Author: Tomas Rutkauskas

How to create an 'Easter Egg' in an application

Answer:

1. Give the form a field of type String:


Match: string;


2. Declare a constant that represents the character sequence that needs to be typed 
in order
     for the Easter Egg to appear. For example:

1   const
2     Target = ' abc ' #1;



(In this example, you have to type "a"  "b"  "c" and finally CTRL - A)


3. Set the forms KeyPreview property to True.


4. In the dialog's OnCreate event handler, do this:


3   procedure TMyAboutBox.FormCreate(Sender: TObject);
4   begin
5     Match := ''
6   end;



5. In the dialog's OnKeyPress event handler, do this:

7   
8   procedure TMyAboutBox.FormKeyPress(Sender: TObject; var Key: Char);
9   begin
10    Match := Match + Key;
11    if Pos(Match, Target) <> 1 then
12      Match := ''
13    else if Match = Target then
14      ShowMessage('Congratulations')
15  end;