www.pudn.com > Indy_9_00_14_src.zip > IdContainers.pas

unit IdContainers; 
 
{********************************************************************} 
{*  IdContainers.pas                                                 *} 
{*                                                                  *} 
{*  Provides compatibility with the Contnr.pas unit from            *} 
{*  Delphi 5 not found in Delphi 4.                                 *} 
{*                                                                  *} 
{*  Based on ideas from the Borland VCL Contnr.pas interface.       *} 
{*                                                                  *} 
{********************************************************************} 
 
{ 
  $Log:  10109: IdContainers.pas  
{ 
{   Rev 1.0    2002.11.12 10:33:52 PM  czhower 
} 
  Revision 1.0  2001-02-20 02:02:09-05  dsiders 
  Initial revision 
} 
 
interface 
 
uses 
  SysUtils, Classes; 
 
 
type 
 
  {TIdObjectList} 
 
  TIdObjectList = class(TList) 
  private 
    FOwnsObjects: Boolean; 
  protected 
    function GetItem(AIndex: Integer): TObject; 
    procedure SetItem(AIndex: Integer; AObject: TObject); 
    procedure Notify(AItemPtr: Pointer; AAction: TListNotification); override; 
  public 
    constructor Create; overload; 
    constructor Create(AOwnsObjects: Boolean); overload; 
    function Add(AObject: TObject): Integer; 
    function FindInstanceOf(AClassRef: TClass; AMatchExact: Boolean = True; AStartPos: Integer = 0): Integer; 
    function IndexOf(AObject: TObject): Integer; 
    function Remove(AObject: TObject): Integer; 
    procedure Insert(AIndex: Integer; AObject: TObject); 
    property Items[AIndex: Integer]: TObject read GetItem write SetItem; default; 
    property OwnsObjects: Boolean read FOwnsObjects write FOwnsObjects; 
  end; 
 
 
implementation 
 
 
{TIdObjectList} 
 
function TIdObjectList.Add(AObject: TObject): Integer; 
begin 
  Result := inherited Add(AObject); 
end; 
 
 
constructor TIdObjectList.Create; 
begin 
  inherited Create; 
  FOwnsObjects := True; 
end; 
 
 
constructor TIdObjectList.Create(AOwnsObjects: Boolean); 
begin 
  inherited Create; 
  FOwnsObjects := AOwnsObjects; 
end; 
 
 
function TIdObjectList.FindInstanceOf(AClassRef: TClass; 
  AMatchExact: Boolean = True; AStartPos: Integer = 0): Integer; 
var 
  iPos: Integer; 
  bIsAMatch: Boolean; 
 
begin 
  Result := -1;   // indicates item is not in object list 
 
  for iPos := AStartPos to Count - 1 do 
  begin 
    bIsAMatch := 
      ((not AMatchExact) and Items[iPos].InheritsFrom(AClassRef)) or 
      (AMatchExact and (Items[iPos].ClassType = AClassRef)); 
 
    if (bIsAMatch) then 
    begin 
      Result := iPos; 
      break; 
    end; 
  end; 
end; 
 
function TIdObjectList.GetItem(AIndex: Integer): TObject; 
begin 
  Result := inherited Items[AIndex]; 
end; 
 
 
function TIdObjectList.IndexOf(AObject: TObject): Integer; 
begin 
  Result := inherited IndexOf(AObject); 
end; 
 
 
procedure TIdObjectList.Insert(AIndex: Integer; AObject: TObject); 
begin 
  inherited Insert(AIndex, AObject); 
end; 
 
 
procedure TIdObjectList.Notify(AItemPtr: Pointer; AAction: TListNotification); 
begin 
  if (OwnsObjects and (AAction = lnDeleted)) then 
    TObject(AItemPtr).Free; 
 
  inherited Notify(AItemPtr, AAction); 
end; 
 
 
function TIdObjectList.Remove(AObject: TObject): Integer; 
begin 
  Result := inherited Remove(AObject); 
end; 
 
 
procedure TIdObjectList.SetItem(AIndex: Integer; AObject: TObject); 
begin 
  inherited Items[AIndex] := AObject; 
end; 
 
end.