interface/wx/log.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        log.h
   3 // Purpose:     interface of wxLogWindow
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows license
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9
  10 /**
  11     Different standard log levels (you may also define your own) used with
  12     wxLog::OnLog() by standard wxLog functions wxLogError(), wxLogWarning(),
  13     etc...
  14 */
  15 enum wxLogLevelValues
  16 {
  17     wxLOG_FatalError, //!< program can't continue, abort immediately
  18     wxLOG_Error,      //!< a serious error, user must be informed about it
  19     wxLOG_Warning,    //!< user is normally informed about it but may be ignored
  20     wxLOG_Message,    //!< normal message (i.e. normal output of a non GUI app)
  21     wxLOG_Status,     //!< informational: might go to the status line of GUI app
  22     wxLOG_Info,       //!< informational message (a.k.a. 'Verbose')
  23     wxLOG_Debug,      //!< never shown to the user, disabled in release mode
  24     wxLOG_Trace,      //!< trace messages are also only enabled in debug mode
  25     wxLOG_Progress,   //!< used for progress indicator (not yet)
  26     wxLOG_User = 100, //!< user defined levels start here
  27     wxLOG_Max = 10000
  28 };
  29
  30 /**
  31     The type used to specify a log level.
  32
  33     Default values of ::wxLogLevel used by wxWidgets are contained in the
  34     ::wxLogLevelValues enumeration.
  35 */
  36 typedef unsigned long wxLogLevel;
  37
  38
  39 /**
  40     @class wxLogWindow
  41
  42     This class represents a background log window: to be precise, it collects all
  43     log messages in the log frame which it manages but also passes them on to the
  44     log target which was active at the moment of its creation. This allows you, for
  45     example, to show all the log messages in a frame but still continue to process
  46     them normally by showing the standard log dialog.
  47
  48     @library{wxbase}
  49     @category{logging}
  50
  51     @see wxLogTextCtrl
  52 */
  53 class wxLogWindow : public wxLogInterposer
  54 {
  55 public:
  56     /**
  57         Creates the log frame window and starts collecting the messages in it.
  58
  59         @param pParent
  60             The parent window for the log frame, may be @NULL
  61         @param szTitle
  62             The title for the log frame
  63         @param show
  64             @true to show the frame initially (default), otherwise
  65             Show() must be called later.
  66         @param passToOld
  67             @true to process the log messages normally in addition to
  68             logging them in the log frame (default), @false to only log them in the
  69             log frame.
  70     */
  71     wxLogWindow(wxWindow* pParent, const wxString& szTitle, bool show = true,
  72                 bool passToOld = true);
  73
  74     /**
  75         Returns the associated log frame window. This may be used to position or resize
  76         it but use Show() to show or hide it.
  77     */
  78     wxFrame* GetFrame() const;
  79
  80     /**
  81         Called if the user closes the window interactively, will not be
  82         called if it is destroyed for another reason (such as when program
  83         exits).
  84
  85         Return @true from here to allow the frame to close, @false to
  86         prevent this from happening.
  87
  88         @see OnFrameDelete()
  89     */
  90     virtual bool OnFrameClose(wxFrame* frame);
  91
  92     /**
  93         Called immediately after the log frame creation allowing for
  94         any extra initializations.
  95     */
  96     virtual void OnFrameCreate(wxFrame* frame);
  97
  98     /**
  99         Called right before the log frame is going to be deleted: will
 100         always be called unlike OnFrameClose().
 101     */
 102     virtual void OnFrameDelete(wxFrame* frame);
 103
 104     /**
 105         Shows or hides the frame.
 106     */
 107     void Show(bool show = true);
 108 };
 109
 110
 111
 112 /**
 113     @class wxLogInterposerTemp
 114
 115     A special version of wxLogChain which uses itself as the new log target.
 116     It forwards log messages to the previously installed one in addition to
 117     processing them itself. Unlike wxLogInterposer, it doesn't delete the old
 118     target which means it can be used to temporarily redirect log output.
 119
 120     As per wxLogInterposer, this class must be derived from to implement
 121     wxLog::DoLog and/or wxLog::DoLogString methods.
 122
 123     @library{wxbase}
 124     @category{logging}
 125 */
 126 class wxLogInterposerTemp : public wxLogChain
 127 {
 128 public:
 129     /**
 130         The default constructor installs this object as the current active log target.
 131     */
 132     wxLogInterposerTemp();
 133 };
 134
 135
 136
 137 /**
 138     @class wxLogChain
 139
 140     This simple class allows you to chain log sinks, that is to install a new sink but
 141     keep passing log messages to the old one instead of replacing it completely as
 142     wxLog::SetActiveTarget does.
 143
 144     It is especially useful when you want to divert the logs somewhere (for
 145     example to a file or a log window) but also keep showing the error messages
 146     using the standard dialogs as wxLogGui does by default.
 147
 148     Example of usage:
 149
 150     @code
 151     wxLogChain *logChain = new wxLogChain(new wxLogStderr);
 152
 153     // all the log messages are sent to stderr and also processed as usually
 154     ...
 155
 156     // don't delete logChain directly as this would leave a dangling
 157     // pointer as active log target, use SetActiveTarget() instead
 158     delete wxLog::SetActiveTarget(...something else or NULL...);
 159     @endcode
 160
 161     @library{wxbase}
 162     @category{logging}
 163 */
 164 class wxLogChain : public wxLog
 165 {
 166 public:
 167     /**
 168         Sets the specified @c logger (which may be @NULL) as the default log
 169         target but the log messages are also passed to the previous log target if any.
 170     */
 171     wxLogChain(wxLog* logger);
 172
 173     /**
 174         Destroys the previous log target.
 175     */
 176     virtual ~wxLogChain();
 177
 178     /**
 179         Detaches the old log target so it won't be destroyed when the wxLogChain object
 180         is destroyed.
 181     */
 182     void DetachOldLog();
 183
 184     /**
 185         Returns the pointer to the previously active log target (which may be @NULL).
 186     */
 187     wxLog* GetOldLog() const;
 188
 189     /**
 190         Returns @true if the messages are passed to the previously active log
 191         target (default) or @false if PassMessages() had been called.
 192     */
 193     bool IsPassingMessages() const;
 194
 195     /**
 196         By default, the log messages are passed to the previously active log target.
 197         Calling this function with @false parameter disables this behaviour
 198         (presumably temporarily, as you shouldn't use wxLogChain at all otherwise) and
 199         it can be reenabled by calling it again with @a passMessages set to @true.
 200     */
 201     void PassMessages(bool passMessages);
 202
 203     /**
 204         Sets another log target to use (may be @NULL).
 205
 206         The log target specified in the wxLogChain(wxLog*) constructor or in a
 207         previous call to this function is deleted.
 208         This doesn't change the old log target value (the one the messages are
 209         forwarded to) which still remains the same as was active when wxLogChain
 210         object was created.
 211     */
 212     void SetLog(wxLog* logger);
 213 };
 214
 215
 216
 217 /**
 218     @class wxLogGui
 219
 220     This is the default log target for the GUI wxWidgets applications.
 221
 222     Please see @ref overview_log_customize for explanation of how to change the
 223     default log target.
 224
 225     An object of this class is used by default to show the log messages created
 226     by using wxLogMessage(), wxLogError() and other logging functions. It
 227     doesn't display the messages logged by them immediately however but
 228     accumulates all messages logged during an event handler execution and then
 229     shows them all at once when its Flush() method is called during the idle
 230     time processing. This has the important advantage of showing only a single
 231     dialog to the user even if several messages were logged because of a single
 232     error as it often happens (e.g. a low level function could log a message
 233     because it failed to open a file resulting in its caller logging another
 234     message due to the failure of higher level operation requiring the use of
 235     this file). If you need to force the display of all previously logged
 236     messages immediately you can use wxLog::FlushActive() to force the dialog
 237     display.
 238
 239     Also notice that if an error message is logged when several informative
 240     messages had been already logged before, the informative messages are
 241     discarded on the assumption that they are not useful -- and may be
 242     confusing and hence harmful -- any more after the error. The warning
 243     and error messages are never discarded however and any informational
 244     messages logged after the first error one are also kept (as they may
 245     contain information about the error recovery). You may override DoLog()
 246     method to change this behaviour.
 247
 248     At any rate, it is possible that that several messages were accumulated
 249     before this class Flush() method is called. If this is the case, Flush()
 250     uses a custom dialog which shows the last message directly and allows the
 251     user to view the previously logged ones by expanding the "Details"
 252     wxCollapsiblePane inside it. This custom dialog also provides the buttons
 253     for copying the log messages to the clipboard and saving them to a file.
 254
 255     However if only a single message is present when Flush() is called, just a
 256     wxMessageBox() is used to show it. This has the advantage of being closer
 257     to the native behaviour but it doesn't give the user any possibility to
 258     copy or save the message (except for the recent Windows versions where @c
 259     Ctrl-C may be pressed in the message box to copy its contents to the
 260     clipboard) so you may want to override DoShowSingleMessage() to customize
 261     wxLogGui -- the dialogs sample shows how to do this.
 262
 263     @library{wxcore}
 264     @category{logging}
 265 */
 266 class wxLogGui : public wxLog
 267 {
 268 public:
 269     /**
 270         Default constructor.
 271     */
 272     wxLogGui();
 273
 274     /**
 275         Presents the accumulated log messages, if any, to the user.
 276
 277         This method is called during the idle time and should show any messages
 278         accumulated in wxLogGui#m_aMessages field to the user.
 279      */
 280     virtual void Flush();
 281
 282 protected:
 283     /**
 284         Returns the appropriate title for the dialog.
 285
 286         The title is constructed from wxApp::GetAppDisplayName() and the
 287         severity string (e.g. "error" or "warning") appropriate for the current
 288         wxLogGui#m_bErrors and wxLogGui#m_bWarnings values.
 289      */
 290     wxString GetTitle() const;
 291
 292     /**
 293         Returns wxICON_ERROR, wxICON_WARNING or wxICON_INFORMATION depending on
 294         the current maximal severity.
 295
 296         This value is suitable to be used in the style parameter of
 297         wxMessageBox() function.
 298      */
 299     int GetSeverityIcon() const;
 300
 301     /**
 302         Forgets all the currently stored messages.
 303
 304         If you override Flush() (and don't call the base class version), you
 305         must call this method to avoid messages being logged over and over
 306         again.
 307      */
 308     void Clear();
 309
 310
 311     /**
 312         Method called by Flush() to show a single log message.
 313
 314         This function can be overridden to show the message in a different way.
 315         By default a simple wxMessageBox() call is used.
 316
 317         @param message
 318             The message to show (it can contain multiple lines).
 319         @param title
 320             The suggested title for the dialog showing the message, see
 321             GetTitle().
 322         @param style
 323             One of @c wxICON_XXX constants, see GetSeverityIcon().
 324      */
 325     virtual void DoShowSingleLogMessage(const wxString& message,
 326                                         const wxString& title,
 327                                         int style);
 328
 329     /**
 330         Method called by Flush() to show multiple log messages.
 331
 332         This function can be overridden to show the messages in a different way.
 333         By default a special log dialog showing the most recent message and
 334         allowing the user to expand it to view the previously logged ones is
 335         used.
 336
 337         @param messages
 338             Array of messages to show; it contains more than one element.
 339         @param severities
 340             Array of message severities containing @c wxLOG_XXX values.
 341         @param times
 342             Array of time_t values indicating when each message was logged.
 343         @param title
 344             The suggested title for the dialog showing the message, see
 345             GetTitle().
 346         @param style
 347             One of @c wxICON_XXX constants, see GetSeverityIcon().
 348      */
 349     virtual void DoShowMultipleLogMessages(const wxArrayString& messages,
 350                                            const wxArrayInt& severities,
 351                                            const wxArrayLong& times,
 352                                            const wxString& title,
 353                                            int style);
 354
 355
 356     /**
 357         All currently accumulated messages.
 358
 359         This array may be empty if no messages were logged.
 360
 361         @see m_aSeverity, m_aTimes
 362      */
 363     wxArrayString m_aMessages;
 364
 365     /**
 366         The severities of each logged message.
 367
 368         This array is synchronized with wxLogGui#m_aMessages, i.e. the n-th
 369         element of this array corresponds to the severity of the n-th message.
 370         The possible severity values are @c wxLOG_XXX constants, e.g.
 371         wxLOG_Error, wxLOG_Warning, wxLOG_Message etc.
 372      */
 373     wxArrayInt m_aSeverity;
 374
 375     /**
 376         The time stamps of each logged message.
 377
 378         The elements of this array are time_t values corresponding to the time
 379         when the message was logged.
 380      */
 381     wxArrayLong m_aTimes;
 382
 383     /**
 384         True if there any error messages.
 385      */
 386     bool m_bErrors;
 387
 388     /**
 389         True if there any warning messages.
 390
 391         If both wxLogGui#m_bErrors and this member are false, there are only
 392         informational messages to be shown.
 393      */
 394     bool m_bWarnings;
 395
 396     /**
 397         True if there any messages to be shown to the user.
 398
 399         This variable is used instead of simply checking whether
 400         wxLogGui#m_aMessages array is empty to allow blocking further calls to
 401         Flush() while a log dialog is already being shown, even if the messages
 402         array hasn't been emptied yet.
 403      */
 404     bool m_bHasMessages;
 405 };
 406
 407
 408
 409 /**
 410     @class wxLogStream
 411
 412     This class can be used to redirect the log messages to a C++ stream.
 413
 414     Please note that this class is only available if wxWidgets was compiled with
 415     the standard iostream library support (@c wxUSE_STD_IOSTREAM must be on).
 416
 417     @library{wxbase}
 418     @category{logging}
 419
 420     @see wxLogStderr, wxStreamToTextRedirector
 421 */
 422 class wxLogStream : public wxLog
 423 {
 424 public:
 425     /**
 426         Constructs a log target which sends all the log messages to the given
 427         output stream. If it is @NULL, the messages are sent to @c cerr.
 428     */
 429     wxLogStream(std::ostream *ostr = NULL);
 430 };
 431
 432
 433
 434 /**
 435     @class wxLogStderr
 436
 437     This class can be used to redirect the log messages to a C file stream (not to
 438     be confused with C++ streams).
 439
 440     It is the default log target for the non-GUI wxWidgets applications which
 441     send all the output to @c stderr.
 442
 443     @library{wxbase}
 444     @category{logging}
 445
 446     @see wxLogStream
 447 */
 448 class wxLogStderr : public wxLog
 449 {
 450 public:
 451     /**
 452         Constructs a log target which sends all the log messages to the given
 453         @c FILE. If it is @NULL, the messages are sent to @c stderr.
 454     */
 455     wxLogStderr(FILE* fp = NULL);
 456 };
 457
 458
 459
 460 /**
 461     @class wxLogBuffer
 462
 463     wxLogBuffer is a very simple implementation of log sink which simply collects
 464     all the logged messages in a string (except the debug messages which are output
 465     in the usual way immediately as we're presumably not interested in collecting
 466     them for later). The messages from different log function calls are separated
 467     by the new lines.
 468
 469     All the messages collected so far can be shown to the user (and the current
 470     buffer cleared) by calling the overloaded wxLogBuffer::Flush method.
 471
 472     @library{wxbase}
 473     @category{logging}
 474 */
 475 class wxLogBuffer : public wxLog
 476 {
 477 public:
 478     /**
 479         The default ctor does nothing.
 480     */
 481     wxLogBuffer();
 482
 483     /**
 484         Shows all the messages collected so far to the user (using a message box in the
 485         GUI applications or by printing them out to the console in text mode) and
 486         clears the internal buffer.
 487     */
 488     virtual void Flush();
 489
 490     /**
 491         Returns the current buffer contains. Messages from different log function calls
 492         are separated with the new lines in the buffer.
 493         The buffer can be cleared by Flush() which will also show the current
 494         contents to the user.
 495     */
 496     const wxString& GetBuffer() const;
 497 };
 498
 499
 500
 501 /**
 502     @class wxLogInterposer
 503
 504     A special version of wxLogChain which uses itself as the new log target.
 505     It forwards log messages to the previously installed one in addition to
 506     processing them itself.
 507
 508     Unlike wxLogChain which is usually used directly as is, this class must be
 509     derived from to implement wxLog::DoLog and/or wxLog::DoLogString methods.
 510
 511     wxLogInterposer destroys the previous log target in its destructor.
 512     If you don't want this to happen, use wxLogInterposerTemp instead.
 513
 514     @library{wxbase}
 515     @category{logging}
 516 */
 517 class wxLogInterposer : public wxLogChain
 518 {
 519 public:
 520     /**
 521         The default constructor installs this object as the current active log target.
 522     */
 523     wxLogInterposer();
 524 };
 525
 526
 527
 528 /**
 529     @class wxLogTextCtrl
 530
 531     Using these target all the log messages can be redirected to a text control.
 532     The text control must have been created with @c wxTE_MULTILINE style by the
 533     caller previously.
 534
 535     @library{wxbase}
 536     @category{logging}
 537
 538     @see wxTextCtrl, wxStreamToTextRedirector
 539 */
 540 class wxLogTextCtrl : public wxLog
 541 {
 542 public:
 543     /**
 544         Constructs a log target which sends all the log messages to the given text
 545         control. The @a textctrl parameter cannot be @NULL.
 546     */
 547     wxLogTextCtrl(wxTextCtrl* pTextCtrl);
 548 };
 549
 550
 551
 552 /**
 553     @class wxLog
 554
 555     wxLog class defines the interface for the @e log targets used by wxWidgets
 556     logging functions as explained in the @ref overview_log.
 557     The only situations when you need to directly use this class is when you want
 558     to derive your own log target because the existing ones don't satisfy your
 559     needs. Another case is if you wish to customize the behaviour of the standard
 560     logging classes (all of which respect the wxLog settings): for example, set
 561     which trace messages are logged and which are not or change (or even remove
 562     completely) the timestamp on the messages.
 563
 564     Otherwise, it is completely hidden behind the @e wxLogXXX() functions and
 565     you may not even know about its existence.
 566
 567     @note For console-mode applications, the default target is wxLogStderr, so
 568           that all @e wxLogXXX() functions print on @c stderr when @c wxUSE_GUI = 0.
 569
 570
 571     @section log_derivingyours Deriving your own log target
 572
 573     There are two functions which must be implemented by any derived class to
 574     actually process the log messages: DoLog() and DoLogString().
 575     The second function receives a string which just has to be output in some way
 576     and the easiest way to write a new log target is to override just this function
 577     in the derived class.
 578
 579     If more control over the output format is needed, then the first function must
 580     be overridden which allows to construct custom messages depending on the log level
 581     or even do completely different things depending on the message severity
 582     (for example, throw away all messages except warnings and errors, show warnings
 583     on the screen and forward the error messages to the user's (or programmer's) cell
 584     phone - maybe depending on whether the timestamp tells us if it is day or
 585     night in the current time zone).
 586
 587     There also functions to support message buffering. Why are they needed?
 588     Some of wxLog implementations, most notably the standard wxLogGui class,
 589     buffer the messages (for example, to avoid showing the user a zillion of modal
 590     message boxes one after another -- which would be really annoying).
 591
 592     Flush() shows them all and clears the buffer contents.
 593     This function doesn't do anything if the buffer is already empty.
 594
 595     See also:
 596     @li Flush()
 597     @li FlushActive()
 598
 599
 600     @section log_tracemasks Using trace masks
 601
 602     The functions below allow some limited customization of wxLog behaviour
 603     without writing a new log target class (which, aside from being a matter of
 604     several minutes, allows you to do anything you want).
 605     The verbose messages are the trace messages which are not disabled in the
 606     release mode and are generated by wxLogVerbose().
 607     They are not normally shown to the user because they present little interest,
 608     but may be activated, for example, in order to help the user find some program
 609     problem.
 610
 611     As for the (real) trace messages, their handling depends on the currently
 612     enabled trace masks: if AddTraceMask() was called for the mask of the given
 613     message, it will be logged, otherwise nothing happens.
 614
 615     For example,
 616     @code
 617     wxLogTrace( wxTRACE_OleCalls, "IFoo::Bar() called" );
 618     @endcode
 619
 620     will log the message if it was preceded by:
 621
 622     @code
 623     wxLog::AddTraceMask( wxTRACE_OleCalls);
 624     @endcode
 625
 626     The standard trace masks are given in wxLogTrace() documentation.
 627
 628     Finally, the @e wxLog::DoLog() function automatically prepends a time stamp
 629     to all the messages. The format of the time stamp may be changed: it can be
 630     any string with % specifications fully described in the documentation of the
 631     standard @e strftime() function. For example, the default format is
 632     "[%d/%b/%y %H:%M:%S] " which gives something like "[17/Sep/98 22:10:16] "
 633     (without quotes) for the current date. Setting an empty string as the time
 634     format or calling the shortcut wxLog::DisableTimestamp(), disables timestamping
 635     of the messages completely.
 636
 637     See also
 638     @li AddTraceMask()
 639     @li RemoveTraceMask()
 640     @li ClearTraceMasks()
 641     @li GetTraceMasks()
 642     @li IsAllowedTraceMask()
 643     @li SetVerbose()
 644     @li GetVerbose()
 645     @li SetTimestamp()
 646     @li GetTimestamp()
 647     @li SetTraceMask()
 648     @li GetTraceMask()
 649     @li SetRepetitionCounting()
 650     @li GetRepetitionCounting()
 651
 652     @note
 653     Timestamping is disabled for Visual C++ users in debug builds by
 654     default because otherwise it would be impossible to directly go to the line
 655     from which the log message was generated by simply clicking in the debugger
 656     window on the corresponding error message. If you wish to enable it, please
 657     use SetTimestamp() explicitly.
 658
 659
 660     @section log_target Manipulating the log target
 661
 662     The functions in this section work with and manipulate the active log
 663     target. The OnLog() is called by the @e wxLogXXX() functions
 664     and invokes the DoLog() of the active log target if any.
 665
 666     Get/Set methods are used to install/query the current active target and,
 667     finally, DontCreateOnDemand() disables the automatic creation of a standard
 668     log target if none actually exists. It is only useful when the application
 669     is terminating and shouldn't be used in other situations because it may
 670     easily lead to a loss of messages.
 671
 672     See also:
 673     @li OnLog()
 674     @li GetActiveTarget()
 675     @li SetActiveTarget()
 676     @li DontCreateOnDemand()
 677     @li Suspend()
 678     @li Resume()
 679
 680
 681     @library{wxcore}
 682     @category{logging}
 683
 684     @see @ref overview_log
 685 */
 686 class wxLog
 687 {
 688 public:
 689     /**
 690         Add the @a mask to the list of allowed masks for wxLogTrace().
 691
 692         @see RemoveTraceMask(), GetTraceMasks()
 693     */
 694     static void AddTraceMask(const wxString& mask);
 695
 696     /**
 697         Removes all trace masks previously set with AddTraceMask().
 698
 699         @see RemoveTraceMask()
 700     */
 701     static void ClearTraceMasks();
 702
 703     /**
 704         Instructs wxLog to not create new log targets on the fly if there is none
 705         currently. (Almost) for internal use only: it is supposed to be called by the
 706         application shutdown code.
 707
 708         Note that this function also calls ClearTraceMasks().
 709     */
 710     static void DontCreateOnDemand();
 711
 712     /**
 713         Shows all the messages currently in buffer and clears it.
 714         If the buffer is already empty, nothing happens.
 715     */
 716     virtual void Flush();
 717
 718     /**
 719         Flushes the current log target if any, does nothing if there is none.
 720
 721         @see Flush()
 722     */
 723     static void FlushActive();
 724
 725     /**
 726         Returns the pointer to the active log target (may be @NULL).
 727     */
 728     static wxLog* GetActiveTarget();
 729
 730     /**
 731         Returns the current log level limit.
 732     */
 733     static wxLogLevel GetLogLevel();
 734
 735     /**
 736         Returns whether the repetition counting mode is enabled.
 737     */
 738     static bool GetRepetitionCounting();
 739
 740     /**
 741         Returns the current timestamp format string.
 742     */
 743     static const wxString& GetTimestamp();
 744
 745     /**
 746         @deprecated
 747         Returns the current trace mask, see Customization() section for details.
 748     */
 749     static wxTraceMask GetTraceMask();
 750
 751     /**
 752         Returns the currently allowed list of string trace masks.
 753
 754         @see AddTraceMask().
 755     */
 756     static const wxArrayString& GetTraceMasks();
 757
 758     /**
 759         Returns whether the verbose mode is currently active.
 760     */
 761     static bool GetVerbose();
 762
 763     /**
 764         Returns @true if the @a mask is one of allowed masks for wxLogTrace().
 765
 766         See also: AddTraceMask(), RemoveTraceMask()
 767     */
 768     static bool IsAllowedTraceMask(const wxString& mask);
 769
 770     /**
 771         Forwards the message at specified level to the @e DoLog() function of the
 772         active log target if there is any, does nothing otherwise.
 773     */
 774     static void OnLog(wxLogLevel level, const wxString& msg, time_t t);
 775
 776     /**
 777         Remove the @a mask from the list of allowed masks for
 778         wxLogTrace().
 779
 780         @see AddTraceMask()
 781     */
 782     static void RemoveTraceMask(const wxString& mask);
 783
 784     /**
 785         Resumes logging previously suspended by a call to Suspend().
 786         All messages logged in the meanwhile will be flushed soon.
 787     */
 788     static void Resume();
 789
 790     /**
 791         Sets the specified log target as the active one.
 792
 793         Returns the pointer to the previous active log target (may be @NULL).
 794         To suppress logging use a new instance of wxLogNull not @NULL.  If the
 795         active log target is set to @NULL a new default log target will be
 796         created when logging occurs.
 797     */
 798     static wxLog* SetActiveTarget(wxLog* logtarget);
 799
 800     /**
 801         Specifies that log messages with level greater (numerically) than
 802         @a logLevel should be ignored and not sent to the active log target.
 803     */
 804     static void SetLogLevel(wxLogLevel logLevel);
 805
 806     /**
 807         Enables logging mode in which a log message is logged once, and in case exactly
 808         the same message successively repeats one or more times, only the number of
 809         repetitions is logged.
 810     */
 811     static void SetRepetitionCounting(bool repetCounting = true);
 812
 813     /**
 814         Sets the timestamp format prepended by the default log targets to all
 815         messages. The string may contain any normal characters as well as %
 816         prefixed format specificators, see @e strftime() manual for details.
 817         Passing an empty string to this function disables message time stamping.
 818     */
 819     static void SetTimestamp(const wxString& format);
 820
 821     /**
 822         Disables time stamping of the log messages.
 823
 824         @since 2.9.0
 825     */
 826     static void DisableTimestamp();
 827
 828     /**
 829         @deprecated
 830         Sets the trace mask, see @ref log_tracemasks section for details.
 831     */
 832     static void SetTraceMask(wxTraceMask mask);
 833
 834     /**
 835         Activates or deactivates verbose mode in which the verbose messages are
 836         logged as the normal ones instead of being silently dropped.
 837     */
 838     static void SetVerbose(bool verbose = true);
 839
 840     /**
 841         Suspends the logging until Resume() is called.
 842
 843         Note that the latter must be called the same number of times as the former
 844         to undo it, i.e. if you call Suspend() twice you must call Resume() twice as well.
 845
 846         Note that suspending the logging means that the log sink won't be be flushed
 847         periodically, it doesn't have any effect if the current log target does the
 848         logging immediately without waiting for Flush() to be called (the standard
 849         GUI log target only shows the log dialog when it is flushed, so Suspend()
 850         works as expected with it).
 851
 852         @see Resume(), wxLogNull
 853     */
 854     static void Suspend();
 855
 856     /**
 857         Log the given message.
 858
 859         This function should only be called from the DoLog() implementations in
 860         the derived classes (which can't call wxLog::DoLog() directly as it is
 861         protected), it should not be used for logging new messages which can be
 862         only sent to the currently active logger using OnLog() which also
 863         checks if the logging (for this level) is enabled while this method
 864         just directly calls DoLog().
 865
 866         Example of use of this class from wxLogChain:
 867         @code
 868         void wxLogChain::DoLog(wxLogLevel level, const wxString& msg, time_t t)
 869         {
 870             // let the previous logger show it
 871             if ( m_logOld && IsPassingMessages() )
 872                 m_logOld->Log(level, msg, t);
 873
 874             // and also send it to the new one
 875             if ( m_logNew && m_logNew != this )
 876                 m_logNew->Log(level, msg, t);
 877         }
 878         @endcode
 879
 880         @since 2.9.0
 881      */
 882     void Log(wxLogLevel level, const wxString& msg, time_t timestamp);
 883
 884 protected:
 885
 886     /**
 887         Called to process the message of the specified severity. @a msg is the text
 888         of the message as specified in the call of @e wxLogXXX() function which
 889         generated it and @a timestamp is the moment when the message was generated.
 890
 891         The base class version prepends the timestamp to the message, adds a prefix
 892         corresponding to the log level and then calls
 893         DoLogString() with the resulting string.
 894     */
 895     virtual void DoLog(wxLogLevel level, const wxString& msg, time_t timestamp);
 896
 897     /**
 898         Called to log the specified string. The timestamp is already included in the
 899         string but still passed to this function.
 900
 901         A simple implementation may just send the string to @c stdout or, better,
 902         @c stderr.
 903     */
 904     virtual void DoLogString(const wxString& msg, time_t timestamp);
 905 };
 906
 907
 908
 909 /**
 910     @class wxLogNull
 911
 912     This class allows you to temporarily suspend logging. All calls to the log
 913     functions during the life time of an object of this class are just ignored.
 914
 915     In particular, it can be used to suppress the log messages given by wxWidgets
 916     itself but it should be noted that it is rarely the best way to cope with this
 917     problem as @b all log messages are suppressed, even if they indicate a
 918     completely different error than the one the programmer wanted to suppress.
 919
 920     For instance, the example of the overview:
 921
 922     @code
 923       wxFile file;
 924
 925       // wxFile.Open() normally complains if file can't be opened, we don't want it
 926       {
 927         wxLogNull logNo;
 928         if ( !file.Open("bar") )
 929           ... process error ourselves ...
 930       } // ~wxLogNull called, old log sink restored
 931
 932       wxLogMessage("..."); // ok
 933     @endcode
 934
 935     would be better written as:
 936
 937     @code
 938       wxFile file;
 939
 940       // don't try to open file if it doesn't exist, we are prepared to deal with
 941       // this ourselves - but all other errors are not expected
 942       if ( wxFile::Exists("bar") )
 943       {
 944           // gives an error message if the file couldn't be opened
 945           file.Open("bar");
 946       }
 947       else
 948       {
 949           ...
 950       }
 951     @endcode
 952
 953
 954     @library{wxbase}
 955     @category{logging}
 956 */
 957 class wxLogNull : public wxLog
 958 {
 959 public:
 960     /**
 961         Suspends logging.
 962     */
 963     wxLogNull();
 964
 965     /**
 966         Resumes logging.
 967     */
 968     ~wxLogNull();
 969 };
 970
 971
 972
 973 // ============================================================================
 974 // Global functions/macros
 975 // ============================================================================
 976
 977 /** @addtogroup group_funcmacro_log */
 978 //@{
 979
 980 /**
 981     This function shows a message to the user in a safe way and should be safe
 982     to call even before the application has been initialized or if it is
 983     currently in some other strange state (for example, about to crash). Under
 984     Windows this function shows a message box using a native dialog instead of
 985     wxMessageBox() (which might be unsafe to call), elsewhere it simply prints
 986     the message to the standard output using the title as prefix.
 987
 988     @param title
 989         The title of the message box shown to the user or the prefix of the
 990         message string.
 991     @param text
 992         The text to show to the user.
 993
 994     @see wxLogFatalError()
 995
 996     @header{wx/log.h}
 997 */
 998 void wxSafeShowMessage(const wxString& title, const wxString& text);
 999
1000 /**
1001     Returns the error code from the last system call. This function uses
1002     @c errno on Unix platforms and @c GetLastError under Win32.
1003
1004     @see wxSysErrorMsg(), wxLogSysError()
1005
1006     @header{wx/log.h}
1007 */
1008 unsigned long wxSysErrorCode();
1009
1010 /**
1011     Returns the error message corresponding to the given system error code. If
1012     @a errCode is 0 (default), the last error code (as returned by
1013     wxSysErrorCode()) is used.
1014
1015     @see wxSysErrorCode(), wxLogSysError()
1016
1017     @header{wx/log.h}
1018 */
1019 const wxChar* wxSysErrorMsg(unsigned long errCode = 0);
1020
1021 //@}
1022
1023 /** @addtogroup group_funcmacro_log */
1024 //@{
1025 /**
1026     For all normal, informational messages. They also appear in a message box
1027     by default (but it can be changed).
1028
1029     @header{wx/log.h}
1030 */
1031 void wxLogMessage(const char* formatString, ... );
1032 void wxVLogMessage(const char* formatString, va_list argPtr);
1033 //@}
1034
1035 /** @addtogroup group_funcmacro_log */
1036 //@{
1037 /**
1038     For verbose output. Normally, it is suppressed, but might be activated if
1039     the user wishes to know more details about the program progress (another,
1040     but possibly confusing name for the same function could be @c wxLogInfo).
1041
1042     @header{wx/log.h}
1043 */
1044 void wxLogVerbose(const char* formatString, ... );
1045 void wxVLogVerbose(const char* formatString, va_list argPtr);
1046 //@}
1047
1048 /** @addtogroup group_funcmacro_log */
1049 //@{
1050 /**
1051     For warnings - they are also normally shown to the user, but don't
1052     interrupt the program work.
1053
1054     @header{wx/log.h}
1055 */
1056 void wxLogWarning(const char* formatString, ... );
1057 void wxVLogWarning(const char* formatString, va_list argPtr);
1058 //@}
1059
1060 /** @addtogroup group_funcmacro_log */
1061 //@{
1062 /**
1063     Like wxLogError(), but also terminates the program with the exit code 3.
1064     Using @e abort() standard function also terminates the program with this
1065     exit code.
1066
1067     @header{wx/log.h}
1068 */
1069 void wxLogFatalError(const char* formatString, ... );
1070 void wxVLogFatalError(const char* formatString, va_list argPtr);
1071 //@}
1072
1073 /** @addtogroup group_funcmacro_log */
1074 //@{
1075 /**
1076     The functions to use for error messages, i.e. the messages that must be
1077     shown to the user. The default processing is to pop up a message box to
1078     inform the user about it.
1079
1080     @header{wx/log.h}
1081 */
1082 void wxLogError(const char* formatString, ... );
1083 void wxVLogError(const char* formatString, va_list argPtr);
1084 //@}
1085
1086 /** @addtogroup group_funcmacro_log */
1087 //@{
1088 /**
1089     Like wxLogDebug(), trace functions only do something in debug builds and
1090     expand to nothing in the release one. The reason for making it a separate
1091     function is that usually there are a lot of trace messages, so it might
1092     make sense to separate them from other debug messages.
1093
1094     wxLogTrace(const char*,const char*,...) and can be used instead of
1095     wxLogDebug() if you would like to be able to separate trace messages into
1096     different categories which can be enabled or disabled with
1097     wxLog::AddTraceMask() and wxLog::RemoveTraceMask().
1098
1099     @header{wx/log.h}
1100 */
1101 void wxLogTrace(const char *mask, const char* formatString, ... );
1102 void wxVLogTrace(const char *mask, const char* formatString, va_list argPtr);
1103 //@}
1104
1105 /** @addtogroup group_funcmacro_log */
1106 //@{
1107 /**
1108     Like wxLogDebug(), trace functions only do something in debug builds and
1109     expand to nothing in the release one. The reason for making it a separate
1110     function is that usually there are a lot of trace messages, so it might
1111     make sense to separate them from other debug messages.
1112
1113     In this version of wxLogTrace(), trace messages can be separated into
1114     different categories and calls using this function only log the message if
1115     the given @a mask is currently enabled in wxLog. This lets you selectively
1116     trace only some operations and not others by enabling the desired trace
1117     masks with wxLog::AddTraceMask() or by setting the
1118     @ref overview_envvars "@c WXTRACE environment variable".
1119
1120     The predefined string trace masks used by wxWidgets are:
1121
1122     @beginDefList
1123     @itemdef{ wxTRACE_MemAlloc, Trace memory allocation (new/delete) }
1124     @itemdef{ wxTRACE_Messages, Trace window messages/X callbacks }
1125     @itemdef{ wxTRACE_ResAlloc, Trace GDI resource allocation }
1126     @itemdef{ wxTRACE_RefCount, Trace various ref counting operations }
1127     @itemdef{ wxTRACE_OleCalls, Trace OLE method calls (Win32 only) }
1128     @endDefList
1129
1130     @note Since both the mask and the format string are strings, this might
1131           lead to function signature confusion in some cases: if you intend to
1132           call the format string only version of wxLogTrace(), add a "%s"
1133           format string parameter and then supply a second string parameter for
1134           that "%s", the string mask version of wxLogTrace() will erroneously
1135           get called instead, since you are supplying two string parameters to
1136           the function. In this case you'll unfortunately have to avoid having
1137           two leading string parameters, e.g. by adding a bogus integer (with
1138           its "%d" format string).
1139
1140     @header{wx/log.h}
1141 */
1142 void wxLogTrace(const char* mask, const char* formatString, ... );
1143 void wxVLogTrace(const char* mask,
1144                   const char* formatString,
1145                   va_list argPtr);
1146 //@}
1147
1148 /** @addtogroup group_funcmacro_log */
1149 //@{
1150 /**
1151     Like wxLogDebug(), trace functions only do something in debug builds and
1152     expand to nothing in the release one. The reason for making it a separate
1153     function is that usually there are a lot of trace messages, so it might
1154     make sense to separate them from other debug messages.
1155
1156     @deprecated
1157     This version of wxLogTrace() only logs the message if all the bits
1158     corresponding to the @a mask are set in the wxLog trace mask which can be
1159     set by calling wxLog::SetTraceMask(). This version is less flexible than
1160     wxLogTrace(const char*,const char*,...) because it doesn't allow defining
1161     the user trace masks easily. This is why it is deprecated in favour of
1162     using string trace masks.
1163
1164     The following bitmasks are defined for wxTraceMask:
1165
1166     @beginDefList
1167     @itemdef{ wxTraceMemAlloc, Trace memory allocation (new/delete) }
1168     @itemdef{ wxTraceMessages, Trace window messages/X callbacks }
1169     @itemdef{ wxTraceResAlloc, Trace GDI resource allocation }
1170     @itemdef{ wxTraceRefCount, Trace various ref counting operations }
1171     @itemdef{ wxTraceOleCalls, Trace OLE method calls (Win32 only) }
1172     @endDefList
1173
1174     @header{wx/log.h}
1175 */
1176 void wxLogTrace(wxTraceMask mask, const char* formatString, ... );
1177 void wxVLogTrace(wxTraceMask mask, const char* formatString, va_list argPtr);
1178 //@}
1179
1180 /** @addtogroup group_funcmacro_log */
1181 //@{
1182 /**
1183     The right functions for debug output. They only do something in debug mode
1184     (when the preprocessor symbol @c __WXDEBUG__ is defined) and expand to
1185     nothing in release mode (otherwise).
1186
1187     @header{wx/log.h}
1188 */
1189 void wxLogDebug(const char* formatString, ... );
1190 void wxVLogDebug(const char* formatString, va_list argPtr);
1191 //@}
1192
1193 /** @addtogroup group_funcmacro_log */
1194 //@{
1195 /**
1196     Messages logged by this function will appear in the statusbar of the
1197     @a frame or of the top level application window by default (i.e. when using
1198     the second version of the functions).
1199
1200     If the target frame doesn't have a statusbar, the message will be lost.
1201
1202     @header{wx/log.h}
1203 */
1204 void wxLogStatus(wxFrame* frame, const char* formatString, ... );
1205 void wxVLogStatus(wxFrame* frame, const char* formatString, va_list argPtr);
1206 void wxLogStatus(const char* formatString, ... );
1207 void wxVLogStatus(const char* formatString, va_list argPtr);
1208 //@}
1209
1210 /** @addtogroup group_funcmacro_log */
1211 //@{
1212 /**
1213     Mostly used by wxWidgets itself, but might be handy for logging errors
1214     after system call (API function) failure. It logs the specified message
1215     text as well as the last system error code (@e errno or @e ::GetLastError()
1216     depending on the platform) and the corresponding error message. The second
1217     form of this function takes the error code explicitly as the first
1218     argument.
1219
1220     @see wxSysErrorCode(), wxSysErrorMsg()
1221
1222     @header{wx/log.h}
1223 */
1224 void wxLogSysError(const char* formatString, ... );
1225 void wxVLogSysError(const char* formatString, va_list argPtr);
1226 //@}
1227