path: root/vendor/x11iraf/Notes-V1.3.txt

		    	X11IRAF V1.3 REVISIONS NOTES
		    	============================

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				   Last Modified:  Mon Feb  4 14:29:30 MST 2002
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Table of Contents:
------------------

    1. Installation Changes

    2. XImtool Revisions
        2.1  Real-Time WCS/pixel Readout
        2.2  "Peak-up" Cursor Centroid Positioning
            2.2.1  Command Summary
            2.2.2  Resource Summary
        2.3  Auto-Registration of Images
            2.3.1  Command Summary
        2.4  Integrated Control Panel
            2.4.1  Load Panel Changes
            2.4.2  Info Panel Changes
            2.4.3  Tile Panel (NEW)
            2.4.4  Coords Panel (NEW)
        2.5  Support for 16 Display Frames
        2.6  Magnifier
        2.7  Freezing Cursor Readout
        2.8  Cut-Graphs
        2.9  Ruler Markers
	2.10 Summary of Cursor Commands
	2.11 Summary of Application Resources
	2.12 Summary of Command-Line Options

    3. OBM (Widget Server) Revisions
	3.1  New Toolkit Widgets
	    3.1.1  Tabs Widget
	    3.1.2  ListTree Widget
	3.2  Dynamic Widget Creation

    4. Client Display Library (CDL) Revisions
	4.1  Display Protocol Changes
	4.2  New Procedures
	    4.2.1  C Calling Sequence
	    4.2.2  F77 Calling Sequence
	    4.2.3  SPP Calling Sequence
	4.3  Demo Task Updates

    5. Technical Notes
	5.1  IIS Protocol Changes
	    5.1.1 IIS Protocol Summary
	5.2  IRAF 'imd' Interface Changes.
	    5.2.1 Program Initialization
	    5.2.2 WCS Text Changes
	    5.2.3 Cursor Reads
	5.3  ISM Communications
	    5.3.1  Socket Connection
	    5.3.2  Communications Protocol
	    5.3.3  GUI Objects

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1. INSTALLATION CHANGES
=======================
	
	A new script automatically unpacks the distribution and installs
files in the system (or user's directories for a private install), provides
error checking and user interaction to skip parts of the process or change
defaults.  The 'install' script is packaged with both source and binary
distribution files.  To install for general use in the system directories
the script must be run as root user,  it may be run by any user to install
to private directories.

To install from an unpacked source distribution:

	% xmkmf				build the package Makefile
	% make World			build binaries from sources
	% su				become the root user
	# ./install			install the files (interactive)

Only the last two commands are required to install from an unpacked binary
distribution.



2.  XIMTOOL REVISIONS
=====================

	Aside from general bug fixes most of the changes in this release
are all new features for XImtool.  Details on individual features are
explained below, but in summary:

	-  real-time cursor image WCS and actual pixel readout
	-  new cursor centroiding function
	-  ability to "auto-register" frames
	-  integrated/enhanced control panel
	-  support for up to 16 display frames
	-  improved support for image tiling
	-  a "compass" indicator for the display orientation
	-  pixel table readout
	-  image header display (keyword selection, WCS display)
	-  horizontal/vertical cut-graphs of the display
	-  ruler markers on the display
	-  control port for external process communications


	The most significant change in this version is the ability to
access the displayed image pixels or header data to produce the real-pixel
and WCS readouts.  This is done using an external process called an ISM
(Image Support Module) which communicates with ximtool as a "plug-in"
module to enhance the features of the core program. In this case the ISM
is written as an IRAF task (although any application that can send text
over a socket can be used as an ISM regardless of the
language/environment) run at the host level with the ability to access any
supported image format.  Any number of such ISM plug-ins can be developed
to provide e.g. catalog overlay, animation, and so on.

	For the WCS/pixel ISM to operate properly changes to the display
protocol were required to pass the needed information.  These changes are all
backwards compatible with "older" display servers however for the ISM to
work at all you will need to be running at least IRAF V2.11.4.  Updates to
external packages using image display (notably MSCRED) have already been
completed.  Details of the changes required are found in the technical notes
at the end of this document.  

	Users should feel free to contact IRAF site support (iraf@noao.edu)
with any questions.


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			Detailed Revisions Notes
			========================


2.1  Real-Time WCS/pixel Readout
================================

	XImtool now has the ability to display the actual pixel value of
an image (as well as the scaled value previously shown) and the
cursor position in image WCS values (e.g. RA/DEC, GLAT/GLONG, etc).  This
is done using an external task (the 'ism_wcspix.e' binary in the new
distribution) to access the image and pass the coordinate/pixel info-
rmation to the GUI.

	WCS readout is enabled by default but can be toggled or reset
using the 'WCS/Pix' button on the Coords tab in the control panel or the
"ISM" toggle on the alt-gui menubar.  When enabled, images currently in
the server or subsequently displayed will be passed to the external
process where they are cached for access.  Cursor movements generate an
event that maps the current frame buffer position to a position in the
cached image.  The ISM (ISM is Image Support Module) task then reads the
image to determine the pixel value (or a small table of values around the
current position), and computes one or more coordinates from the image
position.  The ISM task also has access to the associated BPM images and
can optionally return bad pixel information during the cursor readout.

	By default, the logical and world image coordinates are displayed
to both the Coords panel readout as well as the main display window wcsbox
text marker.  Alternate coordinate systems (e.g. transformation of
equatorial to galactic coordinates or some other sky system, physical
coords, amplifier coords, etc) can be selected for display by hitting the
"Options" toggle on the Coords panel.  Available coordinate systems are
chosen using the "Type" menu on the panel, the readout format
(sexigesimal, degrees, etc) using the "Format" menu, and the display to
the current panel or main image window using the remaining toggles for
each WCS.  Up to four systems may be displayed at one time, the coordinate
panel and wcsbox marker will adjust size automatically depending on the
display.

	By selecting the "BPM Data" toggle from the Coords.Options panel
ximtool is able to flag pixels in images with an associated bad pixel mask.
This bad pixel mask is currently assumed to be named in the image header
"BPM" keyword by convention.  If the cursor passes over a bad pixel in the
mask, the Coords bpm display as well as the main window wcsbox will change
to a red background color.  Only the Coords display will show the value,
any non-zero value will be flagged with the color change.

	With the ISM enabled the Compass indicator will display a set of
arrows showing North-East if a WCS is available, otherwise just the
current X-Y axes are shown.  The pixel table will display actual pixel
values from the image, with the ISM off the pixel table displays the
scaled image values from the frame buffer.



2.2  "Peak-up" Cursor Centroid Positioning
==========================================

	Several new keystroke commands are available to reposition the
cursor to a centroid or min/max pixel value within a bounding box of the
cursor position,  allowing you to approximate the position with the mouse
and fine tune it quickly before typing the application keystroke command.
The initial box size is controlled with a 'centerBoxSize' GUI resource
(defaults to 5 pixels) but can be adjusted interactively using the Ctrl-[
and Ctrl-] commands to descrease/increase the box size respectively.  A
marker will flash briefly to indicate the box size.

	The Ctrl-0 (zero) key finds either a centroid or the local maximum
pixel value within this box region, Alt-Ctrl-0 (zero) will find the local
minimum value.  In either case the cursor is reposition to the computed
value.  The default peak-up action is to find the centroid position in the
box however this can be changed to find the max pixel by selection the
"Centroid Peaks" option from the main Display control panel or by resetting
the "peakCentroid" GUI resource (defaults to True).

	Centroiding is done using only the scaled screen pixel values and
only pixels above the mean value within the box are used.  It works best
if the box size is set appropriately, the centroid position may appear to
drift if the box is too large and includes too many background pixels.


    2.2.1 Command Summary:
    ----------------------

	Ctrl-0 (zero)		Reposition to centroid/max-pixel
    Alt-Ctrl-0 (zero)		Reposition to min-pixel
	Ctrl-[			Decrease centering box size (min of 5)
	Ctrl-]			Increase centering box size

    2.2.2 Resource Summary:
    -----------------------

	peakCentroid	True	Compute the box centroid position, a
				'False' value force the max value to be used
	centerBoxSize	5	Size of the centroid box, used as cursor
				position +/- this value



2.3  Auto-Registration of Images
================================

	The auto-register feature allows you specify a registration of
two or more display frames with an offset.  When enabled, this registration
is maintained for all frames in the list if any one of them is panned or
zoomed to a new location in the frame buffer.

For example, to use this feature do the following:

    1)  Enable Auto-Register (either on the Control Panel or the tool-
        bar on the alt-gui) and pan/zoom to some star of interest.
    2)  Use Mouse-Button-2 to center the star in the frame.
    3)  Cycle through the frames and you may see a small shift 
        of the star.  For each frame,  position the cursor on the
        star and type Ctrl-o to offset it to the center.  Repeat
        as necessary.  Small corrections will be cumulatively added
	so you can use the Ctrl-0 peak-up command to centroid each
	object in the frame before the Ctrl-o offset.
    4)  Pan around the image in one display frame, then switch frames
	and the new frame should also be panned to the new image with 
	the proper offset.
    5)  A Ctrl-a command will toggle the feature, offsets are only
	allowed when autoreg is enabled.

	Hitting "Register" will zero the offsets, as will toggling the
auto-register function.  What you should see is the object centered in
the frame and as you blink through it remains registered but the panner
box marker is moving around.  Drag the panner around and all frames
still remain registered with the given offset.  The control/info panels
now display what the offset is for each frame.

	The register display list is shared with the blink list and can
be set using the Display control panel.  By default all frames are included
in the list.  For accessing more than four frames, use the box icon in
the Blink/Register box of the Display control panel to bring up a new window
with access to all 16 available frames.


    2.3.1  Command Summary:
    -----------------------

	Ctrl-o			set the offset from center
	Ctrl-a			toggle the Auto-register feature



2.4  Integrated Control Panel
=============================

	The separate windows previous used for Control/Print/Load/Save/etc
have now been integrated into a single window with the appropriate control
panel selectable with a Tab widget.  There are also new Tab panels for
setting the frame tile configuration (see below), more detailed information
on the server status,  and selecting the WCS readout options (see above).

	All panels were updated as part of the integration, however some
changes of note to each panels include:

    Display
	+ View box 
	     -  supports 16 frames
	     -  Frame offset added to readout
	+ Blink/Register
	     -  new box icon button brings up independent control panel w/
		access to all 16 frames
	+ Options
	     -  addition of "Magnifier" and "Centroid Peaks" options
    Print	
	+ Postscript Options
	     - added B5 paper size as option
    Load
	+ Complete redesign of panel (see below)
	+ New options group (see below)
	+ Filename filter accepts a comma-delimited list of templates
    Save
	+ EPS added a save format, saves image w/ no annotation
    Info
	+ Complete redesign of panel (see below)
    Tile
	+ New panel allowing configuration of tile frame layout (see below)
    Coords
	+ New panel allowing selection of WCS readout options (see below)


2.4.1  Load Panel Changes
-------------------------

	The Load panel was redesigned to make directory navigation easier
as well as to provide new features.  The file list box is now larger and
implemented using a more natural directory listing format.  The filename
filter box can now accept a comma-delimited list of templates providing
multiple matches to e.g. "*.fits" and "*.imh" images in the same listing.
Directories are always listed in the output.

A new options group was added to the panel with the following features:

    Auto Load
	If enabled, selecting an image name from the list will force it
	to the display automatically.  Otherwise the Load button at the
	bottom of the panel must be used to load the image.  Specifying
	a filename in the "Load File" text box will load that image either
	with a CR or using the panel Load button.

    Auto Grayscale
	If enabled, color images (e.g. GIF) are converted to grayscale
	automatically, otherwise a private colormap is loaded for the image.

    List Image Headers
	If enabled the file list will change to display only the matching
	image names along with the pixel size, image size, and optional
	title string.  Directory navigation is disabled until this option
	is turned off.  MEF FITS files will be listed with the number
	of extensions they contain but cannot be loaded.

    Frame		
	Select the frame in which to display the image.  The special
	value "Current" is used to display to whichever is the current
	display frame, otherwise any of 16 available frames may be selected.

    Zscale Options	
	The remaining options can be used to specify the z-scale parameters
	used when loading the image.  The algorithm works as follows:

		if (zscale enabled)
		    determine optiminal z1/z2 given 'Nsample' points
		else if (zrange enabled)
		    use image min/max as z1/z2
		else 
		    use panel z1/z2 values

	To load 8-bit data directly the 'zscale' option should be disabled.
	

2.4.2  Info Panel Changes
-------------------------
	The Info panel was revised to provide a greater variety of status
information.  The type of output is controlled by the toggle buttons on
the bottom of the frame, however all output is kept current as the program
runs.  Current info options include:

    Frame	    - Info about the current display frame
    Server	    - Info about various server options, e.g. colormaps,
			memory model, antialias type, etc.
    Clients	    - Show currently connected clients.  Lists available
			connection channels and active ISM clients.
    WCS	    	    - List all WCS and mappings for the current frame
    ISM	    	    - Log of various ISM status messages
    Imtoolrc        - Show current frame buffer configuration table


2.4.3  Tile Panel (NEW)
-----------------------

	With the additional frames, the default tiling scheme proved in-
adequate.   A new control panel Tile frame now allows you to select from
a number of tile configurations, the list of frames to be tiled, a "fill
style" (left-to-right or top-to-bottom), as well as optional labels for
each of the tiles (frame number, image title or image name).

Tile configuration will make use of all frames currently selected in the
"Tile Frame" group in the following manner:

    Disabled	    Do not tile the display
    Manual	    Tile according to "Manual Configuration" settings
    Best	    Optimize layout for frame buffer aspect
    Square	    Always force a square layout (2x2, 3x3, etc)
    Horizontal	    Preferentially tile horizontally (6 frames ==> 3x2)
    Vertical 	    Preferentially tile vertically (6 frames ==> 2x3)
    One Row	    Tile all in one row (Nx1)
    One Column	    Tile all in one column (1xN)


2.4.4  Coords Panel (NEW)
-------------------------

	The Coords Panel is meant to provide a full-featured readout as
well as serve as a control panel for the various options.  The display
window contains the image name/title and frame buffer info, and a selection
of coordinate and image pixel readouts.  The intent is provide more infor-
mation than can fit comfortably on the main image window while still 
taking up as little screen space as possible.  To this end the "Options"
button is used to hide most of the feature controls when not in use (see
below).  Other options on the main panel include:

    WCS/Pix	    Toggle the real-time WCS/pixel readout capability
		    (i.e. the ISM used to access the disk image).  This
		    must be enabled for certain other options to work.

    Pix Table	    Open a panel showing an image pixel table.  The panel
		    shows an array of pixels surrounding the cursor position,
		    either the actual pixel values if the ISM is enabled, or
		    scaled display values otherwise.  The size of the table
		    may be selected from the menubar.

    Header	    Display the current image header in a new panel.  Both
		    the entire image header as well as WCS-specific parts of
		    the header are available under different tabs.  This 
		    option is only active when the ISM is enabled.

    Compass	    Draw an orientation compass on the display panner.  If
		    the ISM is enabled and a WCS is present in the header,
		    the compass will indicate N/E according to the WCS, other-
		    wise the X/Y axes of the image are drawn.

    Options	    Pop-up/down the option control portion of the panel. When
		    enabled, the Coords Panel will change size to reveal the
		    options which can be changed (explained below). 

	The "Readout Values" group controls the selection of WCS type,
location and format to be displayed.  The "Type" menu always provides a
selection of the image Logical, Physical or World systems, which may be
identical depending on the image header.  If a World system is supplied in
the image addition entries for transformations to other sky systems, (e.g.
FK5 to ICRS or galactic/ecliptic) will also be available.  The selection
is dependent on whether the ISM is running as well as WCS information
present in the image.  The "Format" menu allows the use to select a
sexigeimal display, conversion to degrees or radians, or whichever format
is most natural for the coordinate being display.  The two toggle to the
right control whether this WCS is to be displayed on the Panel (i.e. the
Coords Panel window) or the ImgWin (i.e.  the text marker on the main
image window).

	Other options below this group control whether or not to display the
WCS labels, the image name/title, and frame buffer information in the main
Coords Panel display.  The "BPM Data" option controls whether or not the
ISM will try to map any bad-pixel mask associated with the image.  If enabled, 
a bad-pixel mask specified by the image header BPM keyword (currently fixed
by convention but this may be selectable later) will be mapped along with the
image.  Aside from wcs/pixel readouts at each cursor position, any BPM data
values found will also be displayed.  A non-zero value will cause the BPM 
field of the Coords Panel readout as well as the main image window marker
to switch to a red background color to flag the value.

	The last box allows the user to specify a different ISM task to be
executed or to reinitialize the current one.  In most cases this won't need
to be changed, however a custom ISM could be started when using special
data formats.  This command string can also be controlled by the application
"ism_task" resource.



2.5  Support for 16 Display Frames
==================================

	As part of the extensive GUI changes, support for the full 16
frames allowed by the IIS protocol is now available.   IRAF V2.12 or
later client tasks (and CDL library) are required to take advantage of
these frames.  All changes are backwards compatible, older versions of IRAF
will continue to work but cannot access more than the original four
frames.  The new DISPLAY task will automatically sense whether the display
server being used supports 16 frames or the original 4 and adjust the
'frame' parameter maximum accordingly.  The changes are fully backwards
compatible for other servers (e.g. SAOimage, DS9, etc).

	More frames are possible if needed but will require further changes
to the client IRAF code to be effective.  Allowing creation of more than 
16 frames by the Load panel can be done independently but would also require
numerous code change to XImtool.  Please contact site support (iraf@noao.edu)
if there is a need for this, or for workaround suggestions depending on your
application.



2.6  Magnifier
==============

	The magnifier marker appears to be stable and was moved into the
default ximtool GUI and is now enabled by default.  The ximtool-mag command
has been removed.


2.7  Freezing Cursor Readout
============================

	Holding down the Alt key will now freeze the cursor display readout
and draw crosshairs on the screen at the last position.  This can be used
for example to position the cursor but then allow the cursor to be moved to
another window (to enter text, start a program, whatever) without losing
the position information displayed on the screen.


2.8  Cut-Graphs
===============

	XImtool now has the ability to display horizontal and vertical
cut-graphs of the display, these appear as "flip-out" panels that appear
on the bottom and right side of the main display window and are controlled
by the small "H" and "V" buttons in the lower right corner of the window.
When both panels are enabled the corner area of the display also shows an
options panel for the graphs.  Current options are:


    Better Speed 	Draw the graphics so they update at the fastest
			possible rate.  This is done by subsampling pixels
			to produce a smoother graph but without sacrificing
			too much accuracy.

    Better Accuracy 	Draw the graphics using all screen pixels to produce
			the most accurate display.  On fast modern machines
			this can be enabled with no apparent loss of speed,
			however older machines may wish to use this only
			occassionally to limit any lag in the cursor tracking.

    Image Pixels 	(Not Yet Implemented)


    Jump Cursor		If enabled, large jumps of the cursor do not update
			the graphics display, small movements around an object
			of interest will update the display continuously.

    Smooth Cursor	If enabled, all cursor movements cause the display to
			be updated.  This is another option that can be set
			safely on faster machines but will cause a delay on
			slower ones.

    Graphics Cursors	If enabled, the graphics cursors in either of the
			plots are active and can be used to update the cursor
			readout on the main image window and the complementary
			cut-graph.  This can be used for example to freeze
			the cursor in the main display using the Alt key (see
			above), then moving to one of the graphics windows
			to perform cut graphs in only one axis.

	Graphs are (currently) drawn using only the scaled display values 
to avoid complications of accessing multiple images in a mosaic display. Both
plots are labeled using the frame z1/z2 values and contain cursor indicators
which update contuously.



2.9  Ruler Markers
==================

	Holding down the Ctrl key and the Left-Mouse-Button while moving
the mouse will drag out a "ruler marker" measuring the distance from the
initial point to the current mouse position.  Releasing the Ctrl key before
lifting the mouse button will leave the marker on the display, otherwise
it will be erased automatically once the mouse button is released.  Any
number of ruler markers can be created in the frame.

	Distances are measured by default in image logical pixels however
the Right-Mouse-Button can be used inside the marker to popup a menu of
options:

    Sticky		By default rulers are destroyed whenever the display
			changes due to a pan, zoom, flip, or frame change.
			This option will make the ruler "sticky" so it will
			not be erased, subsequent use of the menu to shows
			this option to be "UnSticky" to remove this feature.

    Units		Sub-menu to select the units of the display.  If the
			ISM is enabled and a WCS is present in the image and
			selected as one of the readout options, distances may
			also be read out in units of arcseconds, arcminutes,
			or degrees instead of the default logical pixels. All
			markers created after the unit change will readout in
			the new units as their default.  
			
    Color		Select the color of the marker.

    Draw into Frame 	(Not Yet Implemented)  Draw the marker as overlay
			graphics in the frame.  Doing so will retain the
			marker when printing a hardcopy of the display.

    Destroy		Destroy the marker.

The marker can also be destroyed by hitting the Delete or Backspace key
while the cursor is in the marker.  There is presently no way to move the
marker to a new position in the frame.



2.10 Summary of Cursor Commands
===============================

    * - indicates a new/changed command
    
    Misc Functions
    --------------
    Ctrl-b   		Backward frame
    Ctrl-c   		Center frame
    Ctrl-f   		Forward frame
    Ctrl-i   		Invert
    Ctrl-n   		Normalize
*   Ctrl-m   		Toggle Magnifier
*   Ctrl-p   		Toggle Panner
    Ctrl-r   		Register
*   Ctrl-s   		Match LUTs
    Ctrl-t   		Tile frames toggle
    Ctrl-u   		Unzoom (zoom=1)
    Ctrl-x   		Flip X                
    Ctrl-y   		Flip Y                
    Ctrl-=   		Print
    Ctrl-<   		Decrease blink rate   
    Ctrl->   		Increase blink rate   
    Ctrl-+   		Zoom in
    Ctrl--   		Zoom out

    Alt-1 thru Alt-4    Set frame displayed
    Ctrl-1 thru Ctrl-9  Set integer zoom factor  

    Ctrl-Alt-q  	Quit
    Ctrl-Alt-f  	Fitframe
    
    Panels
    ------
    Alt-b  		Blink frames toggle
    Alt-c  		Control panel
    Alt-h  		Help panel
    Alt-i  		Info box panel
    Alt-l  		Load file panel
    Alt-p  		Print panel
    Alt-s  		Save panel
    Alt-t  		Tcl Shell panel

    Auto-Registration
    -----------------
*   Ctrl-a   		Toggle Auto-Reg
*   Ctrl-o   		Set offset

    Cursor Positioning
    ------------------
*   Ctrl-h/Left_Arrow	move cursor 1 pixel left
*   Ctrl-j/Down_Arrow	move cursor 1 pixel down
*   Ctrl-k/Up_Arrorw	move cursor 1 pixel up
*   Ctrl-l/Right_Arrow	move cursor 1 pixel right

*   Shift-Ctrl-h	move cursor 10 pixels left
*   Shift-Left		move cursor 10 pixels left
*   Shift-Ctrl-j	move cursor 10 pixels down
*   Shift-Down		move cursor 10 pixels down
*   Shift-Ctrl-k	move cursor 10 pixels up
*   Shift-Up		move cursor 10 pixels up
*   Shift-Ctrl-l	move cursor 10 pixels right
*   Shift-Right		move cursor 10 pixels right

    Frame Positioning
    -----------------
    Ctrl-Left 		shift one full frame left
    Ctrl-Down 		shift one full frame down
    Ctrl-Up 		shift one full frame up
    Ctrl-Right 		shift one full frame right

    Ctrl-Alt-Left 	shift one half frame left
    Ctrl-Alt-Down 	shift one half frame down
    Ctrl-Alt-Up 	shift one half frame up
    Ctrl-Alt-Right 	shift one half frame right

    Peak-Up Centroiding
    -------------------
*   Ctrl-[		decrease centering box size
*   Ctrl-]		inrease centering box size
*   Ctrl-0 (zero)	centroid/find local max
*   Alt-Ctrl-0 (zero)	find local min

    Mouse Button Actions
    --------------------
    Shift-Btn1Down	turn on magnifier
    Shift-Btn1Up	turn off magnifier
    Shift-Btn2Down	turn on crosshair cursor
    Shift-Btn2Up	turn off crosshair cursor
    Btn1Down		create marker
    Btn1Motion		resize marker being created
    Btn2Down		zoom on cursor position
    Btn3Down/Motion	brightness/contrast scaling

*   Ctrl-Btn1Down	create ruler marker
*   Ctrl-Btn1Motion	resize ruler marker
*   Ctrl-Btn1Up		destroy ruler marker

*   Alt-Motion		freeze cursor readout



2.11 Summary of Application Resources
=====================================

	Following is a summary of the task client and GUI resources, along
with select resources defined for the main image display Gterm widget.  All
GUI elements can be controlled to some exten with resource definitions
although not all resources are useful.  Feel free to contact site-support
with questions about how to change the appearance of the GUI.  Future
versions of XImtool should feature a control panel to allow some of these 
more critical resources to be redefined at runtime.
	Format for the listing is resource-name, default-value, and type,
with an optional note appended.  See the man page or online help for a full
description of all resources.  A '*' in the leftmost column indicates a new
resource added with this release, some resource apply only to the alternative
GUI.


    Client Program Resources
    ------------------------
    defConfig		 1				Int
    defNFrames		 0				Int
    tileBorderWidth	 3				Int
    tileBorderColor	 9				Int
    autoscale		 False				Boolean
    antialias		 False				Boolean
    antialiasType	 boxcar				String  	(1)
    tileFrames		 False				Boolean
    highlightFrames	 True				Boolean
    gui			 default			String  	(2)
    imtoolrc		 /usr/local/lib/imtoolrc	String
    invert		 False				Boolean
    memModel		 Fast				String 		(3)
    basePixel		 64				Int
    maxColors		 216				Int
    cmapInitialize	 False				Boolean
    cmap1		 none				String		(4)
    cmap2		 none				String		(4)
    cmapDir1		 none				String		(5)
    cmapDir2		 /usr/local/lib/imtoolcmap	String 		(5)
    input_fifo		 /dev/imt1i			String		(6)
    output_fifo		 /dev/imt1o			String		(6)
    unixaddr		 /tmp/.IMT%d			String		(7)
*   ism_addr		 /tmp/.ISM%d			String		(8)
*   ism_task		 "ism_wcspix.e wcspix &"	String		(9)

    Notes:
        1) Options: nearest, bilinear, area, blkavg, boxcar, lowpass, gaussian
        2) Either the string 'default' or the path to a valid GUI file
        3) Options: fast, small, beNiceToServer
        4) Name of a colormap file in the cmapDir[1|2] directory
        5) Path to directory of valid colormaps
        6) Path to FIFO pipe
        7) Unix socket path, a '%d' is replaced with the uid
        8) Unix socket path, a '%d' is replaced with the uid.  This is the
	   socket used by plug-ins to negotiate a socket, once connected the
	   actual communications use a different socket.
        9) Command used to start the default WCS/Pixel readout ISM task.


    GUI	Resources
    -------------
    autoscale		 True				Boolean
    zoomfactors		 1 2 4 8			String
    displayCoords	 True				Boolean
    displayPanner	 True				Boolean
    displayMagnifier	 False				Boolean
    blinkRate		 1.0				Real 		(1)
    pannerArea		 150*150			Geometry
    pannerGeom		 -5+5				Geometry
*   magnifierArea	 100*100			Geometry
*   magnifierGeom	 +5+5				Geometry
    wcsboxGeom		 -5-5				Geometry
    maxContrast		 5.0				Real
*   showToolBar		 False				Boolean
*   showPanelBar	 False				Boolean
    warnings		 True				Boolean
*   centerBoxSize	 5				Int
*   peakCentroid	 True				Boolean

    Notes:
	1) Value represents blink rate in seconds


    Main Image Window (Gterm) Resources
    -----------------------------------
    cmapName		 image				String 		(1)
    basePixel		 64				Int
    warpCursor		 True				Boolean
    raiseWindow		 True				Boolean
    deiconifyWindow	 True				Boolean
    ginmodeCursor	 circle				Cursor
    ginmodeBlinkInterval 500				Int 		(2)
    color0		 Black				Pixel
    color1		 White				Pixel
    background		 Black				Pixel
    foreground		 White				Pixel
    width		 512				Int
    height		 512				Int

    Notes:
	1) Any user-defined name is acceptable
	2) Value represents blink rate in milliseconds



2.12 Summary of Command-Line Options
====================================

    -basePixel <num>                 Base colormap pixel
    -cmap1 <file>                    User colormap 1
    -cmap2 <file>                    User colormap 2
    -cmapDir1 <dir>                  User colormap directory
    -cmapDir2 <dir>                  Default colormap directory
    -cmapInitialize <bool>           initialize colormap
    -cmapName <name>                 Set Colormap name
    -config <num>                    Set initial config number
    -defgui                          Print default GUI and exit
    -displayPanner <bool>            Display Panner box
    -displayMagnifier <bool>         Display Magnifier box
    -displayCoords <bool>            Display WCS Coords box
    -fifo <pipe>                     Fifo pipe to use for connection
    -fifo_only                       Use fifo only for display
    -gui <file>                      GUI file
    -help                            Print help
    -imtoolrc <file>                 Set frame buffer configuration file
    -inet_only | -port_only          Use inet only for display
    -invert                          Start with inverted colormap 
    -ismdev <dev>                    ISM device (socket) template 
    -maxColors <num>                 Max number of image colors to allocate
    -memModel <type>                 Memory model (fast|small|beNiceToServer)
    -nframes <num>                   Number of frames to create at startup
    -port <num>                      Set inet port to use for connection
    -printConfig <name>              Set printer config file
    -tile                            Start in tile-frames mode
    -unix <name>                     Set unix socket to use for connection
    -unix_only                       Use only unix socket for display
    <file>                           File to load at startup



--------------------------------------------------------------------------------

3.  OBM (WIDGET SERVER) REVISIONS
=================================


3.1 New Widgets
---------------

	As part of the OBM modifications two new widgets were added to 
the toolkit.  The widgets were also added to the LISTRES application in
the X11IRAF sources which can be consulted for a complete list of resources.
LISTRES is not normally built with the system but is installed locally on
the NOAO/IRAF development machines.  To build it yourself:

	% cd /<path>/x11iraf/obm/listres	# go to the source directory
	% xmkmf					# create the Makefile
	% make listres				# compile the task

It may then be used as e.g. "listres <widget>" to print a full list of
resources for the named widget.


3.1.1  Tabs Widget
------------------

	The Tabs widget is a composite widget providing an "index tab"
appearance to it's child widgets.  The children will normally be layouts
of more complex panels such as is done for the XImtool Control Panel.
Only the children of the active Tab are visible, the contents of other
Tabs are not displayed until that Tab is raised by selecting it with the
mouse and the left mouse button.

	A new Widget class command was added to allow GUI control of the
active Tab (e.g. to programmatically raise a Tab).  This command is of
the form

	send <tab> setTop <name>

where <tab> is the name of the Tab widget, and <name> is the name of the
child widget to be raised.  Only one Tab widget is required to handle
child widgets, the Tabs will be created automatically.

	The widget code was also modified slightly to allow specific
resource values to hide the appearance of the widget from the display, e.g.
to completely change the appearance of a panel's layout by invisibly raising
a different Tab.  For instance, assuming we have a Tab widget called
'opPanels' with several child widgets containing layouts of other widgets, 
the following resource settings will hide the parent Tabs widget:

    *opPanels.tabLabel:
    *opPanels.font:                   		nil2
    *opPanels.height:                 		0
    *opPanels.width:                  		0
    *opPanels.borderWidth:            		65535
    *opPanels.internalWidth:          		32765
    *opPanels.internalHeight:         		32765

Essentially we set NULL labels and sizes and values for the borderWidth
and internalHeight/Width that have the same bit pattern as a negative value
which internally means the borders are not drawn.  The GUI callback code 
can then use the setTop Widget method to raise the desired Tab meaning the
entire panel will change layouts automatically.  This has advantages over
simply unmapping/mapping the layouts as it doesn't create a window resize
event which may cause the panel to "flash" during the change.

	An example GUI for this widget is in x11iraf$guidemo/tabs.gui


3.1.2  ListTree Widget
----------------------

	The ListTree widget provides a nested list of items, where each
item is either a terminal item in a list, or another list.  Lists may be
"open" meaning their contents are displayed, or "closed" meaning they are
shown as an individual item.  This widget can best be used to represent
e.g. contents of a directory or sections/subsections of a document.

	A new Widget class command was added to allow GUI control of the
list contents.  This command is of the form

	send <listree> setListTree <nested list>

where <listree> is the name of the widget, and <nested list> is a list of
items to be displayed.  This list should be a valid Tcl list, where items
in the list may be lists themselves to produce the nested format.  All
ListTree widget are initially presented with the embedded lists "closed".
There is presently no way to append the contents of the list, the entire
list must be redefined with the above command.  For example, the command

  send list setListTree {a1 {b1 { {a2 {a3 b3 c3 d3}} { b2 {z1 z2}} } } c1}

would produce a nested list such as

	       a1
	       b1
	         a2
	           a3
	           b3
	         b2
	       c1

Specifying the lists is a bit complex, but this widget is a nice way to
handle something like a table of contents in online documentation.

	An example GUI for this widget is in x11iraf$guidemo/ltree.gui


3.2 Dynamic Widget Creation (TBD)
---------------------------------

        In the original implementation of the OBM, the GUI is created or
defined using the 'appInitialize' and 'createObjects' server commands.  
appInitialize initializes the X display but the 'resources' argument just
sets the fallback resources for the application.  A 'createObjects' call
then queries the fallback resource database (either by a named resource o
the 'objects' resource  by default) to get the widget tree and then parses
that as a string to actually create the widgets in the OBM.

        The initial example GUIs all defined an "objects" resource as the
way to define the widgets and all the subsequent GUI tasks followed that form,
however appInitialize requires only a string of resource definitions ('object'
resources or otherwise), and createObjects can take an argument as to which
resource value specifies the widgets to create.  For dynamic widget creation 
all that's really required is that we have a way to append the fallback
resource database with a new list of widgets.

	The solution then was implement a new 'appExtend' server command
that simply sends a new resource string to the OBM to be merged into the
fallback resource DB.  A plug-in would call this to load the widgets, then
call createObjects naming the resource to realize the widgets.  The new
widgets are created as though they were specified from the start and can
receive messages, be destroyed, etc.  The appExtend server method essentially
works by

        - getting the fallback resource database
        - convert resource string arg to a new resource database
        - combine the two resource databases
        - write the combined database back as the new fallback database

For example, the plug-in code for a "Hello, World" GUI panel would look
something like

     appExtend {
         *test_objects:\
             toplevel        TopLevelShell   testPanel\
             testPanel       Form            testForm\
             testForm        Label           testLabel\
             testForm        Command         testQuit
     
         *testLabel.label:                   Hello, world!
         *testQuit.fromHoriz:                testLabel
         *testQuit.label:                    Quit
     }
     createObjects test_objects
     send testPanel map

This code could be uploaded by an ISM plug-in and sourced as Tcl code
in a callback.  It's also possible to define objects w/ existing parents
meaning a plug-in can add buttons to menubars or panels when they first
connect (e.g.  a plug-in can add a new activation button for it to an
existing menubar on the GUI).

	The ability to dynamically create widgets means that plug-in modules
can create their own GUI components, but it also means that meta-widgets such
as Help panels, Image Display panels, etc can be recycled from a library of
code.  To use this effectively, however, some rules need to be established
for an object naming convention, protocols for adding/deleting callbacks and
event handlers, and some method of object orientation is desired in the Tcl
code to make having multiple instances of a meta-widget in a GUI easier to
handle.  These details are still largely TBD, the basic functionality now
exists in this version but may change as we take advantage of it and
implement new plug-in tasks or meta-widgets.


--------------------------------------------------------------------------------

4.  CLIENT DISPLAY LIBRARY (CDL) REVISIONS
==========================================


4.1  Display Protocol Changes
-----------------------------

	The IIS display protocol used was modified to conform to the XImtool
and IRAF changes implemented for the support of WCS mapping information. 
These are detailed in section 5.1 below.

	Unlike the IRAF IMD interface changes though, the WCS version can
be determined when the CDL is first opened so no explicit call to query
this is required by CDL applications.  Tasks may still set/retrieve mapping
information and assume this is handled automatically by the interface.
The hi-level routines for displaying FITS or IRAF images will also send the
mapping information automatically,  it's only when using the low-level
cdl_displayPix() routine or setting the WCS explicitly where the mappings
need to be set by the application.

	Changes remain completely backwards compatible so client tasks need
to be modified only to support the new XImtool features.


4.2  New Procedures
-------------------

	Three new public interface procedures were added in addition to the 
internal changes made to support image mappings:

 cdl_setMapping()  - Set mapping data to be sent with next cdl_setWCS() call.
		     Returns a non-zero status if mapping was set.
 cdl_getMapping()  - Get mapping data returned with last cdl_getWCS() call.
		     Returns a non-zero status if valid mapping available
   cdl_queryMap()  - Given a WCS number return the mapping data for that WCS.
		     Returns a non-zero status if valid mapping available.


4.2.1  C Calling Sequence
-------------------------

 valid = cdl_setMapping (cdl, region, sx,sy,snx,sny, dx,dy,dnx,dny, ref)
  stat = cdl_getMapping (cdl, region, sx,sy,snx,sny, dx,dy,dnx,dny, ref)
stat = cdl_queryMapping (cdl, wcs, region, sx,sy,snx,sny, dx,dy,dnx,dny, objref)

Where the arguments are defined as 

    cdl		      - CDL package pointer returned by cdl_open()
    region            - user-defined name for the region (e.g. 'image',
                        'subras1', 'ccd3', etc).
    sx, sy, snx, sny  - source rect in the object
    dx, dy, dnx, dny  - destinaton rect in the display frame buffer
    ref               - full node!/path/image[sec] image name, same as
                        was immap'd when the image was displayed.  Used
                        for access after the display
    wcs		      - WCS number for a specified mapping



4.2.2  F77 Calling Sequence
---------------------------

           cfsetmapping (region, sx,sy,snx,sny, dx,dy,dnx,dny, ref, ier)
           cfgetmapping (region, sx,sy,snx,sny, dx,dy,dnx,dny, ref, ier)
         cfquerymapping (wcs, region, sx,sy,snx,sny, dx,dy,dnx,dny, objref, ier)

Where the arguments are defined as above and 'ier' is an error status code.


4.2.3  SPP Calling Sequence
---------------------------

         cdl_setMapping (region, sx,sy,snx,sny, dx,dy,dnx,dny, ref, ier)
         cdl_getMapping (region, sx,sy,snx,sny, dx,dy,dnx,dny, ref, ier)
       cdl_queryMapping (wcs, region, sx,sy,snx,sny, dx,dy,dnx,dny, objref, ier)

Where the arguments are defined as above and 'ier' is an error status code.


4.3  Demo Task Updates
----------------------

    o	The DISPLAY demo task in the 'examples' subdirectory was modified
	to show how the cdl_setMappings() call is to be used when displaying
	the image using the low-level procedures.

    o	The CDLTEST test task in the 'test' subdirectory has a new 'Q' 
	command to test the cdl_queryMap() procedure.



--------------------------------------------------------------------------------

5. TECHNICAL NOTES
==================

5.1  IIS Protocol Changes
-------------------------

	For backwards compatability none of the existing IIS protocols were
modified completely, however we take advantage of unused registers to flag
the new features in existing functions (like read/write WCS). The WCS mapping
changes required only that the unused 'x' register be set to indicate the new
behavior was desired, e.g. the wcs text containing the extra mapping data. 

	We also added two new WCS calls that allow us to query the WCS version,
or query a WCS by a specific number corresponding to a mapping.  The WCS
version query will return a string such as "version=10" which can be parsed
by the client to get a version number '10' (corresponding to version 1.0).

	Because of the added mapping text the WCS string length was increased
from 320 to 1024 bytes, the string length used internally depends on whether
the 'x' register has been set.

	Support for the full 16 frames allowed by the bit-flag 'z' register
in the IIS header packet required the masking values be changed at various
places in the code.  This was more a limitation of the initial implementation
than a required change to the protocol.

	A complete summary of the XImtool IIS protocol implementation follows.


5.1.1  IIS Protocol Summary
---------------------------

                 		   IIS Header Packet Summary

                      TID            Subunit     Tct   X   Y    Z   T    Data
              +------------------+-------------+-----+---+---+----+---+--------+
Read Data     | IIS_READ|PACKED  | MEMORY      | -NB | x | y | fr | - | nbytes |
Write Data    | IIS_WRITE|PACKED | MEMORY      | -NB | x | y | fr | - | nbytes |
Read Cursor   | IIS_READ         | IMCURSOR    |  -  | - | - | wcs| - | -      |
Write Cursor  | IIS_WRITE        | IMCURSOR    |  -  | x | y | wcs| - | -      |
Set Frame     | IIS_WRITE        | LUT|COMMAND | -1  | - | - | -  | - | 2      |
Erase Frame   | IIS_WRITE | fb   | FEEDBACK    |  -  | - | - | fr | - | -      |
              |                  |             |     |   |   |    |   |        |
Old Read WCS  | IIS_READ         | WCS         |  -  | - | - | fr | - | 320    |
Old Write WCS | IIS_WRITE|PACKED | WCS         | -N  | - | - | fr |fb | 320    |
              |                  |             |     |   |   |    |   |        |
WCS Version?  | IIS_READ         | WCS         |  -  | 1 | 1 | -  | - | 320    |
WCS by Num.?  | IIS_READ         | WCS         |  -  | 1 | - | fr |wcs| 1024   |
New Read WCS  | IIS_READ         | WCS         |  -  | 1 | - | fr | - | 1024   |
New Write WCS | IIS_WRITE|PACKED | WCS         | -N  | 1 | - | fr |fb | 1024   |
              +------------------+-------------+-----+---+---+----+---+--------+


Where   nbytes | NB  = number of bytes expected or written
        x            = x position of operation in frame buffer coords
        y            = y position of operation in frame buffer coords
        fr           = frame number (passed as bitflag (i.e. 1, 2 ,4 8, etc)
        fb           = frame buffer config number (zero indexed)
        N            = length of WCS string
        wcs          = WCS number (usually zero)
        Data         = the number of bytes of data to be read or written
			following the header packet.

        IIS_WRITE    = 0400000
        IIS_READ     = 0100000
        COMMAND      = 0100000
        PACKED       = 0040000
        IMC_SAMPLE   = 0040000

        MEMORY       = 001
        LUT          = 002
        FEEDBACK     = 005
        IMCURSOR     = 020
        WCS          = 021



5.2  IRAF 'imd' Interface Changes.
----------------------------------

	In order for the XImtool ISM task map exactly the same image that
was passed into the task displaying the image (i.e. the fully qualified
node!path prefix including any image section or kernel args).  It was
necessary to modify the IIS SetWCS command to contain extra information
at the end of the normal WCS text.  This is passed from XImtool to the ISM
at the time of the display if an ISM is already running, or when the ISM
first connects thereafter. 

	To maintain complete backwards compatability it is not possible to
bury this change in the internals of the interface, therefore it will be
necessary for all tasks using the IMD interface to display images to make
revisions to use the new features.  Tasks which are not changed will continue
to work, XImtool will simply disable the ISM when the display client connects
without indicating it is able to pass mapping information.  Client tasks,
modified or not, will also continue to work when connecting to "mapping
unaware" display servers since the interface only send the extra mapping
information to servers which are expecting it.

	To modify a task to make use these changes, there are just a few
routines you need to be aware of:

    imd_wcsver()  - Query the server for new capabilities.  Returns a
		    non-zero version if the server can use the new
	 	    mapping functionality.
imd_setmapping()  - Set mapping data to be sent with next imd_putwcs() call
imd_getmapping()  - Get mapping data returned with last imd_getwcs() call.
		    returns a non-zero status if valid mapping available
 imd_query_map()  - Given a WCS number return the mapping data.  Returns a
		    non-zero status if valid mapping available

where the calling sequence is

         imd_setmapping (reg, sx,sy,snx,sny, dx,dy,dnx,dny, objref)
 valid = imd_getmapping (reg, sx,sy,snx,sny, dx,dy,dnx,dny, objref)
 status = imd_query_map (wcs, reg, sx,sy,snx,sny, dx,dy,dnx,dny, objref)
   version = imd_wcsver ()

In order to maintain compatability with existing servers as well as take
advantage of the new ximtool features, the idea is that all interfaces will
remain the same and any program wishing to use these features will need a
slight modification to 1) determine whether mappings are supported via a
call to imd_wcsver(), and 2) use the new imd_[sg]etmapping() procedures to
set and retrieve the mapping information.  imd_query_map() can be used to
query for the mapping using the wcs number returned from e.g. a cursor read.
Details and examples of these modifications are included below.


5.2.1 Program Initialization
----------------------------

	For a program to use mappings it must first query the server to see
if this is supported, the reply also serves to initialize the imd interface.
This is done using the imd_wcsver() call.  For example, in the DISPLAY task
during startup one would do something like

        # Query server to get the WCS version, this also tells us whether
        # we can use the all 16 supported frames.
        if (imd_wcsver() == 0)
            call clputi ("display.frame.p_max", 4)
        else
            call clputi ("display.frame.p_max", 16)

The call to imd_wcsver() in this case is used to reset the number of allowed
frames depending on the server.  

	This call is REQUIRED before mappings can be used by the interface.
Internally, the interface defaults to a "version" of zero meaning the server
does not support mappings, once the procedure is called the server reply
value is stored in the interface common and returned as the function value.
The return value is always an integer, zero means the server does not support
mappings and a non-zero value is the WCS version number of the display
change (e.g. a value of 10 is version 1.0, 11 is 1.1, etc).

	A 'disable_wcs_maps' boolean environment variable can be set by
the user to force this procedure to always return zero and disable mappings
in case a problem is found after release or the old behavior is desired.


5.2.2 WCS Text Changes
----------------------

	Without getting into the details, if a server is found to be capable
of using mappings in the imd_wcsver() call,  the WCS string sent/read will
have two additional lines of information to define the mapping.  Specifically,

        name - title\n
        a b c d tx ty z1 z2 zt\n
        region_name sx sy snx sny dx dy dnx dny\n
        object_ref

where the new parameters are defined as 

    region_name	      - user-defined name for the region (e.g. 'image',
			'subras1', 'ccd3', etc).
    sx, sy, snx, sny  - source rect in the object
    dx, dy, dnx, dny  - dest rect in the display frame buffer
    object_ref	      - full node!/path/image[sec] image name, same as
			was immap'd when the image was displayed.  Used
			for access after the display

	Since the interfaces remain the same a separate imd_setmapping()
or imd_getmapping() call is required to set/get the additional mapping data.
For example,

To set the WCS:

    # Set the mapping info to be written with the WCS.
    call imd_setmapping (region, sx,sy,snx,sny, dx,dy,dnx,dny, objref)

    # Write the WCS and mapping info to the data.
    call imd_putwcs (ds, frame, Memc[imname], Memc[title],
        a, b, c, d, tx, ty, W_ZS(wdwin), W_ZE(wdwin), W_ZT(wdwin))


To read the frame WCS:

    # Query the server for a wcs.
    if (imd_getwcs (frame, server, image, sz_image, title, sz_title,
        a,b,c,d, tx,ty) == OK) {

	    # If we got that okay, get the mapping information returned.
      	    if (imd_getmapping (reg, sx,sy,snx,sny, dx,dy,dnx,dny, obj) > 0) {
	    	:
	    }
    }

In all cases if the imd_wcsver() initialization says the server can't
do mappings these calls will be no-ops.

	For multiple-image displays to a single frame it's important to
remember that the default WCS for the frame will be the *last* WCS set
by the client.  For example, a mosaic display can set a wcs and mapping
for each of the subrasters, but a final SetWCS call is required to define
an overall WCS for the frame defining the "detector coords".  Note that the
'objref' string should include the MEF extension number so it's mapped
properly by the ISM.


5.2.3 Cursor Reads
-------------------

	The imd_query_map() procedure is used to return the mapping for a
particular WCS number, such as that returned by a cursor read.  It will do
a new WCS query for this regardless of a previous imd_getwcs() call.  Typical
usage would be something like the following in IMEXAMINE:

procedure t_imexamine ()
	:
begin
	:
    wcsver = imd_wcsver()
	:
	:
    while (ie_gcur (ie, curtype, x,y,wcs, key, cmd, SZ_LINE) != EOF) {

	if (imd_query_map (wcs,reg,sx,sy,snx,sny,dx,dy,dnx,dny,imname) > 0) {
	    .... add image name to list
	}

    }
	:
end

[NOTE:  in this example the ie_gcur() procedure was modified to return the
 	wcs from the cursor read.]

The WCS number returned by a cursor read now corresponds to the object id 
used in the server.  It still contains the frame number as before, but the
wcs number itself is used to identify the mapping.


5.3  ISM Communications
-----------------------

	The ISM (Image Support Module) can be any external task which 
connects to XImtool over a socket.  Communications are limited to simple
null-terminated text strings.  In most cases these strings are just the
standard OBM messages sent to XImtool objects but can also include Tcl
callback code (either ISM-specific callbacks, procedures which can be
added to the callback list for existing XImtool objects, or even new GUI
code to create panels and new objects).


5.3.1  Socket Connection
------------------------

	The ISM first requests a connection to XImtool on a dedicated
socket whose default value is "/tmp/.ISM%d", where the '%d' is replaced
by the userid allowing multiple users on a machine to have independent
sockets.  The XImtool 'ism_addr' resource or "-ismdev" command-line option
can be used to change this address, a value of 'none' will disable ISM
communications.  The socket may also be set with an ISMDEV environment
variable which will override the resource or command-line options.

	Once a connection request is received,  XImtool replies with
a message telling the ISM to reconnect on a different socket, it then
frees the initial connection allowing multiple other ISMs to request
their own connection.  The communications between XImtool and the ISM
are carried out entirely over this second negotiated socket.  Once connected,
the ISM appears as just another named object which can receive OBM messages.


5.3.2  Communications Protocol
------------------------------

	Messages from the ISM are written to the connection socket and must
be preceeded by one of the following keywords:

    callback 		Negotiate a connection on another socket
    ready    		Client is ready to begin processing
    quit     		Client is shutting down and disconnecting
    send     		Send a message to another object
 

Messages are of the form:

    connect <name>		Request a connection for the <name> ISM

    ready <name>		Reconnection request for the <name> ISM on 
				negotiated socket, ISM is ready to processing.

    send <obj> '{' <msg> '}' 	Send <msg> to the named <obj>.  The message
				may be any valid string that will be under-
				stood by the recipient.  The object may be
				any object in the GUI or OBM (see below).

    quit			ISM is shutting down. The named is determined
				from the communications channel, ISM is
				responsible for any cleanup of it's callbacks
				before issuing the shutdown.

All messages must be null-terminated.  XImtool will buffer the text until 
a complete message is received.  Once an ISM client has delivered a QUIT
message no further messages will be sent the that ISM.

	In OBM terminology the ISM is a named Client class object, where 
the name is set in the connection request.  Messages sent to the ISM should
use this name, messages sent to "client" are still interpreted to mean the
XImtool client.  

	The content of messages delivered to the ISM are totally free-form
and may contain any text the ISM is expected to understand.


5.3.3  GUI Objects
------------------

	While the ISM can send a message to any object in the task, there
is a GUI Parameter object called 'ism_msg' designed especially to process
messages from the ISM.  The callback in the GUI is expecting a message
beginning with one of the following keywords:

    source		Source message text as Tcl code
    alert		Message contains error text to be displayed in the
			GUI 'alert' box
    deliver		Message text should be passed to a callback routine
			specific to that ISM.  This processing callback may
			have been previously uploaded.  The message text
			may be any form the processing callback is expected
			to understand.
    info		Message text is status output intended for the
			XImtool 'info' panel (connect/disconnect requests, etc)


In all cases the message is expected to be of the form

		<cmd> <ism_name> [ <arg1> <arg2> <...> ]

where <cmd> is one of the above keywords, <ism_name> is the name of the
ISM sending the message.  The remainder of the message is passed as an 'argv'
list to the processing callback uploaded for the ISM.  The ISM is responsible
for formatting these messages.