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	torben	2671	(* *** 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.