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1 | \section{\class{wxCustomDataObject}}\label{wxcustomdataobject} | |
2 | ||
3 | wxCustomDataObject is a specialization of | |
4 | \helpref{wxDataObjectSimple}{wxdataobjectsimple} for some | |
5 | application-specific data in arbitrary (either custom or one of the standard | |
6 | ones). The only restriction is that it is supposed that this data can be | |
7 | copied bitwise (i.e. with {\tt memcpy()}), so it would be a bad idea to make | |
8 | it contain a C++ object (though C struct is fine). | |
9 | ||
10 | By default, wxCustomDataObject stores the data inside in a buffer. To put the | |
11 | data into the buffer you may use either | |
12 | \helpref{SetData}{wxcustomdataobjectsetdata} or | |
13 | \helpref{TakeData}{wxcustomdataobjecttakedata} depending on whether you want | |
14 | the object to make a copy of data or not. | |
15 | ||
16 | If you already store the data in another place, it may be more convenient and | |
17 | efficient to provide the data on-demand which is possible too if you override | |
18 | the virtual functions mentioned below. | |
19 | ||
20 | \wxheading{Virtual functions to override} | |
21 | ||
22 | This class may be used as is, but if you don't want store the data inside the | |
23 | object but provide it on demand instead, you should override | |
24 | \helpref{GetSize}{wxcustomdataobjectgetsize}, | |
25 | \helpref{GetData}{wxcustomdataobjectgetdata} and | |
26 | \helpref{SetData}{wxcustomdataobjectsetdata} (or may be only the first two or | |
27 | only the last one if you only allow reading/writing the data) | |
28 | ||
29 | \wxheading{Derived from} | |
30 | ||
31 | \helpref{wxDataObjectSimple}{wxdataobjectsimple}\\ | |
32 | \helpref{wxDataObject}{wxdataobject} | |
33 | ||
34 | \wxheading{Include files} | |
35 | ||
36 | <wx/dataobj.h> | |
37 | ||
38 | \wxheading{Library} | |
39 | ||
40 | \helpref{wxCore}{librarieslist} | |
41 | ||
42 | \wxheading{See also} | |
43 | ||
44 | \helpref{wxDataObject}{wxdataobject} | |
45 | ||
46 | \latexignore{\rtfignore{\wxheading{Members}}} | |
47 | ||
48 | \membersection{wxCustomDataObject::wxCustomDataObject}\label{wxcustomdataobjectwxcustomdataobject} | |
49 | ||
50 | \func{}{wxCustomDataObject}{\param{const wxDataFormat\& }{format = wxFormatInvalid}} | |
51 | ||
52 | The constructor accepts a {\it format} argument which specifies the (single) | |
53 | format supported by this object. If it isn't set here, | |
54 | \helpref{SetFormat}{wxdataobjectsimplesetformat} should be used. | |
55 | ||
56 | \membersection{wxCustomDataObject::\destruct{wxCustomDataObject}}\label{wxcustomdataobjectdtor} | |
57 | ||
58 | \func{}{\destruct{wxCustomDataObject}}{\void} | |
59 | ||
60 | The destructor will free the data hold by the object. Notice that although it | |
61 | calls a virtual \helpref{Free()}{wxcustomdataobjectfree} function, the base | |
62 | class version will always be called (C++ doesn't allow calling virtual | |
63 | functions from constructors or destructors), so if you override {\tt Free()}, you | |
64 | should override the destructor in your class as well (which would probably | |
65 | just call the derived class' version of {\tt Free()}). | |
66 | ||
67 | \membersection{wxCustomDataObject::Alloc}\label{wxcustomdataobjectalloc} | |
68 | ||
69 | \func{virtual void *}{Alloc}{\param{size\_t }{size}} | |
70 | ||
71 | This function is called to allocate {\it size} bytes of memory from SetData(). | |
72 | The default version just uses the operator new. | |
73 | ||
74 | \membersection{wxCustomDataObject::Free}\label{wxcustomdataobjectfree} | |
75 | ||
76 | \func{virtual void}{Free}{\void} | |
77 | ||
78 | This function is called when the data is freed, you may override it to anything | |
79 | you want (or may be nothing at all). The default version calls operator | |
80 | delete$[]$ on the data. | |
81 | ||
82 | \membersection{wxCustomDataObject::GetSize}\label{wxcustomdataobjectgetsize} | |
83 | ||
84 | \constfunc{virtual size\_t}{GetSize}{\void} | |
85 | ||
86 | Returns the data size in bytes. | |
87 | ||
88 | \membersection{wxCustomDataObject::GetData}\label{wxcustomdataobjectgetdata} | |
89 | ||
90 | \constfunc{virtual void *}{GetData}{\void} | |
91 | ||
92 | Returns a pointer to the data. | |
93 | ||
94 | \membersection{wxCustomDataObject::SetData}\label{wxcustomdataobjectsetdata} | |
95 | ||
96 | \func{virtual void}{SetData}{ | |
97 | \param{size\_t }{size}, \param{const void }{*data}} | |
98 | ||
99 | Set the data. The data object will make an internal copy. | |
100 | ||
101 | \pythonnote{This method expects a string in wxPython. You can pass | |
102 | nearly any object by pickling it first.} | |
103 | ||
104 | \membersection{wxCustomDataObject::TakeData}\label{wxcustomdataobjecttakedata} | |
105 | ||
106 | \func{virtual void}{TakeData}{ | |
107 | \param{size\_t }{size}, \param{const void }{*data}} | |
108 | ||
109 | Like \helpref{SetData}{wxcustomdataobjectsetdata}, but doesn't copy the data - | |
110 | instead the object takes ownership of the pointer. | |
111 | ||
112 | \pythonnote{This method expects a string in wxPython. You can pass | |
113 | nearly any object by pickling it first.} | |
114 |