docs/latex/wx/app.tex

   1 \section{\class{wxApp}}\label{wxapp}
   2
   3 The {\bf wxApp} class represents the application itself. It is used
   4 to:
   5
   6 \begin{itemize}\itemsep=0pt
   7 \item set and get application-wide properties;
   8 \item implement the windowing system message or event loop;
   9 \item initiate application processing via \helpref{wxApp::OnInit}{wxapponinit};
  10 \item allow default processing of events not handled by other
  11 objects in the application.
  12 \end{itemize}
  13
  14 You should use the macro IMPLEMENT\_APP(appClass) in your application implementation
  15 file to tell wxWindows how to create an instance of your application class.
  16
  17 Use DECLARE\_APP(appClass) in a header file if you want the wxGetApp function (which returns
  18 a reference to your application object) to be visible to other files.
  19
  20 \wxheading{Derived from}
  21
  22 \helpref{wxEvtHandler}{wxevthandler}\\
  23 \helpref{wxObject}{wxobject}
  24
  25 \wxheading{Include files}
  26
  27 <wx/app.h>
  28
  29 \wxheading{See also}
  30
  31 \helpref{wxApp overview}{wxappoverview}
  32
  33 \latexignore{\rtfignore{\wxheading{Members}}}
  34
  35 \membersection{wxApp::wxApp}
  36
  37 \func{void}{wxApp}{\void}
  38
  39 Constructor. Called implicitly with a definition of a wxApp object.
  40
  41 The argument is a language identifier; this is an experimental
  42 feature and will be expanded and documented in future versions.
  43
  44 \membersection{wxApp::\destruct{wxApp}}
  45
  46 \func{void}{\destruct{wxApp}}{\void}
  47
  48 Destructor. Will be called implicitly on program exit if the wxApp
  49 object is created on the stack.
  50
  51 \membersection{wxApp::argc}\label{wxappargc}
  52
  53 \member{int}{argc}
  54
  55 Number of command line arguments (after environment-specific processing).
  56
  57 \membersection{wxApp::argv}\label{wxappargv}
  58
  59 \member{char **}{argv}
  60
  61 Command line arguments (after environment-specific processing).
  62
  63 \membersection{wxApp::CreateLogTarget}\label{wxappcreatelogtarget}
  64
  65 \func{virtual wxLog*}{CreateLogTarget}{\void}
  66
  67 Creates a wxLog class for the application to use for logging errors. The default
  68 implementation returns a new wxLogGui class.
  69
  70 \wxheading{See also}
  71
  72 \helpref{wxLog}{wxlog}
  73
  74 \membersection{wxApp::Dispatch}\label{wxappdispatch}
  75
  76 \func{void}{Dispatch}{\void}
  77
  78 Dispatches the next event in the windowing system event queue.
  79
  80 This can be used for programming event loops, e.g.
  81
  82 \begin{verbatim}
  83   while (app.Pending())
  84     Dispatch();
  85 \end{verbatim}
  86
  87 \wxheading{See also}
  88
  89 \helpref{wxApp::Pending}{wxapppending}
  90
  91 \membersection{wxApp::GetAppName}\label{wxappgetappname}
  92
  93 \constfunc{wxString}{GetAppName}{\void}
  94
  95 Returns the application name.
  96
  97 \wxheading{Remarks}
  98
  99 wxWindows sets this to a reasonable default before
 100 calling \helpref{wxApp::OnInit}{wxapponinit}, but the application can reset it at will.
 101
 102 \membersection{wxApp::GetAuto3D}\label{wxappgetauto3d}
 103
 104 \constfunc{bool}{GetAuto3D}{\void}
 105
 106 Returns TRUE if 3D control mode is on, FALSE otherwise.
 107
 108 \wxheading{See also}
 109
 110 \helpref{wxApp::SetAuto3D}{wxappsetauto3d}
 111
 112 \membersection{wxApp::GetClassName}\label{wxappgetclassname}
 113
 114 \constfunc{wxString}{GetClassName}{\void}
 115
 116 Gets the class name of the application. The class name may be used in a platform specific
 117 manner to refer to the application.
 118
 119 \wxheading{See also}
 120
 121 \helpref{wxApp::SetClassName}{wxappsetclassname}
 122
 123 \membersection{wxApp::GetExitOnFrameDelete}\label{wxappgetexitonframedelete}
 124
 125 \constfunc{bool}{GetExitFrameOnDelete}{\void}
 126
 127 Returns TRUE if the application will exit when the top-level window is deleted, FALSE
 128 otherwise.
 129
 130 \wxheading{See also}
 131
 132 \helpref{wxApp::SetExitOnFrameDelete}{wxappsetexitonframedelete}
 133
 134 \membersection{wxApp::GetTopWindow}\label{wxappgettopwindow}
 135
 136 \constfunc{wxWindow *}{GetTopWindow}{\void}
 137
 138 Returns a pointer to the top window.
 139
 140 \wxheading{Remarks}
 141
 142 If the top window hasn't been set using \helpref{wxApp::SetTopWindow}{wxappsettopwindow}, this
 143 function will find the first top-level window (frame or dialog) and return that.
 144
 145 \wxheading{See also}
 146
 147 \helpref{SetTopWindow}{wxappsettopwindow}
 148
 149 \membersection{wxApp::GetUseBestVisual}\label{wxappgetusebestvisual}
 150
 151 \constfunc{bool}{GetUseBestVisual}{\void}
 152
 153 Returns TRUE if the application will use the best visual on systems that support
 154 different visuals, FALSE otherwise.
 155
 156 \wxheading{See also}
 157
 158 \helpref{SetUseBestVisual}{wxappsetusebestvisual}
 159
 160 \membersection{wxApp::GetVendorName}\label{wxappgetvendorname}
 161
 162 \constfunc{wxString}{GetVendorName}{\void}
 163
 164 Returns the application's vendor name.
 165
 166 \membersection{wxApp::ExitMainLoop}\label{wxappexitmainloop}
 167
 168 \func{void}{ExitMainLoop}{\void}
 169
 170 Call this to explicitly exit the main message (event) loop.
 171 You should normally exit the main loop (and the application) by deleting
 172 the top window.
 173
 174 \membersection{wxApp::Initialized}\label{wxappinitialized}
 175
 176 \func{bool}{Initialized}{\void}
 177
 178 Returns TRUE if the application has been initialized (i.e. if\rtfsp
 179 \helpref{wxApp::OnInit}{wxapponinit} has returned successfully).  This can be useful for error
 180 message routines to determine which method of output is best for the
 181 current state of the program (some windowing systems may not like
 182 dialogs to pop up before the main loop has been entered).
 183
 184 \membersection{wxApp::MainLoop}\label{wxappmainloop}
 185
 186 \func{int}{MainLoop}{\void}
 187
 188 Called by wxWindows on creation of the application. Override this if you wish
 189 to provide your own (environment-dependent) main loop.
 190
 191 \wxheading{Return value}
 192
 193 Returns 0 under X, and the wParam of the WM\_QUIT message under Windows.
 194
 195 \membersection{wxApp::OnActivate}\label{wxapponactivate}
 196
 197 \func{void}{OnActivate}{\param{wxActivateEvent\& }{event}}
 198
 199 Provide this member function to know whether the application is being
 200 activated or deactivated (Windows only).
 201
 202 \wxheading{See also}
 203
 204 \helpref{wxWindow::OnActivate}{wxwindowonactivate}, \helpref{wxActivateEvent}{wxactivateevent}
 205
 206 \membersection{wxApp::OnExit}\label{wxapponexit}
 207
 208 \func{int}{OnExit}{\void}
 209
 210 Provide this member function for any processing which needs to be done as
 211 the application is about to exit.
 212
 213 \membersection{wxApp::OnCharHook}\label{wxapponcharhook}
 214
 215 \func{void}{OnCharHook}{\param{wxKeyEvent\&}{ event}}
 216
 217 This event handler function is called (under Windows only) to allow the window to intercept keyboard events
 218 before they are processed by child windows.
 219
 220 \wxheading{Parameters}
 221
 222 \docparam{event}{The keypress event.}
 223
 224 \wxheading{Remarks}
 225
 226 Use the wxEVT\_CHAR\_HOOK macro in your event table.
 227
 228 If you use this member, you can selectively consume keypress events by calling\rtfsp
 229 \helpref{wxEvent::Skip}{wxeventskip} for characters the application is not interested in.
 230
 231 \wxheading{See also}
 232
 233 \helpref{wxKeyEvent}{wxkeyevent}, \helpref{wxWindow::OnChar}{wxwindowonchar},\rtfsp
 234 \helpref{wxWindow::OnCharHook}{wxwindowoncharhook}, \helpref{wxDialog::OnCharHook}{wxdialogoncharhook}
 235
 236 \membersection{wxApp::OnFatalException}\label{wxapponfatalexception}
 237
 238 \func{void}{OnFatalException}{\void}
 239
 240 This function may be called if something fatal happens: an unhandled
 241 exception under Win32 or a a fatal signal under Unix, for example. However,
 242 this will not happen by default: you have to explicitly call
 243 \helpref{wxHandleFatalExceptions}{wxhandlefatalexceptions} to enable this.
 244
 245 Generally speaking, this function should only show a message to the user and
 246 return. You may attempt to save unsaved data but this is not guaranteed to
 247 work and, in fact, probably won't.
 248
 249 \wxheading{See also}
 250
 251 \helpref{wxHandleFatalExcetions}{wxhandlefatalexceptions}
 252
 253 \membersection{wxApp::OnIdle}\label{wxapponidle}
 254
 255 \func{void}{OnIdle}{\param{wxIdleEvent\& }{event}}
 256
 257 Override this member function for any processing which needs to be done
 258 when the application is idle. You should call wxApp::OnIdle from your own function,
 259 since this forwards OnIdle events to windows and also performs garbage collection for
 260 windows whose destruction has been delayed.
 261
 262 wxWindows' strategy for OnIdle processing is as follows. After pending user interface events for an
 263 application have all been processed, wxWindows sends an OnIdle event to the application object. wxApp::OnIdle itself
 264 sends an OnIdle event to each application window, allowing windows to do idle processing such as updating
 265 their appearance. If either wxApp::OnIdle or a window OnIdle function requested more time, by
 266 caling \helpref{wxIdleEvent::RequestMore}{wxidleeventrequestmore}, wxWindows will send another OnIdle
 267 event to the application object. This will occur in a loop until either a user event is found to be
 268 pending, or OnIdle requests no more time. Then all pending user events are processed until the system
 269 goes idle again, when OnIdle is called, and so on.
 270
 271 \wxheading{See also}
 272
 273 \helpref{wxWindow::OnIdle}{wxwindowonidle}, \helpref{wxIdleEvent}{wxidleevent},\rtfsp
 274 \helpref{wxWindow::SendIdleEvents}{wxappsendidleevents}
 275
 276 \membersection{wxApp::OnEndSession}\label{wxapponendsession}
 277
 278 \func{void}{OnEndSession}{\param{wxCloseEvent\& }{event}}
 279
 280 This is an event handler function called when the operating system or GUI session is
 281 about to close down. The application has a chance to silently save information,
 282 and can optionally close itself.
 283
 284 Use the EVT\_END\_SESSION event table macro to handle query end session events.
 285
 286 The default handler calls \helpref{wxWindow::Close}{wxwindowclose} with a TRUE argument
 287 (forcing the application to close itself silently).
 288
 289 \wxheading{Remarks}
 290
 291 Under X, OnEndSession is called in response to the `die' event.
 292
 293 Under Windows, OnEndSession is called in response to the WM\_ENDSESSION message.
 294
 295 \wxheading{See also}
 296
 297 \helpref{wxWindow::Close}{wxwindowclose},\rtfsp
 298 \helpref{wxWindow::OnCloseWindow}{wxwindowonclosewindow},\rtfsp
 299 \helpref{wxCloseEvent}{wxcloseevent},\rtfsp
 300 \helpref{wxApp::OnQueryEndSession}{wxapponqueryendsession}
 301
 302 \membersection{wxApp::OnInit}\label{wxapponinit}
 303
 304 \func{bool}{OnInit}{\void}
 305
 306 This must be provided by the application, and will usually create the
 307 application's main window, optionally calling \helpref{wxApp::SetTopWindow}{wxappsettopwindow}.
 308
 309 Return TRUE to continue processing, FALSE to exit the application.
 310
 311 \membersection{wxApp::OnQueryEndSession}\label{wxapponqueryendsession}
 312
 313 \func{void}{OnQueryEndSession}{\param{wxCloseEvent\& }{event}}
 314
 315 This is an event handler function called when the operating system or GUI session is
 316 about to close down. Typically, an application will try to save unsaved documents
 317 at this point.
 318
 319 If \helpref{wxCloseEvent::CanVeto}{wxcloseeventcanveto} returns TRUE, the application
 320 is allowed to veto the shutdown by calling \helpref{wxCloseEvent::Veto}{wxcloseeventveto}.
 321 The application might veto the shutdown after prompting for documents to be saved, and the
 322 user has cancelled the save.
 323
 324 Use the EVT\_QUERY\_END\_SESSION event table macro to handle query end session events.
 325
 326 You should check whether the application is forcing the deletion of the window
 327 using \helpref{wxCloseEvent::GetForce}{wxcloseeventgetforce}. If this is TRUE,
 328 destroy the window using \helpref{wxWindow::Destroy}{wxwindowdestroy}.
 329 If not, it is up to you whether you respond by destroying the window.
 330
 331 The default handler calls \helpref{wxWindow::Close}{wxwindowclose} on the top-level window,
 332 and vetoes the shutdown if Close returns FALSE. This will be sufficient for many applications.
 333
 334 \wxheading{Remarks}
 335
 336 Under X, OnQueryEndSession is called in response to the `save session' event.
 337
 338 Under Windows, OnQueryEndSession is called in response to the WM\_QUERYENDSESSION message.
 339
 340 \wxheading{See also}
 341
 342 \helpref{wxWindow::Close}{wxwindowclose},\rtfsp
 343 \helpref{wxWindow::OnCloseWindow}{wxwindowonclosewindow},\rtfsp
 344 \helpref{wxCloseEvent}{wxcloseevent},\rtfsp
 345 \helpref{wxApp::OnEndSession}{wxapponendsession}
 346
 347 \membersection{wxApp::ProcessMessage}\label{wxappprocessmessage}
 348
 349 \func{bool}{ProcessMessage}{\param{MSG *}{msg}}
 350
 351 Windows-only function for processing a message. This function
 352 is called from the main message loop, checking for windows that
 353 may wish to process it. The function returns TRUE if the message
 354 was processed, FALSE otherwise. If you use wxWindows with another class
 355 library with its own message loop, you should make sure that this
 356 function is called to allow wxWindows to receive messages. For example,
 357 to allow co-existance with the Microsoft Foundation Classes, override
 358 the PreTranslateMessage function:
 359
 360 \begin{verbatim}
 361 // Provide wxWindows message loop compatibility
 362 BOOL CTheApp::PreTranslateMessage(MSG *msg)
 363 {
 364   if (wxTheApp && wxTheApp->ProcessMessage(msg))
 365     return TRUE;
 366   else
 367     return CWinApp::PreTranslateMessage(msg);
 368 }
 369 \end{verbatim}
 370
 371 \membersection{wxApp::Pending}\label{wxapppending}
 372
 373 \func{bool}{Pending}{\void}
 374
 375 Returns TRUE if unprocessed events are in the window system event queue.
 376
 377 \wxheading{See also}
 378
 379 \helpref{wxApp::Dispatch}{wxappdispatch}
 380
 381 \membersection{wxApp::SendIdleEvents}\label{wxappsendidleevents}
 382
 383 \func{bool}{SendIdleEvents}{\void}
 384
 385 Sends idle events to all top-level windows.
 386
 387 \func{bool}{SendIdleEvents}{\param{wxWindow*}{ win}}
 388
 389 Sends idle events to a window and its children.
 390
 391 \wxheading{Remarks}
 392
 393 These functions poll the top-level windows, and their children, for idle event processing.
 394 If TRUE is returned, more OnIdle processing is requested by one or more window.
 395
 396 \wxheading{See also}
 397
 398 \helpref{wxApp::OnIdle}{wxapponidle}, \helpref{wxWindow::OnIdle}{wxwindowonidle}, \helpref{wxIdleEvent}{wxidleevent}
 399
 400 \membersection{wxApp::SetAppName}\label{wxappsetappname}
 401
 402 \func{void}{SetAppName}{\param{const wxString\& }{name}}
 403
 404 Sets the name of the application. The name may be used in dialogs
 405 (for example by the document/view framework). A default name is set by
 406 wxWindows.
 407
 408 \wxheading{See also}
 409
 410 \helpref{wxApp::GetAppName}{wxappgetappname}
 411
 412 \membersection{wxApp::SetAuto3D}\label{wxappsetauto3d}
 413
 414 \func{void}{SetAuto3D}{\param{const bool}{ auto3D}}
 415
 416 Switches automatic 3D controls on or off.
 417
 418 \wxheading{Parameters}
 419
 420 \docparam{auto3D}{If TRUE, all controls will be created with 3D appearances unless
 421 overridden for a control or dialog. The default is TRUE}
 422
 423 \wxheading{Remarks}
 424
 425 This has an effect on Windows only.
 426
 427 \wxheading{See also}
 428
 429 \helpref{wxApp::GetAuto3D}{wxappgetauto3d}
 430
 431 \membersection{wxApp::SetClassName}\label{wxappsetclassname}
 432
 433 \func{void}{SetClassName}{\param{const wxString\& }{name}}
 434
 435 Sets the class name of the application. This may be used in a platform specific
 436 manner to refer to the application.
 437
 438 \wxheading{See also}
 439
 440 \helpref{wxApp::GetClassName}{wxappgetclassname}
 441
 442 \membersection{wxApp::SetExitOnFrameDelete}\label{wxappsetexitonframedelete}
 443
 444 \func{void}{SetExitOnFrameDelete}{\param{bool}{ flag}}
 445
 446 Allows the programmer to specify whether the application will exit when the
 447 top-level frame is deleted.
 448
 449 \wxheading{Parameters}
 450
 451 \docparam{flag}{If TRUE (the default), the application will exit when the top-level frame is
 452 deleted. If FALSE, the application will continue to run.}
 453
 454 \membersection{wxApp::SetTopWindow}\label{wxappsettopwindow}
 455
 456 \func{void}{SetTopWindow}{\param{wxWindow* }{window}}
 457
 458 Sets the `top' window. You can call this from within \helpref{wxApp::OnInit}{wxapponinit} to
 459 let wxWindows know which is the main window. You don't have to set the top window;
 460 it's only a convenience so that (for example) certain dialogs without parents can use a
 461 specific window as the top window. If no top window is specified by the application,
 462 wxWindows just uses the first frame or dialog in its top-level window list, when it
 463 needs to use the top window.
 464
 465 \wxheading{Parameters}
 466
 467 \docparam{window}{The new top window.}
 468
 469 \wxheading{See also}
 470
 471 \helpref{wxApp::GetTopWindow}{wxappgettopwindow}, \helpref{wxApp::OnInit}{wxapponinit}
 472
 473
 474 \membersection{wxApp::SetVendorName}\label{wxappsetvendorname}
 475
 476 \func{void}{SetVendorName}{\param{const wxString\& }{name}}
 477
 478 Sets the name of application's vendor. The name will be used
 479 in registry access. A default name is set by
 480 wxWindows.
 481
 482 \wxheading{See also}
 483
 484 \helpref{wxApp::GetVendorName}{wxappgetvendorname}
 485
 486 \membersection{wxApp::GetStdIcon}\label{wxappgetstdicon}
 487
 488 \func{virtual wxIcon}{GetStdIcon}{\param{int }{which}} const
 489
 490 Returns the icons used by wxWindows internally, e.g. the ones used for
 491 message boxes.  This function is used internally and
 492 can be overridden by the user to change the default icons.
 493
 494 \wxheading{Parameters}
 495
 496 \docparam{which}{One of the wxICON\_XXX specifies which icon to return.}
 497
 498 See \helpref{wxMessageBox}{wxmessagebox} for a list of icon identifiers.
 499
 500 \membersection{wxApp::SetUseBestVisual}\label{wxappsetusebestvisual}
 501
 502 \func{void}{SetUseBestVisual}{\param{bool}{ flag}}
 503
 504 Allows the programmer to specify whether the application will use the best visual
 505 on systems that support several visual on the same display. This is typically the
 506 case under Solaris and IRIX, where the default visual is only 8-bit whereas certain
 507 appications are supposed to run in TrueColour mode.
 508
 509 Note that this function has to be called in the constructor of the {\tt wxApp}
 510 instance and won't have any effect when called later on.
 511
 512 This function currently only has effect under GTK.
 513
 514 \wxheading{Parameters}
 515
 516 \docparam{flag}{If TRUE, the app will use the best visual.}
 517