-\section{Streams in wxWindows overview}\label{wxstreamoverview}
+\section{wxStreams overview}\label{wxstreamoverview}
Classes: \helpref{wxStreamBase}{wxstreambase},
\helpref{wxStreamBuffer}{wxstreambuffer}, \helpref{wxInputStream}{wxinputstream},
\wxheading{Purpose of wxStream}
-We went into troubles with c++ std streams on some platform:
-they react quite well in most cases, but in multi-threaded case, for example,
-they have a LOT of problems.
+We had troubles with standard C++ streams on several platforms:
+they react quite well in most cases, but in the multi-threaded case, for example,
+they have many problems. Some Borland Compilers refuse to work at all
+with them and using iostreams on Linux makes writing programs, that are
+binary compatible across different Linux distributions, impossible.
-Then, wxStreams have been built in wxWindows because an application should compile
-and run on all supported platforms and we don't want users depend on release
+Therefore, wxStreams have been added to wxWindows because an application should
+compile and run on all supported platforms and we don't want users to depend on release
X.XX of libg++ or some other compiler to run the program.
wxStreams is divided in two main parts:
+
\begin{enumerate}\itemsep=0pt
\item the core: wxStreamBase, wxStreamBuffer, wxInputStream, wxOutputStream,
wxFilterIn/OutputStream
\wxheading{Generic usage: an example}
-About its usage, it's simple. We can take the example of wxFileInputStream and here is a sample
+Usage is simple. We can take the example of wxFileInputStream and here is some sample
code:
\begin{verbatim}
...
// The constructor initializes the stream buffer and open the file descriptor
// associated to the name of the file.
- wxFileInputStream in\_stream("the\_file\_to\_be\_read");
+ wxFileInputStream in_stream("the_file_to_be_read");
- // Ok, read some bytes ... nb\_datas is expressed in bytes.
- in\_stream.Read(data, nb\_datas);
- if (in\_stream.LastError() != wxStream\_NOERROR) {
+ // Ok, read some bytes ... nb_datas is expressed in bytes.
+ in_stream.Read(data, nb_datas);
+ if (in_stream.LastError() != wxSTREAM_NOERROR) {
// Oh oh, something bad happens.
// For a complete list, look into the documentation at wxStreamBase.
}
// You can also inline all like this.
- if (in\_stream.Read(data, nb\_datas).LastError() != wxStream\_NOERROR) {
+ if (in_stream.Read(data, nb_datas).LastError() != wxSTREAM_NOERROR) {
// Do something.
}
// You can also get the last number of bytes REALLY put into the buffer.
- size\_t really\_read = in\_stream.LastRead();
+ size_t really_read = in_stream.LastRead();
// Ok, moves to the beginning of the stream. SeekI returns the last position
// in the stream counted from the beginning.
- off\_t old_position = in\_stream.SeekI(0, wxFromBeginning);
+ off_t old_position = in_stream.SeekI(0, wxFromBeginning);
// What is my current position ?
- off\_t position = in\_stream.TellI();
+ off_t position = in_stream.TellI();
// wxFileInputStream will close the file descriptor on the destruction.
\end{verbatim}
-\wxheading{Compatibility with c++ stream}
+\wxheading{Compatibility with C++ streams}
As I said previously, we could add a filter stream so it takes an istream
argument and builds a wxInputStream from it: I don't think it should
be difficult to implement it and it may be available in the fix of wxWindows 2.0.
+