xtappprocessevent(3) [hpux man page]

XtAppProcessEvent()													       XtAppProcessEvent()

Name
  XtAppProcessEvent - get and process one input event of a specified type.

Synopsis
  void XtAppProcessEvent(app_context, mask)
	 XtAppContext app_context;
	 XtInputMask mask;

Inputs
  app_context
	    Specifies the application context for which to process events.

  mask	    Specifies what types of events to process.

Description
  XtAppProcessEvent()  processes  one X event, alternate input source event or timer event in app_context.  The mask argument specifies which
  types of events are to be processed; it is the bitwise inclusive OR ( ) of any of the values XtIMXEvent, XtIMTimer, or  XtIMAlternateInput,
  or the value XtIMAll which specifies all three event types.

  If  there  is  no  event  or	input  of  the	appropriate type to process, if there is a background work procedure registered (see XtAppAd-
  dWorkProc()) XtAppProcessEvent() calls that procedure and checks again for input from all specified  sources.   If  there  are  no  pending
  events and no work procedures registered, XtAppProcessEvent() blocks until an event of one of the specified types occurs.

  If  X  events  are specified in mask, and no events are immediately available, XtAppProcessEvent() flushes the output buffer of each of the
  Displays in app_context.  If there is more than one of the requested types of input available, it is undefined which will be processed.

  XtAppProcessEvent() handles timer and alternate input events by calling the callback procedures registered for those events  (see  XtAppAd-
  dTimeOut()  and XtAppAddInput()).  It handles X events by passing them to XtDispatchEvent().	XtDispatchEvent() handles an event by passing
  it to the appropriate event handlers (see XtAddEventHandler()) or to the Translation Manager (which is itself an event handler).

Usage
  Programs rarely need this much control over the event dispatching mechanism.	Most programs use XtAppMainLoop().

Structures
  The XtInputMask type and its possible values are defined as follows:

     typedef unsigned long    XtInputMask;

     #define XtIMXEvent 	     1
     #define XtIMTimer		     2
     #define XtIMAlternateInput      4
     #define XtIMAll (XtIMXEvent   XtIMTimer   XtIMAlternateInput)

See Also
  XtAppAddInput(1), XtAppAddTimeOut(1), XtAppAddWorkProc(1), XtAppMainLoop(1), XtAppNextEvent(1), XtAppPeekEvent(1), XtAppPending(1), XtDis-
  patchEvent(1).

Xt - Event Handling													       XtAppProcessEvent()

XtAppNextEvent(3Xt)						   XT FUNCTIONS 					       XtAppNextEvent(3Xt)

NAME

       XtAppNextEvent, XtAppPending, XtAppPeekEvent, XtAppProcessEvent, XtDispatchEvent, XtAppMainLoop - query and process events and input

SYNTAX

       void XtAppNextEvent(app_context, event_return)
	     XtAppContext app_context;
	     XEvent *event_return;

       Boolean XtAppPeekEvent(app_context, event_return)
	     XtAppContext app_context;
	     XEvent *event_return;

       XtInputMask XtAppPending(app_context)
	     XtAppContext app_context;

       void XtAppProcessEvent(app_context, mask)
	     XtAppContext app_context;
	     XtInputMask mask;

       Boolean XtDispatchEvent(event)
	     XEvent *event;

       void XtAppMainLoop(app_context)
	     XtAppContext app_context;

ARGUMENTS

       app_context
		 Specifies the application context that identifies the application .

       event	 Specifies a pointer to the event structure that is to be dispatched to the appropriate event handler.

       event_return
		 Returns the event information to the specified event structure.

       mask	 Specifies what types of events to process.  The mask is the bitwise inclusive OR of any combination of XtIMXEvent, XtIMTimer,
		 XtIMAlternateInput, and XtIMSignal.  As a convenience, the X Toolkit defines the symbolic name XtIMAll to be the bitwise inclu-
		 sive OR of all event types.

DESCRIPTION

       If the X event queue is empty, XtAppNextEvent flushes the X output buffers of each Display in the application context and waits for an
       event while looking at the other input sources, timeout timeout values, and signal handlers and calling any callback procedures triggered
       by them.  This wait time can be used for background processing (see Section 7.8).

       If there is an event in the queue, XtAppPeekEvent fills in the event and returns a nonzero value. If no X input is on the queue, XtAppPeek-
       Event flushes the output buffer and blocks until input is available (possibly calling some timeout callbacks in the process).  If the input
       is an event, XtAppPeekEvent fills in the event and returns a nonzero value.  Otherwise, the input is for an alternate input source, and
       XtAppPeekEvent returns zero.

       The XtAppPending function returns a nonzero value if there are events pending from the X server, timer pending, or other input sources
       pending. The value returned is a bit mask that is the OR of XtIMXEvent, XtIMTimer, XtIMAlternateInput, and XtIMSignal (see XtAppProcess-
       Event).	If there are no events pending, XtAppPending flushes the output buffer and returns zero.

       The XtAppProcessEvent function processes one timer, alternate input, signal source, or X event.	If there is nothing of the appropriate
       type to process, XtAppProcessEvent blocks until there is.  If there is more than one type of thing available to process, it is undefined
       which will get processed.  Usually, this procedure is not called by client applications (see XtAppMainLoop).  XtAppProcessEvent processes
       timer events by calling any appropriate timer callbacks, alternate input by calling any appropriate alternate input callbacks, signal
       source by calling any appropriate signal callbacks, and X events by calling XtDispatchEvent.

       When an X event is received, it is passed to XtDispatchEvent, which calls the appropriate event handlers and passes them the widget, the
       event, and client-specific data registered with each procedure.	If there are no handlers for that event registered, the event is ignored
       and the dispatcher simply returns.  The order in which the handlers are called is undefined.

       The XtDispatchEvent function sends those events to the event handler functions that have been previously registered with the dispatch rou-
       tine.  XtDispatchEvent returns True if it dispatched the event to some handler and False if it found no handler to dispatch the event to.
       The most common use of XtDispatchEvent is to dispatch events acquired with the XtAppNextEvent procedure.  However, it also can be used to
       dispatch user-constructed events.  XtDispatchEvent also is responsible for implementing the grab semantics for XtAddGrab.

       The XtAppMainLoop function first reads the next incoming X event by calling XtAppNextEvent and then it dispatches the event to the appro-
       priate registered procedure by calling XtDispatchEvent.	This constitutes the main loop of X Toolkit applications, and, as such, it does
       not return unless XtAppSetExitFlag is called.  Applications are expected to exit in response to some user action.  There is nothing special
       about XtAppMainLoop; it is simply an loop that calls XtAppNextEvent and then XtDispatchEvent, until XtAppGetExitFlag() returns true.

       Applications can provide their own version of this loop, which tests some global termination flag or tests that the number of top-level
       widgets is larger than zero before circling back to the call to XtAppNextEvent.

SEE ALSO

       X Toolkit Intrinsics - C Language Interface
       Xlib - C Language X Interface

X Version 11							    Release 6.6 					       XtAppNextEvent(3Xt)