utils/uutlEnumHelper.pas

unit uutlEnumHelper;

(*  Package:      Utils
    Prefix:       utl - UTiLs
    Beschreibung: diese Unit stellt einen Mechanismus zur Verfügung, ohne viel Aufwand,
                  Helper Klassen für Enums zu implementieren
    Verwendung:
      {$MACRO ON}

      interface
        {$define __ENUM_INTERFACE}
        {$define __ENUM_HELPER:=TSomeEnumH}{$define __ENUM_TYPE:=TSomeEnum}{$define __ENUM_LENGTH:=4}
        {$I uutlEnumHelper.inc}(
          E: (enVal1, enVal2, enVal3, enVal4);
          N: 'enVal1,enVal2,enVal3,enVal4';
        ); end;
        //... mehr davon
        {$undef __ENUM_INTERFACE}

      implementation
        {$define __ENUM_IMPLEMENTATION}
        {$define __ENUM_HELPER:=TSomeEnumH}{$define __ENUM_TYPE:=TSomeEnum}{$I uutlEnumHelper.inc}
        {$undef __ENUM_IMPLEMENTATION}   *)

interface

uses
  SysUtils, StrUtils;

type
  EConvertErrorAlias = SysUtils.EConvertError;

function LookupString(const aStr, aTable: String; out found: integer): boolean;
function PickString(const aTable: String; const aIndex: integer): string;
function LookupVal(const aVal: Pointer; const aPtr: Pointer; const aStep, aCount: PtrInt; out found: integer): boolean;

implementation

function LookupString(const aStr, aTable: String; out found: integer): boolean;
var
  tbl: string;
  i,p,k: integer;
  t: string;
begin
  Result:= false;
  tbl:= aTable + ',';
  t:= '';
  k:= 0;
  i:= 1;
  while i < Length(tbl) do begin
    p:= PosEx(',',tbl,i);
    t:= Trim(Copy(tbl, i, p-i));
    i:= p+1;
    if CompareText(t, aStr)=0 then begin
      found:= k;
      Result:= true;
      exit;
    end else
      inc(k);
  end;
end;

function PickString(const aTable: String; const aIndex: integer): string;
var
  tbl: String;
  k,i,p: integer;
begin
  result:= '';
  tbl:= aTable + ',';
  i:= 1;
  k:= aIndex;
  while (k>0) and (i>0) do begin
    i:= PosEx(',',tbl, i) + 1;
    dec(k);
  end;
  p:= PosEx(',',tbl, i);
  if p<=0 then
    Result:= ''
  else
    Result:= Trim(Copy(tbl, i, p-i));
end;


function LookupVal(const aVal: Pointer; const aPtr: Pointer; const aStep, aCount: PtrInt; out found: integer): boolean;
var
  pt: Pointer;
  i: integer;
begin
  Result:= false;
  pt:= aPtr;
  for i:= 0 to aCount-1 do begin
    if CompareMem(pt, aVal, aStep) then begin
      Result:= true;
      found:= i;
      exit;
    end;
    inc(pt, aStep);
  end;
end;

end.