Change default filename in Save Snippet Info dlg

The default file name was always "SnippetInfo", which could lead to
accidental overwrites of previously save information. The default was
changed to be a name based on the snippet display name.

Modified TSourceFileInfo with new property to prevent default file names
from being converted as necessary to make them safe Pascal identifiers:
we don't want this to happen in the Save Snippet Information dialogue.

Author: delphidabbler

Src/USaveInfoMgr.pas

@@ -273,7 +273,6 @@ constructor TSaveInfoMgr.InternalCreate(AView: IView);
 const
   DlgHelpKeyword = 'SnippetInfoFileDlg';
 resourcestring
-  sDefFileName = 'SnippetInfo';
   // descriptions of supported file filter strings
   sRTFDesc = 'Rich text file';
   sTextDesc = 'Plain text file';
@@ -301,19 +300,20 @@ constructor TSaveInfoMgr.InternalCreate(AView: IView);
     sHTML5Desc,
     [etUTF8]
   );
-  fSourceFileInfo.DefaultFileName := sDefFileName;
   fSourceFileInfo.FileTypeInfo[sfXHTML] := TSourceFileTypeInfo.Create(
     '.html',
     sXHTMLDesc,
     [etUTF8]
   );
-  fSourceFileInfo.DefaultFileName := sDefFileName;
   fSourceFileInfo.FileTypeInfo[sfMarkdown] := TSourceFileTypeInfo.Create(
     '.md',
     sMarkdownDesc,
     [etUTF8, etUTF16LE, etUTF16BE, etSysDefault]
   );
-  fSourceFileInfo.DefaultFileName := sDefFileName;
+
+  // set default file name without converting to valid Pascal identifier
+  fSourceFileInfo.RequirePascalDefFileName := False;
+  fSourceFileInfo.DefaultFileName := fView.Description;
 
   fSaveDlg := TSaveSourceDlg.Create(nil);
   fSaveDlg.HelpKeyword := DlgHelpKeyword;

Src/USourceFileInfo.pas

@@ -103,6 +103,8 @@   TSourceFileInfo = class(TObject)
       fFilterIdxToFileTypeMap: TDictionary<Integer,TSourceFileType>;
       ///  <summary>Value of DefaultFileName property.</summary>
       fDefaultFileName: string;
+      ///  <summary>Value of <c>RequirePascalDefFileName</c> property.</summary>
+      fRequirePascalDefFileName: Boolean;
       ///  <summary>Filter string for use in open / save dialog boxes from
       ///  descriptions and file extensions of each supported file type.
       ///  </summary>
@@ -153,10 +155,18 @@   TSourceFileInfo = class(TObject)
       read GetFileTypeInfo write SetFileTypeInfo;
 
     ///  <summary>Default source code file name.</summary>
-    ///  <remarks>Must be a valid Pascal identifier. Invalid characters are
-    ///  replaced by underscores.</remarks>
+    ///  <remarks>If, and only if, <c>RequirePascalDefFileName</c> is
+    ///  <c>True</c> the default file name is modified so that name is a valid
+    ///  Pascal identifier.</remarks>
     property DefaultFileName: string
       read fDefaultFileName write SetDefaultFileName;
+
+    ///  <summary>Determines whether any value assigned to
+    ///  <c>DefaultFileName</c> is converted to a valid Pascal identifier or
+    ///  not.</summary>
+    property RequirePascalDefFileName: Boolean
+      read fRequirePascalDefFileName write fRequirePascalDefFileName
+      default True;
   end;
 
 
@@ -178,6 +188,7 @@ constructor TSourceFileInfo.Create;
   inherited Create;
   fFileTypeInfo := TDictionary<TSourceFileType,TSourceFileTypeInfo>.Create;
   fFilterIdxToFileTypeMap := TDictionary<Integer,TSourceFileType>.Create;
+  fRequirePascalDefFileName := True;
 end;
 
 destructor TSourceFileInfo.Destroy;
@@ -232,19 +243,24 @@ procedure TSourceFileInfo.SetDefaultFileName(const Value: string);
 var
   Idx: Integer; // loops through characters of filename
 begin
-  // convert to "camel" case
-  fDefaultFileName := StrStripWhiteSpace(StrCapitaliseWords(Value));
-  // replaces invalid Pascal identifier characters with underscore
-  if (fDefaultFileName <> '')
-    and not TCharacter.IsLetter(fDefaultFileName[1])
-    and (fDefaultFileName[1] <> '_') then
-    fDefaultFileName[1] := '_';
-  for Idx := 2 to Length(fDefaultFileName) do
-    if not TCharacter.IsLetterOrDigit(fDefaultFileName[Idx])
-      and (fDefaultFileName[Idx] <> '_') then
-      fDefaultFileName[Idx] := '_';
-  Assert((fDefaultFileName <> '') and IsValidIdent(fDefaultFileName),
-    ClassName + '.SetFileName: Not a valid identifier');
+  if fRequirePascalDefFileName then
+  begin
+    // convert to "camel" case
+    fDefaultFileName := StrStripWhiteSpace(StrCapitaliseWords(Value));
+    // replaces invalid Pascal identifier characters with underscore
+    if (fDefaultFileName <> '')
+      and not TCharacter.IsLetter(fDefaultFileName[1])
+      and (fDefaultFileName[1] <> '_') then
+      fDefaultFileName[1] := '_';
+    for Idx := 2 to Length(fDefaultFileName) do
+      if not TCharacter.IsLetterOrDigit(fDefaultFileName[Idx])
+        and (fDefaultFileName[Idx] <> '_') then
+        fDefaultFileName[Idx] := '_';
+    Assert((fDefaultFileName <> '') and IsValidIdent(fDefaultFileName),
+      ClassName + '.SetFileName: Not a valid identifier');
+  end
+  else
+    fDefaultFileName := Value;
 end;
 
 procedure TSourceFileInfo.SetFileTypeInfo(const FileType: TSourceFileType;