unit DmClasses;

interface

uses
 System.SysUtils, System.Classes, Vcl.Controls, Vcl.StdCtrls, Vcl.ExtCtrls, Messages, Graphics, Windows;

type
 [ComponentPlatformsAttribute (pidWin32 or pidWin64)]
 TDmPanel = class(TPanel)
 protected
   FFrameColor: TColor;
   FFrameVisible: boolean;
   procedure WMPaint(var m: TWMPaint); message WM_PAINT;
 published
   property FrameColor: TColor read FFrameColor write FFrameColor;
   property FrameVisible: boolean read FFrameVisible write FFrameVisible;
 end;

procedure Register;

implementation

procedure DrawWindowFrame(wnd: HWND; AColor: TColor);
var
 c: TCanvas;
 R, DR: TRect;

begin
 GetWindowRect(wnd, R);

 DR.Left := 0;
 DR.Top := 0;
 DR.Width := R.Right - R.Left;
 DR.Height := R.Bottom - R.Top;

 c := TCanvas.Create;
 with c do
 begin
   Handle := GetWindowDC(wnd);
   Brush.Style := bsClear;
   Pen.Color := AColor;
   Pen.Style := psDot;
   Pen.Width := 1;
   Rectangle(DR);
   ReleaseDC(wnd, Handle);
   Handle := 0;
   Free;
 end;
end;

procedure TDmPanel.WMPaint(var m: TWMPaint);
begin
 m.Result := 0;
 DefaultHandler(m);
 if FrameVisible then DrawWindowFrame(Handle, FFrameColor);
end;

procedure Register;
begin
 RegisterComponents('TDmClasses', [TDmPanel]);
end;

end.