\helpref{wxLogPassThrough}{wxlogpassthrough},\\
\helpref{wxStreamToTextRedirector}{wxstreamtotextredirector}
\helpref{wxLogPassThrough}{wxlogpassthrough},\\
\helpref{wxStreamToTextRedirector}{wxstreamtotextredirector}
the base {\it wxLog} class which defines the standard interface for a {\it log
target} as well as several standard implementations of it and a family of
functions to use with them.
the base {\it wxLog} class which defines the standard interface for a {\it log
target} as well as several standard implementations of it and a family of
functions to use with them.
wxLogInfo}).
\item{\bf wxLogStatus} is for status messages - they will go into the status
bar of the active or specified (as the first argument) \helpref{wxFrame}{wxframe} if it has one.
wxLogInfo}).
\item{\bf wxLogStatus} is for status messages - they will go into the status
bar of the active or specified (as the first argument) \helpref{wxFrame}{wxframe} if it has one.
handy for logging errors after system call (API function) failure. It logs the
specified message text as well as the last system error
code ({\it errno} or {\it ::GetLastError()} depending on the platform) and
handy for logging errors after system call (API function) failure. It logs the
specified message text as well as the last system error
code ({\it errno} or {\it ::GetLastError()} depending on the platform) and
The usage of these functions should be fairly straightforward, however it may
be asked why not use the other logging facilities, such as C standard stdio
functions or C++ streams. The short answer is that they're all very good
The usage of these functions should be fairly straightforward, however it may
be asked why not use the other logging facilities, such as C standard stdio
functions or C++ streams. The short answer is that they're all very good
-generic mechanisms, but are not really adapted for wxWindows, while the log
-classes are. Some of advantages in using wxWindows log functions are:
+generic mechanisms, but are not really adapted for wxWidgets, while the log
+classes are. Some of advantages in using wxWidgets log functions are:
\item{\bf Completeness} Usually, an error message should be presented to the user
when some operation fails. Let's take a quite simple but common case of a file
error: suppose that you're writing your data file on disk and there is not
\item{\bf Completeness} Usually, an error message should be presented to the user
when some operation fails. Let's take a quite simple but common case of a file
error: suppose that you're writing your data file on disk and there is not
(say, in {\it wxFile::Write}), so the calling function doesn't really know the
exact reason of the failure, it only knows that the data file couldn't be
(say, in {\it wxFile::Write}), so the calling function doesn't really know the
exact reason of the failure, it only knows that the data file couldn't be
situation, the exact error code (and the corresponding error message) will be
given to the user together with "high level" message about data file writing
error.
situation, the exact error code (and the corresponding error message) will be
given to the user together with "high level" message about data file writing
error.
from \helpref{wxLog}{wxlog}. As such, it implements the virtual functions of
the base class which are called when a message is logged. Only one log target
is {\it active} at any moment, this is the one used by {\it wxLogXXX()}
from \helpref{wxLog}{wxlog}. As such, it implements the virtual functions of
the base class which are called when a message is logged. Only one log target
is {\it active} at any moment, this is the one used by {\it wxLogXXX()}
stderr by default as its name suggests.
\item{\bf wxLogStream} This class has the same functionality as wxLogStderr,
but uses {\it ostream} and cerr instead of {\it FILE *} and stderr.
stderr by default as its name suggests.
\item{\bf wxLogStream} This class has the same functionality as wxLogStderr,
but uses {\it ostream} and cerr instead of {\it FILE *} and stderr.
applications (it is used by default if you don't do anything) and provides the
most reasonable handling of all types of messages for given platform.
\item{\bf wxLogWindow} This log target provides a "log console" which
applications (it is used by default if you don't do anything) and provides the
most reasonable handling of all types of messages for given platform.
\item{\bf wxLogWindow} This log target provides a "log console" which