docs/latex/wx/arrstrng.tex

   1 \section{\class{wxArrayString}}\label{wxarraystring}
   2
   3 wxArrayString is an efficient container for storing
   4 \helpref{wxString}{wxstring} objects. It has the same features as all
   5 \helpref{wxArray}{wxarray} classes, i.e. it dynamically expands when new items
   6 are added to it (so it is as easy to use as a linked list), but the access
   7 time to the elements is constant, instead of being linear in number of
   8 elements as in the case of linked lists. It is also very size efficient and
   9 doesn't take more space than a C array {\it wxString[]} type (wxArrayString
  10 uses its knowledge of internals of wxString class to achieve this).
  11
  12 This class is used in the same way as other dynamic \helpref{arrays}{wxarray},
  13 except that no {\it WX\_DEFINE\_ARRAY} declaration is needed for it. When a
  14 string is added or inserted in the array, a copy of the string is created, so
  15 the original string may be safely deleted (e.g. if it was a {\it char *}
  16 pointer the memory it was using can be freed immediately after this). In
  17 general, there is no need to worry about string memory deallocation when using
  18 this class - it will always free the memory it uses itself.
  19
  20 The references returned by \helpref{Item}{wxarraystringitem},
  21 \helpref{Last}{wxarraystringlast} or
  22 \helpref{operator[]}{wxarraystringoperatorindex} are not constant, so the
  23 array elements may be modified in place like this
  24
  25 \begin{verbatim}
  26     array.Last().MakeUpper();
  27 \end{verbatim}
  28
  29 There is also a varian of wxArrayString called wxSortedArrayString which has
  30 exactly the same methods as wxArrayString, but which always keeps the string
  31 in it in (alphabetical) order. wxSortedArrayString uses binary search in its
  32 \helpref{Index}{wxarraystringindex} function (insteadf of linear search for
  33 wxArrayString::Index) which makes it much more efficient if you add strings to
  34 the array rarely (because, of course, you have to pay for Index() efficiency
  35 by having Add() be slower) but search for them often. Several methods should
  36 not be used with sorted array (basicly, all which break the order of items)
  37 which is mentioned in their description.
  38
  39 Final word: none of the methods of wxArrayString is virtual including its
  40 destructor, so this class should not be used as a base class.
  41
  42 \wxheading{Derived from}
  43
  44 Although this is not true strictly speaking, this class may be considered as a
  45 specialization of \helpref{wxArray}{wxarray} class for the wxString member
  46 data: it is not implemented like this, but it does have all of the wxArray
  47 functions.
  48
  49 \wxheading{Include files}
  50
  51 <wx/string.h>
  52
  53 \wxheading{See also}
  54
  55 \helpref{wxArray}{wxarray}, \helpref{wxString}{wxstring}, \helpref{wxString overview}{wxstringoverview}
  56
  57 \latexignore{\rtfignore{\wxheading{Members}}}
  58
  59 \membersection{wxArrayString::wxArrayString}\label{wxarraystringctor}
  60
  61 \func{}{wxArrayString}{\void}
  62
  63 \func{}{wxArrayString}{\param{const wxArrayString\&}{ array}}
  64
  65 Default and copy constructors.
  66
  67 Note that when an array is assigned to a sorted array, its contents is
  68 automatically sorted during construction.
  69
  70 \membersection{wxArrayString::\destruct{wxArrayString}}\label{wxarraystringdtor}
  71
  72 \func{}{\destruct{wxArrayString}}{}
  73
  74 Destructor frees memory occupied by the array strings. For the performance
  75 reasons it is not virtual, so this class should not be derived from.
  76
  77 \membersection{wxArrayString::operator=}\label{wxarraystringoperatorassign}
  78
  79 \func{wxArrayString \&}{operator $=$}{\param{const wxArrayString\&}{ array}}
  80
  81 Assignment operator.
  82
  83 \membersection{wxArrayString::operator[]}\label{wxarraystringoperatorindex}
  84
  85 \func{wxString\&}{operator[]}{\param{size\_t }{nIndex}}
  86
  87 Return the array element at position {\it nIndex}. An assert failure will
  88 result from an attempt to access an element beyond the end of array in debug
  89 mode, but no check is done in release mode.
  90
  91 This is the operator version of \helpref{Item}{wxarraystringitem} method.
  92
  93 \membersection{wxArrayString::Add}\label{wxarraystringadd}
  94
  95 \func{void}{Add}{\param{const wxString\& }{str}}
  96
  97 Appends a new item to the array.
  98
  99 {\bf Warning:} For sorted arrays, the index of the inserted item will not be,
 100 in general, equal to \helpref{GetCount()}{wxarraystringgetcount} - 1 because
 101 the item is inserted at the correct position to keep the array sorted and not
 102 appended.
 103
 104 See also: \helpref{Insert}{wxarraystringinsert}
 105
 106 \membersection{wxArrayString::Alloc}\label{wxarraystringalloc}
 107
 108 \func{void}{Alloc}{\param{size\_t }{nCount}}
 109
 110 Preallocates enough memory to store {\it nCount} items. This function may be
 111 used to improve array class performance before adding a known number of items
 112 consecutively.
 113
 114 See also: \helpref{Dynamic array memory management}{wxarraymemorymanagement}
 115
 116 \membersection{wxArrayString::Clear}\label{wxarraystringclear}
 117
 118 \func{void}{Clear}{\void}
 119
 120 Clears the array contents and frees memory.
 121
 122 See also: \helpref{Empty}{wxarraystringempty}
 123
 124 \membersection{wxArrayString::Count}\label{wxarraystringcount}
 125
 126 \constfunc{size\_t}{Count}{\void}
 127
 128 Returns the number of items in the array. This function is deprecated and is
 129 for backwards compatibility only, please use
 130 \helpref{GetCount}{wxarraystringgetcount} instead.
 131
 132 \membersection{wxArrayString::Empty}\label{wxarraystringempty}
 133
 134 \func{void}{Empty}{\void}
 135
 136 Empties the array: after a call to this function
 137 \helpref{GetCount}{wxarraystringgetcount} will return $0$. However, this
 138 function does not free the memory used by the array and so should be used when
 139 the array is going to be reused for storing other strings. Otherwise, you
 140 should use \helpref{Clear}{wxarraystringclear} to empty the array and free
 141 memory.
 142
 143 \membersection{wxArrayString::GetCount}\label{wxarraystringgetcount}
 144
 145 \constfunc{size\_t}{GetCount}{\void}
 146
 147 Returns the number of items in the array.
 148
 149 \membersection{wxArrayString::Index}\label{wxarraystringindex}
 150
 151 \func{int}{Index}{\param{const char *}{ sz}, \param{bool}{ bCase = TRUE}, \param{bool}{ bFromEnd = FALSE}}
 152
 153 Search the element in the array, starting from the beginning if
 154 {\it bFromEnd} is FALSE or from end otherwise. If {\it bCase}, comparison is
 155 case sensitive (default), otherwise the case is ignored.
 156
 157 This function uses linear search for wxArrayString and binary search for
 158 wxSortedArrayString, but it ignores the {\it bCase} and {\it bFromEnd}
 159 parameters in the latter case.
 160
 161 Returns index of the first item matched or wxNOT\_FOUND if there is no match.
 162
 163 \membersection{wxArrayString::Insert}\label{wxarraystringinsert}
 164
 165 \func{void}{Insert}{\param{const wxString\& }{str}, \param{size\_t}{ nIndex}}
 166
 167 Insert a new element in the array before the position {\it nIndex}. Thus, for
 168 example, to insert the string in the beginning of the array you would write
 169
 170 \begin{verbatim}
 171 Insert("foo", 0);
 172 \end{verbatim}
 173
 174 If {\it nIndex} is equal to {\it GetCount() + 1} this function behaves as
 175 \helpref{Add}{wxarraystringadd}.
 176
 177 {\bf Warning:} this function should not be used with sorted array because it
 178 could break the order of items and, for example, subsequent calls to
 179 \helpref{Index()}{wxarraystringindex} would not work then!
 180
 181 \membersection{wxArrayString::IsEmpty}\label{wxarraystringisempty}
 182
 183 \func{}{IsEmpty}{}
 184
 185 Returns TRUE if the array is empty, FALSE otherwise. This function returns the
 186 same result as {\it GetCount() == 0} but is probably easier to read.
 187
 188 \membersection{wxArrayString::Item}\label{wxarraystringitem}
 189
 190 \constfunc{wxString\&}{Item}{\param{size\_t }{nIndex}}
 191
 192 Return the array element at position {\it nIndex}. An assert failure will
 193 result from an attempt to access an element beyond the end of array in debug
 194 mode, but no check is done in release mode.
 195
 196 See also \helpref{operator[]}{wxarraystringoperatorindex} for the operator
 197 version.
 198
 199 \membersection{wxArrayString::Last}\label{wxarraystringlast}
 200
 201 \func{}{Last}{}
 202
 203 Returns the last element of the array. Attempt to access the last element of
 204 an empty array will result in assert failure in debug build, however no checks
 205 are done in release mode.
 206
 207 \membersection{wxArrayString::Remove (by value)}\label{wxarraystringremoveval}
 208
 209 \func{void}{Remove}{\param{const char *}{ sz}}
 210
 211 Removes the first item matching this value. An assert failure is provoked by
 212 an attempt to remove an element which does not exist in debug build.
 213
 214 See also: \helpref{Index}{wxarraystringindex}, \helpref{Remove}{wxarraystringremove}
 215
 216 \membersection{wxArrayString::Remove (by index)}\label{wxarraystringremove}
 217
 218 \func{void}{Remove}{\param{size\_t }{nIndex}}
 219
 220 Removes the item at given position.
 221
 222 See also: \helpref{Remove}{wxarraystringremoveval}
 223
 224 \membersection{wxArrayString::Shrink}\label{wxarraystringshrink}
 225
 226 \func{void}{Shrink}{\void}
 227
 228 Releases the extra memory allocated by the array. This function is useful to
 229 minimize the array memory consumption.
 230
 231 See also: \helpref{Alloc}{wxarraystringalloc}, \helpref{Dynamic array memory management}{wxarraymemorymanagement}
 232
 233 \membersection{wxArrayString::Sort (alphabetically)}\label{wxarraystringsort}
 234
 235 \func{void}{Sort}{\param{bool}{ reverseOrder = FALSE}}
 236
 237 Sorts the array in alphabetical order or in reverse alphabetical order if
 238 {\it reverseOrder} is TRUE.
 239
 240 {\bf Warning:} this function should not be used with sorted array because it
 241 could break the order of items and, for example, subsequent calls to
 242 \helpref{Index()}{wxarraystringindex} would not work then!
 243
 244 See also: \helpref{Sort}{wxarraystringsortcallback}
 245
 246 \membersection{wxArrayString::Sort (user defined)}\label{wxarraystringsortcallback}
 247
 248 \func{void}{Sort}{\param{CompareFunction }{compareFunction}}
 249
 250 Sorts the array using the specified {\it compareFunction} for item comparison.
 251 {\it CompareFunction} is defined as a function taking two {\it const
 252 wxString\&} parameters and returning {\it int} value less than, equal to or
 253 greater than 0 if the first string is less than, equal to or greater than the
 254 second one.
 255
 256 \wxheading{Example}
 257
 258 The following example sorts strings by their length.
 259
 260 \begin{verbatim}
 261 static int CompareStringLen(const wxString& first, const wxString& second)
 262 {
 263     return first.length() - second.length();
 264 }
 265
 266 ...
 267
 268 wxArrayString array;
 269
 270 array.Add("one");
 271 array.Add("two");
 272 array.Add("three");
 273 array.Add("four");
 274
 275 array.Sort(CompareStringLen);
 276 \end{verbatim}
 277
 278 {\bf Warning:} this function should not be used with sorted array because it
 279 could break the order of items and, for example, subsequent calls to
 280 \helpref{Index()}{wxarraystringindex} would not work then!
 281
 282 See also: \helpref{Sort}{wxarraystringsort}
 283