Revise handling of file extensions in save dialogues

This commit applies to the custom file save dialogues used when saving
units or annotated source code files.

The code to detect file types and to look up filter indexes depended on
file extensions being different for each file type, which cannot be
guaranteed.

Relevant code was updated to remove this dependency.

NOTE: This change was made because HTML 5 documents, when added, will
use the same .html file extension and XTHML documents.

Author: delphidabbler

Src/UOpenDialogHelper.pas

@@ -44,18 +44,20 @@ function FilterIndexToExt(const Dlg: TOpenDialog): string;
       prepended '.'.
   }
 
-function ExtToFilterIndex(const FilterStr, Ext: string;
-  const DefValue: Integer): Integer;
-  {Calculates index of a file extension in a "|" delimited file filter string as
-  used in standard file dialog boxes.
-    @param FilterStr [in] List of file types and extensions. Has format
-      "file desc 1|ext 1|file desc 2|ext 2 etc...".
-    @param Ext [in] Extension to be found.
-    @param DefValue [in] Default 1 based index to use if Ext is not in
-      FilterStr.
-    @return 1 based index of extension in filter string or -1 if extension not
-      in list.
-  }
+///  <summary>Calculates the index of a file type description in a &quot;|&quot;
+///  delimited string, as used in Windows standard file dialogue boxes.
+///  </summary>
+///  <param name="FilterStr"><c>string</c> [in] List of file types and
+///  extensions. Must have format
+///  <c>file desc 1|(*.ext1)|file desc 2|(*.ext2)</c> etc...</param>
+///  <param name="Desc"><c>string</c> [in] File type description to be found.
+///  </param>
+///  <param name="DefIdx"><c>Integer</c> [in] Default 1 based index to use if
+///  <c>Desc</c> is not in <c>FilterStr</c>.</param>
+///  <returns><c>Integer</c>. 1 based index of the file type description in the
+///  filter string, or <c>DefIdx</c> if the description is not found.</returns>
+function FilterDescToIndex(const FilterStr, Desc: string;
+  const DefIdx: Integer): Integer;
 
 function FileOpenEditedFileNameWithExt(const Dlg: TOpenDialog): string;
   {Gets full path to the file that is currently entered in a file open dialog
@@ -96,47 +98,42 @@ function FilterIndexToExt(const Dlg: TOpenDialog): string;
   end;
 end;
 
-function ExtToFilterIndex(const FilterStr, Ext: string;
-  const DefValue: Integer): Integer;
-  {Calculates index of a file extension in a "|" delimited file filter string as
-  used in standard file dialog boxes.
-    @param FilterStr [in] List of file types and extensions. Has format
-      "file desc 1|ext 1|file desc 2|ext 2 etc...".
-    @param Ext [in] Extension to be found.
-    @param DefValue [in] Default 1 based index to use if Ext is not in
-      FilterStr.
-    @return 1 based index of extension in filter string or -1 if extension not
-      in list.
-  }
+function FilterDescToIndex(const FilterStr, Desc: string;
+  const DefIdx: Integer): Integer;
 var
   FilterParts: TStringList; // stores filter split into component parts
-  Extensions: TStringList;  // list of extensions in filter string
-  Idx: Integer;             // loops thru extensions in filter string
+  Descs: TStringList;       // list of file type descriptions in filter string
+  Idx: Integer;             // loops thru Descs in filter string
+  DescStr: string;
+  DescEnd: Integer;
 begin
-  Extensions := nil;
+  Descs := nil;
   FilterParts := TStringList.Create;
   try
     // Split filter string into parts (divided by | chars):
-    // even number indexes are descriptions and odd indexes are extensions
+    // even number indexes are descriptions and odd indexes are Descs
     StrExplode(FilterStr, '|', FilterParts);
-    // Record only extensions (every 2nd entry starting at index 1)
-    Extensions := TStringList.Create;
-    Idx := 1;
+    // Record only Descs (every 2nd entry starting at index 1)
+    Descs := TStringList.Create;
+    Idx := 0;
     while Idx < FilterParts.Count do
     begin
-      Extensions.Add(ExtractFileExt(FilterParts[Idx]));
+      DescStr := FilterParts[Idx];
+      DescEnd := StrPos('(', DescStr) - 2;
+      DescStr := Copy(DescStr, 1, DescEnd);
+      Descs.Add(DescStr);
       Inc(Idx, 2);
     end;
     // Check if required extension in list
-    Result := Extensions.IndexOf(Ext);
+    Result := Descs.IndexOf(Desc);
     if Result >= 0 then
-      // extension in list, increment by 1 since filter indexes are 1 based
+      // description in list, increment by 1 since filter indexes are 1 based
       Inc(Result)
     else
-      Result := DefValue;
+      Result := DefIdx;
   finally
-    FreeAndNil(Extensions);
-    FreeAndNil(FilterParts);
+    Descs.Free;
+    FilterParts.Free;
   end;
 end;
 

Src/USaveSourceDlg.pas

@@ -38,11 +38,11 @@ interface
   ///  <summary>Type of handler for event triggered by TSaveSourceDlg to get
   ///  list of encodings supported for a file type.</summary>
   ///  <param name="Sender">TObject [in] Object triggering event.</param>
-  ///  <param name="Ext">string [in] Extension that defines type of file being
-  ///  queried.</param>
+  ///  <param name="FilterIdx">string [in] Filter index that specifies the type
+  ///  of file being queried.</param>
   ///  <param name="Encodings">TSourceFileEncodings [in/out] Assigned an array
   ///  of records that specify supported encodings.</param>
-  TEncodingQuery = procedure(Sender: TObject; const Ext: string;
+  TEncodingQuery = procedure(Sender: TObject; const FilterIdx: Integer;
     var Encodings: TSourceFileEncodings) of object;
 
 type
@@ -475,7 +475,7 @@ procedure TSaveSourceDlg.DoTypeChange;
   // handle OnEncodingQuery)
   SetLength(Encodings, 0);
   if Assigned(fOnEncodingQuery) then
-    fOnEncodingQuery(Self, SelectedExt, Encodings);
+    fOnEncodingQuery(Self, FilterIndex, Encodings);
   if Length(Encodings) = 0 then
     Encodings := TSourceFileEncodings.Create(
       TSourceFileEncoding.Create(etSysDefault, sANSIEncoding)

Src/USaveSourceMgr.pas

@@ -49,10 +49,11 @@   TSaveSourceMgr = class abstract(TNoPublicConstructObject)
     ///  Provides array of encodings supported for a file extension.</summary>
     ///  <param name="Sender">TObject [in] Reference to object that triggered
     ///  event.</param>
-    ///  <param name="Ext">string [in] Name of extension to check.</param>
+    ///  <param name="FilterIdx">string [in] Index of file type withing dialog's
+    ///  filter string to check.</param>
     ///  <param name="Encodings">TSourceFileEncodings [in/out] Receives array of
     ///  supported encodings.</param>
-    procedure EncodingQueryHandler(Sender: TObject; const Ext: string;
+    procedure EncodingQueryHandler(Sender: TObject; const FilterIdx: Integer;
       var Encodings: TSourceFileEncodings);
     ///  <summary>Handles custom save dialog's OnPreview event. Displays source
     ///  code appropriately formatted in preview dialog box.</summary>
@@ -81,6 +82,12 @@   TSaveSourceMgr = class abstract(TNoPublicConstructObject)
     ///  <returns>TEncodedData - Formatted source code, syntax highlighted if
     ///  required.</returns>
     function GenerateOutput(const FileType: TSourceFileType): TEncodedData;
+    ///  <summary>Returns the source file type associated with the selected
+    ///  index in the save dialogue box.</summary>
+    ///  <remarks>This method assumes that the filter string entries are in the
+    ///  same order as elements of the <c>TSourceFileType</c> enumeration.
+    ///  </remarks>
+    function FileTypeFromFilterIdx: TSourceFileType;
   strict protected
     ///  <summary>Internal constructor. Initialises managed save source dialog
     ///  box and records information about supported file types.</summary>
@@ -178,18 +185,16 @@ procedure TSaveSourceMgr.DoExecute;
 begin
   // Set up dialog box
   fSaveDlg.Filter := fSourceFileInfo.FilterString;
-  fSaveDlg.FilterIndex := ExtToFilterIndex(
+  fSaveDlg.FilterIndex := FilterDescToIndex(
     fSaveDlg.Filter,
-    fSourceFileInfo.FileTypeInfo[Preferences.SourceDefaultFileType].Extension,
+    fSourceFileInfo.FileTypeInfo[Preferences.SourceDefaultFileType].DisplayName,
     1
   );
   fSaveDlg.FileName := fSourceFileInfo.DefaultFileName;
   // Display dialog box and save file if user OKs
   if fSaveDlg.Execute then
   begin
-    FileType := fSourceFileInfo.FileTypeFromExt(
-      ExtractFileExt(fSaveDlg.FileName)
-    );
+    FileType := FileTypeFromFilterIdx;
     FileContent := GenerateOutput(FileType).ToString;
     Encoding := TEncodingHelper.GetEncoding(fSaveDlg.SelectedEncoding);
     try
@@ -201,14 +206,27 @@ procedure TSaveSourceMgr.DoExecute;
 end;
 
 procedure TSaveSourceMgr.EncodingQueryHandler(Sender: TObject;
-  const Ext: string; var Encodings: TSourceFileEncodings);
+  const FilterIdx: Integer; var Encodings: TSourceFileEncodings);
 var
   FileType: TSourceFileType;  // type of file that has given extension
 begin
-  FileType := fSourceFileInfo.FileTypeFromExt(Ext);
+  FileType := FileTypeFromFilterIdx;
   Encodings := fSourceFileInfo.FileTypeInfo[FileType].Encodings;
 end;
 
+function TSaveSourceMgr.FileTypeFromFilterIdx: TSourceFileType;
+var
+  FilterIdx: Integer; // dlg FilterIndex adjusted to be 0 based
+begin
+  FilterIdx := fSaveDlg.FilterIndex - 1;
+  Assert(
+    (FilterIdx >= Ord(Low(TSourceFileType)))
+      and (FilterIdx <= Ord(High(TSourceFileType))),
+    ClassName + '.FileTypeFromFilterIdx: FilerIdx out of range'
+  );
+  Result := TSourceFileType(FilterIdx)
+end;
+
 function TSaveSourceMgr.GenerateOutput(const FileType: TSourceFileType):
   TEncodedData;
 var
@@ -231,7 +249,7 @@ function TSaveSourceMgr.GenerateOutput(const FileType: TSourceFileType):
 procedure TSaveSourceMgr.HiliteQueryHandler(Sender: TObject; const Ext: string;
   var CanHilite: Boolean);
 begin
-  CanHilite := IsHilitingSupported(fSourceFileInfo.FileTypeFromExt(Ext));
+  CanHilite := IsHilitingSupported(FileTypeFromFilterIdx);
 end;
 
 constructor TSaveSourceMgr.InternalCreate;
@@ -262,6 +280,13 @@ constructor TSaveSourceMgr.InternalCreate;
       TSourceFileEncoding.Create(etUTF8, sUTF8Encoding)
     ]
   );
+  fSourceFileInfo.FileTypeInfo[sfHTML5] := TSourceFileTypeInfo.Create(
+    '.html',
+    GetFileTypeDesc(sfHTML5),
+    [
+      TSourceFileEncoding.Create(etUTF8, sUTF8Encoding)
+    ]
+  );
   fSourceFileInfo.FileTypeInfo[sfXHTML] := TSourceFileTypeInfo.Create(
     '.html',
     GetFileTypeDesc(sfXHTML),
@@ -305,7 +330,7 @@ procedure TSaveSourceMgr.PreviewHandler(Sender: TObject);
 var
   FileType: TSourceFileType;  // type of source file to preview
 begin
-  FileType := fSourceFileInfo.FileTypeFromExt(fSaveDlg.SelectedExt);
+  FileType := FileTypeFromFilterIdx;
   // Display preview dialog box. We use save dialog as owner to ensure preview
   // dialog box is aligned over save dialog box
   TPreviewDlg.Execute(

Src/USourceFileInfo.pas

@@ -105,9 +105,6 @@   TSourceFileInfo = class(TObject)
     ///  <summary>Builds filter string for use in open / save dialog boxes from
     ///  descriptions and file extensions of each supported file type.</summary>
     function FilterString: string;
-    ///  <summary>Finds source file type associated with a file extension.
-    ///  </summary>
-    function FileTypeFromExt(const Ext: string): TSourceFileType;
     ///  <summary>Array of information about each supported file type that is
     ///  of use to save source dialog boxes.</summary>
     property FileTypeInfo[const FileType: TSourceFileType]: TSourceFileTypeInfo
@@ -132,22 +129,6 @@ implementation
 
 { TSourceFileInfo }
 
-function TSourceFileInfo.FileTypeFromExt(const Ext: string): TSourceFileType;
-var
-  FT: TSourceFileType;  // loops thru all source file types
-begin
-  // Assume text file type if extension not recognised
-  Result := sfText;
-  for FT := Low(TSourceFileType) to High(TSourceFileType) do
-  begin
-    if StrSameText(Ext, fFileTypeInfo[FT].Extension) then
-    begin
-      Result := FT;
-      Break;
-    end;
-  end;
-end;
-
 function TSourceFileInfo.FilterString: string;
 const
   cFilterFmt = '%0:s (*%1:s)|*%1:s';  // format string for creating file filter