MGH_DGPLAYER__DEFINE Class
  
   MGH_DGplayer Purpose
  
   A window for displaying & managing direct graphics sequences
Category
      
       Widgets, Direct Graphics. Properties
     The following properties (ie keywords to the Init, GetProperty &
      SetProperty methods) are supported: 
  
   CUMULATIVE (Init, Get, Set) 
    
     The number of frames to superpose on each display. Default is
    
     1. If CUMULATIVE is zero or negative then all frames up to the
          current one are superposed. 
  
   N_FRAMES (Get) 
    
     The number of frames currently managed by the animator. 
  
   SLAVE (Init, Get, Set) 
    
     Set this property to specify that the player will be controlled
          externally. 
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    This software is provided subject to the following conditions:
    1.  NIWA makes no representations or warranties regarding the
    
     accuracy of the software, the use to which the software may
    
     be put or the results to be obtained from the use of the
    
     software.  Accordingly NIWA accepts no liability for any loss
    
     or damage (whether direct of indirect) incurred by any person
          through the use of or reliance on the software.
    2.  NIWA is to be acknowledged as the original author of the
    
     software where the software is used or presented in any form. 
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Modification History
  
   Mark Hadfield, 2001-09: 
          Written. 
  
   Mark Hadfield, 2002-10: 
          - Updated for IDL 5.6.
    
     - Fixed up code, which had been thoroughly broken by changes in
              MGH_DGwindow. 
  
   Mark Hadfield, 2004-05: 
    
     A light overhaul for IDL 6.1: accelerator keys added and some of the
          animation code modernised.