Newsgroups: comp.infosystems.gopher
Subject:+MENU block suggestion for graphic & document gopher menus
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References: <2eit8e$14bb@msuinfo.cl.msu.edu>
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Organization: Biology, Indiana University - Bloomington
Keywords: Gopher+
Dear Gopher+ client developers & users with suggestions,
I'd like to suggest a set of gopher+ block extensions that would let
gopher links be located as hotspots within images or any arbitrary gopher
document. This is an alternative to the not-yet-implemented (?)
gview/gviewspot method envisioned by the Gopher team at U.Minnesota. It
is also an answer to the functionality of NCSA Mosaic's network hypertext.
Since this is basically a client method, we need some consensus among
client developers that this is a useful method to implement. If this idea
doesn't seem best, please suggest alternatives.
Reasons I rejected gview/gviewspot include (a) not yet implemented in any
client, (b) would apparently require more server revisions, (c) would
apparently require two fetches of data from server to get (1) image file
and (2) directory data.
My approach is to specify a set of block extensions, +MENU, +MENURECT,
+MENUBYTES, +MENUSTRING (maybe others as it develops), that can be
attached to any current gopher document, including images and rich text.
The +MENU block contains any number of gopher+ links to other items, and
the +MENURECT, etc, specify locations of the 'hotspots' of each gopher
item within the image or text.
The server side of this is already basically present in U.Minnesota's
gopherd v2. In your /usr/local/etc/gopherd.conf file, add a line like
blockext .gopher+-menu MENU
Then let your gopherd server make a .cache+ file of any set of links or
folder you want to have as a MENU block, and copy the .cache+ to
some/path/my-graphic-folder.gopher+-menu (for instance)
Then create an image (or rich-text or whatever) for that directory
information, called
some/path/my-graphic-folder.gif (for instance)
Now any gopher+ client can fetch this image, and if it uses "$" for the
directory information, or uses "my-graphic-folder<tab>!" to get info for
that item, it will get the contents of my-graphic-folder.gopher+-menu as a
+MENU block. Note that the menu information is all shifted one space to
right (see example below) so current gopher+ clients should not be
confused by having this menu information contained within a super-menu.
The "my-graphic-folder.gopher+-menu" file (or the original gopher directory
it came from) now also needs to be editted to add lines such as +MENURECT
to associate each item with a location in the my-graphic-folder.gif image.
A MENURECT item here is just the (left, top, right, bottom) vertices of
a hotspot rectangle within the image. When Joe User clicks mouse within
that rectangle, it will active the assocated gopher item as if he selected
that item from a standard gopher menu. Likewise MENUSTRING can specify
a text string in some (rich) text document to associate a gopher item with.
What the client needs to be able to do to deal with these MENU blocks are
(a) display image from some format (GIF is suggested as most common
standard), (b) locate user mouse clicks on the image, (c) link the MENU
information to those clicks on the image, (d) respond to a gopher item
selected from this image in essentially the same way as selections from
a usual gopher menu.
This work looks fairly straight forward for a Mac/Macapp program. I don't
know if MSWindows or XWindows will have any special problems with this.
For rich text documents (e.g. with fonts, styles, formatting), the same
basic problems hold, but the data format differs. I'm suggesting
Microsoft's Rich Text Format (RTF) as the most common format that is
readily available to produce documents in (mac and msdos, and some unix
translators), and is reasonably easy to program to (see Paul DuBois'
RTFreader software at gopher/ftp:ftp.primate.wisc.edu).
P.S, this format should be convertable to/from the HTML documents
used by WWW, although several gopher+ extensions are not supported
yet by HTML.
-- don
Here is an example link ---------------------------
Try this to get the MENU block info:
telnet ftp.bio.indiana.edu 70
9/Gopher+TEST/go+incoming/graphic-menu !
------------------------------------------------------
Type=I+
Name=graphic-menu [26Nov93, 15kb] [26Nov93, 2kb] [26Nov93, 10kb]
Path=9/Gopher+TEST/go+incoming/graphic-menu
Host=ftp.bio.indiana.edu
Port=70
Admin=Don Gilbert <Archive@Bio.Indiana.Edu>
ModDate=Fri Nov 26 09:56:02 1993 <19931126095602>
URL: gopher://ftp.bio.indiana.edu:70/I/9/Gopher+TEST/go+incoming/graphic-menu
Size Language Document Type
---------- ------------- ----------------------------
14k English (USA) image/gif
9k English (USA) image/JPEG
Example---------------------------
+COMMENT:
This MENU specifies a gopher+menu associated with any gopher item, esp. image or
text document. The contents of a MENU block are just the contents that
gopher+ server sends to client, or those contained in a ".cache+" file created
by UMinn's gopherd. You need to use a file suffix/extension like ".gopher+-menu"
and include the following line in your /usr/local/etc/gopherd.conf file:
blockext: .gopher+-menu MENU
Implementation of these block names MENU, MENURECT, MENUBYTES, MENUSTRING and
MENUDEFAULT must be done in gopher+ clients that wish to support these methods.
With this implementation, gopher+ can serve graphic and (hyper-)text based menus.
One could even serve rich-text documents that mix styled text and graphics,
if gopher client software learns to display a rich-text document format. I
plan to look at using Microsoft's RTF format.
Note that the MENURECT, MENUSTRING, etc, items which specify where an item
is must be *within* the MENU block itself. You would do this by editing
the ".gopher+-menu" file from which this menu block is created.
+MENU:
+INFO: 1Gopher+ Mol. Biology services 1/Gopher+TEST/go+molbio ftp.bio.indiana.edu 70 +
+ADMIN:
Admin: Don Gilbert <Archive@Bio.Indiana.Edu>
...
+COMMENT:
This MENURECT specifies the item's location rectangle on a gopher+ menu-image
Gopher+ clients must be modified to interpret this block.
+MENURECT:
left top right bottom
+MENURECT:
300 0 400 100
+COMMENT:
This MENUDEFAULT specifies the an optional default item for any gopher+ menu-image
or menu-text .
Gopher+ clients must be modified to interpret this block.
+MENUDEFAULT:
+MENUDEFAULT:
+COMMENT:
This MENUBYTES specifies the item's location as a byte range in a gopher+ menu-text
Gopher+ clients must be modified to interpret this block. If 'stopbyte' is missing,
only the 'startbyte' location is indexed for the item location.
+MENUBYTES:
startbyte stopbyte
+MENUBYTES:
100 500
+COMMENT:
This MENULINE specifies the item's location as a line number and character range
in a gopher+ menu-text. This is a modification of MENUBYTES to allow for
text that has newline translation and may differ in byte count on different
platforms. 'linenumber' indexes a line, from 0 at top, and 'startchar' and
'stopchar' index characters within that line. If startchar & stopchar are
missing, the entire line is indexed.
Gopher+ clients must be modified to interpret this block.
+MENULINE:
linenumber startchar stopchar
+MENULINE:
100 500
+COMMENT:
This MENUSTRING specifies the item's location as a string in a gopher+ menu-text
Gopher+ clients must be modified to interpret this block. The string should
be enclosed in " or ' characters. An optional repeat-value specifies which
occurence of the string to match, from the top of the text.
+MENUSTRING:
"some string" repeat-value
+MENUSTRING:
"bob was here" 3