[Lazarus] Lazarus support for Sorting is completely inadequate.

[Avishai]

Lazarus support for Sorting is completely inadequate.  You can not
sort a list of strings without knowing the language of the list.  This
should be a simple process. I would like to try to improve this, but I
will need some help from the Lazarus community.

It appears that each Control that has a List has its own separate Sort
routine and each is different.  I would think that there would be a
single Sort routine and could be called by each control.

This could be a starting point that could be expanded to include other
Languages and Sort Methods, but it is only a suggestion.

{===== Sorting =====}

const
  SortAscending: Boolean = True;

function SortHebrew(List: TStringList; Index1, Index2: Integer):
Integer;  {Hebrew}
begin
  Result:= UTF8CompareStr(List[Index1],List[Index2]);
  if not SortAscending then
    Result:= -Result;
end;

function SortPortuguese(List: TStringList; Index1, Index2: Integer):
Integer;  {Portuguese}
begin
  Result:= WideCompareText(UTF8Decode(List[Index1]),UTF8Decode(List[Index2]));
  if not SortAscending then
    Result:= -Result;
end;

{===== Numeric Sort =====}

function DoNumSort(List: TStringList; Index1, Index2: Integer): Integer;
var
  N1, N2: Double;
begin
  N1:= StrToFloatDef(List[Index1],0);
  N2:= StrToFloatDef(List[Index2],0);
  if N1 < N2 then
    result := -1
  else if N1 > N2 then
    result := 1
  else
  result := 0;
  if not SortAscending then
    Result:= -Result;
end;

procedure SortNumeric(Items: TStrings);
var
  Alist: TStringList;
begin
  Alist:= TStringList.Create;
    with Items do begin
      Alist.CommaText:= CommaText;
      Alist.CustomSort(@DoNumSort);
      CommaText:= Alist.commaText;
    end;
  FreeAndNil(Alist);
end;

{ This is the User Sort main routine }
{ Example Call: SortStringList(Memo1.Lines, HebrewSort); }
{ Example Call: SortStringList(ListBox1.Items, HebrewSort); }
{ Example Call: SortStringList(ComboBox1.Items, HebrewSort); }

function SortStringList(AStringList: TStrings; SortStyle: Integer): Integer;
var
  SortList: TStringList;
begin
  SortList:= TStringList.Create;
    SortList.CaseSensitive:= True;
    SortList.Assign(AStringList);
	{ Sort according to Language }
    case SortStyle of
      EnglishSort: SortList.Sort;
      HebrewSort: SortList.CustomSort(@SortHebrew);
      PortugueseSort: SortList.CustomSort(@SortPortuguese);
      NumericSort: SortList.CustomSort(@DoNumSort);
	  { need input from Lazarus community for other Sort Methods }
    end;
    AStringList.Assign(SortList);
  FreeAndNil(SortList);
end;

-- 
Shalom,
Avishai
avishai.gore at gmail.com
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