType font (TTF) / Direct3D output';
         Wizardform.ReadyMemo.Lines.Add('      '+msg);
       end;
+      if PageLang.Values[0] or PageLang.Values[1] or PageLang.Values[2] or PageLang.Values[3] or PageLang.Values[4] then
+      begin
+        Wizardform.ReadyMemo.Lines.Add('');
+        Wizardform.ReadyMemo.Lines.Add('User interface language:');
+        msg:='Default (English)';
+        if (PageLang.Values[1]) then
+          msg:='Japanese (日本語)';
+        if (PageLang.Values[2]) then
+          msg:='Simplified Chinese (简体中文)';
+        if (PageLang.Values[3]) then
+          msg:='Spanish (Español)';
+        if (PageLang.Values[4]) then
+          msg:='Traditional Chinese (繁體/正體中文)';
+        Wizardform.ReadyMemo.Lines.Add('      '+msg);
+      end;
       if PageVer.Values[0] or PageVer.Values[1] or PageVer.Values[2] or PageVer.Values[3] then
       begin
         Wizardform.ReadyMemo.Lines.Add('');
@@ -416,6 +439,48 @@ begin
         end;
         FileLines.SaveToFile(ExpandConstant('{app}\dosbox-x.conf'));
       end;
+      if FileExists(ExpandConstant('{app}\dosbox-x.conf')) and (PageLang.Values[1] or PageLang.Values[2] or PageLang.Values[3] or PageLang.Values[4]) then
+      begin
+        FileLines := TStringList.Create;
+        FileLines.LoadFromFile(ExpandConstant('{app}\dosbox-x.conf'));
+        section := '';
+        for i := 0 to FileLines.Count - 1 do
+        begin
+          line := Trim(FileLines[i]);
+          if (Length(line)>2) and (Copy(line, 1, 1) = '[') and (Copy(line, Length(line), 1) = ']') then
+            section := Copy(line, 2, Length(line)-2);
+          if (Length(line)>0) and (Copy(line, 1, 1) <> '#') and (Copy(line, 1, 1) <> '[') and (Pos('=', line) > 1) then
+          begin
+            linetmp := Trim(Copy(line, 1, Pos('=', line) - 1));
+            if (CompareText(linetmp, 'language') = 0) and (CompareText(section, 'dosbox') = 0) then
+            begin
+              linetmp := Trim(Copy(line, 1, Pos('=', line)));
+              if (PageLang.Values[1]) and FileExists(ExpandConstant('{app}\languages\ja_JP.lng')) then
+                FileLines[i] := linetmp+' ja_JP';
+              if (PageLang.Values[2]) and FileExists(ExpandConstant('{app}\languages\zh_CN.lng')) then
+                FileLines[i] := linetmp+' zh_CN';
+              if (PageLang.Values[3]) and FileExists(ExpandConstant('{app}\languages\es_ES.lng')) then
+                FileLines[i] := linetmp+' es_ES';
+              if (PageLang.Values[4]) and FileExists(ExpandConstant('{app}\languages\zh_TW.lng')) then
+                FileLines[i] := linetmp+' zh_TW';
+            end;
+            if (CompareText(linetmp, 'country') = 0) and (CompareText(section, 'config') = 0) then
+            begin
+              linetmp := Trim(Copy(line, 1, Pos('=', line)));
+              if (PageLang.Values[1]) then
+                FileLines[i] := linetmp+' 81,932';
+              if (PageLang.Values[2]) then
+                FileLines[i] := linetmp+' 86,936';
+              if (PageLang.Values[3]) then
+                FileLines[i] := linetmp+' 34,858';
+              if (PageLang.Values[4]) then
+                FileLines[i] := linetmp+' 886,950';
+              break;
+            end
+          end
+        end;
+        FileLines.SaveToFile(ExpandConstant('{app}\dosbox-x.conf'));
+      end;
       if FileExists(ExpandConstant('{app}\dosbox-x.conf')) and (PageVer.Values[0] or PageVer.Values[1] or PageVer.Values[2] or PageVer.Values[3]) then
       begin
         FileLines := TStringList.Create;