bindtags(n) Tk Built-In Commands bindtags(n)_________________________________________________________________NAMEbindtags - Determine which bindings apply to a window, and
order of evaluation
SYNOPSISbindtags window ?tagList?
_________________________________________________________________DESCRIPTION
When a binding is created with the bind command, it is
associated either with a particular window such as .a.b.c,
a class name such as Button, the keyword all, or any other
string. All of these forms are called binding tags. Each
window contains a list of binding tags that determine how
events are processed for the window. When an event occurs
in a window, it is applied to each of the window's tags in
order: for each tag, the most specific binding that
matches the given tag and event is executed. See the bind
command for more information on the matching process.
By default, each window has four binding tags consisting
of the name of the window, the window's class name, the
name of the window's nearest toplevel ancestor, and all,
in that order. Toplevel windows have only three tags by
default, since the toplevel name is the same as that of
the window. The bindtags command allows the binding tags
for a window to be read and modified.
If bindtags is invoked with only one argument, then the
current set of binding tags for window is returned as a
list. If the tagList argument is specified to bindtags,
then it must be a proper list; the tags for window are
changed to the elements of the list. The elements of
tagList may be arbitrary strings; however, any tag start-
ing with a dot is treated as the name of a window; if no
window by that name exists at the time an event is pro-
cessed, then the tag is ignored for that event. The order
of the elements in tagList determines the order in which
binding scripts are executed in response to events. For
example, the command
bindtags .b {all . Button .b}
reverses the order in which binding scripts will be evalu-
ated for a button named .b so that all bindings are
invoked first, following by bindings for .b's toplevel
(``.''), followed by class bindings, followed by bindings
for .b.
The bindtags command may be used to introduce arbitrary
additional binding tags for a window, or to remove stan-
dard tags. For example, the command
bindtags .b {.b TrickyButton . all}
Tk 4.0 1
bindtags(n) Tk Built-In Commands bindtags(n)
replaces the Button tag for .b with TrickyButton. This
means that the default widget bindings for buttons, which
are associated with the Button tag, will no longer apply
to .b, but any bindings associated with TrickyButton (per-
haps some new button behavior) will apply.
SEE ALSO
bind
KEYWORDS
binding, event, tag
Tk 4.0 2
