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Diffstat (limited to 'Master/tlpkg/tlperl/lib/Tk/bindtags.pod')
-rw-r--r-- | Master/tlpkg/tlperl/lib/Tk/bindtags.pod | 107 |
1 files changed, 0 insertions, 107 deletions
diff --git a/Master/tlpkg/tlperl/lib/Tk/bindtags.pod b/Master/tlpkg/tlperl/lib/Tk/bindtags.pod deleted file mode 100644 index 3ee6ddb9473..00000000000 --- a/Master/tlpkg/tlperl/lib/Tk/bindtags.pod +++ /dev/null @@ -1,107 +0,0 @@ -# Copyright (c) 1990 The Regents of the University of California. -# Copyright (c) 1994-1996 Sun Microsystems, Inc. -# See the file "license.terms" for information on usage and redistribution -# of this file, and for a DISCLAIMER OF ALL WARRANTIES. -# -# - -=head1 NAME - -Tk::bindtags - Determine which bindings apply to a window, and order of evaluation - -=for category Binding Events and Callbacks - -=head1 SYNOPSIS - -I<$widget>-E<gt>B<bindtags>([I<tagList>]); - -I<@tags> = I<$widget>-E<gt>B<bindtags>; - -=head1 DESCRIPTION - -When a binding is created with the B<bind> command, it is -associated either with a particular window such as I<$widget>, -a class name such as B<Tk::Button>, the keyword B<all>, or any -other string. -All of these forms are called I<binding tags>. -Each window has a list of binding tags that determine how -events are processed for the window. -When an event occurs in a window, it is applied to each of the -window's tags in order: for each tag, the most specific binding -that matches the given tag and event is executed. -See the L<Tk::bind> documentation for more information on the matching -process. - -By default, each window has four binding tags consisting of the -the window's class name, name of the window, the name of the window's -nearest toplevel ancestor, and B<all>, in that order. -Toplevel windows have only three tags by default, since the toplevel -name is the same as that of the window. - -Note that this order is I<different> from order used by Tcl/Tk. -Tcl/Tk has the window ahead of the class name in the binding order. -This is because Tcl is procedural rather than object oriented and -the normal way for Tcl/Tk applications to override class bindings -is with an instance binding. However, with perl/Tk the normal way -to override a class binding is to derive a class. The perl/Tk order -causes instance bindings to execute after the class binding, and -so instance bind callbacks can make use of state changes (e.g. changes -to the selection) than the class bindings have made. - -The B<bindtags> command allows the binding tags for a window to be -read and modified. - -If I<$widget>-E<gt>B<bindtags> is invoked without an argument, then the -current set of binding tags for $widget is returned as a list. -If the I<tagList> argument is specified to B<bindtags>, -then it must be a reference to and array; the tags for $widget are changed -to the elements of the array. (A reference to an anonymous array can -be created by enclosin the elements in B<[ ]>.) -The elements of I<tagList> may be arbitrary strings or widget objects, -if no window exists for an object at the time an event is processed, -then the tag is ignored for that event. -The order of the elements in I<tagList> determines the order in -which binding callbacks are executed in response to events. -For example, the command - - $b->bindtags([$b,ref($b),$b->toplevel,'all']) - -applies the Tcl/Tk binding order which binding callbacks will be -evaluated for a button (say) B<$b> so that B<$b>'s instance bindings -are invoked first, following by bindings for B<$b>'s class, followed by -bindings for B<$b>'s toplevel, followed by 'B<all>' bindings. - -If I<tagList> is an empty list i.e. B<[]>, then the binding -tags for $widget are returned to the perl/Tk default state described above. - -The B<bindtags> command may be used to introduce arbitrary -additional binding tags for a window, or to remove standard tags. -For example, the command - - $b->bindtags(['TrickyButton',$b->toplevel,'all']) - -replaces the (say) B<Tk::Button> tag for B<$b> with B<TrickyButton>. -This means that the default widget bindings for buttons, which are -associated with the B<Tk::Button> tag, will no longer apply to B<$b>, -but any bindings associated with B<TrickyButton> (perhaps some -new button behavior) will apply. - -=head1 BUGS - -The current mapping of the 'native' Tk behaviour of this method -i.e. returning a list but only accepting a reference to an array is -counter intuitive. The perl/Tk interface may be tidied up, returning -a list is sensible so, most likely fix will be to allow a list to be -passed to I<set> the bindtags. - -=head1 SEE ALSO - -L<Tk::bind|Tk::bind> -L<Tk::callbacks|Tk::callbacks> - -=head1 KEYWORDS - -binding, event, tag - -=cut - |