X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/42ff6409d9aff9ba1b771842a256feaeb40e28cd..0ddefeb07f03c1beac0dea55617ea50f3fdbcd8b:/docs/latex/wx/log.tex diff --git a/docs/latex/wx/log.tex b/docs/latex/wx/log.tex index bab8c50278..4521d9ae99 100644 --- a/docs/latex/wx/log.tex +++ b/docs/latex/wx/log.tex @@ -1,3 +1,14 @@ +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% +%% Name: log.tex +%% Purpose: wxLog and related classes documentation +%% Author: Vadim Zeitlin +%% Modified by: +%% Created: some time ago +%% RCS-ID: $Id$ +%% Copyright: (c) 1997-2001 Vadim Zeitlin +%% License: wxWindows license +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + \section{\class{wxLog}}\label{wxlog} wxLog class defines the interface for the {\it log targets} used by wxWindows @@ -19,36 +30,57 @@ logging facilities. No base class +\wxheading{Include files} + + + \latexignore{\rtfignore{\wxheading{Function groups}}} \membersection{Static functions} The functions in this section work with and manipulate the active log target. -The {\it OnLog()} is called by the {\it wxLogXXX()} functions and invokes the -{\it DoLog()} of the active log target if any. Get/Set methods are used to -install/query the current active target and, finally, {\it -DontCreateOnDemand()} disables the automatic creation of a standard log target -if none actually exists. It is only useful when the application is terminating -and shouldn't be used in other situations because it may easily lead to a loss -of messages. +The \helpref{OnLog()}{wxlogonlog} is called by the {\it wxLogXXX()} functions +and invokes the \helpref{DoLog()}{wxlogdolog} of the active log target if any. +Get/Set methods are used to install/query the current active target and, +finally, \helpref{DontCreateOnDemand()}{wxlogdontcreateondemand} disables the +automatic creation of a standard log target if none actually exists. It is +only useful when the application is terminating and shouldn't be used in other +situations because it may easily lead to a loss of messages. \helpref{OnLog}{wxlogonlog}\\ \helpref{GetActiveTarget}{wxloggetactivetarget}\\ \helpref{SetActiveTarget}{wxlogsetactivetarget}\\ -\helpref{DontCreateOnDemand}{wxlogdontcreateondemand} - -\membersection{Message buffering} - -Some of wxLog implementations, most notably the standard -\helpref{wxLogGui}{wxloggui} class, buffer the messages (for example, to avoid -showing the user a zillion of modal message boxes one after another - which -would be really annoying). {\it Flush()} shows them all and clears the buffer -contents. Although this function doesn't do anything if the buffer is already -empty, {\it HasPendingMessages()} is also provided which allows to explicitly -verify it. +\helpref{DontCreateOnDemand}{wxlogdontcreateondemand}\\ +\helpref{Suspend}{wxlogsuspend}\\ +\helpref{Resume}{wxlogresume} + +\membersection{Logging functions} + +There are two functions which must be implemented by any derived class to +actually process the log messages: \helpref{DoLog}{wxlogdolog} and +\helpref{DoLogString}{wxlogdologstring}. The second function receives a string +which just has to be output in some way and the easiest way to write a new log +target is to override just this function in the derived class. If more control +over the output format is needed, then the first function must be overridden +which allows to construct custom messages depending on the log level or even +do completely different things depending on the message severity (for example, +throw away all messages except warnings and errors, show warnings on the +screen and forward the error messages to the user's (or programmer's) cell +phone - maybe depending on whether the timestamp tells us if it is day or +night in the current time zone). + +There also functions to support message buffering. Why are they needed? +Some of wxLog implementations, most notably the standard wxLogGui class, +buffer the messages (for example, to avoid showing the user a zillion of modal +message boxes one after another - which would be really annoying). +\helpref{Flush()}{wxlogflush} shows them all and clears the buffer contents. +Although this function doesn't do anything if the buffer is already empty, +\helpref{HasPendingMessages()}{wxloghaspendingmessages} is also provided which +allows to explicitly verify it. \helpref{Flush}{wxlogflush}\\ -\helpref{HasPendingMessages}{haspendingmessages} +\helpref{FlushActive}{wxlogflushactive}\\ +\helpref{HasPendingMessages}{wxloghaspendingmessages} \membersection{Customization}\label{wxlogcustomization} @@ -57,30 +89,50 @@ without writing a new log target class (which, aside of being a matter of several minutes, allows you to do anything you want). The verbose messages are the trace messages which are not disabled in the -release mode and are generated by {\it wxLogVerbose()}. They are not normally -shown to the user because they present little interest, but may be activated, -for example, in order to help the user find some program problem. - -As for the (real) trace messages, they come in different kinds: - -\begin{itemize}\itemsep=0pt -\item{wxTraceMemAlloc} for the messages about creating and deleting objects -\item{wxTraceMessages} for tracing the windowing system messages/events -\item{wxTraceResAlloc} for allocating and releasing the system ressources -\item{wxTraceRefCount} for reference counting related messages -\item{wxTraceOleCalls} for the OLE (or COM) method invocations (wxMSW only) -\item{other} the remaining bits are free for user-defined trace levels -\end{itemize} - -The trace mask is a bit mask which tells which (if any) of these trace -messages are going to be actually logged. For the trace message to appear -somewhere, all the bits in the mask used in the call to {\it wxLogTrace()} -function must be set in the current trace mask. For example, +release mode and are generated by \helpref{wxLogVerbose}{wxlogverbose}. They +are not normally shown to the user because they present little interest, but +may be activated, for example, in order to help the user find some program +problem. + +As for the (real) trace messages, their handling depends on the settings of +the (application global) {\it trace mask}. There are two ways to specify it: +either by using \helpref{SetTraceMask}{wxlogsettracemask} and +\helpref{GetTraceMask}{wxloggettracemask} and using +\helpref{wxLogTrace}{wxlogtrace} which takes an integer mask or by using +\helpref{AddTraceMask}{wxlogaddtracemask} for string trace masks. + +The difference between bit-wise and string trace masks is that a message using +integer trace mask will only be logged if all bits of the mask are set in the +current mask while a message using string mask will be logged simply if the +mask had been added before to the list of allowed ones. + +For example, + \begin{verbatim} -wxLogTrace(wxTraceRefCount | wxTraceOle, "Active object ref count: %d", nRef); +// wxTraceOleCalls is one of standard bit masks +wxLogTrace(wxTraceRefCount | wxTraceOleCalls, "Active object ref count: %d", nRef); \end{verbatim} -will do something only if the current trace mask contains both wxTraceRefCount -and wxTraceOle. +will do something only if the current trace mask contains both +{\tt wxTraceRefCount} and {\tt wxTraceOle}, but + +\begin{verbatim} +// wxTRACE_OleCalls is one of standard string masks +wxLogTrace(wxTRACE_OleCalls, "IFoo::Bar() called"); +\end{verbatim} + +will log the message if it was preceded by + +\begin{verbatim} +wxLog::AddTraceMask(wxTRACE_OleCalls); +\end{verbatim} + +Using string masks is simpler and allows to easily add custom ones, so this is +the preferred way of working with trace messages. The integer trace mask is +kept for compatibility and for additional (but very rarely needed) flexibility +only. + +The standard trace masks are given in \helpref{wxLogTrace}{wxlogtrace} +documentation. Finally, the {\it wxLog::DoLog()} function automatically prepends a time stamp to all the messages. The format of the time stamp may be changed: it can be @@ -90,10 +142,20 @@ standard {\it strftime()} function. For example, the default format is (without quotes) for the current date. Setting an empty string as the time format disables timestamping of the messages completely. +{\bf NB:} Timestamping is disabled for Visual C++ users in debug builds by +default because otherwise it would be impossible to directly go to the line +from which the log message was generated by simply clicking in the debugger +window on the corresponding error message. If you wish to enable it, please use +\helpref{SetTimestamp}{wxlogsettimestamp} explicitly. + +\helpref{AddTraceMask}{wxlogaddtracemask}\\ +\helpref{RemoveTraceMask}{wxlogremovetracemask}\\ +\helpref{ClearTraceMasks}{wxlogcleartracemasks}\\ +\helpref{IsAllowedTraceMask}{wxlogisallowedtracemask}\\ \helpref{SetVerbose}{wxlogsetverbose}\\ \helpref{GetVerbose}{wxloggetverbose}\\ -\helpref{SetTimeStampFormat}{wxlogsettimestampformat}\\ -\helpref{GetTimeStampFormat}{wxloggettimestampformat}\\ +\helpref{SetTimestamp}{wxlogsettimestamp}\\ +\helpref{GetTimestamp}{wxloggettimestamp}\\ \helpref{SetTraceMask}{wxlogsettracemask}\\ \helpref{GetTraceMask}{wxloggettracemask} @@ -104,6 +166,24 @@ format disables timestamping of the messages completely. }} +\membersection{wxLog::AddTraceMask}\label{wxlogaddtracemask} + +\func{static void}{AddTraceMask}{\param{const wxString\& }{mask}} + +Add the {\it mask} to the list of allowed masks for +\helpref{wxLogTrace}{wxlogtrace}. + +See also: \helpref{RemoveTraceMask}{wxlogremovetracemask} + +\membersection{wxLog::ClearTraceMasks}\label{wxlogcleartracemasks} + +\func{static void}{ClearTraceMasks}{\void} + +Removes all trace masks previously set with +\helpref{AddTraceMask}{wxlogaddtracemask}. + +See also: \helpref{RemoveTraceMask}{wxlogremovetracemask} + \membersection{wxLog::OnLog}\label{wxlogonlog} \func{static void}{OnLog}{\param{wxLogLevel }{ level}, \param{const char * }{ message}} @@ -124,12 +204,65 @@ Returns the pointer to the active log target (may be NULL). Sets the specified log target as the active one. Returns the pointer to the previous active log target (may be NULL). +\membersection{wxLog::Suspend}\label{wxlogsuspend} + +\func{static void}{Suspend}{\void} + +Suspends the logging until \helpref{Resume}{wxlogresume} is called. Note that +the latter must be called the same number of times as the former to undo it, +i.e. if you call Suspend() twice you must call Resume() twice as well. + +Note that suspending the logging means that the log sink won't be be flushed +periodically, it doesn't have any effect if the current log target does the +logging immediately without waiting for \helpref{Flush}{wxlogflush} to be +called (the standard GUI log target only shows the log dialog when it is +flushed, so Suspend() works as expected with it). + +\wxheading{See also:} + +\helpref{Resume}{wxlogresume},\\ +\helpref{wxLogNull}{wxlogoverview} + +\membersection{wxLog::Resume}\label{wxlogresume} + +\func{static void}{Resume}{\void} + +Resumes logging previously suspended by a call to +\helpref{Suspend}{wxlogsuspend}. All messages logged in the meanwhile will be +flushed soon. + +\membersection{wxLog::DoLog}\label{wxlogdolog} + +\func{virtual void}{DoLog}{\param{wxLogLevel }{level}, \param{const wxChar }{*msg}, \param{time\_t }{timestamp}} + +Called to process the message of the specified severity. {\it msg} is the text +of the message as specified in the call of {\it wxLogXXX()} function which +generated it and {\it timestamp} is the moment when the message was generated. + +The base class version prepends the timestamp to the message, adds a prefix +corresponding to the log level and then calls +\helpref{DoLogString}{wxlogdologstring} with the resulting string. + +\membersection{wxLog::DoLogString}\label{wxlogdologstring} + +\func{virtual void}{DoLogString}{\param{const wxChar }{*msg}, \param{time\_t }{timestamp}} + +Called to log the specified string. The timestamp is already included into the +string but still passed to this function. + +A simple implementation may just send the string to {\tt stdout} or, better, +{\tt stderr}. + \membersection{wxLog::DontCreateOnDemand}\label{wxlogdontcreateondemand} \func{static void}{DontCreateOnDemand}{\void} Instructs wxLog to not create new log targets on the fly if there is none -currently. (Almost) for internal use only. +currently. (Almost) for internal use only: it is supposed to be called by the +application shutdown code. + +Note that this function also calls +\helpref{ClearTraceMasks}{wxlogcleartracemasks}. \membersection{wxLog::Flush}\label{wxlogflush} @@ -138,7 +271,17 @@ currently. (Almost) for internal use only. Shows all the messages currently in buffer and clears it. If the buffer is already empty, nothing happens. -\membersection{wxLog::HasPendingMessages}\label{haspendingmessages} +\membersection{wxLog::FlushActive}\label{wxlogflushactive} + +\func{static void}{FlushActive}{\void} + +Flushes the current log target if any, does nothing if there is none. + +See also: + +\helpref{Flush}{wxlogflush} + +\membersection{wxLog::HasPendingMessages}\label{wxloghaspendingmessages} \constfunc{bool}{HasPendingMessages}{\void} @@ -147,29 +290,29 @@ user). (Almost) for internal use only. \membersection{wxLog::SetVerbose}\label{wxlogsetverbose} -\func{void}{SetVerbose}{\param{bool }{ verbose = TRUE}} +\func{static void}{SetVerbose}{\param{bool }{ verbose = TRUE}} Activates or desactivates verbose mode in which the verbose messages are logged as the normal ones instead of being silently dropped. \membersection{wxLog::GetVerbose}\label{wxloggetverbose} -\constfunc{bool}{GetVerbose}{\void} +\func{static bool}{GetVerbose}{\void} Returns whether the verbose mode is currently active. -\membersection{wxLog::SetTimeStampFormat}\label{wxlogsettimestampformat} +\membersection{wxLog::SetTimestamp}\label{wxlogsettimestamp} -\func{void}{SetTimeStampFormat}{\param{const char * }{ format}} +\func{void}{SetTimestamp}{\param{const char * }{ format}} Sets the timestamp format prepended by the default log targets to all messages. The string may contain any normal characters as well as \% prefixed format specificators, see {\it strftime()} manual for details. -Passing an empty string to this function disables message timestamping. +Passing a NULL value (not empty string) to this function disables message timestamping. -\membersection{wxLog::GetTimeStampFormat}\label{wxloggettimestampformat} +\membersection{wxLog::GetTimestamp}\label{wxloggettimestamp} -\constfunc{const char *}{GetTimeStampFormat}{\void} +\constfunc{const char *}{GetTimestamp}{\void} Returns the current timestamp format string. @@ -184,3 +327,134 @@ section for details. Returns the current trace mask, see \helpref{Customization}{wxlogcustomization} section for details. + +\membersection{wxLog::IsAllowedTraceMask}\label{wxlogisallowedtracemask} + +\func{static bool}{IsAllowedTraceMask}{\param{const wxChar *}{mask}} + +Returns TRUE if the {\it mask} is one of allowed masks for +\helpref{wxLogTrace}{wxlogtrace}. + +See also: \helpref{AddTraceMask}{wxlogaddtracemask}, +\helpref{RemoveTraceMask}{wxlogremovetracemask} + +\membersection{wxLog::RemoveTraceMask}\label{wxlogremovetracemask} + +\func{static void}{RemoveTraceMask}{\param{const wxString\& }{mask}} + +Remove the {\it mask} from the list of allowed masks for +\helpref{wxLogTrace}{wxlogtrace}. + +See also: \helpref{AddTraceMask}{wxlogaddtracemask} + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% wxLogChain %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +\section{\class{wxLogChain}}\label{wxlogchain} + +This simple class allows to chain log sinks, that is to install a new sink but +keep passing log messages to the old one instead of replacing it completely as +\helpref{SetActiveTarget}{wxlogsetactivetarget} does. + +It is especially useful when you want to divert the logs somewhere (for +example to a file or a log window) but also keep showing the error messages +using the standard dialogs as \helpref{wxLogGui}{wxloggui} does by default. + +Example of usage: + +\begin{verbatim} +wxLogChain *logChain = new wxLogChain(new wxLogStderr); + +// all the log messages are sent to stderr and also processed as usually +... + +delete logChain; + +\end{verbatim} + +\wxheading{Derived from} + +\helpref{wxLog}{wxlog} + +\wxheading{Include files} + + + +\latexignore{\rtfignore{\wxheading{Members}}} + +\membersection{wxLogChain::wxLogChain}\label{wxlogchainwxlogchain} + +\func{}{wxLogChain}{\param{wxLog *}{logger}} + +Sets the specified {\tt logger} (which may be {\tt NULL}) as the default log +target but the log messages are also passed to the previous log target if any. + +\membersection{wxLogChain::\destruct{wxLogChain}} + +\func{}{\destruct{wxLogChain}}{\void} + +Destroys the previous log target. + +\membersection{wxLogChain::GetOldLog}\label{wxlogchaingetoldlog} + +\constfunc{wxLog *}{GetOldLog}{\void} + +Returns the pointer to the previously active log target (which may be {\tt +NULL}). + +\membersection{wxLogChain::IsPassingMessages}\label{wxlogchainispassingmessages} + +\constfunc{bool}{IsPassingMessages}{\void} + +Returns {\tt TRUE} if the messages are passed to the previously active log +target (default) or {\tt FALSE} if \helpref{PassMessages}{wxlogchainpassmessages} +had been called. + +\membersection{wxLogChain::PassMessages}\label{wxlogchainpassmessages} + +\func{void}{PassMessages}{\param{bool }{passMessages}} + +By default, the log messages are passed to the previously active log target. +Calling this function with {\tt FALSE} parameter disables this behaviour +(presumably temporarily, as you shouldn't use wxLogChain at all otherwise) and +it can be reenabled by calling it again with {\it passMessages} set to {\tt +TRUE}. + +\membersection{wxLogChain::SetLog}\label{wxlogchainsetlog} + +\func{void}{SetLog}{\param{wxLog *}{logger}} + +Sets another log target to use (may be {\tt NULL}). The log target specified +in the \helpref{constructor}{wxlogchainwxlogchain} or in a previous call to +this function is deleted. + +This doesn't change the old log target value (the one the messages are +forwarded to) which still remains the same as was active when wxLogChain +object was created. + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% wxLogChain %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +\section{\class{wxLogPassThrough}}\label{wxlogpassthrough} + +A special version of \helpref{wxLogChain}{wxlogchain} which uses itself as the +new log target. Maybe more clearly, it means that this is a log target which +forwards the log messages to the previously installed one in addition to +processing them itself. + +Unlike \helpref{wxLogChain}{wxlogchain} which is usually used directly as is, +this class must be derived from to implement \helpref{DoLog}{wxlogdolog} +and/or \helpref{DoLogString}{wxlogdologstring} methods. + +\wxheading{Derived from} + +\helpref{wxLogChain}{wxlogchain} + +\wxheading{Include files} + + + +\latexignore{\rtfignore{\wxheading{Members}}} + +\membersection{wxLogPassThrough::wxLogPassThrough}\label{wxlogpassthroughctor} + +Default ctor installs this object as the current active log target. +