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 wxChar *}
  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 variant 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 (instead 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 (basically, 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/arrstr.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 Default constructor.
  64
  65 \func{}{wxArrayString}{\param{const wxArrayString\&}{ array}}
  66
  67 Copy constructor. Note that when an array is assigned to a sorted array, its contents is
  68 automatically sorted during construction.
  69
  70 \func{}{wxArrayString}{\param{size\_t}{ sz}, \param{const char**}{ arr}}
  71
  72 \func{}{wxArrayString}{\param{size\_t}{ sz}, \param{const wchar\_t**}{ arr}}
  73
  74 Constructor from a C string array. Pass a size {\it sz} and array {\it arr}.
  75
  76 \func{}{wxArrayString}{\param{size\_t}{ sz}, \param{const wxString*}{ arr}}
  77
  78 Constructor from a wxString array. Pass a size {\it sz} and array {\it arr}.
  79
  80 \membersection{wxArrayString::\destruct{wxArrayString}}\label{wxarraystringdtor}
  81
  82 \func{}{\destruct{wxArrayString}}{}
  83
  84 Destructor frees memory occupied by the array strings. For the performance
  85 reasons it is not virtual, so this class should not be derived from.
  86
  87 \membersection{wxArrayString::operator=}\label{wxarraystringoperatorassign}
  88
  89 \func{wxArrayString \&}{operator $=$}{\param{const wxArrayString\&}{ array}}
  90
  91 Assignment operator.
  92
  93 \membersection{wxArrayString::operator==}\label{wxarraystringoperatorequal}
  94
  95 \constfunc{bool}{operator $==$}{\param{const wxArrayString\&}{ array}}
  96
  97 Compares 2 arrays respecting the case. Returns true only if the arrays have
  98 the same number of elements and the same strings in the same order.
  99
 100 \membersection{wxArrayString::operator!=}\label{wxarraystringoperatornotequal}
 101
 102 \constfunc{bool}{operator $!=$}{\param{const wxArrayString\&}{ array}}
 103
 104 Compares 2 arrays respecting the case. Returns true if the arrays have
 105 different number of elements or if the elements don't match pairwise.
 106
 107 \membersection{wxArrayString::operator[]}\label{wxarraystringoperatorindex}
 108
 109 \func{wxString\&}{operator[]}{\param{size\_t }{nIndex}}
 110
 111 Return the array element at position {\it nIndex}. An assert failure will
 112 result from an attempt to access an element beyond the end of array in debug
 113 mode, but no check is done in release mode.
 114
 115 This is the operator version of \helpref{Item}{wxarraystringitem} method.
 116
 117 \membersection{wxArrayString::Add}\label{wxarraystringadd}
 118
 119 \func{size\_t}{Add}{\param{const wxString\& }{str}, \param{size\_t}{ copies = $1$}}
 120
 121 Appends the given number of {\it copies} of the new item {\it str} to the
 122 array and returns the index of the first new item in the array.
 123
 124 {\bf Warning:} For sorted arrays, the index of the inserted item will not be,
 125 in general, equal to \helpref{GetCount()}{wxarraystringgetcount} - 1 because
 126 the item is inserted at the correct position to keep the array sorted and not
 127 appended.
 128
 129 See also: \helpref{Insert}{wxarraystringinsert}
 130
 131 \membersection{wxArrayString::Alloc}\label{wxarraystringalloc}
 132
 133 \func{void}{Alloc}{\param{size\_t }{nCount}}
 134
 135 Preallocates enough memory to store {\it nCount} items. This function may be
 136 used to improve array class performance before adding a known number of items
 137 consecutively.
 138
 139 See also: \helpref{Dynamic array memory management}{wxarraymemorymanagement}
 140
 141 \membersection{wxArrayString::Clear}\label{wxarraystringclear}
 142
 143 \func{void}{Clear}{\void}
 144
 145 Clears the array contents and frees memory.
 146
 147 See also: \helpref{Empty}{wxarraystringempty}
 148
 149 \membersection{wxArrayString::Empty}\label{wxarraystringempty}
 150
 151 \func{void}{Empty}{\void}
 152
 153 Empties the array: after a call to this function
 154 \helpref{GetCount}{wxarraystringgetcount} will return $0$. However, this
 155 function does not free the memory used by the array and so should be used when
 156 the array is going to be reused for storing other strings. Otherwise, you
 157 should use \helpref{Clear}{wxarraystringclear} to empty the array and free
 158 memory.
 159
 160 \membersection{wxArrayString::GetCount}\label{wxarraystringgetcount}
 161
 162 \constfunc{size\_t}{GetCount}{\void}
 163
 164 Returns the number of items in the array.
 165
 166 \membersection{wxArrayString::Index}\label{wxarraystringindex}
 167
 168 \func{int}{Index}{\param{const wxString\& }{ sz}, \param{bool}{ bCase = true}, \param{bool}{ bFromEnd = false}}
 169
 170 Search the element in the array, starting from the beginning if
 171 {\it bFromEnd} is false or from end otherwise. If {\it bCase}, comparison is
 172 case sensitive (default), otherwise the case is ignored.
 173
 174 This function uses linear search for wxArrayString and binary search for
 175 wxSortedArrayString, but it ignores the {\it bCase} and {\it bFromEnd}
 176 parameters in the latter case.
 177
 178 Returns index of the first item matched or {\tt wxNOT\_FOUND} if there is no match.
 179
 180 \membersection{wxArrayString::Insert}\label{wxarraystringinsert}
 181
 182 \func{void}{Insert}{\param{const wxString\& }{str}, \param{size\_t}{ nIndex}, \param{size\_t }{copies = $1$}}
 183
 184 Insert the given number of {\it copies} of the new element in the array before the position {\it nIndex}. Thus, for
 185 example, to insert the string in the beginning of the array you would write
 186
 187 \begin{verbatim}
 188 Insert("foo", 0);
 189 \end{verbatim}
 190
 191 If {\it nIndex} is equal to {\it GetCount()} this function behaves as
 192 \helpref{Add}{wxarraystringadd}.
 193
 194 {\bf Warning:} this function should not be used with sorted arrays because it
 195 could break the order of items and, for example, subsequent calls to
 196 \helpref{Index()}{wxarraystringindex} would then not work!
 197
 198 \membersection{wxArrayString::IsEmpty}\label{wxarraystringisempty}
 199
 200 \func{bool}{IsEmpty}{}
 201
 202 Returns true if the array is empty, false otherwise. This function returns the
 203 same result as {\it GetCount() == 0} but is probably easier to read.
 204
 205 \membersection{wxArrayString::Item}\label{wxarraystringitem}
 206
 207 \constfunc{wxString\&}{Item}{\param{size\_t }{nIndex}}
 208
 209 Return the array element at position {\it nIndex}. An assert failure will
 210 result from an attempt to access an element beyond the end of array in debug
 211 mode, but no check is done in release mode.
 212
 213 See also \helpref{operator[]}{wxarraystringoperatorindex} for the operator
 214 version.
 215
 216 \membersection{wxArrayString::Last}\label{wxarraystringlast}
 217
 218 \func{wxString&}{Last}{}
 219
 220 Returns the last element of the array. Attempt to access the last element of
 221 an empty array will result in assert failure in debug build, however no checks
 222 are done in release mode.
 223
 224 \membersection{wxArrayString::Remove}\label{wxarraystringremove}
 225
 226 \func{void}{Remove}{\param{const wxString\&}{ sz}}
 227
 228 Removes the first item matching this value. An assert failure is provoked by
 229 an attempt to remove an element which does not exist in debug build.
 230
 231 See also: \helpref{Index}{wxarraystringindex}
 232
 233 \membersection{wxArrayString::RemoveAt}\label{wxarraystringremoveat}
 234
 235 \func{void}{RemoveAt}{\param{size\_t }{nIndex}, \param{size\_t }{count = $1$}}
 236
 237 Removes {\it count} items starting at position {\it nIndex} from the array.
 238
 239 \membersection{wxArrayString::Shrink}\label{wxarraystringshrink}
 240
 241 \func{void}{Shrink}{\void}
 242
 243 Releases the extra memory allocated by the array. This function is useful to
 244 minimize the array memory consumption.
 245
 246 See also: \helpref{Alloc}{wxarraystringalloc}, \helpref{Dynamic array memory management}{wxarraymemorymanagement}
 247
 248 \membersection{wxArrayString::Sort}\label{wxarraystringsort}
 249
 250 \func{void}{Sort}{\param{bool}{ reverseOrder = false}}
 251
 252 Sorts the array in alphabetical order or in reverse alphabetical order if
 253 {\it reverseOrder} is true. The sort is case-sensitive.
 254
 255 {\bf Warning:} this function should not be used with sorted array because it
 256 could break the order of items and, for example, subsequent calls to
 257 \helpref{Index()}{wxarraystringindex} would then not work!
 258
 259 \func{void}{Sort}{\param{CompareFunction }{compareFunction}}
 260
 261 Sorts the array using the specified {\it compareFunction} for item comparison.
 262 {\it CompareFunction} is defined as a function taking two {\it const
 263 wxString\&} parameters and returning an {\it int} value less than, equal to or
 264 greater than 0 if the first string is less than, equal to or greater than the
 265 second one.
 266
 267 \wxheading{Example}
 268
 269 The following example sorts strings by their length.
 270
 271 \begin{verbatim}
 272 static int CompareStringLen(const wxString& first, const wxString& second)
 273 {
 274     return first.length() - second.length();
 275 }
 276
 277 ...
 278
 279 wxArrayString array;
 280
 281 array.Add("one");
 282 array.Add("two");
 283 array.Add("three");
 284 array.Add("four");
 285
 286 array.Sort(CompareStringLen);
 287 \end{verbatim}
 288
 289 {\bf Warning:} this function should not be used with sorted array because it
 290 could break the order of items and, for example, subsequent calls to
 291 \helpref{Index()}{wxarraystringindex} would then not work!
 292