VkApp(3x)
VkApp - Class used by all ViewKit applications to handle initialization
As shipped in IRIX 6.5.15. Last changed in IRIX 6.5.5.
NAME VkApp - Class used by all ViewKit applications to handle initialization INHERITS FROM VkComponent : VkCallbackObject HEADER FILE #include <Vk/VkApp.h> PUBLIC PROTOCOL SUMMARY Constructors VkApp(char *appClassName, int *arg_c, char **arg_v, XrmOptionDescRec *optionList = NULL, int sizeOfOptionList = 0 ) VkApp(char *appClassName, int *arg_c, char **arg_v, ArgList argList, Cardinal argCount, void (*preRealizeFunction)(Widget w), XrmOptionDescRec *optionList, int sizeOfOptionList) Version Information static const int ViewKitMajorRelease static const int ViewKitMinorRelease static const char ViewKitReleaseString[] void setVersionString(const char *str) const char *versionString() void setAboutDialog(VkDialogManager *aboutDialog) void setStartupDialog(VkDialogManager *startupDialog) Runtime Interaction virtual void run() void run(Boolean(*appEventHandler)(XEvent &)) void runOneEvent(Boolean(*appEventHandler)(XEvent &) = NULL) void run_first() virtual void handlePendingEvents() void handlePendingEvents(Boolean(*appEventHandler)(XEvent &)) XtInputMask handleOnePendingEvent(Boolean(*appEventHandler)(XEvent &) = NULL) virtual void handleRawEvent(XEvent *event) virtual void quitYourself() virtual void terminate(int status = 0) Operations on Application Windows void setMainWindow(VkSimpleWindow *win) virtual void raise() virtual void lower() virtual void iconify() virtual void open() virtual void show() virtual void hide() void startupIconified(Boolean flag) Application Cursor Control virtual Cursor busyCursor() virtual Cursor normalCursor() void setNormalCursor(Cursor c) void setBusyCursor(Cursor c) void setBusyCursor(VkCursorList *cl) void showCursor(Cursor c) Support for Busy States virtual void busy(const char *msg = NULL, VkSimpleWindow *parent = NULL) virtual void veryBusy(const char *msg = NULL, VkSimpleWindow *parent = NULL) virtual void notBusy() void setBusyDialog(VkBusyDialog *d) virtual void progressing(const char *msg = NULL); Convenient Access Functions XtAppContext appContext() const char *name() const Display *display() const char **argv() const char *argv(int index) const int argc() const char *applicationClassName() const VkSimpleWindow *mainWindow() const void setFallbacks(char **fallbacks) char *shellGeometry() const Boolean startupIconified() const virtual const char *className() const VkApp *theApplication Visual Control static void useOverlayApps(const Boolean flag) Help system int helpInit(char *client, char *sep); int helpMsg(char *key, char *book, char *userData); int helpIndexMsg(char *key, char *book); static const char *const helpInitCallback; static const char *const helpMsgCallback; static const char *const helpIndexMsgCallback; void useSGIHelp(); static void sgiHelpInit(VkCallbackObject* caller, void* clientData, void* callData); static void sgiHelpMsg(VkCallbackObject* caller, void* clientData, void* callData); static void sgiHelpIndexMsg(VkCallbackObject* caller, void* clientData, void* callData); PROTECTED PROTOCOL SUMMARY int parseCommandLine(XrmOptionDescRec *opt, Cardinal numOptions) VkComponentList _winList virtual void afterRealizeHook() COMMAND LINE OPTIONS ASSOCIATED WITH THIS CLASS -scheme Sets the scheme for the application's resources. -useOverlayApps If true, this resource causes the entire application to use the deepest available overlay planes. -useOverlayDialogs If true, this resource causes all dialogs to use the deepest available overlay planes. -useOverlayMenus If true, this resource causes all menus to use the deepest available overlay planes. X RESOURCES ASSOCIATED WITH THIS CLASS busyCursorForeground The foreground color used by the busy cursor. busyCursorBackground The background color used by the busy cursor. iconic If true, this resource causes the entire application to startup iconified. normalCursorForeground The foreground color used by the normal cursor. normalCursorBackground The background color used by the normal cursor. silenceWarnings If True, an application will install error and warning handlers that effectively hide all Xt warnings. Some of these messages are unavoidable, and this resource can be set before a product is shipped. useOverlayApps This is equivalent to the command-line switch -useOverlayApps. useOverlayDialogs This is equivalent to the command-line switch -useOverlayDialogs. useOverlayMenus This is equivalent to the command-line switch -useOverlayMenus. X DEBUGGING RESOURCES ASSOCIATED WITH THIS CLASS There are some resources that are only available in the debugging versions of the library. Non-debugging versions of the library simply ignore them. debugResources If this resource is set to true, the application will save the contents of its resource database to /usr/tmp/resources.db. debugXtMode If true, the application will core dump when any X or Xt warning or error occurs. printEvent if non-zero, ViewKit will print information about each event to stderr. Currently (6/96) the name of each event, the name of the widget that got the event, and the widget's classname are printed. CLASS DESCRIPTION VkApp provides various central facilities required by all ViewKit applications. All applications must create a single instance of VkApp or a derived class. The following constructor is the normal one. Most applications will have no reason to use any other. VkApp(char *appClassName, int *arg_c, char **arg_v, XrmOptionDescRec *optionList = NULL, int sizeOfOptionList = 0); The following constructor is rarely needed. It is used when an application must set creation-time resources on the invisible top-level shell widget that VkApp creates. One use of it is for an application that runs entirely in a non-default visual, and also has Motif drag and drop enabled. Such an application should use this constructor to set the visual attributes for the shell that the VkApp constructor creates, so that they match those used for the rest of the application. Setting the visual attributes this way allows the application to have all of its shells in a single non-default visual. (As of 6/96, if an application does not ensure that its visuals match, Motif drag and drop will core dump. There are non-obvious work-arounds, and a genuine multi-visual application must still use them.) VkApp(char *appClassName, int *arg_c, char **arg_v, ArgList argList, Cardinal argCount, void (*preRealizeFunction)(Widget w), XrmOptionDescRec *optionList, int sizeOfOptionList); Upon instantiation, VkApp calls various Xt functions to connect to the X server and initialize the Xt Intrinsics. ViewKit applications should not call XtAppInitialize() or other similar Xt initialization functions directly. VkApp uses the application-context style Xt functions throughout, and wherever applicable, ViewKit applications must use the app-context versions of all Xt functions. The simplest use of the VkApp class is to create an instance, create other windows as needed (see VkSimpleWindow), and call VkApp::run(), as seen in the following example program. #include <Vk/VkApp.h> #include <Vk/VkSimpleWindow.h> void main ( int argc, char **argv ) { VkApp *app = new VkApp("Application", &argc, argv); VkSimpleWindow *win = new VkSimpleWindow("window"); win->show(); app->run(); } An application's instance of VkApp can be referenced as theApplication throughout an application, in any file that includes VkApp.h. This allows easy use of various VkApp facilities, such as the busy() facility, and easy access to the X Display pointer, the Xt application context, and so on. Deriving Subclasses It is often useful to create subclasses of VkApp to support additional application-wide services. One typical use of a derived class is to parse additional command-line arguments. For example, the following simple example specifies a -verbose command-line argument, using an XrmOptionDescRec. This array is passed to the protected member function parseCommandLine() to extract the flag, if it exists. The value of all recovered options are placed in the application's resource database, where they can be retrieved as needed. Notice that parseCommandLine() returns an updated value of argc which must be used to update the value of argc as passed in by the calling application. Failure to do so will cause problems for applications that reference this value after instantiating a VkApp object. (Applications can avoid any difficulties by not referencing args directly, and using theApplication->argc() instead.) #include <Vk/VkApp.h> class App : public VkApp { private: // Declare a description of the command line options static XrmOptionDescRec _cmdLineOptions[]; public: App(char *appClassName, int *arg_c, char **arg_v, XrmOptionDescRec *optionList = NULL, int sizeOfOptionList = 0); }; // Describe the command line options XrmOptionDescRec App::_cmdLineOptions[] = { { "-verbose", "*verbose", XrmoptionNoArg, "TRUE", }, }; // Constructor App::MyApp(char *appClassName, int *arg_c, char **arg_v, XrmOptionDescRec *optionList, int sizeOfOptionList) : VkApp(appClassName, arg_c, arg_v, optionList, sizeOfOptionList) { // Parse the command line *arg_c = parseCommandLine(_cmdLineOptions, XtNumber(_cmdLineOptions)); } Derived classes may also need access to the windows currently used in an application. The _winList member provides access to a list of windows, in the form of a VkComponentList object (see VkComponentList(3x)). VIEWKIT VERSIONS The ViewKit supports several constants that can be used to identify the current ViewKit release. These are: ViewKitMajorRelease; static const int ViewKitMajorRelease; This integer value identifies the major release of the ViewKit. For example, in a 1.2 release, this value would be "1". Should it prove necessary to use conditional statements in your code to handle different versions of the library, this value can be useful. ViewKitMinorRelease; static const int ViewKitMinorRelease; This integer value identifies the current minor release of the ViewKit. For example, in a 1.2 release, this value would be "2". Should it prove necessary to use conditional statements in your code to handle different versions of the library, this value can be useful. ViewKitReleaseString static const char ViewKitReleaseString[]; This string contains the complete major and minor release information on the ViewKit. You can identify the version of the ViewKit an application is compiled with by running: strings program | grep "ViewKit Release" FUNCTION DESCRIPTIONS VkApp() VkApp(char *appClassName, int *arg_c, char **arg_v, XrmOptionDescRec *optionList = NULL, int sizeOfOptionList = 0) The VkApp constructor initializes the Xt Intrinsics by calling XtToolkitInitialize(), XtCreateApplicationContext() and XtOpenDisplay(). The constructor also creates a shell to serve as a parent for all other main windows. The ViewKit supports the multi- shell architecture described in the book "X Window System Toolkit", Asente and Swick, 1990. All other windows are created as popup children of the shell created by VkApp, which is never visible. The VkApp constructor also installs various error handlers and retrieves the application resources recognized by VkApp. The first argument indicates the class name of the application, which is used to load application resources. The second and third arguments must be a pointer to argc and the application's argv array. These arguments are passed to XtOpenDisplay() and the recognized arguments are removed. The following constructor is rarely needed. It is only used when an application must set creation-time resources on the invisible top-level shell widget that VkApp creates. This constructor operates just like the (shorter) more common one (above), except that it provides control over the resources used when the application's top level shell is created. The motivation for this is that without it you cannot have a single- visual application that was not in the default visual. VkApp(char *appClassName, int *arg_c, char **arg_v, ArgList argList, Cardinal argCount, void (*preRealizeFunction)(Widget w), XrmOptionDescRec *optionList, int sizeOfOptionList); One use of this constructor is for an application that runs entirely in a non-default visual, and also has Motif drag and drop enabled. Such an application should use this constructor to set the visual attributes for the shell that the VkApp constructor creates, so that they match those used for the rest of the application. Setting the visual attributes this way allows the application to have all of its shells in a single non-default visual. (As of 6/96, if an application does not ensure that its visuals match, Motif drag and drop will core dump. There are non-obvious work-arounds, and a genuine multi-visual application must still use them.) o Any resource that can be passed on the argList, such as default font list, should be passed in that way. o Visual information cannot be known until after the display is opened, and so cannot be passed in on the argList. o preRealizeFunction(w) will be called with the baseWidget (i.e the shell). It will be called after widget creation, but before the widget is realized. At that time, the application can find the visual information it needs, and do an XtSetValues() call. The manual not withstanding, since the widget has not yet been realized, this is OK - provided that the call sets all visual resources consistently. setAboutDialog void setAboutDialog(VkDialogManager *dialog); This function allows applications to replace the dialog displayed when the user asks for help on "Product Info". The default behavior of this help item is to display a VkInformationDialog that reports the name and version information for this application (See setVersionInfo, and VkInformationDialog). Applications that wish to customize the dialog that appears in this case can install any subclass of VkDialogManager using this function. The new dialog will be posted with a string that identifies the name of the application and the version, but otherwise the content of the dialog is up to the application. (See VkDialogManager and VkGenericDialog for more information on dialogs.) o The string "Application Name:" in the default popup dialog can be localized by adding a resource, vkAppNameL10NString, with a translated string to the application's app-defaults file. For example; *vkAppNameL10NString: Application Name: setVersionString void setVersionString(const char *str); This function specifies a string to be used as the version of an application based on the ViewKit. This string appears by default in the "Product Info" dialog. versionString const char *versionString(); This function retrieves the currently installed version string. run virtual void run(); This function should be called instead of XtAppMainLoop() in ViewKit programs. run() calls run_first() to do some internal initialization, and then enters a custom main loop that dispatches application events, raw X events, and normal Xt events. (see handleRawEvent().) void run(Boolean(*appEventHandler)(XEvent &)) This is the easiest way to customize ViewKit's X event loop. This entry allows an application to customize the event loop without taking responsibility for the entire event loop. For each event, the application can either supplement or replace the main event loop handling. Each time through the event loop, before doing any event processing of its own, run() calls appEventHandler() with the event. If appEventHandler() has completely handled the event, it returns TRUE and no further handling of that event occurs. If ViewKit handling of that event is still needed, then appEventHandler() must return FALSE. void run_first() run_first() is called by run(). Any application that overrides run() must ensure that run_first() gets called. See Overriding VkApp::run(), below, for more information. void runOneEvent(Boolean(*appEventHandler)(XEvent &) = NULL) runOneEvent() is the event handling function called by run(). It does whatever things ViewKit needs beyond the standard Xt event handling. Any application that overrides run() must ensure that some ViewKit event handling function gets called. See Overriding VkApp::run(), below, for more information. handlePendingEvents virtual void handlePendingEvents(); handlePendingEvents() retrieves and dispatches all X11 events, timers, and alternate input. It does not block -- it returns when there is nothing pending. It does not call any workproc's. void VkApp::handlePendingEvents(Boolean(*appEventHandler)(XEvent &)) This version is exactly the same as handlePendingEvents(), above, except that it allows an application's event handler to also see each event. See runOneEvent(Boolean(*appEventHandler)(XEvent &) = NULL), above, for more information. XtInputMask VkApp::handleOnePendingEvent( Boolean(*appEventHandler)(XEvent &) = NULL) handleOnePendingEvent() returns after handling a single event, or immediately if there are no events. The return value is the mask returned by XtAppPending(), which will be zero if there are no pending events. The purpose of this routine is to permit construction of non-blocking event loops that do something before (and/or after) each event. Overriding VkApp::run() run() consists of: void VkApp::run() { run_first(); while (True) { runOneEvent((Boolean(*)(XEvent &)) NULL); } } In most cases, an application does not need to override VkApp::run() to control events. Instead, the application can do such things as: use standard X mechanisms to add event handlers; use one or more workproc's; maintain its own queue of all that it needs to do, and then dispatch that work in a single workproc; If the above are not sufficient, the next thing to look into is calling run(Boolean(*appEventHandler)(XEvent &)). If an application really does need to override run(), though, then the application must call run_first() before the first event processing is done, and it must call one of the ViewKit event processing routines from the application's event loop. If it does not do those two things, it may not be compatible with a future release of ViewKit. An application can override VkApp::run() to add application code that will be executed each time through the event loop. runOneEvent() will only return if there was an X11 event. Otherwise it will service any workproc's, and then block waiting for the next X11 event. Such an overridden event loop might look like the following: MyApp::run() { run_first(); for (;;) { <application code here> runOneEvent(); <application code here> } } If the application does not want to block in ViewKit when there are no X11 events, it can use the following event loop. Note that since handlePendingEvents() neither blocks nor calls any workproc's, the application must take care of both of those things. MyApp::run() { XEvent event; run_first(); for (;;) { <application code, if any here> handlePendingEvents(); <application code to handle any workproc's here> // Block until there are more events XtAppPeekEvent( appContext(), &event); } } Alternatively, the loop could call handleOnePendingEvent() if it needs to take control each time through the event loop. Demonstration program For a demonstration program illustrating the several ways to customize the event loop, see /usr/share/src/ViewKit/Basic/run.c++. quitYourself; virtual void quitYourself(); Applications that wish to exit, but that wish to allow other parts of the applications to abort the shutdown should call quitYourself(). QuitYourself() loops through each top level VkSimpleWindow (or subclass) calling each window's okToQuit() method. The windows are queried in the reverse order in which they are created, except that the window designated as the main window is checked last. (See VkSimpleWindow for more information.) If any object's okToQuit() method returns FALSE, the shutdown is terminated. If the resource quitMode is set to all, then no action is taken unless all windows return TRUE. If they do, then all windows are deleted and the application is terminated. If the resource quitMode is not set to all, then any window that returns TRUE is deleted and any window that returns FALSE is not deleted. terminate virtual void terminate(int status = 0); terminate() is called within the ViewKit when any fatal error occurs. Because terminate() is a virtual function, it can be overloaded by derived class that need to perform some cleanup before exiting. Classes that override terminate() should perform their clean up and call their base class's terminate() method. This function is not meant for clean shutdowns, but is normally reserved for situations in which the termination cannot be stopped. You may also want to consider using the UNIX atexit() facility (See atexit(3C)). Terminate() is called automatically when all windows have been deleted. Also see quitYourself(). handleRawEvent virtual void handleRawEvent(XEvent *event); Some events do not have a type and are not dispatched by the Xt dispatch mechanism. These events include client messages and events registered for non-widgets (for example, a PropertyNotify on the root window). When such an event is received, VkApp calls the virtual function handleRawEvent() for event loops the VkApp instance as well as for all VkSimpleWindow instances. setMainWindow void setMainWindow(VkSimpleWindow *win); Specify a subclass of VkSimpleWindow to be treated as the main window of the application. This window is used by default for centering dialogs that have not specified otherwise, and is also treated differently when the application is being shut down. See quitYourself(). raise virtual void raise(); Raises all visible windows in the application. lower virtual void lower(); Lowers all visible windows in the application. iconify virtual void iconify(); Iconifies all visible windows in the application. open virtual void open(); Opens all iconified windows in the application. show virtual void show(); Make all hidden, non-iconified windows visible. hide virtual void hide(); Remove all visible, non-iconified windows from the screen. startupIconified void startupIconified(Boolean flag); If called before an application enters the event loop (run()), this will cause the application to start in an iconified state. busyCursor virtual Cursor busyCursor(); Returns the current busy cursor used by the application. normalCursor virtual Cursor normalCursor(); Returns the current normal cursor used by the application. setNormalCursor void setNormalCursor(Cursor c); Sets the normal cursor used by the application. If the application is not busy, this cursor will be displayed in all windows. If the application is busy, this cursor will become visible when the application returns from its busy state. setBusyCursor void setBusyCursor(Cursor c); void setBusyCursor(VkCursorList *cl); Sets the busy cursor used by the application. If the application is busy, this cursor will be displayed in all windows immediately. If the application is not busy, this cursor will become visible when the application becomes busy. If a VkCursorList object is specified as the busy cursor, the application can support an animated cursor. The application will cycle through one cursor each time the application calls progressing(). By default, a initial VkCursorList is installed in all ViewKit applications. showCursor void showCursor(Cursor c); This function temporarily displays a cursor in all windows. The cursor can be reset by calling this function with a NULL cursor argument. The cursor will also be reset if the program becomes busy or returns from a busy state. This function is intended for use only for briefly displaying a cursor. For more permanent cursors, use setNormalCursor(), or setBusyCursor(). busy veryBusy notBusy virtual void busy(const char *msg = NULL, VkSimpleWindow *parent = NULL); virtual void veryBusy(const char *msg = NULL, VkSimpleWindow *parent = NULL); virtual void notBusy(); Applications that expect to be unable to process events for some length of time should call busy() when they enter the busy state and call notBusy() when the program is no longer busy. Calls can be nested, but there must be matching pairs of busy() and notBusy() calls. If no arguments are given to busy(), the application simply displays a busy cursor. The application also blocks out all input, to prevent any type-ahead problems that might occur. If an string is given as the first argument, a dialog is posted to display the string. The string is treated first as the name of a resource that indicates a message to be displayed. If no resource is found the string is used as the message itself. If a VkSimpleWindow (or subclass) is specified, the dialog will be posted over this window. (See VkBusyDialog and VkDialogManager for more details on dialog behavior). The veryBusy() function is intended for use when the application expects to be busy for an extended period of time. In this release, veryBusy() simply calls busy(). In future releases, veryBusy() may take some more interesting or appropriate action. Calling notBusy() undoes the affect of the most recent call to busy(). If the number of notBusy() calls matches the number of busy() calls, the application restores the normal cursor, enables device input, and unposts any busy dialog currently being displayed. progressing void progressing(char *msg = NULL); If an application is busy, and has a VkCursorList object installed, this member function causes the next cursor in the list to be displayed. This function should be called periodically while an application is busy. If an option string is provided, the string is displayed in a busy dialog. setBusyDialog void setBusyDialog(VkBusyDialog *d); By default, busy() displays a dialog using the VkBusyDialog class. (See VkBusyDialog(3X)). Applications that wish to alter this behavior can call setBusyDialog() to display an alternate dialog. This dialog must be implemented using a subclass of VkDialogManager. Calling setBusyDialog() with a NULL argument restores the default VkBusyDialog. (See also, VkInterruptDialog(3X)). Applications should call setBusyDialog() only when the application is not busy. appContext XtAppContext appContext() const; This access function returns the application context used by the application. name char *name() const; This access function returns the base name by which the application was invoked. display Display *display() const; Returns a pointer to the X Display structure associated with this application's connection to the X server. argv() char **argv() const; Returns a pointer to the argv array supplied to this application, but with all recognized command line arguments removed. argv char *argv(int index) const; Returns a specific entry in the argv array. argc int argc() const; Returns the number of command line arguments remaining after all recognized arguments have been removed. applicationClassName char *applicationClassName() const; Returns the application class name. mainWindow VkSimpleWindow *mainWindow() const; Returns a pointer to the VkSimpleWindow (or subclass) object installed as the application's main window. setFallbacks static void setFallbacks(char **fallbacks) Sets fallbacks as the specification_list needed to call XtAppSetFallbackResources(3X). setFallbacks() must be called before the application constructs its VkApp object, because the VkApp constructor does call XtAppSetFallbackResources(3X), passing it the specification_list. shellGeometry char *shellGeometry() const; Returns the geometry of the base shell of the application. Some windows may wish to use this size as their own. startupIconified Boolean startupIconified() const; Calling this function before run() is entered will cause all application windows to start up as icons. className virtual const char *className() const; Returns the class name of the VkApp (or subclass) instance being used. *theApplication VkApp *theApplication; This pointer can be used to reference the single instance of VkApp (or subclass) that must exist in any ViewKit application. useOverlayApps() static void useOverlayApps(const Boolean flag) Effectively, useOverlayApps(TRUE) defaults the entire application into the deepest available overlay planes. The normal default for the (unrealized) VkApp shell is the normal planes. That sets the default for all of its descendants to be the normal planes also. useOverlayApps(TRUE) sets the VkApp shell in the deepest available overlay planes, thus resetting the default planes for the entire application. helpInit() helpMsg() helpIndexMsg() helpInitCallback helpMsgCallback helpIndexMsgCallback useSGIHelp() sgiHelpInit() sgiHelpMsg() sgiHelpIndexMsg() int helpInit(char *client, char *sep); int helpMsg(char *key, char *book, char *userData); int helpIndexMsg(char *key, char *book); static const char *const helpInitCallback; static const char *const helpMsgCallback; static const char *const helpIndexMsgCallback; void useSGIHelp(); static void sgiHelpInit(VkCallbackObject* caller, void* clientData, void* callData); static void sgiHelpMsg(VkCallbackObject* caller, void* clientData, void* callData); static void sgiHelpIndexMsg(VkCallbackObject* caller, void* clientData, void* callData); Historically, the way to provide help from a ViewKit application has been to link the application with a library that implemented the C functions SGIHelpInit(), SGIHelpMsg(), and SGIHelpIndexMsg(). ViewKit and the application would call these functions in response to users' requests for help. Help can also be provided by adding callbacks to the helpInitCallback, helpMsgCallback, and helpIndexMsgCallback lists. Instead of calling the SGIHelp*() functions, ViewKit and the application call the VkApp methods helpInit(), helpMsg(), and helpIndexMsg(). If there are no callbacks installed on the corresponding callback lists, the VkApp help methods call the corresponding SGIHelp*() methods so that old applications continue to work. If callbacks are installed, the callbacks are called instead. An application that provides help using the sgihelp program can call the VkApp method useSGIHelp(), which will install sgiHelpInit() on the helpInitCallback list, sgiHelpMsg() on the helpMsgCallback list, and sgiHelpIndexMsg() on the helpIndexMsgCallback list. sgiHelpInit(), sgiHelpMsg(), and sgiHelpIndexMsgx() interact with the sgihelp program to provide the same help that applications used to get by linking with -lhelpmsg. An application wishing to provide its own help mechanism can add its own callbacks to the callback lists. The callData arguments for the helpInitCallback, helpMsgCallback, and helpIndexMsgCallback lists are of type VkApp::HelpInitArgs*, VkApp::HelpMsgArgs*, and VkApp::HelpIndexMsgArgs* respectively. After installing these callbacks, helpInit() will need to be called. PROTECTED PROTOCOL SUMMARY parseCommandLine() int parseCommandLine(XrmOptionDescRec *opt, Cardinal num); This function can be called by subclasses to extract arguments from the command line. _winList VkComponentList _winList; This member can be accessed by derived classes that need to manipulate the application's top-level windows. See VkComponentList(3X). afterRealizeHook() virtual void afterRealizeHook(); Some applications need to perform certain actions only after the application's windows have been realized. Examples might include installing a colormap, or setting up properties on the application's windows. INHERITED MEMBER FUNCTIONS Inherited from VkComponent installDestroyHandler(), removeDestroyHandler(), widgetDestroyed(), setDefaultResources(), getResources(), manage(), unmanage(), baseWidget(), okToQuit(), _name, _baseWidget, _w, deleteCallback Inherited from VkCallbackObject callCallbacks(), addCallback(), removeCallback(), removeAllCallbacks() KNOWN DERIVED CLASSES VkMsgApp CLASSES USED BY THIS CLASS VkComponent, VkComponentList, VkDialogManager, VkSimpleWindow KNOWN CLASSES THAT USE THIS CLASS VkApp, VkBackground, VkDialogManager, VkDoubleBuffer, VkFatalErrorDialog, VkGraph, VkHelpPane, VkInterruptDialog, VkMenuBar, VkMsgFacility, VkNode, VkPeriodic, VkPipe, VkResizer, VkSimpleWindow SEE ALSO VkComponent, VkDialogManager, VkMsgApp, VkSimpleWindow, VkWindow, VkCursorList ViewKit Programmer's Guide The X Window System, DEC Press, Bob Sheifler and Jim Gettys The X Window System Toolkit, DEC Press, Paul Asente and Ralph Swick The OSF/Motif Programmers Reference, Prentice Hall, OSF