For everybody thats use a lot Chained lists on your projects:

uses SysUtils;
 
type
  PPointer = ^Pointer;
 
  TChainedList = class
  private
    FFirst   : Pointer;
    FLast    : Pointer;
    FCurrent : Pointer;
    FCount   : Integer;
    function GetCurrent: PPointer;
  public
    constructor Create;
    destructor Destroy; override;
 
    function First : TChainedList;
    function Last  : TChainedList;
    function Prior : TChainedList;
    function Next  : TChainedList;
 
    function Add: TChainedList;
    function Remove: TChainedList; overload;
    function Remove(AChainedReleaser: Pointer): TChainedList; overload;
 
    property Current: PPointer read GetCurrent;
    property Count: Integer read FCount;
  end;
 
implementation
 
type
  PChainedItem = ^TChainedItem;
  TChainedItem = record
    Prior, Next: PChainedItem;
    Data: Pointer;
  end;
 
{ TChainedList }
 
constructor TChainedList.Create;
begin
  FCount := 0;
  FFirst := nil;
  FLast := nil;
  FCurrent := nil;
end;
 
destructor TChainedList.Destroy;
begin
  First;
  while Current <> nil do
    Remove;
 
  inherited;
end;
 
function TChainedList.GetCurrent: PPointer;
begin
  if FCurrent <> nil then
    Result := @PChainedItem(FCurrent).Data
  else
    Result := nil;
end;
 
function TChainedList.First: TChainedList;
begin
  FCurrent := FFirst;
  Result := Self;
end;
 
function TChainedList.Last: TChainedList;
begin
  FCurrent := FLast;
  Result := Self;
end;
 
function TChainedList.Prior: TChainedList;
begin
  if FCurrent <> nil then
    FCurrent := PChainedItem(FCurrent)^.Prior
  else
    FCurrent := nil;
  Result := Self;
end;
 
function TChainedList.Next: TChainedList;
begin
  if FCurrent <> nil then
    FCurrent := PChainedItem(FCurrent)^.Next
  else
    FCurrent := nil;
  Result := Self;
end;
 
function TChainedList.Add: TChainedList;
var
  pNew: PChainedItem;
begin
  New(pNew);
  pNew^.Prior := nil;
  pNew^.Next := nil;
  pNew^.Data := nil;
 
  if FFirst = nil then
  begin
    FFirst := pNew;
    FLast := pNew;
  end else
  begin
    pNew^.Prior := PChainedItem(FLast);
    PChainedItem(FLast)^.Next := pNew;
    FLast := pNew;
  end;
 
  FCurrent := FLast;
  Result := Self;
  Inc(FCount);
end;
 
function TChainedList.Remove: TChainedList;
var
  pCur: PChainedItem;
begin
  pCur := FCurrent;
  if pCur^.Data <> nil then
    raise Exception.Create('Current item memory leak detected.');
 
  if pCur^.Next <> nil then
    pCur^.Next^.Prior := pCur^.Prior;
 
  if pCur^.Prior <> nil then
    pCur^.Prior^.Next := pCur^.Next;
 
  if pCur = FFirst then
  begin
    FFirst := pCur^.Next;
    FCurrent := FFirst;
  end else if pCur = FLast then
  begin
    FLast := pCur^.Prior;
    FCurrent := FLast;
  end else
    FCurrent := pCur^.Next;
 
  Result := Self;
  Dispose(pCur);
  Dec(FCount);
end;
 
function TChainedList.Remove(AChainedReleaser: Pointer): TChainedList;
type
  TRelease = procedure(APointer: Pointer);
var
  PdrRelease: TRelease;
begin
  @PdrRelease := AChainedReleaser;
  PdrRelease(PChainedItem(FCurrent)^.Data);
  PChainedItem(FCurrent)^.Data := nil;
  Result := Remove;
end;

See how to use it here: Delphi: Chained List

Hugs!

For everybody that needs the ToolButton position:

type
  TToolButtonAccess = class(TToolButton);
 
function ToolButtonScreenPos(AToolButton: TToolButton): TPoint;
begin
  GetDCOrgEx(TToolButtonAccess(AToolButton).Canvas.Handle, Result);
  Inc(Result.X, AToolButton.Left);
  Inc(Result.Y, AToolButton.Top);
end;

Hugs!

For everybody that needs the Speedbutton position:

type
  TSpeedButtonAccess = class(TSpeedButton);
 
function SpeedButtonScreenPos(ASpeedButton: TSpeedButton): TPoint;
begin
  GetDCOrgEx(TSpeedButtonAccess(ASpeedButton).Canvas.Handle, Result);
  Inc(Result.X, ASpeedButton.Left);
  Inc(Result.Y, ASpeedButton.Top);
end;

Hugs!

For everybody that need to show something only on the useful area of the desktop I wrote this function:

function DesktopClientArea: TRect;
var
  rDesktop, rWinBar: TRect;
begin
  Windows.GetWindowRect(GetDesktopWindow, rDesktop);
  Windows.GetWindowRect(FindWindow('Shell_TrayWnd', nil), rWinBar);
  SubtractRect(Result, rDesktop, rWinBar);
end;

Hugs!

With this procedure you can change the Drop Shadow effect provided by windows XP/Vista on all windows without need to reset the computer.

procedure ChangeDropShadow(AActive: boolean);
var
  Buff: Cardinal;
  Param: Pointer;
  DevMode: TDeviceMode;
begin
  with TRegistry.Create do
  begin
    RootKey := HKEY_CURRENT_USER;
    if OpenKey('\Control Panel\Desktop\', false) then
    begin
      ReadBinaryData('UserPreferencesMask', Buff, 4);
      if AActive then
        Buff := Buff or (1 shl 18)
      else
        Buff := Buff xor (Buff and (1 shl 18));
      WriteBinaryData('UserPreferencesMask', Buff, 4);
      Param := nil;
      if AActive then
        Param := @AActive;
 
      SystemParametersInfo(SPI_SETDROPSHADOW, 0,
        Param, SPIF_SENDWININICHANGE);
    end;
    Free;
  end;
end;

Hugs!