X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/57bf907d8e45ced18486d74c04f41c06034b7e65..1b7751aaa9a86d76a850b9267bc0c201e3cea30f:/interface/wx/stream.h diff --git a/interface/wx/stream.h b/interface/wx/stream.h index d668a6d6d4..51b983dd8a 100644 --- a/interface/wx/stream.h +++ b/interface/wx/stream.h @@ -3,98 +3,135 @@ // Purpose: interface of wxStreamBase and its derived classes // Author: wxWidgets team // RCS-ID: $Id$ -// Licence: wxWindows license +// Licence: wxWindows licence ///////////////////////////////////////////////////////////////////////////// + /** - @class wxCountingOutputStream + These enumeration values are returned by various functions in the context + of wxStream classes. +*/ +enum wxStreamError +{ + wxSTREAM_NO_ERROR = 0, //!< No error occurred. + wxSTREAM_EOF, //!< EOF reached in Read() or similar. + wxSTREAM_WRITE_ERROR, //!< generic write error on the last write call. + wxSTREAM_READ_ERROR //!< generic read error on the last read call. +}; - wxCountingOutputStream is a specialized output stream which does not write any - data anywhere, instead it counts how many bytes would get written if this were a - normal stream. This can sometimes be useful or required if some data gets - serialized to a stream or compressed by using stream compression and thus the - final size of the stream cannot be known other than pretending to write the stream. - One case where the resulting size would have to be known is if the data has - to be written to a piece of memory and the memory has to be allocated before - writing to it (which is probably always the case when writing to a memory stream). +/** + @class wxStreamBase + + This class is the base class of most stream related classes in wxWidgets. + It must not be used directly. @library{wxbase} @category{streams} + + @see wxStreamBuffer */ -class wxCountingOutputStream : public wxOutputStream +class wxStreamBase { public: /** - Creates a wxCountingOutputStream object. + Creates a dummy stream object. It doesn't do anything. */ - wxCountingOutputStream(); + wxStreamBase(); /** Destructor. */ - virtual ~wxCountingOutputStream(); + virtual ~wxStreamBase(); /** - Returns the current size of the stream. + This function returns the last error. */ - size_t GetSize() const; -}; - + wxStreamError GetLastError() const; + /** + Returns the length of the stream in bytes. If the length cannot be + determined (this is always the case for socket streams for example), + returns ::wxInvalidOffset. -/** - @class wxBufferedInputStream + @since 2.5.4 + */ + virtual wxFileOffset GetLength() const; - This stream acts as a cache. It caches the bytes read from the specified - input stream (see wxFilterInputStream). - It uses wxStreamBuffer and sets the default in-buffer size to 1024 bytes. - This class may not be used without some other stream to read the data - from (such as a file stream or a memory stream). + /** + This function returns the size of the stream. + For example, for a file it is the size of the file. - @library{wxbase} - @category{streams} + @warning + There are streams which do not have size by definition, such as socket + streams. In that cases, GetSize() returns 0 so you should always test its + return value. + */ + virtual size_t GetSize() const; - @see wxStreamBuffer, wxInputStream, wxBufferedOutputStream -*/ -class wxBufferedInputStream : public wxFilterInputStream -{ -public: /** - Constructor using the provided buffer or default. + Returns @true if no error occurred on the stream. - @param stream - The associated low-level stream. - @param buffer - The buffer to use if non-@NULL. Notice that the ownership of this - buffer is taken by the stream, i.e. it will delete it. If this - parameter is @NULL a default 1KB buffer is used. + @see GetLastError() */ - wxBufferedInputStream(wxInputStream& stream, - wxStreamBuffer *buffer = NULL); + virtual bool IsOk() const; /** - Constructor allowing to specify the size of the buffer. + Returns @true if the stream supports seeking to arbitrary offsets. + */ + virtual bool IsSeekable() const; - This is just a more convenient alternative to creating a wxStreamBuffer - of the given size and using the other overloaded constructor of this - class. + /** + Resets the stream state. - @param stream - The associated low-level stream. - @param bufsize - The size of the buffer, in bytes. + By default, resets the stream to good state, i.e. clears any errors. + Since wxWidgets 2.9.3 can be also used to explicitly set the state to + the specified error (the @a error argument didn't exist in the previous + versions). - @since 2.9.0 + @see GetLastError() */ - wxBufferedInputStream(wxInputStream& stream, size_t bufsize); + void Reset(wxStreamError error = wxSTREAM_NO_ERROR); /** - Destructor. + Returns the opposite of IsOk(). + You can use this function to test the validity of the stream as if + it was a pointer: + + @code + bool DoSomething(wxInputStream& stream) + { + wxInt32 data; + if (!stream.Read(&data, 4)) + return false; + ... + } + @endcode */ - virtual ~wxBufferedInputStream(); -}; + bool operator!() const; + +protected: + + /** + Internal function. + It is called when the stream needs to change the current position. + + @param pos + Offset to seek to. + @param mode + One of the ::wxSeekMode enumeration values. + + @return The new stream position or ::wxInvalidOffset on error. + */ + virtual wxFileOffset OnSysSeek(wxFileOffset pos, wxSeekMode mode); + /** + Internal function. + It is called when the stream needs to know the real position. + @return The current stream position. + */ + virtual wxFileOffset OnSysTell() const; +}; /** @class wxStreamBuffer @@ -113,6 +150,13 @@ public: class wxStreamBuffer { public: + /** BufMode flags */ + enum BufMode + { + read, + write, + read_write + }; /** Constructor, creates a new stream buffer using @a stream as a parent stream @@ -147,8 +191,13 @@ public: and calling SetBufferIO() but is more convenient. @since 2.9.0 + + @param bufsize + The size of buffer in bytes. + @param stream + The associated input stream, the buffer will be used in read mode. */ - wxStreamBuffer(wxInputStream& stream, size_t bufsize); + wxStreamBuffer(size_t bufsize, wxInputStream& stream); /** Constructor for an output buffer of the specified size. @@ -157,8 +206,13 @@ public: and calling SetBufferIO() but is more convenient. @since 2.9.0 + + @param bufsize + The size of buffer in bytes. + @param stream + The associated output stream, the buffer will be used in write mode. */ - wxStreamBuffer(wxOutputStream& stream, size_t bufsize); + wxStreamBuffer(size_t bufsize, wxOutputStream& stream); /** Constructor; creates a new empty stream buffer which won't flush any data @@ -194,7 +248,7 @@ public: Destructor. It finalizes all IO calls and frees all internal buffers if necessary. */ - wxStreamBuffer(); + ~wxStreamBuffer(); /** Fill the IO buffer. @@ -313,7 +367,7 @@ public: @return Upon successful completion, it returns the new offset as measured in bytes from the beginning of the stream. - Otherwise, it returns wxInvalidOffset. + Otherwise, it returns ::wxInvalidOffset. */ virtual wxFileOffset Seek(wxFileOffset pos, wxSeekMode mode); @@ -370,7 +424,7 @@ public: the stream. @return Returns the current position in the stream if possible, - wxInvalidOffset in the other case. + ::wxInvalidOffset in the other case. */ virtual wxFileOffset Tell() const; @@ -400,6 +454,11 @@ public: @class wxOutputStream wxOutputStream is an abstract base class which may not be used directly. + It is the base class of all streams which provide a Write() function, + i.e. which can be used to output data (e.g. to a file, to a socket, etc). + + If you want to create your own output stream, you'll need to derive from this + class and implement the protected OnSysWrite() function only. @library{wxbase} @category{streams} @@ -449,7 +508,7 @@ public: @param mode One of wxFromStart, wxFromEnd, wxFromCurrent. - @return The new stream position or wxInvalidOffset on error. + @return The new stream position or ::wxInvalidOffset on error. */ virtual wxFileOffset SeekO(wxFileOffset pos, wxSeekMode mode = wxFromStart); @@ -477,137 +536,413 @@ public: by one of the two streams. */ wxOutputStream& Write(wxInputStream& stream_in); -}; + /** + Writes exactly the specified number of bytes from the buffer. -/** - Enumeration values used by wxFilterClassFactory. -*/ -enum wxStreamProtocolType -{ - wxSTREAM_PROTOCOL, //!< wxFileSystem protocol (should be only one). - wxSTREAM_MIMETYPE, //!< MIME types the stream handles. - wxSTREAM_ENCODING, //!< The HTTP Content-Encodings the stream handles. - wxSTREAM_FILEEXT //!< File extensions the stream handles. -}; + Returns @true if exactly @a size bytes were written. Otherwise, returns + @false and LastWrite() should be used to retrieve the exact amount of + the data written if necessary. + This method uses repeated calls to Write() (which may return writing + only part of the data) if necessary. -/** - @class wxFilterClassFactory + @since 2.9.5 + */ + bool WriteAll(const void* buffer, size_t size); - Allows the creation of filter streams to handle compression formats such - as gzip and bzip2. +protected: + /** + Internal function. It is called when the stream wants to write data of the + specified size @a bufsize into the given @a buffer. - For example, given a filename you can search for a factory that will - handle it and create a stream to decompress it: + It should return the size that was actually wrote (which maybe zero if + @a bufsize is zero or if an error occurred; in this last case the internal + variable @c m_lasterror should be appropriately set). + */ + size_t OnSysWrite(const void* buffer, size_t bufsize); +}; - @code - factory = wxFilterClassFactory::Find(filename, wxSTREAM_FILEEXT); - if (factory) - stream = factory-NewStream(new wxFFileInputStream(filename)); - @endcode - wxFilterClassFactory::Find can also search for a factory by MIME type, - HTTP encoding or by wxFileSystem protocol. - The available factories can be enumerated using wxFilterClassFactory::GetFirst() - and wxFilterClassFactory::GetNext(). +/** + @class wxInputStream + + wxInputStream is an abstract base class which may not be used directly. + It is the base class of all streams which provide a Read() function, + i.e. which can be used to read data from a source (e.g. a file, a socket, etc). + + If you want to create your own input stream, you'll need to derive from this + class and implement the protected OnSysRead() function only. @library{wxbase} @category{streams} - - @see wxFilterInputStream, wxFilterOutputStream, wxArchiveClassFactory, - @ref overview_archive */ -class wxFilterClassFactory : public wxObject +class wxInputStream : public wxStreamBase { public: /** - Returns @true if this factory can handle the given protocol, MIME type, HTTP - encoding or file extension. - - When using @c wxSTREAM_FILEEXT for the second parameter, the first parameter - can be a complete filename rather than just an extension. + Creates a dummy input stream. */ - bool CanHandle(const wxString& protocol, - wxStreamProtocolType type = wxSTREAM_PROTOCOL) const; + wxInputStream(); /** - A static member that finds a factory that can handle a given protocol, MIME - type, HTTP encoding or file extension. Returns a pointer to the class - factory if found, or @NULL otherwise. - It does not give away ownership of the factory. - - When using @c wxSTREAM_FILEEXT for the second parameter, the first parameter - can be a complete filename rather than just an extension. + Destructor. */ - static const wxFilterClassFactory* Find(const wxString& protocol, - wxStreamProtocolType type = wxSTREAM_PROTOCOL); + virtual ~wxInputStream(); - //@{ /** - GetFirst and GetNext can be used to enumerate the available factories. - For example, to list them: + Returns @true if some data is available in the stream right now, so that + calling Read() wouldn't block. + */ + virtual bool CanRead() const; - @code - wxString list; - const wxFilterClassFactory *factory = wxFilterClassFactory::GetFirst(); + /** + Returns @true after an attempt has been made to read past the end of the + stream. + */ + virtual bool Eof() const; - while (factory) { - list << factory->GetProtocol() << _T("\n"); - factory = factory->GetNext(); - } - @endcode + /** + Returns the first character in the input queue and removes it, + blocking until it appears if necessary. - GetFirst()/GetNext() return a pointer to a factory or @NULL if no more - are available. They do not give away ownership of the factory. + On success returns a value between 0 - 255; on end of file returns @c wxEOF. */ - static const wxFilterClassFactory* GetFirst(); - const wxFilterClassFactory* GetNext() const; - //@} + int GetC(); /** - Returns the wxFileSystem protocol supported by this factory. - Equivalent to @code wxString(*GetProtocols()) @endcode. + Returns the last number of bytes read. */ - wxString GetProtocol() const; + virtual size_t LastRead() const; /** - Returns the protocols, MIME types, HTTP encodings or file extensions - supported by this factory, as an array of null terminated strings. - It does not give away ownership of the array or strings. + Returns the first character in the input queue without removing it. + */ + virtual char Peek(); - For example, to list the file extensions a factory supports: + /** + Reads the specified amount of bytes and stores the data in buffer. + To check if the call was successful you must use LastRead() to check + if this call did actually read @a size bytes (if it didn't, GetLastError() + should return a meaningful value). - @code - wxString list; - const wxChar *const *p; + @warning + The buffer absolutely needs to have at least the specified size. - for (p = factory->GetProtocols(wxSTREAM_FILEEXT); *p; p++) - list << *p << _T("\n"); - @endcode + @return This function returns a reference on the current object, so the + user can test any states of the stream right away. */ - virtual const wxChar * const* GetProtocols(wxStreamProtocolType type = wxSTREAM_PROTOCOL) const = 0; + virtual wxInputStream& Read(void* buffer, size_t size); - //@{ /** - Create a new input or output stream to decompress or compress a given stream. + Reads data from the input queue and stores it in the specified output stream. + The data is read until an error is raised by one of the two streams. - If the parent stream is passed as a pointer then the new filter stream - takes ownership of it. If it is passed by reference then it does not. + @return This function returns a reference on the current object, so the + user can test any states of the stream right away. */ - wxFilterInputStream* NewStream(wxInputStream& stream) const; - wxFilterOutputStream* NewStream(wxOutputStream& stream) const; - wxFilterInputStream* NewStream(wxInputStream* stream) const; - wxFilterOutputStream* NewStream(wxOutputStream* stream) const; - //@} + wxInputStream& Read(wxOutputStream& stream_out); /** - Remove the file extension of @a location if it is one of the file - extensions handled by this factory. - */ - wxString PopExtension(const wxString& location) const; + Reads exactly the specified number of bytes into the buffer. - /** + Returns @true only if the entire amount of data was read, otherwise + @false is returned and the number of bytes really read can be retrieved + using LastRead(), as with Read(). + + This method uses repeated calls to Read() (which may return after + reading less than the requested number of bytes) if necessary. + + @warning + The buffer absolutely needs to have at least the specified size. + + @since 2.9.5 + */ + bool ReadAll(void* buffer, size_t size); + + /** + Changes the stream current position. + + This operation in general is possible only for seekable streams + (see wxStreamBase::IsSeekable()); non-seekable streams support only + seeking positive amounts in mode @c wxFromCurrent (this is implemented + by reading data and simply discarding it). + + @param pos + Offset to seek to. + @param mode + One of wxFromStart, wxFromEnd, wxFromCurrent. + + @return The new stream position or ::wxInvalidOffset on error. + */ + virtual wxFileOffset SeekI(wxFileOffset pos, wxSeekMode mode = wxFromStart); + + /** + Returns the current stream position or ::wxInvalidOffset if it's not + available (e.g. socket streams do not have a size nor a current stream + position). + */ + virtual wxFileOffset TellI() const; + + /** + This function is only useful in read mode. + It is the manager of the "Write-Back" buffer. This buffer acts like a + temporary buffer where data which has to be read during the next read IO + call are put. This is useful when you get a big block of data which you + didn't want to read: you can replace them at the top of the input queue + by this way. + + Be very careful about this call in connection with calling SeekI() on + the same stream. Any call to SeekI() will invalidate any previous call + to this method (otherwise you could SeekI() to one position, "unread" a + few bytes there, SeekI() to another position and data would be either + lost or corrupted). + + @return Returns the amount of bytes saved in the Write-Back buffer. + */ + size_t Ungetch(const void* buffer, size_t size); + + /** + This function acts like the previous one except that it takes only one + character: it is sometimes shorter to use than the generic function. + */ + bool Ungetch(char c); + +protected: + + /** + Internal function. It is called when the stream wants to read data of the + specified size @a bufsize and wants it to be placed inside @a buffer. + + It should return the size that was actually read or zero if EOF has been + reached or an error occurred (in this last case the internal @c m_lasterror + variable should be set accordingly as well). + */ + size_t OnSysRead(void* buffer, size_t bufsize) = 0; +}; + + + + +/** + @class wxCountingOutputStream + + wxCountingOutputStream is a specialized output stream which does not write any + data anywhere, instead it counts how many bytes would get written if this were a + normal stream. This can sometimes be useful or required if some data gets + serialized to a stream or compressed by using stream compression and thus the + final size of the stream cannot be known other than pretending to write the stream. + One case where the resulting size would have to be known is if the data has + to be written to a piece of memory and the memory has to be allocated before + writing to it (which is probably always the case when writing to a memory stream). + + @library{wxbase} + @category{streams} +*/ +class wxCountingOutputStream : public wxOutputStream +{ +public: + /** + Creates a wxCountingOutputStream object. + */ + wxCountingOutputStream(); + + /** + Destructor. + */ + virtual ~wxCountingOutputStream(); + + /** + Returns the current length of the stream. + + This is the amount of data written to the stream so far, in bytes. + */ + virtual wxFileOffset GetLength() const; +}; + + +/** + @class wxBufferedInputStream + + This stream acts as a cache. It caches the bytes read from the specified + input stream (see wxFilterInputStream). + It uses wxStreamBuffer and sets the default in-buffer size to 1024 bytes. + This class may not be used without some other stream to read the data + from (such as a file stream or a memory stream). + + @library{wxbase} + @category{streams} + + @see wxStreamBuffer, wxInputStream, wxBufferedOutputStream +*/ +class wxBufferedInputStream : public wxFilterInputStream +{ +public: + /** + Constructor using the provided buffer or default. + + @param stream + The associated low-level stream. + @param buffer + The buffer to use if non-@NULL. Notice that the ownership of this + buffer is taken by the stream, i.e. it will delete it. If this + parameter is @NULL a default 1KB buffer is used. + */ + wxBufferedInputStream(wxInputStream& stream, + wxStreamBuffer *buffer = NULL); + + /** + Constructor allowing to specify the size of the buffer. + + This is just a more convenient alternative to creating a wxStreamBuffer + of the given size and using the other overloaded constructor of this + class. + + @param stream + The associated low-level stream. + @param bufsize + The size of the buffer, in bytes. + + @since 2.9.0 + */ + wxBufferedInputStream(wxInputStream& stream, size_t bufsize); + + /** + Destructor. + */ + virtual ~wxBufferedInputStream(); +}; + + + + +/** + Enumeration values used by wxFilterClassFactory. +*/ +enum wxStreamProtocolType +{ + wxSTREAM_PROTOCOL, //!< wxFileSystem protocol (should be only one). + wxSTREAM_MIMETYPE, //!< MIME types the stream handles. + wxSTREAM_ENCODING, //!< The HTTP Content-Encodings the stream handles. + wxSTREAM_FILEEXT //!< File extensions the stream handles. +}; + +/** + @class wxFilterClassFactory + + Allows the creation of filter streams to handle compression formats such + as gzip and bzip2. + + For example, given a filename you can search for a factory that will + handle it and create a stream to decompress it: + + @code + factory = wxFilterClassFactory::Find(filename, wxSTREAM_FILEEXT); + if (factory) + stream = factory->NewStream(new wxFFileInputStream(filename)); + @endcode + + wxFilterClassFactory::Find can also search for a factory by MIME type, + HTTP encoding or by wxFileSystem protocol. + The available factories can be enumerated using wxFilterClassFactory::GetFirst() + and wxFilterClassFactory::GetNext(). + + @library{wxbase} + @category{streams} + + @see wxFilterInputStream, wxFilterOutputStream, wxArchiveClassFactory, + @ref overview_archive +*/ +class wxFilterClassFactory : public wxObject +{ +public: + /** + Returns @true if this factory can handle the given protocol, MIME type, HTTP + encoding or file extension. + + When using @c wxSTREAM_FILEEXT for the second parameter, the first parameter + can be a complete filename rather than just an extension. + */ + bool CanHandle(const wxString& protocol, + wxStreamProtocolType type = wxSTREAM_PROTOCOL) const; + + /** + A static member that finds a factory that can handle a given protocol, MIME + type, HTTP encoding or file extension. Returns a pointer to the class + factory if found, or @NULL otherwise. + It does not give away ownership of the factory. + + When using @c wxSTREAM_FILEEXT for the second parameter, the first parameter + can be a complete filename rather than just an extension. + */ + static const wxFilterClassFactory* Find(const wxString& protocol, + wxStreamProtocolType type = wxSTREAM_PROTOCOL); + + //@{ + /** + GetFirst and GetNext can be used to enumerate the available factories. + For example, to list them: + + @code + wxString list; + const wxFilterClassFactory *factory = wxFilterClassFactory::GetFirst(); + + while (factory) { + list << factory->GetProtocol() << wxT("\n"); + factory = factory->GetNext(); + } + @endcode + + GetFirst()/GetNext() return a pointer to a factory or @NULL if no more + are available. They do not give away ownership of the factory. + */ + static const wxFilterClassFactory* GetFirst(); + const wxFilterClassFactory* GetNext() const; + //@} + + /** + Returns the wxFileSystem protocol supported by this factory. + Equivalent to @code wxString(*GetProtocols()) @endcode. + */ + wxString GetProtocol() const; + + /** + Returns the protocols, MIME types, HTTP encodings or file extensions + supported by this factory, as an array of null terminated strings. + It does not give away ownership of the array or strings. + + For example, to list the file extensions a factory supports: + + @code + wxString list; + const wxChar *const *p; + + for (p = factory->GetProtocols(wxSTREAM_FILEEXT); *p; p++) + list << *p << wxT("\n"); + @endcode + */ + virtual const wxChar * const* GetProtocols(wxStreamProtocolType type = wxSTREAM_PROTOCOL) const = 0; + + //@{ + /** + Create a new input or output stream to decompress or compress a given stream. + + If the parent stream is passed as a pointer then the new filter stream + takes ownership of it. If it is passed by reference then it does not. + */ + virtual wxFilterInputStream* NewStream(wxInputStream& stream) const = 0; + virtual wxFilterOutputStream* NewStream(wxOutputStream& stream) const = 0; + virtual wxFilterInputStream* NewStream(wxInputStream* stream) const = 0; + virtual wxFilterOutputStream* NewStream(wxOutputStream* stream) const = 0; + //@} + + /** + Remove the file extension of @a location if it is one of the file + extensions handled by this factory. + */ + wxString PopExtension(const wxString& location) const; + + /** Adds this class factory to the list returned by GetFirst()/GetNext(). It is not necessary to do this to use the filter streams. It is usually @@ -764,218 +1099,57 @@ public: }; - /** - @class wxInputStream - - wxInputStream is an abstract base class which may not be used directly. + @class wxWrapperInputStream - @library{wxbase} - @category{streams} -*/ -class wxInputStream : public wxStreamBase -{ -public: - /** - Creates a dummy input stream. - */ - wxInputStream(); - - /** - Destructor. - */ - virtual ~wxInputStream(); - - /** - Returns @true if some data is available in the stream right now, so that - calling Read() wouldn't block. - */ - virtual bool CanRead() const; + A wrapper input stream is a kind of filter stream which forwards all the + operations to its base stream. This is useful to build utility classes such + as wxFSInputStream. - /** - Returns @true after an attempt has been made to read past the end of the - stream. - */ - virtual bool Eof() const; - - /** - Returns the first character in the input queue and removes it, - blocking until it appears if necessary. - - On success returns a value between 0 - 255; on end of file returns @c wxEOF. - */ - int GetC(); - - /** - Returns the last number of bytes read. - */ - virtual size_t LastRead() const; - - /** - Returns the first character in the input queue without removing it. - */ - virtual char Peek(); - - /** - Reads the specified amount of bytes and stores the data in buffer. - - @warning - The buffer absolutely needs to have at least the specified size. - - @return This function returns a reference on the current object, so the - user can test any states of the stream right away. - */ - virtual wxInputStream& Read(void* buffer, size_t size); - - /** - Reads data from the input queue and stores it in the specified output stream. - The data is read until an error is raised by one of the two streams. - - @return This function returns a reference on the current object, so the - user can test any states of the stream right away. - */ - wxInputStream& Read(wxOutputStream& stream_out); - - /** - Changes the stream current position. - - @param pos - Offset to seek to. - @param mode - One of wxFromStart, wxFromEnd, wxFromCurrent. - - @return The new stream position or wxInvalidOffset on error. - */ - virtual wxFileOffset SeekI(wxFileOffset pos, wxSeekMode mode = wxFromStart); - - /** - Returns the current stream position. - */ - virtual wxFileOffset TellI() const; - - /** - This function is only useful in read mode. - It is the manager of the "Write-Back" buffer. This buffer acts like a - temporary buffer where data which has to be read during the next read IO - call are put. This is useful when you get a big block of data which you - didn't want to read: you can replace them at the top of the input queue - by this way. - - Be very careful about this call in connection with calling SeekI() on - the same stream. Any call to SeekI() will invalidate any previous call - to this method (otherwise you could SeekI() to one position, "unread" a - few bytes there, SeekI() to another position and data would be either - lost or corrupted). - - @return Returns the amount of bytes saved in the Write-Back buffer. - */ - size_t Ungetch(const void* buffer, size_t size); - - /** - This function acts like the previous one except that it takes only one - character: it is sometimes shorter to use than the generic function. - */ - bool Ungetch(char c); -}; - - -/** - These enumeration values are returned by various functions in the context - of wxStream classes. -*/ -enum wxStreamError -{ - wxSTREAM_NO_ERROR = 0, //!< No error occurred. - wxSTREAM_EOF, //!< EOF reached in Read() or similar. - wxSTREAM_WRITE_ERROR, //!< generic write error on the last write call. - wxSTREAM_READ_ERROR //!< generic read error on the last read call. -}; - -/** - @class wxStreamBase - - This class is the base class of most stream related classes in wxWidgets. - It must not be used directly. + @note + The interface of this class is the same as that of wxInputStream. + Only a constructor differs and it is documented below. @library{wxbase} @category{streams} - @see wxStreamBuffer + @see wxFSInputStream, wxFilterInputStream + @since 2.9.4 */ -class wxStreamBase +class wxWrapperInputStream : public wxFilterInputStream { public: + //@{ /** - Creates a dummy stream object. It doesn't do anything. - */ - wxStreamBase(); - - /** - Destructor. - */ - virtual ~wxStreamBase(); - - /** - This function returns the last error. - */ - wxStreamError GetLastError() const; - - /** - Returns the length of the stream in bytes. If the length cannot be - determined (this is always the case for socket streams for example), - returns @c wxInvalidOffset. - - @since 2.5.4 - */ - virtual wxFileOffset GetLength() const; - - /** - This function returns the size of the stream. - For example, for a file it is the size of the file. - - @warning - There are streams which do not have size by definition, such as socket - streams. In that cases, GetSize returns 0 so you should always test its - return value. - */ - virtual size_t GetSize() const; - - /** - Returns @true if no error occurred on the stream. - - @see GetLastError() - */ - virtual bool IsOk() const; - - /** - Returns @true if the streams supports seeking to arbitrary offsets. - */ - virtual bool IsSeekable() const; + Initializes a wrapper stream. - /** - Internal function. It is called when the stream wants to read data of the - specified size. It should return the size that was actually read. + If the parent stream is passed as a pointer then the new wrapper stream + takes ownership of it. If it is passed by reference then it does not. */ - size_t OnSysRead(void* buffer, size_t bufsize); + wxWrapperInputStream(wxInputStream& stream); + wxWrapperInputStream(wxInputStream* stream); + //@} +protected: /** - See OnSysRead(). - */ - size_t OnSysWrite(const void* buffer, size_t bufsize); - + Default constructor, use InitParentStream() to finish initialization. -protected: + This constructor can be used by the derived classes from their own + constructors when the parent stream can't be specified immediately. + The derived class must call InitParentStream() later to do it. + */ + wxWrapperInputStream(); + //@{ /** - Internal function. - It is called when the stream needs to change the current position. - */ - virtual wxFileOffset OnSysSeek(wxFileOffset pos, wxSeekMode mode); + Set up the wrapped stream for an object initialized using the default + constructor. - /** - Internal function. - It is called when the stream needs to know the real position. - */ - virtual wxFileOffset OnSysTell() const; + The ownership logic is the same as for the non-default constructor, + i.e. this object takes ownership of the stream if it's passed by + pointer but not if it's passed by reference. + */ + void InitParentStream(wxInputStream& stream); + void InitParentStream(wxInputStream* stream); + //@} }; -