Notes on image display widgets --  R. S. Hill.

                                                 23 Apr 2004

   Two bugfixes since last upload.  See README.

                                                 11 Dec 2001

   Pan window attempts to preserve aspect ratio.  !DUMP variable
   eliminated.  Retain=2 default added, which is useful if you are
   on a remote workstation used as an X terminal.  For multiple-windows
   widgets, the color-changing events weren't being propagated from]
   image to image, so changes to gangexamine had to be made.

                                                 20 Jan 2001

   Little future work is expected on these widgets (too much time
   was spent on them already!).

   Some of the features noted earlier as desirable have now been added.
   The earlier notes below now have annotations marked *STATUS*
   to explain what has and has not been done.

   The main limitation of these widgets is that they are general, for
   quick and dirty work on the fly.  The other main limitation is that
   they were written from one person's perspective.



                                                 11 Oct 2000

   The underlying __define files get minor polishing fairly frequently
   to make all the objects work better together.

   The following are limitations I am not yet entirely happy with and
   would like to improve if I get time someday, but not soon:

        (1)  The EXAMINE popup.

             (a)  The popup itself is awkward.  In widgets
                  with multiple displays, you could have two EXAMINE popups
                  existing at once and not know which is which.  
                  
                  *STATUS*  There should now be more clarity here.
                  Subwidgets are labeled with the number of the
                  associated main display window.

             (b)  The logfile manipulation is kludgy. 

                  *STATUS*  This has been much improved.  Log files
                  are gone, and the user can either write to the
                  command-line window, using "journal" to take care
                  of logging, or pop a text display window that
                  isn't saved.

             (c)  The aperture growth photometry does not compute a 
                  real error but borrows it from an overall APER 
                  computation done at the end after you have settled
                  on a sky annulus to use (although the flux itself
                  always comes from the growth curve photometry).

                  *STATUS*  Still the same.

             (d)  Might be nice to have statistics and listings on
                  different-sized image areas, not corresponding to 
                  zoom box.

                  *STATUS*  Still the same.

             (e)  The outlier (Tukey) statistics are hard to format
                  in a clear way, in part because they are not as
                  familiar as the usual mean and std dev.

                  *STATUS*  Somewhat improved, perhaps.

             (f)  You can't send the cursor to specific coordinates
                  that you type in.

                  *STATUS*  Still the same.

        (2)  The DISPLAY popup.

             (a)  Turning the zoom window crosshair on and off doesn't
                  propagate to the other display in XCTV2.

                  *STATUS*  Fixed.

             (b)  Similarly to the EXAMINE popup, in multiple-display widgets
                  you could have two DISPLAY popups and not know which 
                  one belongs to which image.
                   
                  *STATUS*  Improved.

             (c)  Graphics color is always 255; it would be nice to
                  be able to choose.

                  *STATUS*  Still the same.

    However, coming soon:
        (1)  In XCTV2, "Same Scaling" and "Blink" together in a
             button menu called "MULTI" (less crowded menu area)
        (2)  DISPLAY CONTROL shortened to DISPLAY (ditto).
        (3)  Ability to move cross-hair around within zoom window.
        (4)  Fixing of some initialization bugs when the objects are
             used with options not in XCTV and XCTV2.
        (5)  24-bit graphics color fixed for decomposed=1.
        (6)  Zoom factor will propagate from one window to the
             other in XCTV2.

    *STATUS*  All of these are now implemented.