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{Library}
  54
  55 \helpref{wxBase}{librarieslist}
  56
  57 \wxheading{See also}
  58
  59 \helpref{wxArray}{wxarray}, \helpref{wxString}{wxstring}, \helpref{wxString overview}{wxstringoverview}
  60
  61 \latexignore{\rtfignore{\wxheading{Members}}}
  62
  63 \membersection{wxArrayString::wxArrayString}\label{wxarraystringctor}
  64
  65 \func{}{wxArrayString}{\void}
  66
  67 Default constructor.
  68
  69 \func{}{wxArrayString}{\param{const wxArrayString\&}{ array}}
  70
  71 Copy constructor. Note that when an array is assigned to a sorted array, its contents is
  72 automatically sorted during construction.
  73
  74 \func{}{wxArrayString}{\param{size\_t}{ sz}, \param{const char**}{ arr}}
  75
  76 \func{}{wxArrayString}{\param{size\_t}{ sz}, \param{const wchar\_t**}{ arr}}
  77
  78 Constructor from a C string array. Pass a size {\it sz} and array {\it arr}.
  79
  80 \func{}{wxArrayString}{\param{size\_t}{ sz}, \param{const wxString*}{ arr}}
  81
  82 Constructor from a wxString array. Pass a size {\it sz} and array {\it arr}.
  83
  84 \membersection{wxArrayString::\destruct{wxArrayString}}\label{wxarraystringdtor}
  85
  86 \func{}{\destruct{wxArrayString}}{}
  87
  88 Destructor frees memory occupied by the array strings. For the performance
  89 reasons it is not virtual, so this class should not be derived from.
  90
  91 \membersection{wxArrayString::operator=}\label{wxarraystringoperatorassign}
  92
  93 \func{wxArrayString \&}{operator $=$}{\param{const wxArrayString\&}{ array}}
  94
  95 Assignment operator.
  96
  97 \membersection{wxArrayString::operator==}\label{wxarraystringoperatorequal}
  98
  99 \constfunc{bool}{operator $==$}{\param{const wxArrayString\&}{ array}}
 100
 101 Compares 2 arrays respecting the case. Returns true only if the arrays have
 102 the same number of elements and the same strings in the same order.
 103
 104 \membersection{wxArrayString::operator!=}\label{wxarraystringoperatornotequal}
 105
 106 \constfunc{bool}{operator $!=$}{\param{const wxArrayString\&}{ array}}
 107
 108 Compares 2 arrays respecting the case. Returns true if the arrays have
 109 different number of elements or if the elements don't match pairwise.
 110
 111 \membersection{wxArrayString::operator[]}\label{wxarraystringoperatorindex}
 112
 113 \func{wxString\&}{operator[]}{\param{size\_t }{nIndex}}
 114
 115 Return the array element at position {\it nIndex}. An assert failure will
 116 result from an attempt to access an element beyond the end of array in debug
 117 mode, but no check is done in release mode.
 118
 119 This is the operator version of \helpref{Item}{wxarraystringitem} method.
 120
 121 \membersection{wxArrayString::Add}\label{wxarraystringadd}
 122
 123 \func{size\_t}{Add}{\param{const wxString\& }{str}, \param{size\_t}{ copies = $1$}}
 124
 125 Appends the given number of {\it copies} of the new item {\it str} to the
 126 array and returns the index of the first new item in the array.
 127
 128 {\bf Warning:} For sorted arrays, the index of the inserted item will not be,
 129 in general, equal to \helpref{GetCount()}{wxarraystringgetcount} - 1 because
 130 the item is inserted at the correct position to keep the array sorted and not
 131 appended.
 132
 133 See also: \helpref{Insert}{wxarraystringinsert}
 134
 135 \membersection{wxArrayString::Alloc}\label{wxarraystringalloc}
 136
 137 \func{void}{Alloc}{\param{size\_t }{nCount}}
 138
 139 Preallocates enough memory to store {\it nCount} items. This function may be
 140 used to improve array class performance before adding a known number of items
 141 consecutively.
 142
 143 See also: \helpref{Dynamic array memory management}{wxarraymemorymanagement}
 144
 145 \membersection{wxArrayString::Clear}\label{wxarraystringclear}
 146
 147 \func{void}{Clear}{\void}
 148
 149 Clears the array contents and frees memory.
 150
 151 See also: \helpref{Empty}{wxarraystringempty}
 152
 153 \membersection{wxArrayString::Empty}\label{wxarraystringempty}
 154
 155 \func{void}{Empty}{\void}
 156
 157 Empties the array: after a call to this function
 158 \helpref{GetCount}{wxarraystringgetcount} will return $0$. However, this
 159 function does not free the memory used by the array and so should be used when
 160 the array is going to be reused for storing other strings. Otherwise, you
 161 should use \helpref{Clear}{wxarraystringclear} to empty the array and free
 162 memory.
 163
 164 \membersection{wxArrayString::GetCount}\label{wxarraystringgetcount}
 165
 166 \constfunc{size\_t}{GetCount}{\void}
 167
 168 Returns the number of items in the array.
 169
 170 \membersection{wxArrayString::Index}\label{wxarraystringindex}
 171
 172 \func{int}{Index}{\param{const wxString\& }{ sz}, \param{bool}{ bCase = true}, \param{bool}{ bFromEnd = false}}
 173
 174 Search the element in the array, starting from the beginning if
 175 {\it bFromEnd} is false or from end otherwise. If {\it bCase}, comparison is
 176 case sensitive (default), otherwise the case is ignored.
 177
 178 This function uses linear search for wxArrayString and binary search for
 179 wxSortedArrayString, but it ignores the {\it bCase} and {\it bFromEnd}
 180 parameters in the latter case.
 181
 182 Returns index of the first item matched or {\tt wxNOT\_FOUND} if there is no match.
 183
 184 \membersection{wxArrayString::Insert}\label{wxarraystringinsert}
 185
 186 \func{void}{Insert}{\param{const wxString\& }{str}, \param{size\_t}{ nIndex}, \param{size\_t }{copies = $1$}}
 187
 188 Insert the given number of {\it copies} of the new element in the array before the position {\it nIndex}. Thus, for
 189 example, to insert the string in the beginning of the array you would write
 190
 191 \begin{verbatim}
 192 Insert("foo", 0);
 193 \end{verbatim}
 194
 195 If {\it nIndex} is equal to {\it GetCount()} this function behaves as
 196 \helpref{Add}{wxarraystringadd}.
 197
 198 {\bf Warning:} this function should not be used with sorted arrays because it
 199 could break the order of items and, for example, subsequent calls to
 200 \helpref{Index()}{wxarraystringindex} would then not work!
 201
 202 \membersection{wxArrayString::IsEmpty}\label{wxarraystringisempty}
 203
 204 \func{bool}{IsEmpty}{}
 205
 206 Returns true if the array is empty, false otherwise. This function returns the
 207 same result as {\it GetCount() == 0} but is probably easier to read.
 208
 209 \membersection{wxArrayString::Item}\label{wxarraystringitem}
 210
 211 \constfunc{wxString\&}{Item}{\param{size\_t }{nIndex}}
 212
 213 Return the array element at position {\it nIndex}. An assert failure will
 214 result from an attempt to access an element beyond the end of array in debug
 215 mode, but no check is done in release mode.
 216
 217 See also \helpref{operator[]}{wxarraystringoperatorindex} for the operator
 218 version.
 219
 220 \membersection{wxArrayString::Last}\label{wxarraystringlast}
 221
 222 \func{wxString&}{Last}{}
 223
 224 Returns the last element of the array. Attempt to access the last element of
 225 an empty array will result in assert failure in debug build, however no checks
 226 are done in release mode.
 227
 228 \membersection{wxArrayString::Remove}\label{wxarraystringremove}
 229
 230 \func{void}{Remove}{\param{const wxString\&}{ sz}}
 231
 232 Removes the first item matching this value. An assert failure is provoked by
 233 an attempt to remove an element which does not exist in debug build.
 234
 235 See also: \helpref{Index}{wxarraystringindex}
 236
 237 \membersection{wxArrayString::RemoveAt}\label{wxarraystringremoveat}
 238
 239 \func{void}{RemoveAt}{\param{size\_t }{nIndex}, \param{size\_t }{count = $1$}}
 240
 241 Removes {\it count} items starting at position {\it nIndex} from the array.
 242
 243 \membersection{wxArrayString::Shrink}\label{wxarraystringshrink}
 244
 245 \func{void}{Shrink}{\void}
 246
 247 Releases the extra memory allocated by the array. This function is useful to
 248 minimize the array memory consumption.
 249
 250 See also: \helpref{Alloc}{wxarraystringalloc}, \helpref{Dynamic array memory management}{wxarraymemorymanagement}
 251
 252 \membersection{wxArrayString::Sort}\label{wxarraystringsort}
 253
 254 \func{void}{Sort}{\param{bool}{ reverseOrder = false}}
 255
 256 Sorts the array in alphabetical order or in reverse alphabetical order if
 257 {\it reverseOrder} is true. The sort is case-sensitive.
 258
 259 {\bf Warning:} this function should not be used with sorted array because it
 260 could break the order of items and, for example, subsequent calls to
 261 \helpref{Index()}{wxarraystringindex} would then not work!
 262
 263 \func{void}{Sort}{\param{CompareFunction }{compareFunction}}
 264
 265 Sorts the array using the specified {\it compareFunction} for item comparison.
 266 {\it CompareFunction} is defined as a function taking two {\it const
 267 wxString\&} parameters and returning an {\it int} value less than, equal to or
 268 greater than 0 if the first string is less than, equal to or greater than the
 269 second one.
 270
 271 \wxheading{Example}
 272
 273 The following example sorts strings by their length.
 274
 275 \begin{verbatim}
 276 static int CompareStringLen(const wxString& first, const wxString& second)
 277 {
 278     return first.length() - second.length();
 279 }
 280
 281 ...
 282
 283 wxArrayString array;
 284
 285 array.Add("one");
 286 array.Add("two");
 287 array.Add("three");
 288 array.Add("four");
 289
 290 array.Sort(CompareStringLen);
 291 \end{verbatim}
 292
 293 {\bf Warning:} this function should not be used with sorted array because it
 294 could break the order of items and, for example, subsequent calls to
 295 \helpref{Index()}{wxarraystringindex} would then not work!
 296