Softwareentwicklung in C++ - ASC

6 #include ” simple event handler . h”
7
10.2 Das DDD 295
8 //−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
9 /∗ This c l a s s reads the user input from s t d i n and passes i t on
10 ∗ to the r e g i s t e r e d handler word by word in the form o f
11 ∗ WordEvent i n s t a n c e s .
12 ∗/
13
14 class SimpleInputHandling
15 {
16 protected :
17
18 /∗ The maximum length of accepted input words . I f an input word
19 ∗ i s longer i t w i l l be s p l i t up i n t o two input words .
20 ∗/
21 static const uint32 MAXWORDLENGTH = 256;
22
23 private :
24
25 /∗ This i s a pure s t a t i c method c o l l e c t i o n . Therefore f o r b i d
26 ∗ c o nstructing an instance .
27 ∗/
28 SimpleInputHandling ( ) { } ;
29
30 /∗ I f construction i s not p o s s i b l e , a l s o d e s t r u c t i o n does
31 ∗ not make any sense at a l l .
32 ∗/
33 virtual ˜ SimpleInputHandling ( ) { } ;
34
35 protected :
36
37 /∗ This v a r i a b l e i s used i n t e r n a l l y to stop the dispatcher
38 ∗ loop . I f i t i s s e t the loop w i l l stop a f t e r the next
39 ∗ word that has been obtained from the user input .
40 ∗/
41 static bool s t o p d i s p a t c h e r l o o p ;
42
43 /∗ This i s the event handler that obtains the n o t i f i c a t i o n s
44 ∗ about the user input words .
45 ∗/
46 static EventHandler ∗ event handler ;
47
48 public :
49
50 /∗ This method i s used to s e t the r e s p o n s i b l e event handler .
51 ∗ I f there i s already a handler s e t , the new one w i l l r e p l a c e
52 ∗ the old one . Please note that the old event handler w i l l
53 ∗ NOT be deleted !
54 ∗ @param handler The event handler that i s r e s p o n s i b l e f o r
55 ∗ events from now on .
56 ∗/
57 static void setEventHandler ( EventHandler ∗ handler )
58 {
59 event handler = handler ;
60 }
61
62 /∗ This method i s c a l l e d to s t a r t the dispatcher loop . I t w i l l
63 ∗ NOT return u n t i l the loop i s stopped because multithreading
64 ∗ i s not implemented here . To stop the loop the method
65 ∗ stopDispatcher has to be c a l l e d . Then t h i s method w i l l return
66 ∗ a f t e r the next word that has been dispatched .
67 ∗ I f no handler i s s e t t h i s method w i l l return immediately ( j u s t
68 ∗ because exceptions are not known yet ) .
69 ∗/
70 static void runDispatcher ( ) ;
71