TForm1 = class(TForm)
    Label1: TLabel;
    BitBtn1: TBitBtn;
    Edit1: TEdit;
    Label2: TLabel;
    Label3: TLabel;
    Label4: TLabel;
    procedure FormCreate(Sender: TObject);
    procedure FormMouseWheel(Sender: TObject; Shift: TShiftState;
      WheelDelta: Integer; MousePos: TPoint; var Handled: Boolean);
  private
  public
    E, L, M: integer;
    FocusReturn: TCmFocusChanged;
    procedure CMMouseEnter (var message: TMessage); message cm_MouseEnter;
    procedure CMMouseLeave (var message: TMessage); message cm_MouseLeave;
    procedure CmFocusChanged (var Msg: TCmFocusChanged); message cm_FocusChanged;
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
  E:=0; L:=0; M:=0;
  OnMouseWheel := FormMouseWheel;
end;

procedure TForm1.CmFocusChanged(var Msg: TCmFocusChanged);
begin
  if Msg.Sender.Name <> 'Edit1' then
    FocusReturn := Msg;
  Label3.Caption := 'Focus on ' + Msg.Sender.Name;
  inherited;
end;

procedure TForm1.CMMouseEnter(var Message: TMessage);
begin
inc(E);
Label1.Caption := 'ENTER: ' + IntToStr(E);
if Message.LParam = Integer(Edit1) then
begin
  Screen.Cursor := crHandPoint;
  Edit1.Font.Style := Edit1.Font.Style + [fsUnderline];
  if Edit1.CanFocus then Edit1.SetFocus;
end;
inherited;
end;

procedure TForm1.CMMouseLeave(var Message: TMessage);
begin
inc(L);
Label2.Caption := 'LEAVE: ' + IntToStr(L);;
if Message.LParam = Integer(Edit1) then
begin
  Edit1.Font.Style := Edit1.Font.Style - [fsUnderline];
  Screen.Cursor := crDefault;
  if FocusReturn.Sender.CanFocus then FocusReturn.Sender.SetFocus;
end;
inherited;
end;

procedure TForm1.FormMouseWheel(Sender: TObject; Shift: TShiftState;
  WheelDelta: Integer; MousePos: TPoint; var Handled: Boolean);
begin
  M:= M + WheelDelta;
  Label4.Caption := 'WHELL: ' + IntToStr(M);
  if Edit1.Focused then
  begin
    Edit1.Tag := Edit1.Tag + WheelDelta;
    Edit1.Text := 'TAG: ' + IntToStr(Edit1.Tag)
  end
end;

procedure TfvMain.Chart1MouseDown(Sender: TObject; Button: TMouseButton;
  Shift: TShiftState; X, Y: Integer);
begin
  Chart1.SetFocus;
end;