CentrED/UOLib/UListSort.pas

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(*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at
* http://www.opensource.org/licenses/cddl1.php.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at
* http://www.opensource.org/licenses/cddl1.php. If applicable,
* add the following below this CDDL HEADER, with the fields enclosed
* by brackets "[]" replaced with your own identifying * information:
* Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*
*
* Portions Copyright 2007 Andreas Schneider
*)
unit UListSort;
{$mode objfpc}{$H+}
interface
uses
Classes;
type
TListSortCompare = function(Left, Right: TObject): Integer of object;
procedure ListSort(List: TList; Compare: TListSortCompare);
implementation
procedure ListSort(List: TList; Compare: TListSortCompare);
var
iMin, iMax: Integer;
Temp: Pointer;
procedure sift;
var
i, j: integer;
begin
i := iMin;
j := 2 * i;
Temp := Pointer(List[i]);
while j <= iMax do
begin
if j < iMax then
if Compare(TObject(List[j]), TObject(List[j + 1])) > 0 then inc(j);
if Compare(TObject(Temp), TObject(List[j])) <= 0 then break;
List[i] := Pointer(List[j]);
i := j;
j := 2 * i;
end;
List[i] := Temp;
end;
begin
if List.Count > 0 then
begin
iMax := List.Count - 1;
iMin := iMax div 2 + 1;
while iMin > 0 do
begin
dec(iMin);
sift;
end;
while iMax > 0 do
begin
Temp := Pointer(List[iMin]);
List[iMin] := Pointer(List[iMax]);
List[iMax] := Temp;
dec(iMax);
sift;
end;
end;
end;
end.