From: Vadim Zeitlin Date: Sun, 10 Jan 1999 23:15:35 +0000 (+0000) Subject: 1. wxFile docs updated, wxTextFile and wxTempFile docs written (thanks HelpGen :-) X-Git-Url: https://git.saurik.com/wxWidgets.git/commitdiff_plain/247aba106508dfd3c8beeff07817b0f2d6525c69 1. wxFile docs updated, wxTextFile and wxTempFile docs written (thanks HelpGen :-) Added file classes section to the "classes by category" and tfile.tex - file classes/functions overview, feel free to add stuff there. 2. wxArray docs finally written. git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@1368 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775 --- diff --git a/docs/latex/wx/array.tex b/docs/latex/wx/array.tex index 41d5c66f3f..1944a7153b 100644 --- a/docs/latex/wx/array.tex +++ b/docs/latex/wx/array.tex @@ -1,3 +1,484 @@ \section{\class{wxArray}}\label{wxarray} -TODO +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 +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 +compile your application in debug mode to use it (see \helpref{debugging +overview}{debuggingoverview} for details). So, unlike the arrays in some other +languages, attempt to access an element beyond the arrays bound doesn't +automatically expand the array but provokes an assertion failure instead in +debug build and does nothing (except possibly crashing your program) in the +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) +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 you may find some +useful hints about optimizing wxArray memory usage. As for executable size, all +wxArray functions are inline, so they do not take {\it any space at all}. + +wxWindows has three different kinds of array. All of them derive from +wxBaseArray class which works with untyped data and can not be used directly. +The standard macros WX\_DEFINE\_ARRAY(), WX\_DEFINE\_SORTED\_ARRAY() and +WX\_DEFINE\_OBJARRAY() are used to define a new class deriving from it. The +classes declared will be called in this documentation wxArray, wxSortedArray and +wxObjArray but you should keep in mind that no classes with such names actually +exist, each time you use one of WX\_DEFINE\_XXXARRAY macro you define a class +with a new name. In fact, these names are "template" names and each usage of one +of the macros mentioned above creates a template specialization for the given +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 +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. + +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 +\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. As wxArray this array can not +be used + +wxObjArray class treats its elements like "objects". It may delete them when +they are removed from the array (invoking the correct destructor) and copies +them using the objects copy constructor. In order to implement this behaviour +the definition of the wxObjArray arrays is split in two parts: first, you should +declare the new wxObjArray class using WX\_DECLARE\_OBJARRAY() macro and then +you must include the file defining the implementation of template type: + and define the array class with WX\_DEFINE\_OBJARRAY() macro +from a point where the full (as opposed to `forward') declaration of the array +elements class is in scope. As it probably sounds very complicated here is an +example: + +\begin{verbatim} +#include + +// we must forward declare the array because it's used inside the class +// declaration +class MyDirectory; +class MyFile; + +// this defines two new types: ArrayOfDirectories and ArrayOfFiles which can be +// now used as shown below +WX_DECLARE_OBJARRAY(MyDirectory, ArrayOfDirectories); +WX_DECLARE_OBJARRAY(MyFile, ArrayOfFiles); + +class MyDirectory +{ +... + ArrayOfDirectories m_subdirectories; // all subdirectories + ArrayOfFiles m_files; // all files in this directory +}; + +... + +// now that we have MyDirectory declaration in scope we may finish the +// definition of ArrayOfDirectories +#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 + +\begin{verbatim} +typedef std::vector ArrayOfDirectories; +\end{verbatim} +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 +just to write + +\begin{verbatim} +WX_DEFINE_ARRAY(MyDirectory *, ArrayOfDirectories); +WX_DEFINE_SORTED_ARRAY(MyFile *, ArrayOfFiles); +\end{verbatim} + +\wxheading{See also:} + +\helpref{Container classes overview}{wxcontaineroverview}, \helpref{wxList}{wxlist} + +\wxheading{Required headers:} + + for wxArray and wxSortedArray and additionally +for wxObjArray. + +\latexignore{\rtfignore{\wxheading{Function groups}}} + +\membersection{Macros for template array definition} + +To use an array you must first define the array class. This is done with the +help of the macros in this section. The class of array elements must be (at +least) forward declared for WX\_DEFINE\_ARRAY, WX\_DEFINE\_SORTED\_ARRAY and +WX\_DECLARE\_OBJARRAY macros and must be fully declared before you use +WX\_DEFINE\_OBJARRAY macro. + +\helpref{WX\_DEFINE\_ARRAY}{wxdefinearray}\\ +\helpref{WX\_DEFINE\_SORTED\_ARRAY}{wxdefinesortedarray}\\ +\helpref{WX\_DECLARE\_OBJARRAY}{wxdeclareobjarray}\\ +\helpref{WX\_DEFINE\_OBJARRAY}{wxdefineobjarray} + +\membersection{Constructors and destructors} + +Array classes are 100\% C++ objects and as such they have the appropriate copy +constructors and assignment operators. Copying wxArray just copies the elements +but copying wxObjArray copies the arrays items. However, for memory-efficiency +sake, neither of these classes has virtual destructor. It is not very important +for wxArray which has trivial destructor anyhow, but it does mean that you +should avoid deleting wxObjArray through a wxBaseArray pointer (as you would +never use wxBaseArray anyhow it shouldn't be a problem) and that you should not +derive your own classes from the array classes. + +\helpref{wxArray default constructor}{wxarrayctordef} +\helpref{wxArray copy constructors and assignment operators}{wxarrayctorcopy} +\helpref{\destruct{wxArray}}{wxarraydtor} + +\membersection{Memory management}\label{wxarraymemorymanagement} + +Automatic array memory management is quite trivial: the array starts by +preallocating some minimal amount of memory (defined by +WX\_ARRAY\_DEFAULT\_INITIAL\_SIZE) and when further new items exhaust already +allocated memory it reallocates it adding 50\% of the currently allocated +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} +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. + +\helpref{Alloc}{wxarrayalloc}\\ +\helpref{Shrink}{wxarrayshrink} + +\membersection{Number of elements and simple item access} + +Functions in this section return the total number of array elements and allow to +retrieve them - possibly using just the C array indexing $[]$ operator which +does exactly the same as \helpref{Item()}{wxarrayitem} method. + +\helpref{Count}{wxarraycount}\\ +\helpref{GetCount}{wxarraygetcount}\\ +\helpref{IsEmpty}{wxarrayisempty}\\ +\helpref{Item}{wxarrayitem}\\ +\helpref{Last}{wxarraylast} + +\membersection{Adding items} +\helpref{Add}{wxarrayadd}\\ +\helpref{Insert}{wxarrayinsert} + +\membersection{Removing items} +\helpref{WX\_CLEAR\_ARRAY}{wxcleararray}\\ +\helpref{Empty}{wxarrayempty}\\ +\helpref{Clear}{wxarrayclear}\\ +\helpref{Remove}{wxarrayremove} + +\membersection{Searching and sorting} +\helpref{Index}{wxarrayindex}\\ +\helpref{Sort}{wxarraysort} + +%%%%% MEMBERS HERE %%%%% +\helponly{\insertatlevel{2}{ + +\wxheading{Members} + +}} + +\membersection{WX\_DEFINE\_ARRAY}\label{wxdefinearray} +\func{}{WX\_DEFINE\_ARRAY}{\param{}{T}, \param{name}} + +This macro defines a new array class named {\it name} and containing the +elements of type {\it T}. Example: +\begin{verbatim} +WX_DEFINE_ARRAY(int, wxArrayInt); + +class MyClass; +WX_DEFINE_ARRAY(MyClass *, wxArrayOfMyClass); +\end{verbatim} + +Note that wxWindows predefines the following standard array classes: wxArrayInt, +wxArrayLong and wxArrayPtrVoid. + +\membersection{WX\_DEFINE\_SORTED\_ARRAY}\label{wxdefinesortedarray} +\func{}{WX\_DEFINE\_SORTED\_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: +\begin{verbatim} +WX_DEFINE_SORTED_ARRAY(int, wxArrayInt); + +class MyClass; +WX_DEFINE_SORTED_ARRAY(MyClass *, wxArrayOfMyClass); +\end{verbatim} + +You will have to initialize the objects of this class by passing a comparaison +function to the array object constructor like this: +\begin{verbatim} +int CompareInts(int n1, int n2) +{ + return n1 - n2; +} + +wxArrayInt sorted(CompareInts); + +int CompareMyClassObjects(MyClass *item1, MyClass *item2) +{ + // sort the items by their address... + return Stricmp(item1->GetAddress(), item2->GetAddress()); +} + +wxArrayOfMyClass another(CompareMyClassObjects); +\end{verbatim} + +\membersection{WX\_DECLARE\_OBJARRAY}\label{wxdeclareobjarray} +\func{}{WX\_DECLARE\_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: +\begin{verbatim} +class MyClass; +WX_DEFINE_OBJARRAY(MyClass, wxArrayOfMyClass); // note: not "MyClass *"! +\end{verbatim} +You must use \helpref{WX\_DEFINE\_OBJARRAY()}{wxdefineobjarray} macro to define +the array class - otherwise you would get link errors. + +\membersection{WX\_DEFINE\_OBJARRAY}\label{wxdefineobjarray} +\func{}{WX\_DEFINE\_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 +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. + +Example of usage: +\begin{verbatim} +// first declare the class! +class MyClass +{ +public: + MyClass(const MyClass&); + + ... + + virtual ~MyClass(); +}; + +#include +WX_DEFINE_OBJARRAY(wxArrayOfMyClass); +\end{verbatim} + +\membersection{WX\_CLEAR\_ARRAY}\label{wxcleararray} +\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 +when you call Empty(). + +\membersection{Default constructors}\label{wxarrayctor} +\func{}{wxArray}{} +\func{}{wxObjArray}{} + +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 +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. + +\membersection{wxArray copy constructor and assignemnt operator}\label{wxarrayctorcopy} +\func{}{wxArray}{\param{const wxArray\& }{array}} +\func{}{wxSortedArray}{\param{const wxSortedArray\& }{array}} +\func{}{wxObjArray}{\param{const wxObjArray\& }{array}} + +\func{wxArray\&}{operator=}{\param{const wxArray\& }{array}} +\func{wxSortedArray\&}{operator=}{\param{const wxSortedArray\& }{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 +the items of pointer type) for wxArray and wxSortedArray and a deep copy (i.e. +the array element are copied too) for wxObjArray. + +\membersection{wxArray::\destruct{wxArray}}\label{wxarraydtor} +\func{}{\destruct{wxArray}}{} +\func{}{\destruct{wxSortedArray}}{} +\func{}{\destruct{wxObjArray}}{} + +The wxObjArray destructor deletes all the items owned by the array. This is not +done by wxArray and wxSortedArray versions - you may use +\helpref{WX\_CLEAR\_ARRAY}{wxcleararray} macro for this. + +\membersection{wxArray::Add}\label{wxarrayadd} +\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 +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. + +\membersection{wxArray::Alloc}\label{wxarrayalloc} +\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 +advance because it will save unneeded memory reallocation. If the array already +has enough memory for the given number of items, nothing happens. + +\membersection{wxArray::Clear}\label{wxarrayclear} +\func{\void}{Clear}{\void} + +This function does the same as \helpref{Empty()}{wxarrayempty} and additionally +frees the memory allocated to the array. + +\membersection{wxArray::Count}\label{wxarraycount} +\constfunc{size\_t}{Count}{\void} + +Same as \helpref{GetCount()}{wxarraygetcount}. This function is deprecated - +it exists only for compatibility. + +\membersection{wxObjArray::Detach}\label{wxobjarraydetach} +\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} + +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 +\helpref{Clear()}{wxarrayclear} for this. + +\membersection{wxArray::GetCount}\label{wxarraygetcount} +\constfunc{size\_t}{GetCount}{\void} + +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}} + +The first version of the function is for wxArray and wxObjArray, the second is +for wxSortedArray only. + +Searches the element in the array, starting from either beginning or the end +depending on the value of {\it searchFromEnd} parameter. wxNOT\_FOUND is +returned if the element is not found, otherwise the index of the element is +returned. + +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). + +\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}} + +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 +between the overloaded versions of this function. + +\membersection{wxArray::IsEmpty}\label{wxarrayisempty} +\constfunc{bool}{IsEmpty}{} + +Returns TRUE if the array is empty, FALSE otherwise. + +\membersection{wxArray::Item}\label{wxarrayitem} +\constfunc{T\&}{Item}{\param{size\_t }{index}} + +Returns the item at the given position in the array. If {\it index} is out of +bounds, an assert failure is raised in the debug builds but nothing special is +done in the release build. + +The returned value is of type "reference to the array element type" for all of +the array classes. + +\membersection{wxArray::Last}\label{wxarraylast} +\constfunc{T\&}{Last}{\void} + +Returns the last element in the array, i.e. is the same as Item(GetCount() - 1). +An assert failure is raised in the debug mode if the array is empty. + +The returned value is of type "reference to the array element type" for all of +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 +\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.Remove(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} + +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. +However, if a new item is added to the array, some extra memory will be +allocated again. + +\membersection{wxArray::Sort}\label{wxarraysort} +\func{\void}{Sort}{\param{CMPFUNC }{compareFunction}} + +The notation CMPFUNC should be read as if we had the following declaration: +\begin{verbatim} +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 +{\it int} which is passed two arguments of type {\it T *}. + +Sorts the array using the specified compare function: this function 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. + +wxSortedArray doesn't have this function because it is always sorted. diff --git a/docs/latex/wx/category.tex b/docs/latex/wx/category.tex index f9b7786266..c67d98c573 100644 --- a/docs/latex/wx/category.tex +++ b/docs/latex/wx/category.tex @@ -326,6 +326,17 @@ product. \twocolitem{\helpref{wxRecordSet}{wxrecordset}}{Class representing one or more record} \end{twocollist} +{\large {\bf File related classes}} + +wxWindows has several small classes to work with disk files, see \helpref{file classes +overview}{wxfileoverview} for more details. + +\begin{twocollist}\itemsep=0pt +\twocolitem{\helpref{wxFile}{wxfile}}{Low-level file input/output} +\twocolitem{\helpref{wxTempFile}{wxtempfile}}{Class to safely replace an existing file} +\twocolitem{\helpref{wxTextFile}{wxtextfile}}{Class for working with text files as with arrays of lines} +\end{twocollist} + {\large {\bf Miscellaneous}} \begin{twocollist}\itemsep=0pt @@ -339,5 +350,3 @@ product. \twocolitem{\helpref{wxTimer}{wxtimer}}{Timer class} \twocolitem{\helpref{wxSystemSettings}{wxsystemsettings}}{System settings class} \end{twocollist} - - diff --git a/docs/latex/wx/classes.tex b/docs/latex/wx/classes.tex index 3e0b6cbc0e..91435ff864 100644 --- a/docs/latex/wx/classes.tex +++ b/docs/latex/wx/classes.tex @@ -182,6 +182,8 @@ $$\image{14cm;0cm}{wxclass.ps}$$ \input text.tex \input textdlg.tex \input valtext.tex +\input tempfile.tex +\input textfile.tex \input thread.tex \input time.tex \input timer.tex diff --git a/docs/latex/wx/file.tex b/docs/latex/wx/file.tex index fec5c31d87..da864d38db 100644 --- a/docs/latex/wx/file.tex +++ b/docs/latex/wx/file.tex @@ -1,12 +1,66 @@ \section{\class{wxFile}}\label{wxfile} -A wxFile performs raw file I/O. Note that wxFile::Flush is not implemented on some Windows compilers -due to a missing fsync function, which reduces the usefulness of this class. +A wxFile performs raw file I/O. This is a very small class designed to +minimize the overhead of using it - in fact, there is hardly any overhead at +all, but using it brings you automatic error checking and hides differences +between platforms and compilers. \wxheading{Derived from} None. +\wxheading{Constants} + +wx/file.h defines the following constants: +{\small +\begin{verbatim} +#define wxS_IRUSR 00400 +#define wxS_IWUSR 00200 +#define wxS_IXUSR 00100 + +#define wxS_IRGRP 00040 +#define wxS_IWGRP 00020 +#define wxS_IXGRP 00010 + +#define wxS_IROTH 00004 +#define wxS_IWOTH 00002 +#define wxS_IXOTH 00001 + +// default mode for the new files: corresponds to umask 022 +#define wxS_DEFAULT (wxS_IRUSR | wxS_IWUSR | wxS_IRGRP | wxS_IWGRP | wxS_IROTH | wxS_IWOTH) +\end{verbatim} +} + +These constants define the file access rights and are used with +\helpref{wxFile::Create}{wxfilecreate} and \helpref{wxFile::Open}{wxfileopen}. + +The {\it OpenMode} enumeration defines the different modes for opening a file, +it's defined inside wxFile class so its members should be specified with {\it +wxFile::} scope resolution prefix. It is also used with +\helpref{wxFile::Access}{wxfileaccess} function. + +\twocolwidtha{7cm}% +\begin{twocollist}\itemsep=0pt +\twocolitem{{\bf wxFile::read}}{Open file for reading or test if it can be opened for reading with Access()} +\twocolitem{{\bf wxFile::write}}{Open file for writing deleting the contents of the file if it already exists +or test if it can be opened for writing with Access()} +\twocolitem{{\bf wxFile::read\_write}}{Open file for reading and writing; can not be used with Access()} +\twocolitem{{\bf wxFile::write\_append}}{Open file for appending: the file is opened for writing, but the old +contents of the file is not erased and the file pointer is initially placed at the end of the file; +can not be used with Access()} +\end{twocollist} + +Other constants defined elsewhere but used by wxFile functions are wxInvalidOffset which represents an +invalid value of type {\it off\_t} and is returned by functions returning {\it off\_t} on error and the seek +mode constants used with \helpref{Seek()}{wxfileseek}: + +\twocolwidtha{7cm} +\begin{twocollist}\itemsep=0pt +\twocolitem{{\bf wxFromStart}}{Count offset from the start of the file} +\twocolitem{{\bf wxFromCurrent}}{Count offset from the current position of the file pointer} +\twocolitem{{\bf wxFromEnd}}{Count offset from the end of the file (backwards)} +\end{twocollist} + \latexignore{\rtfignore{\wxheading{Members}}} \membersection{wxFile::wxFile}\label{wxfileconstr} @@ -17,7 +71,10 @@ Default constructor. \func{}{wxFile}{\param{const char*}{ filename}, \param{wxFile::OpenMode}{ mode = wxFile::read}} -Opens a file with the given mode. +Opens a file with the given mode. As there is no way to return whether the +operation was successful or not from the constructor you should test the +return value of \helpref{IsOpened}{wxfileisopened} to check that it didn't +fail. \func{}{wxFile}{\param{int}{ fd}} @@ -29,19 +86,31 @@ Opens a file with the given file descriptor, which has already been opened. \docparam{mode}{The mode in which to open the file. May be one of {\bf wxFile::read}, {\bf wxFile::write} and {\bf wxFile::read\_write}.} -\docparam{fd}{An existing file descriptor.} +\docparam{fd}{An existing file descriptor (see \helpref{Attach()}{wxfileattach} for the list of predefined descriptors)} \membersection{wxFile::\destruct{wxFile}} \func{}{\destruct{wxFile}}{\void} -Destructor. This is not virtual, for efficiency. +Destructor will close the file. -\membersection{wxFile::Attach}\label{wxfileattach} +NB: it is not virtual so you should {\it not} derive from wxFile! + +\membersection{wxFile::Access}\label{wxfileaccess} +\func{static bool}{Access}{\param{const char *}{ name}, \param{OpenMode}{ mode} +This function verifies if we may access the given file in specified mode. Only +values of wxFile::read or wxFile::write really make sense here. + +\membersection{wxFile::Attach}\label{wxfileattach} \func{void}{Attach}{\param{int}{ fd}} -Attaches an existing file descriptor to the wxFile object. +Attaches an existing file descriptor to the wxFile object. Example of predefined +file descriptors are 0, 1 and 2 which correspond to stdin, stdout and stderr (and +have symbolic names of wxFile::fd\_stdin, wxFile::fd\_stdout and wxFile::fd\_stderr). + +The descriptor should be already opened and it will be closed by wxFile +object. \membersection{wxFile::Close}\label{wxfileclose} @@ -51,11 +120,22 @@ Closes the file. \membersection{wxFile::Create}\label{wxfilecreate} -\func{bool}{Create}{\param{const char*}{ filename}, \param{bool}{ overwrite = FALSE}} +\func{bool}{Create}{\param{const char*}{ filename}, \param{bool}{ overwrite = FALSE}, \param{int }{access = wxS\_DEFAULT}} Creates a file for writing. If the file already exists, setting {\bf overwrite} to TRUE will ensure it is overwritten. +\membersection{wxFile::Detach}\label{wxfiledetach} +\func{void}{Detach}{\void} + +Get back a file descriptor from wxFile object - the caller is responsible for closing the file if this +descriptor is opened. \helpref{IsOpened()}{wxfileisopened} will return FALSE after call to Detach(). + +\membersection{wxFile::fd}\label{wxfilefd} +\constfunc{int}{fd}{\void} + +Returns the file descriptor associated with the file. + \membersection{wxFile::Eof}\label{wxfileeof} \constfunc{bool}{Eof}{\void} @@ -66,13 +146,17 @@ Returns TRUE if the end of the file has been reached. \func{static bool}{Exists}{\param{const char*}{ filename}} -Returns TRUE if the file exists. +Returns TRUE if the given name specifies an existing regular file. \membersection{wxFile::Flush}\label{wxfileflush} \func{bool}{Flush}{\void} -Flushes the file descriptor. Not implemented for some Windows compilers. +Flushes the file descriptor. + +Note that wxFile::Flush is not implemented on some Windows compilers +due to a missing fsync function, which reduces the usefulness of this function +(it can still be called but it will do nothing on unsupported compilers). \membersection{wxFile::IsOpened}\label{wxfileisopened} @@ -112,7 +196,7 @@ Reads the specified number of bytes into a buffer, returning the actual number r \wxheading{Return value} -The number of bytes read, or the symbol {\bf ofsInvalid} (-1) if there was an error. +The number of bytes read, or the symbol {\bf wxInvalidOffset} (-1) if there was an error. \membersection{wxFile::Seek}\label{wxfileseek} @@ -128,7 +212,7 @@ Seeks to the specified position. \wxheading{Return value} -The actual offset position achieved, or ofsInvalid on failure. +The actual offset position achieved, or wxInvalidOffset on failure. \membersection{wxFile::SeekEnd}\label{wxfileseekend} @@ -142,13 +226,14 @@ Moves the file pointer to the specified number of bytes before the end of the fi \wxheading{Return value} -The actual offset position achieved, or ofsInvalid on failure. +The actual offset position achieved, or wxInvalidOffset on failure. \membersection{wxFile::Tell}\label{wxfiletell} \constfunc{off\_t}{Tell}{\void} -Returns the current position. +Returns the current position or wxInvalidOffset if file is not opened or if another +error occured. \membersection{wxFile::Write}\label{wxfilewrite} @@ -166,4 +251,7 @@ Writes the specified number of bytes from a buffer. TRUE if the operation was successful. +\membersection{wxFile::Write}\label{wxfilewrites} +\func{bool}{Write}{\param{const wxString& }{s}} +Writes the contents of the string to the file, returns TRUE on success diff --git a/docs/latex/wx/tcontain.tex b/docs/latex/wx/tcontain.tex index 6240359e43..8f8cc6d47d 100644 --- a/docs/latex/wx/tcontain.tex +++ b/docs/latex/wx/tcontain.tex @@ -21,7 +21,7 @@ your programs as well if you wish. The list classes in wxWindows are double-linked lists which may either own the objects they contain (meaning that the list deletes the object when it is removed from the list or the list itself is destroyed) or just store the -pointers depending on whether you called or not +pointers depending on whether you called or not \helpref{wxList::DeleteContents}{wxlistdeletecontents} method. Dynamic arrays resemble to C arrays but with two important differences: they diff --git a/docs/latex/wx/topics.tex b/docs/latex/wx/topics.tex index 8d72072f1d..cda8c6764d 100644 --- a/docs/latex/wx/topics.tex +++ b/docs/latex/wx/topics.tex @@ -38,4 +38,5 @@ This chapter contains a selection of topic overviews. \input tstring.tex \input tdnd.tex \input tthreads.tex +\input tfile.tex \input tusage.tex