Reference Guide > W Routines > WtLoop Procedure
  
WtLoop Procedure
Handles the dispatching of events and calling of callback routines.
Usage
WtLoop
Parameters
None.
Returned Value
None.
Keywords
Noblock — If specified and nonzero, events are dispatched in the background, and WtLoop returns immediately to process PV‑WAVE commands from the command line.
Discussion
WtLoop causes PV‑WAVE to loop indefinitely, processing the events and dispatching callbacks, handlers, and timers.
 
note
Rogue Wave has ported a subset of the Widget Toolbox (Wt) functionality that is available for Motif to Microsoft Windows. Because the Widget Toolbox under Windows is not a complete implementation, we recommend that Windows developers use the PV‑WAVE Widgets (Ww) layer or the VDA Tools when developing GUI applications.
For interapplication development using cwavec() or cwavefor(), the default behavior of WwLoop is to block, even if the Noblock keyword is set. To force nonblocking, set Noblock = 2 and then call WtProcessEvent periodically to service the event loop.
Motif Example
This example creates a Motif button labeled Done.
PRO example
   COMMON block, top
   @wtxmclasses.pro
   top=WtInit('wt_ex4', 'Examples')
   widget=WtCreate('Done', xmPushButtonWidgetClass, top)
   status=WtAddCallback(widget, 'activateCallback', $
      'CancelHelp')
   status=WtSet(top, /Realize)
   WtLoop
END
Version 2017.0
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