1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:
24:
25:
26:
27:
28:
29:
30:
31:
32:
33:
34:
35:
36:
37:
38:
39:
40:
41:
42:
43:
44:
45:
46:
47:
48:

unit ColorBoxTest;

interface

uses
  SysUtils, Classes, Controls, StdCtrls, ExtCtrls,Messages;

type
  TColorBoxTest = class(TColorBox)
  private
  protected
    procedure WMLButtonDown(var Message: TWMLButtonDown); message WM_LBUTTONDOWN;
  public
  published
    property DragMode;
    property DragKind;
  end;

procedure Register;

implementation

uses Types,Windows;
procedure Register;
begin
  RegisterComponents('Test', [TColorBoxTest]);
end;

{ TColorBoxTest }

procedure TColorBoxTest.WMLButtonDown(var Message: TWMLButtonDown);
var r: TRect;
begin
  if DragMode = dmAutomatic then begin
    r := ClientRect;                           
    r.Right := r.Left+r.Bottom-r.Top;
    InflateRect(r,-2,-2);
    if PtInRect(r,Point(Message.XPos,Message.YPos)) then  // Mouse is over the color
    begin
      SetFocus;
      BeginDrag(False);
      Exit;
    end;
  end;
  inherited;
end;

end.