X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/6be663cf0d9c0ce48dea6c1c2f628ed376f128c0..e06b95691f1cc89509100700985101c34da7759e:/docs/latex/wx/array.tex diff --git a/docs/latex/wx/array.tex b/docs/latex/wx/array.tex index 22c204212a..73f53089f1 100644 --- a/docs/latex/wx/array.tex +++ b/docs/latex/wx/array.tex @@ -2,7 +2,7 @@ This section describes the so called {\it dynamic arrays}. This is a C array-like data structure i.e. the member access time is constant (and not -linear in number of container elements as for linked lists). However, these +linear according to the number of container elements as for linked lists). However, these arrays are dynamic in the sense that they will automatically allocate more memory if there is not enough of it for adding a new element. They also perform range checking on the index values but in debug mode only, so please be sure to @@ -15,7 +15,7 @@ release build. The array classes were designed to be reasonably efficient, both in terms of run-time speed and memory consumption and the executable size. The speed of -array item access if, of course, constant (independent of number of elements) +array item access is, of course, constant (independent of the number of elements) making them much more efficient than linked lists (\helpref{wxList}{wxlist}). Adding items to the arrays is also implemented in more or less constant time - but the price is preallocating the memory in advance. In the \helpref{memory management}{wxarraymemorymanagement} section @@ -35,11 +35,18 @@ element type. wxArray is suitable for storing integer types and pointers which it does not treat as objects in any way, i.e. the element pointed to by the pointer is not -deleted when the element is removed from the array \&c. It should be noted that -all of wxArray functions are inline, so it costs strictly nothing to define as +deleted when the element is removed from the array. It should be noted that +all of wxArray's functions are inline, so it costs strictly nothing to define as many array types as you want (either in terms of the executable size or the speed) as long as at least one of them is defined and this is always the case -because wxArrays are used by wxWindows internally. +because wxArrays are used by wxWindows internally. This class has one serious +limitation: it can only be used for storing integral types (bool, char, short, +int, long and their unsigned variants) or pointers (of any kind). An attempt +to use with objects of sizeof() greater than sizeof(long) will provoke a +runtime assertion failure, however declaring a wxArray of floats will not (on +the machines where sizeof(float) <= sizeof(long)), yet it will {\bf not} work, +please use wxObjArray for storing floats and doubles (NB: a more efficient +wxArrayDouble class is scheduled for the next release of wxWindows). wxSortedArray is a wxArray variant which should be used when searching in the array is a frequently used operation. It requires you to define an additional @@ -51,9 +58,8 @@ slower: it is $O(log(N))$ instead of constant time (neglecting time spent in memory allocation routine). However, in a usual situation elements are added to an array much less often than searched inside it, so wxSortedArray may lead to huge performance improvements compared to wxArray. Finally, it should be -noticed that, as wxArray, wxSortedArray can not be used to store anything of -sizeof() larger than max(sizeof(long), sizeof(void *)) - an assertion failure -will be raised from the constructor otherwise. +noticed that, as wxArray, wxSortedArray can be only used for storing integral +types or pointers. wxObjArray class treats its elements like "objects". It may delete them when they are removed from the array (invoking the correct destructor) and copies @@ -89,12 +95,13 @@ class MyDirectory ... // now that we have MyDirectory declaration in scope we may finish the -// definition of ArrayOfDirectories +// definition of ArrayOfDirectories -- note that this expands into some C++ +// code and so should only be compiled once (i.e., don't put this in the +// header, but into a source file or you will get linkin errors) #include // this is a magic incantation which must be done! WX_DEFINE_OBJARRAY(ArrayOfDirectories); // that's all! - \end{verbatim} It is not as elegant as writing @@ -106,7 +113,7 @@ typedef std::vector ArrayOfDirectories; but is not that complicated and allows the code to be compiled with any, however dumb, C++ compiler in the world. -The things are much simpler for wxArray and wxSortedArray however: it is enough +Things are much simpler for wxArray and wxSortedArray however: it is enough just to write \begin{verbatim} @@ -134,8 +141,10 @@ WX\_DECLARE\_OBJARRAY macros and must be fully declared before you use WX\_DEFINE\_OBJARRAY macro. \helpref{WX\_DEFINE\_ARRAY}{wxdefinearray}\\ +\helpref{WX\_DEFINE\_EXPORTED\_ARRAY}{wxdefinearray}\\ \helpref{WX\_DEFINE\_SORTED\_ARRAY}{wxdefinesortedarray}\\ -\helpref{WX\_DECLARE\_OBJARRAY}{wxdeclareobjarray}\\ +\helpref{WX\_DEFINE\_SORTED\_EXPORTED\_ARRAY}{wxdefinesortedarray}\\ +\helpref{WX\_DECLARE\_EXPORTED\_OBJARRAY}{wxdeclareobjarray}\\ \helpref{WX\_DEFINE\_OBJARRAY}{wxdefineobjarray} \membersection{Constructors and destructors} @@ -186,13 +195,15 @@ does exactly the same as \helpref{Item()}{wxarrayitem} method. \membersection{Adding items} \helpref{Add}{wxarrayadd}\\ -\helpref{Insert}{wxarrayinsert} +\helpref{Insert}{wxarrayinsert}\\ +\helpref{WX\_APPEND\_ARRAY}{wxappendarray} \membersection{Removing items} \helpref{WX\_CLEAR\_ARRAY}{wxcleararray}\\ \helpref{Empty}{wxarrayempty}\\ \helpref{Clear}{wxarrayclear}\\ +\helpref{RemoveAt}{wxarrayremoveat}\\ \helpref{Remove}{wxarrayremove} \membersection{Searching and sorting} @@ -209,10 +220,14 @@ does exactly the same as \helpref{Item()}{wxarrayitem} method. \membersection{WX\_DEFINE\_ARRAY}\label{wxdefinearray} -\func{}{WX\_DEFINE\_ARRAY}{\param{}{T}, \param{name}} +\func{}{WX\_DEFINE\_ARRAY}{\param{}{T}, \param{}{name}} + +\func{}{WX\_DEFINE\_EXPORTED\_ARRAY}{\param{}{T}, \param{}{name}} This macro defines a new array class named {\it name} and containing the -elements of type {\it T}. Example: +elements of type {\it T}. The second form is used when compiling DLL +under Windows and array needs to be visible outside the DLL. +Example: \begin{verbatim} WX_DEFINE_ARRAY(int, wxArrayInt); @@ -228,11 +243,17 @@ wxArrayLong and wxArrayPtrVoid. \func{}{WX\_DEFINE\_SORTED\_ARRAY}{\param{}{T}, \param{}{name}} +\func{}{WX\_DEFINE\_SORTED\_EXPORTED\_ARRAY}{\param{}{T}, \param{}{name}} + This macro defines a new sorted array class named {\it name} and containing -the elements of type {\it T}. Example: +the elements of type {\it T}. The second form is used when compiling DLL +under Windows and array needs to be visible outside the DLL. + + +Example: \begin{verbatim} -WX_DEFINE_SORTED_ARRAY(int, wxArrayInt); +WX_DEFINE_SORTED_ARRAY(int, wxSortedArrayInt); class MyClass; WX_DEFINE_SORTED_ARRAY(MyClass *, wxArrayOfMyClass); @@ -246,7 +267,7 @@ int CompareInts(int n1, int n2) return n1 - n2; } -wxArrayInt sorted(CompareInts); +wxSortedArrayInt sorted(CompareInts); int CompareMyClassObjects(MyClass *item1, MyClass *item2) { @@ -261,8 +282,13 @@ wxArrayOfMyClass another(CompareMyClassObjects); \func{}{WX\_DECLARE\_OBJARRAY}{\param{}{T}, \param{}{name}} +\func{}{WX\_DECLARE\_EXPORTED\_OBJARRAY}{\param{}{T}, \param{}{name}} + This macro declares a new object array class named {\it name} and containing -the elements of type {\it T}. Example: +the elements of type {\it T}. The second form is used when compiling DLL +under Windows and array needs to be visible outside the DLL. + +Example: \begin{verbatim} class MyClass; @@ -303,9 +329,16 @@ public: WX_DEFINE_OBJARRAY(wxArrayOfMyClass); \end{verbatim} +\membersection{WX\_APPEND\_ARRAY}\label{wxappendarray} + +\func{void}{WX\_APPEND\_ARRAY}{\param{wxArray\& }{array}, \param{wxArray\& }{other}} + +This macro may be used to append all elements of the {\it other} array to the +{\it array}. The two arrays must be of the same type. + \membersection{WX\_CLEAR\_ARRAY}\label{wxcleararray} -\func{\void}{WX\_CLEAR\_ARRAY}{\param{wxArray\& }{array}} +\func{void}{WX\_CLEAR\_ARRAY}{\param{wxArray\& }{array}} This macro may be used to delete all elements of the array before emptying it. It can not be used with wxObjArrays - but they will delete their elements anyhow @@ -313,9 +346,9 @@ when you call Empty(). \membersection{Default constructors}\label{wxarrayctordef} -\func{}{wxArray}{} +\func{}{wxArray}{\void} -\func{}{wxObjArray}{} +\func{}{wxObjArray}{\void} Default constructor initializes an empty array object. @@ -335,11 +368,11 @@ element passed to it is less than, equal to or greater than the second one. \func{}{wxObjArray}{\param{const wxObjArray\& }{array}} -\func{wxArray\&}{operator=}{\param{const wxArray\& }{array}} +\func{wxArray\&}{operator$=$}{\param{const wxArray\& }{array}} -\func{wxSortedArray\&}{operator=}{\param{const wxSortedArray\& }{array}} +\func{wxSortedArray\&}{operator$=$}{\param{const wxSortedArray\& }{array}} -\func{wxObjArray\&}{operator=}{\param{const wxObjArray\& }{array}} +\func{wxObjArray\&}{operator$=$}{\param{const wxObjArray\& }{array}} The copy constructors and assignment operators perform a shallow array copy (i.e. they don't copy the objects pointed to even if the source array contains @@ -348,11 +381,11 @@ the array element are copied too) for wxObjArray. \membersection{wxArray::\destruct{wxArray}}\label{wxarraydtor} -\func{}{\destruct{wxArray}}{} +\func{}{\destruct{wxArray}}{\void} -\func{}{\destruct{wxSortedArray}}{} +\func{}{\destruct{wxSortedArray}}{\void} -\func{}{\destruct{wxObjArray}}{} +\func{}{\destruct{wxObjArray}}{\void} The wxObjArray destructor deletes all the items owned by the array. This is not done by wxArray and wxSortedArray versions - you may use @@ -360,26 +393,29 @@ done by wxArray and wxSortedArray versions - you may use \membersection{wxArray::Add}\label{wxarrayadd} -\func{\void}{Add}{\param{T }{item}} +\func{void}{Add}{\param{T }{item}} -\func{\void}{Add}{\param{T *}{item}} +\func{void}{Add}{\param{T *}{item}} -\func{\void}{Add}{\param{T \&}{item}} +\func{void}{Add}{\param{T \&}{item}} Appends a new element to the array (where {\it T} is the type of the array elements.) The first version is used with wxArray and wxSortedArray. The second and the -third are used with wxObjArray. There is an {\bf important difference} between +third are used with wxObjArray. There is an important difference between them: if you give a pointer to the array, it will take ownership of it, i.e. will delete it when the item is deleted from the array. If you give a reference to the array, however, the array will make a copy of the item and will not take ownership of the original item. Once again, it only makes sense for wxObjArrays because the other array types never take ownership of their elements. +You may also use \helpref{WX\_APPEND\_ARRAY}{wxappendarray} macro to append all +elements of one array to another one. + \membersection{wxArray::Alloc}\label{wxarrayalloc} -\func{\void}{Alloc}{\param{size\_t }{count}} +\func{void}{Alloc}{\param{size\_t }{count}} Preallocates memory for a given number of array elements. It is worth calling when the number of items which are going to be added to the array is known in @@ -388,7 +424,7 @@ has enough memory for the given number of items, nothing happens. \membersection{wxArray::Clear}\label{wxarrayclear} -\func{\void}{Clear}{\void} +\func{void}{Clear}{\void} This function does the same as \helpref{Empty()}{wxarrayempty} and additionally frees the memory allocated to the array. @@ -405,17 +441,16 @@ it exists only for compatibility. \func{T *}{Detach}{\param{size\_t }{index}} Removes the element from the array, but, unlike, - \helpref{Remove()}{wxarrayremove} doesn't delete it. The function returns the pointer to the removed element. \membersection{wxArray::Empty}\label{wxarrayempty} -\func{\void}{Empty}{\void} +\func{void}{Empty}{\void} Empties the array. For wxObjArray classes, this destroys all of the array elements. For wxArray and wxSortedArray this does nothing except marking the -array of being empty - this function does not free the allocated memory, use +array of being empty - this function does not free the allocated memory, use \helpref{Clear()}{wxarrayclear} for this. \membersection{wxArray::GetCount}\label{wxarraygetcount} @@ -442,16 +477,22 @@ Linear search is used for the wxArray and wxObjArray classes but binary search in the sorted array is used for wxSortedArray (this is why searchFromEnd parameter doesn't make sense for it). +{\bf NB:} even for wxObjArray classes, the operator==() of the elements in the +array is {\bf not} used by this function. It searches exactly the given +element in the array and so will only succeed if this element had been +previously added to the array, but fail even if another, identical, element is +in the array. + \membersection{wxArray::Insert}\label{wxarrayinsert} -\func{\void}{Insert}{\param{T }{item}, \param{size\_t }{n}} +\func{void}{Insert}{\param{T }{item}, \param{size\_t }{n}} -\func{\void}{Insert}{\param{T *}{item}, \param{size\_t }{n}} +\func{void}{Insert}{\param{T *}{item}, \param{size\_t }{n}} -\func{\void}{Insert}{\param{T \&}{item}, \param{size\_t }{n}} +\func{void}{Insert}{\param{T \&}{item}, \param{size\_t }{n}} -Insert a new item into the array before the item {\it n} - thus, {\it -Insert(something, 0u}} will insert an item in such way that it will become the +Insert a new item into the array before the item {\it n} - thus, {\it Insert(something, 0u)} will +insert an item in such way that it will become the first array element. Please see \helpref{Add()}{wxarrayadd} for explanation of the differences @@ -459,7 +500,7 @@ between the overloaded versions of this function. \membersection{wxArray::IsEmpty}\label{wxarrayisempty} -\constfunc{bool}{IsEmpty}{} +\constfunc{bool}{IsEmpty}{\void} Returns TRUE if the array is empty, FALSE otherwise. @@ -486,12 +527,13 @@ the array classes. \membersection{wxArray::Remove}\label{wxarrayremove} -\func{\void}{Remove}{\param{size\_t }{index}} - \func{\void}{Remove}{\param{T }{item}} -Removes the element from the array either by index or by value. When an element -is removed from wxObjArray it is deleted by the array - use +Removes the element from the array either by value: the first item of the +array equal to {\it item} is removed, an assert failure will result from an +attempt to remove an item which doesn't exist in the array. + +When an element is removed from wxObjArray it is deleted by the array - use \helpref{Detach()}{wxobjarraydetach} if you don't want this to happen. On the other hand, when an object is removed from a wxArray nothing happens - you should delete the it manually if required: @@ -505,9 +547,28 @@ array.Remove(n) See also \helpref{WX\_CLEAR\_ARRAY}{wxcleararray} macro which deletes all elements of a wxArray (supposed to contain pointers). +\membersection{wxArray::RemoveAt}\label{wxarrayremoveat} + +\func{\void}{RemoveAt}{\param{size\_t }{index}} + +Removes the element from the array either by index. When an element +is removed from wxObjArray it is deleted by the array - use +\helpref{Detach()}{wxobjarraydetach} if you don't want this to happen. On the +other hand, when an object is removed from a wxArray nothing happens - you +should delete the it manually if required: + +\begin{verbatim} +T *item = array[n]; +delete item; +array.RemoveAt(n) +\end{verbatim} + +See also \helpref{WX\_CLEAR\_ARRAY}{wxcleararray} macro which deletes all +elements of a wxArray (supposed to contain pointers). + \membersection{wxArray::Shrink}\label{wxarrayshrink} -\func{\void}{Shrink}{\void} +\func{void}{Shrink}{\void} Frees all memory unused by the array. If the program knows that no new items will be added to the array it may call Shrink() to reduce its memory usage. @@ -516,7 +577,7 @@ allocated again. \membersection{wxArray::Sort}\label{wxarraysort} -\func{\void}{Sort}{\param{CMPFUNC }{compareFunction}} +\func{void}{Sort}{\param{CMPFUNC }{compareFunction}} The notation CMPFUNC should be read as if we had the following declaration: @@ -524,7 +585,7 @@ The notation CMPFUNC should be read as if we had the following declaration: template int CMPFUNC(T *first, T *second); \end{verbatim} -where {\it T} is the type of the array elements. I.e. it is a function returning +where {\it T} is the type of the array elements. I.e. it is a function returning {\it int} which is passed two arguments of type {\it T *}. Sorts the array using the specified compare function: this function should