GPR_$SET_REFRESH_ENTRY            GPR Calls             GPR_$SET_REFRESH_ENTRY


NAME
     gpr_$set_refresh_entry - specifies the entry points of refresh pro-
     cedures.

FORMAT
     gpr_$set_refresh_entry (window_procedure, disp_mem_procedure, status)

DESCRIPTION
     This routine specifies the entry points of application-supplied pro-
     cedures that refresh the displayed image in a direct window and hidden
     display memory.

     The Display Manager determines when the window needs to be redrawn based
     on the amount of activity the user generates on the screen.  When a
     redrawing operation is necessary, the Display Manager calls the
     application-supplied procedure the next time that the application
     acquires the display.  Two input parameters are passed to the window
     refresh procedure.

   Input Parameters
     window_procedure
          Entry point for the application-supplied procedure that refreshes
          the Display Manager window, in gpr_$rwin_pr_t format.  This is a
          pointer to a procedure.

     disp_mem_procedure
          Entry point for the application-supplied procedure that refreshes
          the application's hidden display memory, in gpr_$rhdm_pr_t format.
          This is a pointer to a procedure.

   Output Parameters
     status
          Completion status, in status_$t format.

SEE ALSO
     gpr_$set_obscured_opt.

NOTES
     Callback of refresh routines are affected by your obscured option. See
     gpr_$set_obscured_opt for more information.

        ⊕  unobscured -- When false, this Boolean value indicates that the
           window is obscured.

        ⊕  position_changed -- When true, this Boolean value indicates that
           the window has moved or grown since the display was released.

     Refresh procedures for overlays must call gpr_$clear with the color
     parameter set to 0 before calling any GPR draw routines.