Softwareentwicklung in C++ - ASC

221 return ( d e l e t o r ) ;
222 }
223
224 /∗ This i s the c a l l b a c k implementation
225 ∗ @param obj The pointer to the o b j e c t to be deleted
226 ∗/
227 virtual void deleteObject ( void ∗ obj )
228 {
229 delete static cast(obj ) ;
230 }
231 } ;
232
233
234 #endif // c o n c r e t e o b j e c t d e l e t o r s h
10.2.6 ArgumentHandler
10.2 Das DDD 271
Neben dem Vector ist auch die Basisklasse ArgumentHandler und alles, was
sich rund um diese Klasse herum abspielt, ein relativ abgeschlossenes Thema
für sich. Also wenden wir uns ihr gleich einmal zu. Der ArgumentHandler ist
ganz einfach nur eine abstrakte Basis, über die das CommandlineHandling die
einzelnen Parameter zur Auswertung weitergeben kann. Dementsprechend
einfach ist auch dieses Interface:
1 // simple argument handler . h − i n t e r f a c e f o r an argument handler
2
3 #ifndef simple argument handler h
4 #define simple argument handler h
5
6 //−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
7 /∗ An abstract base c l a s s of a very simple argument handler .
8 ∗ A concrete implementation of a handler has to be derived from
9 ∗ t h i s base and obtains n o t i f i c a t i o n s f o r every s i n g l e argument .
10 ∗/
11
12 class ArgumentHandler
13 {
14 public :
15
16 /∗ Destructor
17 ∗ The d e s t r u c t o r i s j u s t implemented to make sure that a v i r t u a l
18 ∗ d e s t r u c t o r e x i s t s
19 ∗/
20 virtual ˜ ArgumentHandler ( ) { }
21
22 /∗ This method i s a c a l l b a c k used to n o t i f y the handler o f an
23 ∗ argument that was obtained .
24 ∗ @param index The index of the argument . All arguments are
25 ∗ numbered in a consecutive order s t a r t i n g at 0 .
26 ∗ @param arg A pointer to the argument that was obtained . This
27 ∗ parameter i s declared as a void ∗ , because argument
28 ∗ n o t i f i c a t i o n s are performed in a typed manner .
29 ∗ Depending on the expected argument type the t r i g g e r
30 ∗ c l a s s of a n o t i f i c a t i o n has to perform the according
31 ∗ conversion . I f e . g . an i n t argument i s expected
32 ∗ the n o t i f i c a t i o n i s done with an i n t ∗ .
33 ∗/
34 virtual void argumentNotification ( uint32 index , const void ∗ arg ) = 0 ;
35 } ;