X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/06ad863606966ceee6e7eea537f8d427f0d891a9..706f14210b7d782742b4fdbaea0adc25bdcced4d:/docs/latex/wx/array.tex diff --git a/docs/latex/wx/array.tex b/docs/latex/wx/array.tex index 0cd2f78b5b..e814dfad1e 100644 --- a/docs/latex/wx/array.tex +++ b/docs/latex/wx/array.tex @@ -39,21 +39,27 @@ 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 function for comparing two elements of the array element type and always stores -its items in the sorted order (according to this function). Thus, it's +its items in the sorted order (according to this function). Thus, it is \helpref{Index()}{wxarrayindex} function execution time is $O(log(N))$ instead of $O(N)$ for the usual arrays but the \helpref{Add()}{wxarrayadd} method is 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 @@ -69,7 +75,7 @@ example: \begin{verbatim} #include -// we must forward declare the array because it's used inside the class +// we must forward declare the array because it is used inside the class // declaration class MyDirectory; class MyFile; @@ -89,7 +95,9 @@ 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 linking errors) #include // this is a magic incantation which must be done! WX_DEFINE_OBJARRAY(ArrayOfDirectories); @@ -109,15 +117,19 @@ Things are much simpler for wxArray and wxSortedArray however: it is enough just to write \begin{verbatim} -WX_DEFINE_ARRAY(MyDirectory *, ArrayOfDirectories); -WX_DEFINE_SORTED_ARRAY(MyFile *, ArrayOfFiles); +WX_DEFINE_ARRAY(int, ArrayOfDirectories); +WX_DEFINE_SORTED_ARRAY(int, ArrayOfFiles); \end{verbatim} +i.e. there is only one {\tt DEFINE} macro and no need for separate +{\tt DECLARE} one. + + \wxheading{See also:} \helpref{Container classes overview}{wxcontaineroverview}, \helpref{wxList}{wxlist} -\wxheading{Required headers:} +\wxheading{Include files} for wxArray and wxSortedArray and additionally for wxObjArray. @@ -133,9 +145,27 @@ 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\_USER\_EXPORTED\_ARRAY}{wxdefinearray}\\ \helpref{WX\_DEFINE\_SORTED\_ARRAY}{wxdefinesortedarray}\\ -\helpref{WX\_DECLARE\_OBJARRAY}{wxdeclareobjarray}\\ -\helpref{WX\_DEFINE\_OBJARRAY}{wxdefineobjarray} +\helpref{WX\_DEFINE\_SORTED\_EXPORTED\_ARRAY}{wxdefinesortedarray}\\ +\helpref{WX\_DEFINE\_SORTED\_USER\_EXPORTED\_ARRAY}{wxdefinesortedarray}\\ +\helpref{WX\_DECLARE\_EXPORTED\_OBJARRAY}{wxdeclareobjarray}\\ +\helpref{WX\_DECLARE\_USER\_EXPORTED\_OBJARRAY}{wxdeclareobjarray}\\ +\helpref{WX\_DEFINE\_OBJARRAY}{wxdefineobjarray}\\ +\helpref{WX\_DEFINE\_EXPORTED\_OBJARRAY}{wxdefineobjarray}\\ +\helpref{WX\_DEFINE\_USER\_EXPORTED\_OBJARRAY}{wxdefineobjarray} + +To slightly complicate the matters even further, the operator $->$ defined by +default for the array iterators by these macros only makes sense if the array +element type is not a pointer itself and, although it still works, this +provokes warnings from some compilers and to avoid them you should use the +{\tt \_PTR} versions of the macros above. For example, to define an array of +pointers to {\tt double} you should use + +\begin{verbatim} +WX_DEFINE_ARRAY_PTR(double *, MyArrayOfDoublePointers); +\end{verbatim} \membersection{Constructors and destructors} @@ -162,7 +192,7 @@ amount, but no more than some maximal number which is defined by ARRAY\_MAXSIZE\_INCREMENT constant. Of course, this may lead to some memory being wasted (ARRAY\_MAXSIZE\_INCREMENT in the worst case, i.e. 4Kb in the current implementation), so the \helpref{Shrink()}{wxarrayshrink} function is -provided to unallocate the extra memory. The \helpref{Alloc()}{wxarrayalloc} +provided to deallocate the extra memory. The \helpref{Alloc()}{wxarrayalloc} function can also be quite useful if you know in advance how many items you are going to put in the array and will prevent the array code from reallocating the memory more times than needed. @@ -185,13 +215,16 @@ does exactly the same as \helpref{Item()}{wxarrayitem} method. \membersection{Adding items} \helpref{Add}{wxarrayadd}\\ -\helpref{Insert}{wxarrayinsert} +\helpref{Insert}{wxarrayinsert}\\ +\helpref{SetCount}{wxarraysetcount}\\ +\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} @@ -210,8 +243,16 @@ does exactly the same as \helpref{Item()}{wxarrayitem} method. \func{}{WX\_DEFINE\_ARRAY}{\param{}{T}, \param{}{name}} +\func{}{WX\_DEFINE\_EXPORTED\_ARRAY}{\param{}{T}, \param{}{name}} + +\func{}{WX\_DEFINE\_USER\_EXPORTED\_ARRAY}{\param{}{T}, \param{}{name}, \param{}{exportspec}} + 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 wxWindows as +a DLL under Windows and array needs to be visible outside the DLL. The third is +needed for exporting an array from a user DLL. + +Example: \begin{verbatim} WX_DEFINE_ARRAY(int, wxArrayInt); @@ -227,25 +268,34 @@ wxArrayLong and wxArrayPtrVoid. \func{}{WX\_DEFINE\_SORTED\_ARRAY}{\param{}{T}, \param{}{name}} +\func{}{WX\_DEFINE\_SORTED\_EXPORTED\_ARRAY}{\param{}{T}, \param{}{name}} + +\func{}{WX\_DEFINE\_SORTED\_USER\_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 wxWindows as +a DLL under Windows and array needs to be visible outside the DLL. The third is +needed for exporting an array from a user DLL. + +Example: \begin{verbatim} -WX_DEFINE_SORTED_ARRAY(int, wxArrayInt); +WX_DEFINE_SORTED_ARRAY(int, wxSortedArrayInt); class MyClass; WX_DEFINE_SORTED_ARRAY(MyClass *, wxArrayOfMyClass); \end{verbatim} -You will have to initialize the objects of this class by passing a comparaison +You will have to initialize the objects of this class by passing a comparison function to the array object constructor like this: + \begin{verbatim} int CompareInts(int n1, int n2) { return n1 - n2; } -wxArrayInt sorted(CompareInts); +wxSortedArrayInt sorted(CompareInts); int CompareMyClassObjects(MyClass *item1, MyClass *item2) { @@ -260,12 +310,20 @@ wxArrayOfMyClass another(CompareMyClassObjects); \func{}{WX\_DECLARE\_OBJARRAY}{\param{}{T}, \param{}{name}} +\func{}{WX\_DECLARE\_EXPORTED\_OBJARRAY}{\param{}{T}, \param{}{name}} + +\func{}{WX\_DECLARE\_USER\_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 wxWindows as +a DLL under Windows and array needs to be visible outside the DLL. The third is +needed for exporting an array from a user DLL. + +Example: \begin{verbatim} class MyClass; -WX_DEFINE_OBJARRAY(MyClass, wxArrayOfMyClass); // note: not "MyClass *"! +WX_DECLARE_OBJARRAY(MyClass, wxArrayOfMyClass); // note: not "MyClass *"! \end{verbatim} You must use \helpref{WX\_DEFINE\_OBJARRAY()}{wxdefineobjarray} macro to define @@ -275,6 +333,10 @@ the array class - otherwise you would get link errors. \func{}{WX\_DEFINE\_OBJARRAY}{\param{}{name}} +\func{}{WX\_DEFINE\_EXPORTED\_OBJARRAY}{\param{}{name}} + +\func{}{WX\_DEFINE\_USER\_EXPORTED\_OBJARRAY}{\param{}{name}} + This macro defines the methods of the array class {\it name} not defined by the \helpref{WX\_DECLARE\_OBJARRAY()}{wxdeclareobjarray} macro. You must include the file before using this macro and you must have the full @@ -282,7 +344,8 @@ declaration of the class of array elements in scope! If you forget to do the first, the error will be caught by the compiler, but, unfortunately, many compilers will not give any warnings if you forget to do the second - but the objects of the class will not be copied correctly and their real destructor will -not be called. +not be called. The latter two forms are merely aliases of the first to satisfy +some people's sense of symmetry when using the exported declarations. Example of usage: @@ -302,9 +365,16 @@ 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 @@ -312,16 +382,16 @@ 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. \func{}{wxSortedArray}{\param{int (*)(T first, T second)}{compareFunction}} There is no default constructor for wxSortedArray classes - you must initialize it -with a function to use for item comparaison. It is a function which is passed +with a function to use for item comparison. It is a function which is passed two arguments of type {\it T} where {\it T} is the array element type and which should return a negative, zero or positive value according to whether the first element passed to it is less than, equal to or greater than the second one. @@ -359,26 +429,33 @@ 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}, \param{size\_t}{ copies = $1$}} -\func{\void}{Add}{\param{T *}{item}} +\func{void}{Add}{\param{T *}{item}} -\func{\void}{Add}{\param{T \&}{item}} +\func{void}{Add}{\param{T \&}{item}, \param{size\_t}{ copies = $1$}} -Appends a new element to the array (where {\it T} is the type of the array -elements.) +Appends the given number of {\it copies} of the {\it item} to the array +consisting of the elements of type {\it T}. 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. +because the other array types never take ownership of their elements. Also note +that you cannot append more than one pointer as reusing it would lead to +deleting it twice (or more) and hence to a crash. + +You may also use \helpref{WX\_APPEND\_ARRAY}{wxappendarray} macro to append all +elements of one array to another one but it is more efficient to use +{\it copies} parameter and modify the elements in place later if you plan to +append a lot of items. \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 @@ -387,7 +464,7 @@ 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. @@ -404,17 +481,16 @@ 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} @@ -425,7 +501,7 @@ Return the number of items in the array. \membersection{wxArray::Index}\label{wxarrayindex} -\func{int}{Index}{\param{T\& }{item}, \param{bool }{searchFromEnd = FALSE}} +\func{int}{Index}{\param{T\& }{item}, \param{bool }{searchFromEnd = false}} \func{int}{Index}{\param{T\& }{item}} @@ -441,26 +517,32 @@ 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}, \param{size\_t }{copies = $1$}} -\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}, \param{size\_t }{copies = $1$}} -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. +Insert the given number of {\it copies} of the {\it item} into the array before +the existing 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 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. +Returns true if the array is empty, false otherwise. \membersection{wxArray::Item}\label{wxarrayitem} @@ -485,15 +567,16 @@ 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 an element from the array 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: +should delete it manually if required: \begin{verbatim} T *item = array[n]; @@ -504,9 +587,41 @@ 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}, \param{size\_t }{count = $1$}} + +Removes {\it count} elements starting at {\it index} from 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 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::SetCount}\label{wxarraysetcount} + +\func{void}{SetCount}{\param{size\_t }{count}, \param{T }{defval = T($0$)}} + +This function ensures that the number of array elements is at least +{\it count}. If the array has already {\it count} or mroe items, nothing is +done. Otherwise, {\tt count - GetCount()} elements are added and initialized to +the value {\it defval}. + +\wxheading{See also} + +\helpref{GetCount}{wxarraygetcount} + \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. @@ -515,7 +630,7 @@ 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: @@ -523,7 +638,7 @@ 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