X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/b6b1d47f2ca0859063ebcf849d9c3be8603ff9fb..02a3b39120a618998dc690e95c3983606ea97745:/docs/latex/wx/log.tex diff --git a/docs/latex/wx/log.tex b/docs/latex/wx/log.tex index 134c3b8741..e0acaf998f 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 @@ -28,14 +39,13 @@ No base class \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, -\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. +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}\\ @@ -44,19 +54,33 @@ of messages. \helpref{Suspend}{wxlogsuspend}\\ \helpref{Resume}{wxlogresume} -\membersection{Message buffering} - -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). {\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. +\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{FlushActive}{wxlogflushactive}\\ -\helpref{HasPendingMessages}{haspendingmessages} +\helpref{HasPendingMessages}{wxloghaspendingmessages} \membersection{Customization}\label{wxlogcustomization} @@ -204,9 +228,31 @@ flushed, so Suspend() works as expected with it). \func{static void}{Resume}{\void} Resumes logging previously suspended by a call to -\helpref{Suspend|wxlogsuspend}. All messages logged in the meanwhile will be +\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} @@ -235,7 +281,7 @@ See also: \helpref{Flush}{wxlogflush} -\membersection{wxLog::HasPendingMessages}\label{haspendingmessages} +\membersection{wxLog::HasPendingMessages}\label{wxloghaspendingmessages} \constfunc{bool}{HasPendingMessages}{\void} @@ -244,14 +290,14 @@ 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. @@ -301,3 +347,382 @@ Remove the {\it mask} from the list of allowed masks for 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}{wxlogoverview} 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. + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% wxLogGui %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +\section{\class{wxLogGui}}\label{wxloggui} + +This is the default log target for the GUI wxWindows applications. It is passed +to \helpref{wxLog::SetActiveTarget}{wxlogsetactivetarget} at the program +startup and is deleted by wxWindows during the program shut down. + +\wxheading{Derived from} + +\helpref{wxLog}{wxlog} + +\wxheading{Include files} + + + +\latexignore{\rtfignore{\wxheading{Members}}} + +\membersection{wxLogGui::wxLogGui} + +\func{}{wxLogGui}{\void} + +Default constructor. + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% wxLogNull %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +\section{\class{wxLogNull}}\label{wxlognull} + +This class allows to temporarily suspend logging. All calls to the log +functions during the life time of an object of this class are just ignored. + +In particular, it can be used to suppress the log messages given by wxWindows +itself but it should be noted that it is rarely the best way to cope with this +problem as {\bf all} log messages are suppressed, even if they indicate a +completely different error than the one the programmer wanted to suppress. + +For instance, the example of the overview: + +{\small +\begin{verbatim} + wxFile file; + + // wxFile.Open() normally complains if file can't be opened, we don't want it + { + wxLogNull logNo; + if ( !file.Open("bar") ) + ... process error ourselves ... + } // ~wxLogNull called, old log sink restored + + wxLogMessage("..."); // ok +\end{verbatim} +} + +would be better written as: + +{\small +\begin{verbatim} + wxFile file; + + // don't try to open file if it doesn't exist, we are prepared to deal with + // this ourselves - but all other errors are not expected + if ( wxFile::Exists("bar") ) + { + // gives an error message if the file couldn't be opened + file.Open("bar"); + } + else + { + ... + } +\end{verbatim} +} + +\wxheading{Derived from} + +\helpref{wxLog}{wxlog} + +\wxheading{Include files} + + + +\latexignore{\rtfignore{\wxheading{Members}}} + +\membersection{wxLogNull::wxLogNull} + +\func{}{wxLogNull}{\void} + +Suspends logging. + +\membersection{wxLogNull::\destruct{wxLogNull}} + +Resumes logging. + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% wxLogStderr %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +\section{\class{wxLogStderr}}\label{wxlogstderr} + +This class can be used to redirect the log messages to a C file stream (not to +be confused with C++ streams). It is the default log target for the non-GUI +wxWindows applications which send all the output to {\tt stderr}. + +\wxheading{Derived from} + +\helpref{wxLog}{wxlog} + +\wxheading{Include files} + + + +\wxheading{See also} + +\helpref{wxLogStream}{wxlogstream} + +\latexignore{\rtfignore{\wxheading{Members}}} + +\membersection{wxLogStderr::wxLogStderr} + +\func{}{wxLogStderr}{\param{FILE }{*fp = NULL}} + +Constructs a log target which sends all the log messages to the given +{\tt FILE}. If it is {\tt NULL}, the messages are sent to {\tt stderr}. + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% wxLogStream %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +\section{\class{wxLogStream}}\label{wxlogstream} + +This class can be used to redirect the log messages to a C++ stream. + +Please note that this class is only available if wxWindows was compiled with +the standard iostream library support ({\tt wxUSE\_STD\_IOSTREAM} must be on). + +\wxheading{Derived from} + +\helpref{wxLog}{wxlog} + +\wxheading{Include files} + + + +\wxheading{See also} + +\helpref{wxLogStderr}{wxlogstderr},\\ +\helpref{wxStreamToTextRedirector}{wxstreamtotextredirector} + +\latexignore{\rtfignore{\wxheading{Members}}} + +\membersection{wxLogStream::wxLogStream} + +\func{}{wxLogStream}{\param{std::ostream }{*ostr = NULL}} + +Constructs a log target which sends all the log messages to the given +output stream. If it is {\tt NULL}, the messages are sent to {\tt cerr}. + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% wxLogTextCtrl %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +\section{\class{wxLogTextCtrl}}\label{wxlogtextctrl} + +Using these target all the log messages can be redirected to a text control. +The text control must have been created with {\tt wxTE\_MULTILINE} style by the +caller previously. + +\wxheading{Derived from} + +\helpref{wxLog}{wxlog} + +\wxheading{Include files} + + + +\wxheading{See also} + +\helpref{wxLogTextCtrl}{wxlogtextctrl},\\ +\helpref{wxStreamToTextRedirector}{wxstreamtotextredirector} + +\latexignore{\rtfignore{\wxheading{Members}}} + +\membersection{wxLogTextCtrl::wxLogTextCtrl} + +\func{}{wxLogTextCtrl}{\param{wxTextCtrl }{*textctrl}} + +Constructs a log target which sends all the log messages to the given text +control. The {\it textctrl} parameter cannot be {\tt NULL}. + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% wxLogWindow %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +\section{\class{wxLogWindow}}\label{wxlogwindow} + +This class represents a background log window: to be precise, it collects all +log messages in the log frame which it manages but also passes them on to the +log target which was active at the moment of its creation. This allows, for +example, to show all the log messages in a frame but still continue to process +them normally by showing the standard log dialog. + +\wxheading{Derived from} + +\helpref{wxLogPassThrough}{wxlogpassthrough} + +\wxheading{Include files} + + + +\wxheading{See also} + +\helpref{wxLogTextCtrl}{wxlogtextctrl} + +\latexignore{\rtfignore{\wxheading{Members}}} + +\membersection{wxLogWindow::wxLogWindow} + +\func{}{wxLogWindow}{\param{wxFrame }{*parent}, \param{const wxChar }{*title}, \param{bool }{show = {\tt TRUE}}, \param{bool }{passToOld = {\tt TRUE}}} + +Creates the log frame window and starts collecting the messages in it. + +\wxheading{Parameters} + +\docparam{parent}{The parent window for the log frame, may be {\tt NULL}} + +\docparam{title}{The title for the log frame} + +\docparam{show}{{\tt TRUE} to show the frame initially (default), otherwise +\helpref{wxLogWindow::Show}{wxlogwindowshow} must be called later.} + +\docparam{passToOld}{{\tt TRUE} to process the log messages normally in addition to +logging them in the log frame (default), {\tt FALSE} to only log them in the +log frame.} + +\membersection{wxLogWindow::Show}\label{wxlogwindowshow} + +\func{void}{Show}{\param{bool }{show = {\tt TRUE}}} + +Shows or hides the frame. + +\membersection{wxLogWindow::GetFrame} + +\constfunc{wxFrame *}{GetFrame}{\void} + +Returns the associated log frame window. This may be used to position or resize +it but use \helpref{wxLogWindow::Show}{wxlogwindowshow} to show or hide it. + +\membersection{wxLogWindow::OnFrameCreate} + +\func{virtual void}{OnFrameCreate}{\param{wxFrame }{*frame}} + +Called immediately after the log frame creation allowing for +any extra initializations. + +\membersection{wxLogWindow::OnFrameClose}\label{wxlogwindowonframeclose} + +\func{virtual void}{OnFrameClose}{\param{wxFrame }{*frame}} + +Called if the user closes the window interactively, will not be +called if it is destroyed for another reason (such as when program +exits). + +Return {\tt TRUE} from here to allow the frame to close, {\tt FALSE} to +prevent this from happening. + +\wxheading{See also} + +\helpref{wxLogWindow::OnFrameDelete}{wxlogwindowonframedelete} + +\membersection{wxLogWindow::OnFrameDelete}\label{wxlogwindowonframedelete} + +\func{virtual void}{OnFrameDelete}{\param{wxFrame }{*frame}} + +Called right before the log frame is going to be deleted: will +always be called unlike \helpref{OnFrameClose()}{wxlogwindowonframeclose}. + +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% wxLogPassThrough %%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +\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. +