X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/2319d2b09a8c77b81747074a1ad1ebb741a47843..45fcbf3b7a7c9cfd96e67278e4eaa12e8e015651:/docs/latex/wx/tlog.tex?ds=sidebyside diff --git a/docs/latex/wx/tlog.tex b/docs/latex/wx/tlog.tex index 1556d82ffd..8c031a488f 100644 --- a/docs/latex/wx/tlog.tex +++ b/docs/latex/wx/tlog.tex @@ -1,9 +1,7 @@ \section{Log classes overview}\label{wxlogoverview} -Classes: \helpref{wxLog}{wxlog}, \helpref{wxLogStderr}{wxlogstderr}, -\helpref{wxLogOstream}{wxlogostream}, \helpref{wxLogTextCtrl}{wxlogtextctrl}, -\helpref{wxLogWindow}{wxlogwindow}, \helpref{wxLogGui}{wxloggui}, -\helpref{wxLogNull}{wxlognull} +Classes: \helpref{wxLog}{wxlog}, wxLogStderr, +wxLogOstream, wxLogTextCtrl, wxLogWindow, wxLogGui, wxLogNull This is a general overview of logging classes provided by wxWindows. The word logging here has a broad sense, including all of the program output, not only @@ -34,14 +32,13 @@ informational messages preceding them meaningless. \item{\bf wxLogVerbose} is for verbose output. Normally, it's suppressed, but might be activated if the user wishes to know more details about the program progress (another, but possibly confusing name for the same function is {\bf -wxLogInfo} +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. +bar of the active or specified (as the first argument) \helpref{wxFrame}{wxframe} if it has one. \item{\bf wxLogSysError} is mostly used by wxWindows itself, but might be 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 corresponding error +specified message text as well as the last system error +code ({\it errno} or {\it ::GetLastError()} depending on the platform) and the corresponding error message. The second form of this function takes the error code explitly as the first argument. \item{\bf wxLogDebug} is {\bf the} right function for debug output. It only @@ -55,7 +52,6 @@ version of this function takes a trace mask as the first argument which allows to further restrict the amount of messages generated. \end{itemize} -% VZ: Julian, am I pushing too much here? 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 @@ -63,18 +59,18 @@ generic mechanisms, but are not really adapted for wxWindows, while the log classes are. Some of advantages in using wxWindows log functions are: \begin{itemize}\itemsep=0pt -\item{Portability} It's a common practice to use {\it printf()} statements or +\item{\bf Portability} It's a common practice to use {\it printf()} statements or cout/cerr C++ streams for writing out some (debug or otherwise) information. -Although it works just fine under Unix, these messages go strictly nowever +Although it works just fine under Unix, these messages go strictly nowhere under Windows where the stdout of GUI programs is not assigned to anything. Thus, you might view {\it wxLogMessage()} as a simple substitute for {\it printf()}. -\item{Flexibility} The output of wxLog functions can be redirected or +\item{\bf Flexibility} The output of wxLog functions can be redirected or suppressed entirely based on their importance, which is either impossible or difficult to do with traditional methods. For example, only error messages, or only error messages and warnings might be logged, filtering out all informational messages. -\item{Completeness} Usually, an error message should be presented to the user +\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 enough space. The actual error might have been detected inside wxWindows code @@ -126,8 +122,8 @@ clear the log, close it completely or save all messages to file. \item{\bf wxLogNull} The last log class is quite particular: it doesn't do anything. The objects of this class may be instantiated to (temporarily) suppress output of {\it wxLogXXX()} functions. As an example, trying to open a -non-existing file will usually provoke an error message, but if you for some -reason it's unwanted, just use this construction: +non-existing file will usually provoke an error message, but if for some +reasons it's unwanted, just use this construction: {\small \begin{verbatim}