interface/utils.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        utils.h
   3 // Purpose:     interface of wxWindowDisabler
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows license
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9 /**
  10     @class wxWindowDisabler
  11     @wxheader{utils.h}
  12
  13     This class disables all windows of the application (may be with the exception
  14     of one of them) in its constructor and enables them back in its destructor.
  15     This comes in handy when you want to indicate to the user that the application
  16     is currently busy and cannot respond to user input.
  17
  18     @library{wxcore}
  19     @category{FIXME}
  20
  21     @see wxBusyCursor
  22 */
  23 class wxWindowDisabler
  24 {
  25 public:
  26     /**
  27         Disables all top level windows of the applications with the exception of
  28         @a winToSkip if it is not @NULL.
  29     */
  30     wxWindowDisabler(wxWindow* winToSkip = NULL);
  31
  32     /**
  33         Reenables back the windows disabled by the constructor.
  34     */
  35     ~wxWindowDisabler();
  36 };
  37
  38
  39
  40 /**
  41     @class wxBusyCursor
  42     @wxheader{utils.h}
  43
  44     This class makes it easy to tell your user that the program is temporarily busy.
  45     Just create a wxBusyCursor object on the stack, and within the current scope,
  46     the hourglass will be shown.
  47
  48     For example:
  49
  50     @code
  51     wxBusyCursor wait;
  52
  53       for (int i = 0; i  100000; i++)
  54         DoACalculation();
  55     @endcode
  56
  57     It works by calling wxBeginBusyCursor() in the constructor,
  58     and wxEndBusyCursor() in the destructor.
  59
  60     @library{wxcore}
  61     @category{FIXME}
  62
  63     @see wxBeginBusyCursor(), wxEndBusyCursor(), wxWindowDisabler
  64 */
  65 class wxBusyCursor
  66 {
  67 public:
  68     /**
  69         Constructs a busy cursor object, calling wxBeginBusyCursor().
  70     */
  71     wxBusyCursor(wxCursor* cursor = wxHOURGLASS_CURSOR);
  72
  73     /**
  74         Destroys the busy cursor object, calling wxEndBusyCursor().
  75     */
  76     ~wxBusyCursor();
  77 };
  78
  79
  80
  81 // ============================================================================
  82 // Global functions/macros
  83 // ============================================================================
  84
  85 /**
  86     Returns the type of power source as one of @c wxPOWER_SOCKET,
  87     @c wxPOWER_BATTERY or @c wxPOWER_UNKNOWN.
  88     @c wxPOWER_UNKNOWN is also the default on platforms where this
  89     feature is not implemented (currently everywhere but MS Windows).
  90 */
  91 wxPowerType wxGetPowerType();
  92
  93 //@{
  94 /**
  95     This function returns the "user id" also known as "login name" under Unix i.e.
  96     something like "jsmith". It uniquely identifies the current user (on this
  97     system).
  98     Under Windows or NT, this function first looks in the environment
  99     variables USER and LOGNAME; if neither of these is found, the entry @b UserId
 100     in the @b wxWidgets section of the WIN.INI file is tried.
 101     The first variant of this function returns the login name if successful or an
 102     empty string otherwise. The second (deprecated) function returns @true
 103     if successful, @false otherwise.
 104
 105     @see wxGetUserName()
 106 */
 107 wxString wxGetUserId();
 108 bool wxGetUserId(char* buf, int sz);
 109 //@}
 110
 111 /**
 112     @b NB: This function is now obsolete, please use
 113     wxLogFatalError() instead.
 114     Displays @a msg and exits. This writes to standard error under Unix,
 115     and pops up a message box under Windows. Used for fatal internal
 116     wxWidgets errors. See also wxError().
 117 */
 118 void wxFatalError(const wxString& msg,
 119                   const wxString& title = "wxWidgets Fatal Error");
 120
 121 /**
 122     Returns battery state as one of @c wxBATTERY_NORMAL_STATE,
 123     @c wxBATTERY_LOW_STATE, @c wxBATTERY_CRITICAL_STATE,
 124     @c wxBATTERY_SHUTDOWN_STATE or @c wxBATTERY_UNKNOWN_STATE.
 125     @c wxBATTERY_UNKNOWN_STATE is also the default on platforms where
 126     this feature is not implemented (currently everywhere but MS Windows).
 127 */
 128 wxBatteryState wxGetBatteryState();
 129
 130 /**
 131     @b NB: This function is obsolete, please use
 132     wxWindow::FindWindowByName instead.
 133     Find a window by its name (as given in a window constructor or @b Create
 134     function call).
 135     If @a parent is @NULL, the search will start from all top-level
 136     frames and dialog boxes; if non-@NULL, the search will be limited to the given
 137     window hierarchy.
 138     The search is recursive in both cases.
 139     If no such named window is found, @b wxFindWindowByLabel is called.
 140 */
 141 wxWindow* wxFindWindowByName(const wxString& name,
 142                              wxWindow* parent = NULL);
 143
 144 /**
 145     Changes the cursor back to the original cursor, for all windows in the
 146     application.
 147     Use with wxBeginBusyCursor().
 148     See also wxIsBusy(), wxBusyCursor.
 149 */
 150 void wxEndBusyCursor();
 151
 152 /**
 153     This function is deprecated as the ids generated by it can conflict with the
 154     ids defined by the user code, use @c wxID_ANY to assign ids which are
 155     guaranteed to not conflict with the user-defined ids for the controls and menu
 156     items you create instead of using this function.
 157
 158     Generates an integer identifier unique to this run of the program.
 159 */
 160 long wxNewId();
 161
 162 /**
 163     Ensures that ids subsequently generated by @b NewId do not clash with
 164     the given @b id.
 165 */
 166 void wxRegisterId(long id);
 167
 168 /**
 169     @b NB: This function is now obsolete, replaced by Log
 170     functions() and wxLogDebug() in particular.
 171     Display a debugging message; under Windows, this will appear on the
 172     debugger command window, and under Unix, it will be written to standard
 173     error.
 174     The syntax is identical to @b printf: pass a format string and a
 175     variable list of arguments.
 176     @b Tip: under Windows, if your application crashes before the
 177     message appears in the debugging window, put a wxYield call after
 178     each wxDebugMsg call. wxDebugMsg seems to be broken under WIN32s
 179     (at least for Watcom C++): preformat your messages and use OutputDebugString
 180     instead.
 181 */
 182 void wxDebugMsg(const wxString& fmt, ... );
 183
 184 /**
 185     For normal keys, returns @true if the specified key is currently down.
 186     For togglable keys (Caps Lock, Num Lock and Scroll Lock), returns
 187     @true if the key is toggled such that its LED indicator is lit. There is
 188     currently no way to test whether togglable keys are up or down.
 189     Even though there are virtual key codes defined for mouse buttons, they
 190     cannot be used with this function currently.
 191 */
 192 bool wxGetKeyState(wxKeyCode key);
 193
 194 /**
 195     Returns the string containing the description of the current platform in a
 196     user-readable form. For example, this function may return strings like
 197     @c Windows NT Version 4.0 or @c Linux 2.2.2 i386.
 198
 199     @see ::wxGetOsVersion
 200 */
 201 wxString wxGetOsDescription();
 202
 203 /**
 204     Return the (current) user's home directory.
 205
 206     @see wxGetUserHome(), wxStandardPaths
 207 */
 208 wxString wxGetHomeDir();
 209
 210 /**
 211     Sleeps for the specified number of milliseconds. Notice that usage of this
 212     function is encouraged instead of calling usleep(3) directly because the
 213     standard usleep() function is not MT safe.
 214 */
 215 void wxMilliSleep(unsigned long milliseconds);
 216
 217 /**
 218     Sleeps for the specified number of microseconds. The microsecond resolution may
 219     not, in fact, be available on all platforms (currently only Unix platforms with
 220     nanosleep(2) may provide it) in which case this is the same as
 221     wxMilliSleep()(@e microseconds/1000).
 222 */
 223 void wxMicroSleep(unsigned long microseconds);
 224
 225 /**
 226     Shows a message box with the information about the wxWidgets build used,
 227     including its version, most important build parameters and the version of the
 228     underlying GUI toolkit. This is mainly used for diagnostic purposes and can be
 229     invoked by Ctrl-Alt-middle clicking on any wxWindow which doesn't otherwise
 230     handle this event.
 231
 232         @wxsince{2.9.0}
 233 */
 234 void wxInfoMessageBox(wxWindow ( parent = NULL);
 235
 236 /**
 237     Find a menu item identifier associated with the given frame's menu bar.
 238 */
 239 int wxFindMenuItemId(wxFrame* frame, const wxString& menuString,
 240                     const wxString& itemString);
 241
 242 /**
 243     This function enables or disables all top level windows. It is used by
 244     ::wxSafeYield.
 245 */
 246 void wxEnableTopLevelWindows(bool enable = true);
 247
 248 /**
 249     Strips any menu codes from @a str and returns the result.
 250     By default, the functions strips both the mnemonics character (@c '')
 251     which is used to indicate a keyboard shortkey, and the accelerators, which are
 252     used only in the menu items and are separated from the main text by the
 253     @c \t (TAB) character. By using @a flags of
 254     @c wxStrip_Mnemonics or @c wxStrip_Accel to strip only the former
 255     or the latter part, respectively.
 256     Notice that in most cases
 257     wxMenuItem::GetLabelFromText or
 258     wxControl::GetLabelText can be used instead.
 259 */
 260 wxString wxStripMenuCodes(const wxString& str,
 261                             int flags = wxStrip_All);
 262
 263 /**
 264     @b NB: This function is now obsolete, please use wxLogError()
 265     instead.
 266     Displays @a msg and continues. This writes to standard error under
 267     Unix, and pops up a message box under Windows. Used for internal
 268     wxWidgets errors. See also wxFatalError().
 269 */
 270 void wxError(const wxString& msg,
 271             const wxString& title = "wxWidgets Internal Error");
 272
 273 /**
 274     Open the @a url in user's default browser. If @a flags parameter contains
 275     @c wxBROWSER_NEW_WINDOW flag, a new window is opened for the URL
 276     (currently this is only supported under Windows). The @a url may also be a
 277     local file path (with or without @c file:// prefix), if it doesn't
 278     correspond to an existing file and the URL has no scheme @c http:// is
 279     prepended to it by default.
 280     Returns @true if the application was successfully launched.
 281     Note that for some configurations of the running user, the application which
 282     is launched to open the given URL may be URL-dependent (e.g. a browser may be
 283     used for
 284     local URLs while another one may be used for remote URLs).
 285 */
 286 bool wxLaunchDefaultBrowser(const wxString& url, int flags = 0);
 287
 288 /**
 289     Executes a command in an interactive shell window. If no command is
 290     specified, then just the shell is spawned.
 291     See also wxExecute(), @ref overview_sampleexec "Exec sample".
 292 */
 293 bool wxShell(const wxString& command = NULL);
 294
 295 /**
 296     Gets the version and the operating system ID for currently running OS.
 297     See wxPlatformInfo for more details about wxOperatingSystemId.
 298
 299     @see ::wxGetOsDescription, wxPlatformInfo
 300 */
 301 wxOperatingSystemId wxGetOsVersion(int* major = NULL,
 302                                     int* minor = NULL);
 303
 304 /**
 305     Returns the FQDN (fully qualified domain host name) or an empty string on
 306     error.
 307
 308     @see wxGetHostName()
 309 */
 310 wxString wxGetFullHostName();
 311
 312 /**
 313     Changes the cursor to the given cursor for all windows in the application.
 314     Use wxEndBusyCursor() to revert the cursor back
 315     to its previous state. These two calls can be nested, and a counter
 316     ensures that only the outer calls take effect.
 317     See also wxIsBusy(), wxBusyCursor.
 318 */
 319 void wxBeginBusyCursor(wxCursor* cursor = wxHOURGLASS_CURSOR);
 320
 321 /**
 322     Tells the system to delete the specified object when
 323     all other events have been processed. In some environments, it is
 324     necessary to use this instead of deleting a frame directly with the
 325     delete operator, because some GUIs will still send events to a deleted window.
 326     Now obsolete: use wxWindow::Close instead.
 327 */
 328 void wxPostDelete(wxObject* object);
 329
 330 /**
 331     @b NB: This function is obsolete, please use
 332     wxWindow::FindWindowByLabel instead.
 333     Find a window by its label. Depending on the type of window, the label may be a
 334     window title
 335     or panel item label. If @a parent is @NULL, the search will start from all
 336     top-level
 337     frames and dialog boxes; if non-@NULL, the search will be limited to the given
 338     window hierarchy.
 339     The search is recursive in both cases.
 340 */
 341 wxWindow* wxFindWindowByLabel(const wxString& label,
 342                                 wxWindow* parent = NULL);
 343
 344
 345 /**
 346     Returns the mouse position in screen coordinates.
 347 */
 348 wxPoint wxGetMousePosition();
 349
 350 /**
 351     Loads a user-defined Windows resource as a string. If the resource is found,
 352     the function creates
 353     a new character array and copies the data into it. A pointer to this data is
 354     returned. If unsuccessful, @NULL is returned.
 355     The resource must be defined in the @c .rc file using the following syntax:
 356
 357     @code
 358     myResource TEXT file.ext
 359     @endcode
 360
 361     where @c file.ext is a file that the resource compiler can find.
 362     This function is available under Windows only.
 363 */
 364 wxString wxLoadUserResource(const wxString& resourceName,
 365                             const wxString& resourceType = "TEXT");
 366
 367 /**
 368     Returns the amount of free memory in bytes under environments which
 369     support it, and -1 if not supported or failed to perform measurement.
 370 */
 371 wxMemorySize wxGetFreeMemory();
 372
 373 /**
 374     This is a macro defined as @c getenv() or its wide char version in Unicode
 375     mode.
 376     Note that under Win32 it may not return correct value for the variables set
 377     with wxSetEnv(), use wxGetEnv() function
 378     instead.
 379 */
 380 wxChar* wxGetEnv(const wxString& var);
 381
 382 //@{
 383 /**
 384     Copies the current host machine's name into the supplied buffer. Please note
 385     that the returned name is @e not fully qualified, i.e. it does not include
 386     the domain name.
 387     Under Windows or NT, this function first looks in the environment
 388     variable SYSTEM_NAME; if this is not found, the entry @b HostName
 389     in the @b wxWidgets section of the WIN.INI file is tried.
 390     The first variant of this function returns the hostname if successful or an
 391     empty string otherwise. The second (deprecated) function returns @true
 392     if successful, @false otherwise.
 393
 394     @see wxGetFullHostName()
 395 */
 396 wxString wxGetHostName();
 397 bool wxGetHostName(char* buf, int sz);
 398 //@}
 399
 400 /**
 401     Returns the current value of the environment variable @a var in @e value.
 402     @a value may be @NULL if you just want to know if the variable exists
 403     and are not interested in its value.
 404     Returns @true if the variable exists, @false otherwise.
 405 */
 406 bool wxGetEnv(const wxString& var, wxString* value);
 407
 408 /**
 409     Under X only, returns the current display name. See also wxSetDisplayName().
 410 */
 411 wxString wxGetDisplayName();
 412
 413 /**
 414     Ring the system bell.
 415     Note that this function is categorized as a GUI one and so is not thread-safe.
 416 */
 417 void wxBell();
 418
 419 /**
 420     Returns the home directory for the given user. If the @a user is empty
 421     (default value), this function behaves like
 422     wxGetHomeDir() i.e. returns the current user home
 423     directory.
 424     If the home directory couldn't be determined, an empty string is returned.
 425 */
 426 wxString wxGetUserHome(const wxString& user = "");
 427
 428 //@{
 429 /**
 430     @b wxPerl note: In wxPerl this function is called @c Wx::ExecuteStdoutStderr
 431     and it only takes the @c command argument,
 432     and returns a 3-element list @c ( status, output, errors ), where
 433     @c output and @c errors are array references.
 434     Executes another program in Unix or Windows.
 435     The first form takes a command string, such as @c "emacs file.txt".
 436     The second form takes an array of values: a command, any number of
 437     arguments, terminated by @NULL.
 438     The semantics of the third and fourth versions is different from the first two
 439     and is described in more details below.
 440     If @a flags parameter contains @c wxEXEC_ASYNC flag (the default), flow
 441     of control immediately returns. If it contains @c wxEXEC_SYNC, the current
 442     application waits until the other program has terminated.
 443     In the case of synchronous execution, the return value is the exit code of
 444     the process (which terminates by the moment the function returns) and will be
 445     -1 if the process couldn't be started and typically 0 if the process
 446     terminated successfully. Also, while waiting for the process to
 447     terminate, wxExecute will call wxYield(). Because of this, by
 448     default this function disables all application windows to avoid unexpected
 449     reentrancies which could result from the users interaction with the program
 450     while the child process is running. If you are sure that it is safe to not
 451     disable the program windows, you may pass @c wxEXEC_NODISABLE flag to
 452     prevent this automatic disabling from happening.
 453     For asynchronous execution, however, the return value is the process id and
 454     zero value indicates that the command could not be executed. As an added
 455     complication, the return value of -1 in this case indicates that we didn't
 456     launch a new process, but connected to the running one (this can only happen in
 457     case of using DDE under Windows for command execution). In particular, in this,
 458     and only this, case the calling code will not get the notification about
 459     process termination.
 460     If callback isn't @NULL and if execution is asynchronous,
 461     wxProcess::OnTerminate will be called when
 462     the process finishes. Specifying this parameter also allows you to redirect the
 463     standard input and/or output of the process being launched by calling
 464     wxProcess::Redirect. If the child process IO is redirected,
 465     under Windows the process window is not shown by default (this avoids having to
 466     flush an unnecessary console for the processes which don't create any windows
 467     anyhow) but a @c wxEXEC_NOHIDE flag can be used to prevent this from
 468     happening, i.e. with this flag the child process window will be shown normally.
 469     Under Unix the flag @c wxEXEC_MAKE_GROUP_LEADER may be used to ensure
 470     that the new process is a group leader (this will create a new session if
 471     needed). Calling wxKill() passing wxKILL_CHILDREN will
 472     kill this process as well as all of its children (except those which have
 473     started their own session).
 474     The @c wxEXEC_NOEVENTS flag prevents processing of any events from taking
 475     place while the child process is running. It should be only used for very
 476     short-lived processes as otherwise the application windows risk becoming
 477     unresponsive from the users point of view. As this flag only makes sense with
 478     @c wxEXEC_SYNC, @c wxEXEC_BLOCK equal to the sum of both of these flags
 479     is provided as a convenience.
 480     Finally, you may use the third overloaded version of this function to execute
 481     a process (always synchronously, the contents of @a flags is or'd with
 482     @c wxEXEC_SYNC) and capture its output in the array @e output. The
 483     fourth version adds the possibility to additionally capture the messages from
 484     standard error output in the @a errors array.
 485     @b NB: Currently wxExecute() can only be used from the main thread, calling
 486     this function from another thread will result in an assert failure in debug
 487     build and won't work.
 488
 489     @param command
 490         The command to execute and any parameters to pass to it as a
 491         single string.
 492     @param argv
 493         The command to execute should be the first element of this
 494         array, any additional ones are the command parameters and the array must be
 495         terminated with a @NULL pointer.
 496     @param flags
 497         Combination of bit masks wxEXEC_ASYNC,
 498         wxEXEC_SYNC and wxEXEC_NOHIDE
 499     @param callback
 500         An optional pointer to wxProcess
 501
 502     @see wxShell(), wxProcess, @ref overview_sampleexec "Exec sample".
 503 */
 504 long wxExecute(const wxString& command, int sync = wxEXEC_ASYNC,
 505                 wxProcess* callback = NULL);
 506 wxPerl note: long wxExecute(char** argv,
 507                             int flags = wxEXEC_ASYNC,
 508                             wxProcess* callback = NULL);
 509 wxPerl note: long wxExecute(const wxString& command,
 510                             wxArrayString& output,
 511                             int flags = 0);
 512 wxPerl note: long wxExecute(const wxString& command,
 513                             wxArrayString& output,
 514                             wxArrayString& errors,
 515                             int flags = 0);
 516 //@}
 517
 518 /**
 519     Returns a string representing the current date and time.
 520 */
 521 wxString wxNow();
 522
 523 /**
 524     Returns @true if the operating system the program is running under is 64 bit.
 525     The check is performed at run-time and may differ from the value available at
 526     compile-time (at compile-time you can just check if @c sizeof(void*)==8)
 527     since the program could be running in emulation mode or in a mixed 32/64 bit
 528     system
 529     (bi-architecture operating system).
 530     Very important: this function is not 100% reliable on some systems given the
 531     fact
 532     that there isn't always a standard way to do a reliable check on the OS
 533     architecture.
 534 */
 535 bool wxIsPlatform64Bit();
 536
 537 /**
 538     Returns the number uniquely identifying the current process in the system.
 539     If an error occurs, 0 is returned.
 540 */
 541 unsigned long wxGetProcessId();
 542
 543 /**
 544     Equivalent to the Unix kill function: send the given signal @a sig to the
 545     process with PID @e pid. The valid signal values are
 546
 547     @code
 548     enum wxSignal
 549     {
 550         wxSIGNONE = 0,  // verify if the process exists under Unix
 551         wxSIGHUP,
 552         wxSIGINT,
 553         wxSIGQUIT,
 554         wxSIGILL,
 555         wxSIGTRAP,
 556         wxSIGABRT,
 557         wxSIGEMT,
 558         wxSIGFPE,
 559         wxSIGKILL,      // forcefully kill, dangerous!
 560         wxSIGBUS,
 561         wxSIGSEGV,
 562         wxSIGSYS,
 563         wxSIGPIPE,
 564         wxSIGALRM,
 565         wxSIGTERM       // terminate the process gently
 566     };
 567     @endcode
 568
 569     @c wxSIGNONE, @c wxSIGKILL and @c wxSIGTERM have the same meaning
 570     under both Unix and Windows but all the other signals are equivalent to
 571     @c wxSIGTERM under Windows.
 572     Returns 0 on success, -1 on failure. If @a rc parameter is not @NULL, it will
 573     be filled with an element of @c wxKillError enum:
 574
 575     @code
 576     enum wxKillError
 577     {
 578         wxKILL_OK,              // no error
 579         wxKILL_BAD_SIGNAL,      // no such signal
 580         wxKILL_ACCESS_DENIED,   // permission denied
 581         wxKILL_NO_PROCESS,      // no such process
 582         wxKILL_ERROR            // another, unspecified error
 583     };
 584     @endcode
 585
 586     The @a flags parameter can be wxKILL_NOCHILDREN (the default),
 587     or wxKILL_CHILDREN, in which case the child processes of this
 588     process will be killed too. Note that under Unix, for wxKILL_CHILDREN
 589     to work you should have created the process by passing wxEXEC_MAKE_GROUP_LEADER
 590     to wxExecute.
 591
 592     @see wxProcess::Kill, wxProcess::Exists, @ref overview_sampleexec "Exec sample"
 593 */
 594 int wxKill(long pid, int sig = wxSIGTERM, wxKillError rc = NULL,
 595             int flags = 0);
 596
 597 /**
 598     Returns the current state of the mouse.  Returns a wxMouseState
 599     instance that contains the current position of the mouse pointer in
 600     screen coordinates, as well as boolean values indicating the up/down
 601     status of the mouse buttons and the modifier keys.
 602 */
 603 wxMouseState wxGetMouseState();
 604
 605 /**
 606     Returns @true if between two wxBeginBusyCursor() and
 607     wxEndBusyCursor() calls.
 608     See also wxBusyCursor.
 609 */
 610 bool wxIsBusy();
 611
 612 //@{
 613 /**
 614     Copies the user's email address into the supplied buffer, by
 615     concatenating the values returned by wxGetFullHostName()
 616     and wxGetUserId().
 617     Returns @true if successful, @false otherwise.
 618 */
 619 wxString wxGetEmailAddress();
 620 bool wxGetEmailAddress(char* buf, int sz);
 621 //@}
 622
 623 /**
 624     Sleeps for the specified number of seconds.
 625 */
 626 void wxSleep(int secs);
 627
 628 /**
 629     Sets the value of the environment variable @a var (adding it if necessary)
 630     to @e value.
 631     Returns @true on success.
 632
 633     @see wxUnsetEnv()
 634 */
 635 bool wxSetEnv(const wxString& var, const wxString& value);
 636
 637 /**
 638     Returns @true if the current platform is little endian (instead of big
 639     endian).
 640     The check is performed at run-time.
 641
 642     @see @ref overview_byteordermacros "Byte order macros"
 643 */
 644 bool wxIsPlatformLittleEndian();
 645
 646 /**
 647     Under X only, sets the current display name. This is the X host and display
 648     name such
 649     as "colonsay:0.0", and the function indicates which display should be used for
 650     creating
 651     windows from this point on. Setting the display within an application allows
 652     multiple
 653     displays to be used.
 654     See also wxGetDisplayName().
 655 */
 656 void wxSetDisplayName(const wxString& displayName);
 657