X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/e2a6f23364aefcd5095dc6558e3ab8144363fa96..d5db80c26999bab5ad0ee610aeaa59ffb0e9c1c6:/docs/latex/wx/stream.tex

diff --git a/docs/latex/wx/stream.tex b/docs/latex/wx/stream.tex
index 2715542ddd..95e166b23a 100644
--- a/docs/latex/wx/stream.tex
+++ b/docs/latex/wx/stream.tex
@@ -4,6 +4,10 @@
 
 None
 
+\wxheading{Include files}
+
+<wx/stream.h>
+
 \wxheading{See also}
 
 \helpref{wxStreamBase}{wxstreambase}
@@ -16,41 +20,92 @@ None
 % -----------
 % ctor & dtor
 % -----------
-\membersection{wxStreamBuffer::wxStreamBuffer}
+\membersection{wxStreamBuffer::wxStreamBuffer}\label{wxstreambufconst}
 
 \func{}{wxStreamBuffer}{\param{wxStreamBase\&}{ stream}, \param{BufMode}{ mode}}
 
 Constructor, creates a new stream buffer using \it{stream} as a parent stream
 and \it{mode} as the IO mode. \it{mode} can be: wxStreamBuffer::read,
 wxStreamBuffer::write, wxStreamBuffer::read\_write.
+One stream can have many stream buffers but only one is used internally to
+pass IO call (e.g. wxInputStream::Read() -> wxStreamBuffer::Read()). But you
+can call directly wxStreamBuffer::Read without any problems.
+
+\wxheading{Warning}
+
+All errors and messages linked to the stream are stored in the stream object.
 
-\membersection{wxStreamBuffer::wxStreamBuffer}
+\begin{verbatim}
+  streambuffer.Read(...);
+  streambuffer2.Read(...); /* This one erases previous error messages set by 
+                              ``streambuffer'' */
+\end{verbatim}
 
 \func{}{wxStreamBuffer}{\param{BufMode}{ mode}}
 
 Constructor, creates a new empty stream buffer which won't flush any data
-to a stream. \it{mode} specifies the type of the buffer (read, write, read\_write).
+to a stream. \it{mode} specifies the type of the buffer (read, write, read\_write). This stream buffer has the advantage to be stream independent and to
+work only on memory buffers but it is still compatible with the rest of the
+wxStream classes. You can write, read to this special stream and it will
+grow (if it is allowed by the user) its internal buffer. Briefly, it has all
+functionality of a ``normal'' stream.
+
+\wxheading{Warning}
+
+The "read\_write" mode may not work: it isn't completely finished.
+You can create "memory" streams by this way:
+
+\begin{verbatim}
+  wxStreamBuffer *sb = new wxStreamBuffer(wxStreamBuffer::read)
+  wxInputStream *input = new wxInputStream(sb);
 
-\membersection{wxStreamBuffer::wxStreamBuffer}
+  sb->Fixed(FALSE); // It can change the size of the buffer.
 
-\func{}{wxStreamBuffer}{\param{const wxStreamBase\&}{ buffer}}
+  // input is now a read-only memory stream.
+\end{verbatim}
+
+But you should take care when destroying the stream buffer yourself.
+
+\func{}{wxStreamBuffer}{\param{const wxStreamBuffer\&}{buffer}}
+
+Constructor. It initializes the stream buffer with the data of the specified
+stream buffer. The new stream buffer is nearly exactly the same as the
+original: it has the same attributes, the same size, the same position, shares
+the same internal buffer. The interresting point is that they can differ
+in the future but the root is the same.
+
+\wxheading{Warning}
+
+The fact that the two stream buffers shared the same buffer could generate
+segmentation violation if the parent is destroyed and the children continues
+operating. It is advised to use this feature only in very local area of the
+program.
+
+\wxheading{See also}
 
-Constructor, creates a new stream buffer from the specified stream \it{buffer}.
+\helpref{wxStreamBuffer:SetBufferIO}{wxstreambuffersetbufferio}
 
 \membersection{wxStreamBuffer::\destruct{wxStreamBuffer}}
 
 \func{}{wxStreamBuffer}{\destruct{wxStreamBuffer}}
 
-Destructor, destroys the stream buffer.
+Destructor. It finalizes all IO calls and frees all internal buffers if
+necessary. In the case of a children stream buffer, the internal buffer isn't
+freed, this is the job of the parent.
+The "Write-Back" buffer is freed.
 
 % -----------
 % Filtered IO
 % -----------
-\membersection{wxStreamBuffer::Read}\label{wxstreambufread}
+\membersection{wxStreamBuffer::Read}\label{wxstreambufferread}
 
 \func{size\_t}{Read}{\param{void *}{buffer}, \param{size\_t }{size}}
 
 Reads a block of the specified \it{size} and stores datas in \it{buffer}.
+This function uses also the "Write-Back" buffer: in the case there are datas
+waiting in this buffer, they are used before anything else. After that, if there
+are still datas to be read, the stream is read and the stream buffer position
+is incremented.
 
 \wxheading{Return value}
 
@@ -58,45 +113,39 @@ It returns the real read size. If returned size is different of the specified
 \it{size}, an error occured and should be tested using 
 \helpref{LastError}{wxstreambaselasterror}.
 
-\membersection{wxStreamBuffer::Read}\label{wxstreambufreadbuf}
+\wxheading{See also}
+
+\helpref{wxStreamBuffer::Write}{wxstreambufferwrite}
 
 \func{size\_t}{Read}{\param{wxStreamBuffer *}{buffer}}
 
 Reads a \it{buffer}. The function returns when \it{buffer} is full or
 when there aren't datas anymore in the current buffer.
 
-\membersection{wxStreamBuffer::Write}
+\membersection{wxStreamBuffer::Write}\label{wxstreambufferwrite}
 
 \func{size\_t}{Write}{\param{const void *}{buffer}, \param{size\_t }{size}}
 
-Writes a block of the specified \it{size} using datas of \it{buffer}.
-
-\membersection{wxStreamBuffer::Write}
+Writes a block of the specified \it{size} using datas of \it{buffer}. The datas
+are cached in a buffer before being sent in one block to the stream.
 
 \func{size\_t}{Write}{\param{wxStreamBuffer *}{buffer}}
 
-See \helpref{Read}{wxstreambufreadbuf}
-
-\membersection{wxStreamBuffer::WriteBack}
+See \helpref{Read}{wxstreambufferread}.
 
-\func{size\_t}{WriteBack}{\param{const char*}{ buffer}, \param{size\_t}{ size}}
+\membersection{wxStreamBuffer::GetChar}
 
-This function is only useful in ``read'' mode. It puts the specified \it{buffer}
-in the input queue of the stream buf. By this way, the next
-\helpref{Read}{wxstreambufread} call will first use these datas.
+\func{char}{GetChar}{\void}
 
-\membersection{wxStreamBuffer::WriteBack}
+Gets a single char from the stream buffer. It acts like the Read call.
 
-\func{size\_t}{WriteBack}{\param{char }{c}}
+\wxheading{Problem}
 
-As for the previous function, it puts the specified byte in the input queue of the
-stream buffer.
+You aren't directly notified if an error occured during the IO call.
 
-\membersection{wxStreamBuffer::GetChar}
-
-\func{char}{GetChar}{\void}
+\wxheading{See also}
 
-Gets a single char from the stream buffer.
+\helpref{wxStreamBuffer::Read}{wxstreambufferread}
 
 \membersection{wxStreamBuffer::PutChar}
 
@@ -104,17 +153,47 @@ Gets a single char from the stream buffer.
 
 Puts a single char to the stream buffer.
 
+\wxheading{Problem}
+
+You aren't directly notified if an error occured during the IO call.
+
+\wxheading{See also}
+
+\helpref{wxStreamBuffer::Read}{wxstreambufferwrite}
+
 \membersection{wxStreamBuffer::Tell}
 
 \constfunc{off\_t}{Tell}{\void}
 
-Gets the current position in the \it{stream}.
+Gets the current position in the stream. This position is calculated from
+the \it{real} position in the stream and from the internal buffer position: so
+it gives you the position in the \it{real} stream counted from the start of
+the stream.
+
+\wxheading{Return value}
+
+Returns the current position in the stream if possible, wxInvalidOffset in the
+other case.
 
 \membersection{wxStreamBuffer::Seek}\label{wxstreambufferseek}
 
 \func{off\_t}{Seek}{\param{off\_t }{pos}, \param{wxSeekMode }{mode}}
 
-Changes the current position. (TODO)
+Changes the current position.
+
+\it{mode} may be one of the following:
+
+\twocolwidtha{5cm}
+\begin{twocollist}\itemsep=0pt
+\twocolitem{{\bf wxFromStart}}{The position is counted from the start of the stream.}
+\twocolitem{{\bf wxFromCurrent}}{The position is counted from the current position of the stream.}
+\twocolitem{{\bf wxFromEnd}}{The position is counted from the end of the stream.}
+\end{twocollist}
+
+\wxheading{Return value}
+
+Upon successful completion, it returns the new offset as measured in bytes from
+the beginning of the stream. Otherwise, it returns wxInvalidOffset.
 
 % --------------
 % Buffer control
@@ -123,20 +202,47 @@ Changes the current position. (TODO)
 
 \func{void}{ResetBuffer}{\void}
 
-Frees all internal buffers and resets to initial state all variables.
+Resets to the initial state variables concerning the buffer.
 
-\membersection{wxStreamBuffer::SetBufferIO}
+\membersection{wxStreamBuffer::SetBufferIO}\label{wxstreambuffersetbufferio}
 
 \func{void}{SetBufferIO}{\param{char*}{ buffer\_start}, \param{char*}{ buffer\_end}}
 
 Specifies which pointers to use for stream buffering. You need to pass a pointer on the
-start of the buffer end and another on the end.
+start of the buffer end and another on the end. The object will use this buffer
+to cache stream data. It may be used also as a source/destination buffer when
+you create an empty stream buffer (See \helpref{wxStreamBuffer::wxStreamBuffer}{wxstreambufconst}).
+
+\wxheading{Remarks}
+
+When you use this function, you'll have to destroy the IO buffers yourself
+after the stream buffer is destroyed or don't use it anymore.
+In the case you use it with an empty buffer, the stream buffer will not grow
+it when it is full.
+
+\wxheading{See also}
 
-\membersection{wxStreamBuffer::SetBufferIO}
+\helpref{wxStreamBuffer constructor}{wxstreambufconst}\\
+\helpref{wxStreamBuffer::Fixed}{wxstreambufferfixed}\\
+\helpref{wxStreamBuffer::Flushable}{wxstreambufferflushable}
 
 \func{void}{SetBufferIO}{\param{size\_t}{ bufsize}}
 
-Changes the size of the current IO buffer.
+Destroys or invalidates the previous IO buffer and allocates a new one of the
+specified size.
+
+\wxheading{Warning}
+
+All previous pointers aren't valid anymore.
+
+\wxheading{Remark}
+
+The created IO buffer is growable by the object.
+
+\wxheading{See also}
+
+\helpref{wxStreamBuffer::Fixed}{wxstreambufferfixed}\\
+\helpref{wxStreamBuffer::Flushable}{wxstreambufferflushable}
 
 \membersection{wxStreamBuffer::GetBufferStart}
 
@@ -160,13 +266,18 @@ Returns a pointer on the current position of the stream buffer.
 
 \constfunc{off\_t}{GetIntPosition}{\void}
 
-Returns the current position in the stream buffer.
+Returns the current position (counted in bytes) in the stream buffer.
 
 \membersection{wxStreamBuffer::SetIntPosition}
 
 \func{void}{SetIntPosition}{\void}
 
-Sets the current position in the stream buffer.
+Sets the current position (in bytes) in the stream buffer.
+
+\wxheading{Warning}
+
+Since it is a very low-level function, there is no check on the position:
+specify an invalid position can induce unexpected results.
 
 \membersection{wxStreamBuffer::GetLastAccess}
 
@@ -174,15 +285,19 @@ Sets the current position in the stream buffer.
 
 Returns the amount of bytes read during the last IO call to the parent stream.
 
-\membersection{wxStreamBuffer::Fixed}
+\membersection{wxStreamBuffer::Fixed}\label{wxstreambufferfixed}
 
 \func{void}{Fixed}{\param{bool}{ fixed}}
 
 Toggles the fixed flag. Usually this flag is toggled at the same time as 
-\it{flushable}. This flag allows (when it is FALSE) or forbids (when it is TRUE)
-the stream buffer to resize dynamically the IO buffer.
+\it{flushable}. This flag allows (when it has the FALSE value) or forbids
+(when it has the TRUE value) the stream buffer to resize dynamically the IO buffer.
+
+\wxheading{See also}
+
+\helpref{wxStreamBuffer::SetBufferIO}{wxstreambuffersetbufferio}
 
-\membersection{wxStreamBuffer::Flushable}
+\membersection{wxStreamBuffer::Flushable}\label{wxstreambufferflushable}
 
 \func{void}{Flushable}{\param{bool}{ flushable}}
 
@@ -214,5 +329,5 @@ Returns the amount of available datas in the buffer.
 
 \func{wxStreamBase*}{Stream}{\void}
 
-Returns the stream parent of the stream buffer.
+Returns the parent stream of the stream buffer.
 
