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Re: Popup menus and mouse-sensitive graphics w/CL-HTTP
At 10:09 AM 11/22/95, Mark Klein wrote:
>I am porting a Common Lisp system from a Symbolics GUI to a WWW GUI using
>CL-HTTP. The Symbolics code produced screens that typically combined some
>simple graphs (made up of labelled nodes and links) with text. Some text
>and graphic elements, when mouse-selected, opened pop-up menus with action
>options (e.g. add additional link to this node).
>
>Do you have any suggestions on the easiest way to reproduce this UI
>metaphor with CL-HTTP? Some specific questions:
>
>€ HTML doesn't seem to support pop-up menus. Is my only option to create a
>new page with the menu options as anchors? Will CL-HTTP support Java
>applets or the like that could do the job?
Right now, you could use CL-HTTP 47.7 and netscape 2.0 frames to provide equivalent functionality
by reconfiguring the frame to expose a choice pane and including a form with appropriate
choices in that pane. So, when you click on a node, the choice pane displays the appropriate
set of choices. See the bottom of the features page in the CL-HTTP documentation for examples
and pointers to netscape documentation.
CL-HTTP allows you to export and invoke Java scripts but someone needs to
write the relevant scripts. Between Java and livescript, this kind of graphics
should become possible soon.
>
>€ I understand that I can use bitmaps to produce the effect of
>mouse-sensitive graph components, but will I have to write my own code to
>produce the bitmaps and determine which element a user has selected? Is
>there any high-level Lisp code available that does this already?
See the documentation on server-side image maps and client-side image maps.
You can make regions mouse-sensitive but the current standards only allow you
to have one action associated with the mouse click. This may improve as
java or livescript is empowered to handle use mouse-clicks.
Peter Karp's (pkarp@ai.sri.com) group at SRI came up some some code to do CLIM graphics over the
web (Susan Paley in particular), but they have yet to share their code with the CL-HTTP
community. You might ask them what the current status is.
We were considering providing a lisp interface to exporting image maps. This would
allow you to specify regions and mappings suitable for server-side image maps, ergo,
conversion to client-side image maps, directly from lisp and skip the NCSA or CERN image
map intermediate formats.
At the end of the day, it would be most desirable if you or someone could come up
with a utility that everyone could use by being careful to abstract the functionality
from the application.