/tutorial/signal/example0.e

 1class EXAMPLE0
 2   -- Signal example0
 3   -- This example shows the use of SIGNAL_0. This signal only means that an
 4   -- event occurred.
 5
 6create {ANY}
 7   make
 8
 9feature {}
10   event: SIGNAL_0
11
12   make
13      do
14         create event.make
15         register
16         io.put_string("Event occur for first time:%N")
17         event.emit
18         io.put_string("Event occur for second time:%N")
19         event.emit
20      end
21
22   register
23         -- In real examples, other objects will connect to the event so
24         -- arbitrary functions of their choice may be executed when the
25         -- event occur.
26      do
27         event.connect(agent io.put_string("Event occur...%N"))
28         -- functions with arguments may be used too! Simply give their values.
29         event.connect(agent foo)
30      end
31
32   foo
33      do
34         io.put_string(once "This function does what needs to be%
35             % done for this event%N")
36      end
37
38end -- class EXAMPLE0