| Allegro CL version 8.2 Unrevised from 8.1 to 8.2. 8.1 version |
Arguments: widget command enabled?
Applicable on Windows only; not implemented on GTK.
This generic function is called whenever the state of an html-widget
has changed such that
one of the typical HTML-browsing commands should be enabled or
disabled.
For example, if the user moves to the previous page and there is no
further previous page after that, then this function will be called to
tell you that the "Go Back" command should now be disabled. Your
application could add a method to this generic function to disable
whatever "Go Back" button it may have. The default method calls the
html-widget's on-command-change function if it has one, so the
application could instead attach an on-command-change function to an individual
html-widget
instance.
There is also a built-in method for the html-widget-for-browser
subclass, which is used
in html-browser
dialogs,
that modifies the html-browser's toolbar buttons as needed. So if you
use an html-browser
dialog,
you should not need to write any html-widget-command-change methods (or supply
any on-command-change
functions), whereas if you use the lower-level html-widget
control from scratch then you likely
will.
html-widget is the html-widget
whose state has changed.
command is one of the keyword symbols
:back
, :forward
, or
:cancel
.
enabled? is true if the specified command should currently be enabled.
The :back
and :forward
commands
refer to whether there are further pages in the linear chain of
recently-visited pages, indicating whether any "Go Back" and "Go
Forward" commands should currently be enabled.
The :cancel
command refers to whether a page is
currently being downloaded, indicating whether any "Cancel" command
should be enabled. enabled? is passed as
true when a download is beginning, and as nil
when it has finished.
See the html-widget
control.
Copyright (c) 1998-2016, Franz Inc. Oakland, CA., USA. All rights reserved.
This page was not revised from the 8.1 page.
Created 2010.1.21.
| Allegro CL version 8.2 Unrevised from 8.1 to 8.2. 8.1 version |