Softwareentwicklung in C++ - ASC

1 // s i m p l e t e x t d i s p l a y a b l e . h − a d i s p l a y a b l e f o r text
2
3 #ifndef s i m p l e t e x t d i s p l a y a b l e h
4 #define s i m p l e t e x t d i s p l a y a b l e h
5
6 #include < c s t r i n g>
7 #include ” s i m p l e d i s p l a y a b l e . h”
8 #include ” s i m p l e t e x t o u t p u t c o n t e x t . h”
9
10.2 Das DDD 291
10 //−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−
11 /∗ A simple d i s p l a y a b l e f o r text
12 ∗ I t implements the Displayable i n t e r f a c e and i s constructed with an
13 ∗ appropriate s t r i n g . When the c a l l b a c k to
14 ∗ obtain the d i s p l a y r e p r e s e n t a t i o n i s c a l l e d t h i s s t r i n g i s written .
15 ∗ The s t r i n g may be any s t a t i c a l l y or dynamically a l l o c a t e d char ∗ ,
16 ∗ because i t i s copied .
17 ∗/
18 class TextDisplayable : public Displayable
19 {
20 protected :
21
22 /∗ The s t r i n g s t o r i n g the text to be displayed . I t i s a copy o f the
23 ∗ s t r i n g that i s passed on as a parameter o f the constructor .
24 ∗ Therefore i t has to be deleted in the d e s t r u c t o r .
25 ∗/
26 char ∗ t e x t ;
27
28 private :
29
30 /∗ Copy construction i s forbidden
31 ∗/
32 TextDisplayable ( const TextDisplayable & s r c ) {}
33
34 public :
35
36 /∗ Standard constructor
37 ∗ I t has to c a l l the constructor f o r the base c l a s s .
38 ∗ The text passed on i s copied to the t e x t member . I f a 0 pointer
39 ∗ i s given as a parameter t e x t i s i n i t i a l i z e d to an empty
40 ∗ s t r i n g ( j u s t because exceptions are not known yet ) .
41 ∗/
42 explicit TextDisplayable ( const char ∗ text ) :
43 Displayable ( ) , t e x t (0)
44 {
45 i f ( text )
46 {
47 t e x t = new char [ s t r l e n ( text ) + 1 ] ;
48 strcpy ( t e x t , text ) ;
49 }
50 }
51
52 /∗ Destructor
53 ∗ Just to meet the convention
54 ∗/
55 virtual ˜ TextDisplayable ( )
56 {
57 delete t e x t ;
58 }
59
60 /∗ Nothing s p e c i a l has to be done upon r e g i s t r a t i o n
61 ∗ @param handler The handler that t h i s d i s p l a y a b l e was
62 ∗ r e g i s t e r e d with .
63 ∗/
64 virtual void d i s p l a y a b l e R e g i s t e r e d (
65 SimpleOutputHandling &handler ) {}