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1\section{\class{wxHashTable}}\label{wxhashtable}
2
3{\bf Please note} that this class is retained for backward compatibility
4reasons; you should use \helpref{wxHashMap}{wxhashmap}.
5
6This class provides hash table functionality for wxWidgets, and for an
7application if it wishes. Data can be hashed on an integer or string
8key.
9
10\wxheading{Derived from}
11
12\helpref{wxObject}{wxobject}
13
14\wxheading{Include files}
15
16<wx/hash.h>
17
18\wxheading{Library}
19
20\helpref{wxBase}{librarieslist}
21
22\wxheading{Example}
23
24Below is an example of using a hash table.
25
26\begin{verbatim}
27 wxHashTable table(wxKEY_STRING);
28
29 wxPoint *point = new wxPoint(100, 200);
30 table.Put("point 1", point);
31
32 ....
33
34 wxPoint *found_point = (wxPoint *)table.Get("point 1");
35\end{verbatim}
36
37A hash table is implemented as an array of pointers to lists. When no
38data has been stored, the hash table takes only a little more space than
39this array (default size is 1000). When a data item is added, an
40integer is constructed from the integer or string key that is within the
41bounds of the array. If the array element is NULL, a new (keyed) list is
42created for the element. Then the data object is appended to the list,
43storing the key in case other data objects need to be stored in the list
44also (when a `collision' occurs).
45
46Retrieval involves recalculating the array index from the key, and searching
47along the keyed list for the data object whose stored key matches the passed
48key. Obviously this is quicker when there are fewer collisions, so hashing
49will become inefficient if the number of items to be stored greatly exceeds
50the size of the hash table.
51
52\wxheading{See also}
53
54\helpref{wxList}{wxlist}
55
56\latexignore{\rtfignore{\wxheading{Members}}}
57
58\membersection{wxHashTable::wxHashTable}\label{wxhashtablector}
59
60\func{}{wxHashTable}{\param{unsigned int}{ key\_type}, \param{int}{ size = 1000}}
61
62Constructor. {\it key\_type} is one of wxKEY\_INTEGER, or wxKEY\_STRING,
63and indicates what sort of keying is required. {\it size} is optional.
64
65\membersection{wxHashTable::\destruct{wxHashTable}}\label{wxhashtabledtor}
66
67\func{}{\destruct{wxHashTable}}{\void}
68
69Destroys the hash table.
70
71\membersection{wxHashTable::BeginFind}\label{wxhashtablebeginfind}
72
73\func{void}{BeginFind}{\void}
74
75The counterpart of {\it Next}. If the application wishes to iterate
76through all the data in the hash table, it can call {\it BeginFind} and
77then loop on {\it Next}.
78
79\membersection{wxHashTable::Clear}\label{wxhashtableclear}
80
81\func{void}{Clear}{\void}
82
83Clears the hash table of all nodes (but as usual, doesn't delete user data).
84
85\membersection{wxHashTable::Delete}\label{wxhashtabledelete}
86
87\func{wxObject *}{Delete}{\param{long}{ key}}
88
89\func{wxObject *}{Delete}{\param{const wxString\& }{ key}}
90
91Deletes entry in hash table and returns the user's data (if found).
92
93\membersection{wxHashTable::DeleteContents}\label{wxhashtabledeletecontents}
94
95\func{void}{DeleteContents}{\param{bool}{ flag}}
96
97If set to true data stored in hash table will be deleted when hash table object
98is destroyed.
99
100
101\membersection{wxHashTable::Get}\label{wxhashtableget}
102
103\func{wxObject *}{Get}{\param{long}{ key}}
104
105\func{wxObject *}{Get}{\param{const char*}{ key}}
106
107Gets data from the hash table, using an integer or string key (depending on which
108has table constructor was used).
109
110\membersection{wxHashTable::MakeKey}\label{wxhashtablemakekey}
111
112\func{long}{MakeKey}{\param{const wxString\& }{string}}
113
114Makes an integer key out of a string. An application may wish to make a key
115explicitly (for instance when combining two data values to form a key).
116
117\membersection{wxHashTable::Next}\label{wxhashtablenext}
118
119\func{wxHashTable::Node *}{Next}{\void}
120
121If the application wishes to iterate through all the data in the hash
122table, it can call {\it BeginFind} and then loop on {\it Next}. This function
123returns a {\bf wxHashTable::Node} pointer (or NULL if there are no more nodes).
124The return value is functionally equivalent to \textbf{wxNode} but might not be
125implemented as a \textbf{wxNode}. The user will probably only wish to use the
126\textbf{GetData} method to retrieve the data; the node may also be deleted.
127
128\membersection{wxHashTable::Put}\label{wxhashtableput}
129
130\func{void}{Put}{\param{long}{ key}, \param{wxObject *}{object}}
131
132\func{void}{Put}{\param{const char*}{ key}, \param{wxObject *}{object}}
133
134Inserts data into the hash table, using an integer or string key (depending on which
135has table constructor was used). The key string is copied and stored by the hash
136table implementation.
137
138\membersection{wxHashTable::GetCount}\label{wxhashtablegetcount}
139
140\constfunc{size\_t}{GetCount}{\void}
141
142Returns the number of elements in the hash table.
143