examples/Delphi/Observer.pas

(* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is TurboPower SysTools
 *
 * The Initial Developer of the Original Code is
 * TurboPower Software
 *
 * Portions created by the Initial Developer are Copyright (C) 1996-2002
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * ***** END LICENSE BLOCK ***** *)

unit Observer;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, StPtrns, ExtCtrls;


type
  TObserverForm = class(TForm)
    Panel1: TPanel;
    Button1: TButton;
    Edit1: TEdit;
    Label1: TLabel;
    Button2: TButton;
    Button3: TButton;
    Button4: TButton;
    procedure Edit1Change(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure FormDestroy(Sender: TObject);
  private
// Code for the observer

    { Private declarations }
  public
    TheObserver: TStObserver;

    procedure ReceiveNotification1(WhatChanged: TObject);
    procedure ReceiveNotification2(WhatChanged: TObject);
    procedure ReceiveNotification3(WhatChanged: TObject);
    procedure ReceiveNotification4(WhatChanged: TObject);
    { Public declarations }
  end;


var
  ObserverForm: TObserverForm;

implementation

{$R *.DFM}

procedure TObserverForm.Edit1Change(Sender: TObject);
begin
  TheObserver.Notify(TObject(Edit1.Text));
end;

procedure TObserverForm.ReceiveNotification1(WhatChanged: TObject);
begin
  Button1.Caption := String(WhatChanged);
end;

procedure TObserverForm.ReceiveNotification2(WhatChanged: TObject);
begin
  Button2.Caption := String(WhatChanged);
end;

procedure TObserverForm.ReceiveNotification3(WhatChanged: TObject);
begin
  Button3.Caption := String(WhatChanged);
end;

procedure TObserverForm.ReceiveNotification4(WhatChanged: TObject);
begin
  Button4.Caption := String(WhatChanged);
end;

procedure TObserverForm.Button1Click(Sender: TObject);
begin
  Edit1.Text:= 'Reset 1';
end;

procedure TObserverForm.Button2Click(Sender: TObject);
begin
  Edit1.Text:= 'Reset 2';
end;

procedure TObserverForm.Button3Click(Sender: TObject);
begin
  Edit1.Text:= 'Reset 3';
end;

procedure TObserverForm.Button4Click(Sender: TObject);
begin
  Edit1.Text:= 'Reset 4';
end;

procedure TObserverForm.FormCreate(Sender: TObject);
begin
  TheObserver := TStObserver.Create;
  TheObserver.Add(ReceiveNotification1);
  TheObserver.Add(ReceiveNotification2);
  TheObserver.Add(ReceiveNotification3);
  TheObserver.Add(ReceiveNotification4);
end;

procedure TObserverForm.FormDestroy(Sender: TObject);
begin
  TheObserver.Free;
end;

end.
1	(* *** BEGIN LICENSE BLOCK ***
2	* Version: MPL 1.1
3	*
4	* The contents of this file are subject to the Mozilla Public License Version
5	* 1.1 (the "License"); you may not use this file except in compliance with
6	* the License. You may obtain a copy of the License at
7	* http://www.mozilla.org/MPL/
8	*
9	* Software distributed under the License is distributed on an "AS IS" basis,
10	* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
11	* for the specific language governing rights and limitations under the
12	* License.
13	*
14	* The Original Code is TurboPower SysTools
15	*
16	* The Initial Developer of the Original Code is
17	* TurboPower Software
18	*
19	* Portions created by the Initial Developer are Copyright (C) 1996-2002
20	* the Initial Developer. All Rights Reserved.
21	*
22	* Contributor(s):
23	*
24	* *** END LICENSE BLOCK *** *)
25
26	unit Observer;
27
28	interface
29
30	uses
31	Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
32	StdCtrls, StPtrns, ExtCtrls;
33
34
35	type
36	TObserverForm = class(TForm)
37	Panel1: TPanel;
38	Button1: TButton;
39	Edit1: TEdit;
40	Label1: TLabel;
41	Button2: TButton;
42	Button3: TButton;
43	Button4: TButton;
44	procedure Edit1Change(Sender: TObject);
45	procedure Button1Click(Sender: TObject);
46	procedure Button2Click(Sender: TObject);
47	procedure Button3Click(Sender: TObject);
48	procedure Button4Click(Sender: TObject);
49	procedure FormCreate(Sender: TObject);
50	procedure FormDestroy(Sender: TObject);
51	private
52	// Code for the observer
53
54	{ Private declarations }
55	public
56	TheObserver: TStObserver;
57
58	procedure ReceiveNotification1(WhatChanged: TObject);
59	procedure ReceiveNotification2(WhatChanged: TObject);
60	procedure ReceiveNotification3(WhatChanged: TObject);
61	procedure ReceiveNotification4(WhatChanged: TObject);
62	{ Public declarations }
63	end;
64
65
66	var
67	ObserverForm: TObserverForm;
68
69	implementation
70
71	{$R *.DFM}
72
73	procedure TObserverForm.Edit1Change(Sender: TObject);
74	begin
75	TheObserver.Notify(TObject(Edit1.Text));
76	end;
77
78	procedure TObserverForm.ReceiveNotification1(WhatChanged: TObject);
79	begin
80	Button1.Caption := String(WhatChanged);
81	end;
82
83	procedure TObserverForm.ReceiveNotification2(WhatChanged: TObject);
84	begin
85	Button2.Caption := String(WhatChanged);
86	end;
87
88	procedure TObserverForm.ReceiveNotification3(WhatChanged: TObject);
89	begin
90	Button3.Caption := String(WhatChanged);
91	end;
92
93	procedure TObserverForm.ReceiveNotification4(WhatChanged: TObject);
94	begin
95	Button4.Caption := String(WhatChanged);
96	end;
97
98	procedure TObserverForm.Button1Click(Sender: TObject);
99	begin
100	Edit1.Text:= 'Reset 1';
101	end;
102
103	procedure TObserverForm.Button2Click(Sender: TObject);
104	begin
105	Edit1.Text:= 'Reset 2';
106	end;
107
108	procedure TObserverForm.Button3Click(Sender: TObject);
109	begin
110	Edit1.Text:= 'Reset 3';
111	end;
112
113	procedure TObserverForm.Button4Click(Sender: TObject);
114	begin
115	Edit1.Text:= 'Reset 4';
116	end;
117
118	procedure TObserverForm.FormCreate(Sender: TObject);
119	begin
120	TheObserver := TStObserver.Create;
121	TheObserver.Add(ReceiveNotification1);
122	TheObserver.Add(ReceiveNotification2);
123	TheObserver.Add(ReceiveNotification3);
124	TheObserver.Add(ReceiveNotification4);
125	end;
126
127	procedure TObserverForm.FormDestroy(Sender: TObject);
128	begin
129	TheObserver.Free;
130	end;
131
132	end.