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Diffstat (limited to 'Master/tlpkg/tlperl/lib/Tk/focus.pod')
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diff --git a/Master/tlpkg/tlperl/lib/Tk/focus.pod b/Master/tlpkg/tlperl/lib/Tk/focus.pod deleted file mode 100644 index d7e610d5d20..00000000000 --- a/Master/tlpkg/tlperl/lib/Tk/focus.pod +++ /dev/null @@ -1,166 +0,0 @@ -# Copyright (c) 1990-1994 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::focus - Manage the input focus - -=for category User Interaction - -=head1 SYNOPSIS - -S< >I<$widget>-E<gt>B<focus> - -S< >I<$widget>-E<gt>B<focus>I<Option> - -S< >I<$widget>-E<gt>B<focusNext> - -S< >I<$widget>-E<gt>B<focusPrev> - -S< >I<$widget>-E<gt>B<focusFollowsMouse> - -=head1 DESCRIPTION - -The B<focus> methods are used to manage the Tk input focus. -At any given time, one window on each display is designated as -the I<focus window>; any key press or key release events for the -display are sent to that window. -It is normally up to the window manager to redirect the focus among the -top-level windows of a display. For example, some window managers -automatically set the input focus to a top-level window whenever -the mouse enters it; others redirect the input focus only when -the user clicks on a window. -Usually the window manager will set the focus -only to top-level windows, leaving it up to the application to -redirect the focus among the children of the top-level. - -Tk remembers one focus window for each top-level (the most recent -descendant of that top-level to receive the focus); when the window -manager gives the focus -to a top-level, Tk automatically redirects it to the remembered -window. Within a top-level Tk uses an I<explicit> focus model -by default. Moving the mouse within a top-level does not normally -change the focus; the focus changes only when a widget -decides explicitly to claim the focus (e.g., because of a button -click), or when the user types a key such as Tab that moves the -focus. - -The method B<focusFollowsMouse> may be invoked to -create an I<implicit> focus model: it reconfigures Tk so that -the focus is set to a window whenever the mouse enters it. -The methods B<focusNext> and B<focusPrev> -implement a focus order among the windows of a top-level; they -are used in the default bindings for Tab and Shift-Tab, among other -things. - -The B<focus> methods can take any of the following forms: - -=over 4 - -=item I<$widget>-E<gt>B<focusCurrent> - -Returns the focus window on the display containing -the I<$widget>, or an empty string if no window in -this application has the focus on that display. - -=item I<$widget>-E<gt>B<focus> - -If the application currently has the input focus on I<$widget>'s -display, this command resets the input focus for I<$widget>'s display -to I<$widget> and returns an empty string. -If the application doesn't currently have the input focus on -I<$widget>'s display, I<$widget> will be remembered as the focus -for its top-level; the next time the focus arrives at the top-level, -Tk will redirect it to I<$widget>. - -=item I<$widget>-E<gt>B<focusForce> - -Sets the focus of I<$widget>'s display to I<$widget>, even if -the application doesn't currently have the input focus for the display. -This command should be used sparingly, if at all. -In normal usage, an application should not claim the focus for -itself; instead, it should wait for the window manager to give it -the focus. - -=item I<$widget>-E<gt>B<focusLastfor> - -Returns the name of the most recent window to have the input focus -among all the windows in the same top-level as I<$widget>. -If no window in that top-level has ever had the input focus, or -if the most recent focus window has been deleted, then -the top-level is returned. The return value is the window that -will receive the input focus the next time the window manager gives -the focus to the top-level. - -=item I<$widget>-E<gt>B<focusNext> - -=item I<$widget>-E<gt>B<focusPrev> - -B<focusNext> is a utility method used for keyboard traversal, but can be -useful in other contexts. -It sets the focus to the ``next'' window after I<$widget> in focus order. -The focus order is determined by -the stacking order of windows and the structure of the window hierarchy. -Among siblings, the focus order is the same as the stacking order, with the -lowest window being first. -If a window has children, the window is visited first, followed by -its children (recursively), followed by its next sibling. -Top-level windows other than I<$widget> are skipped, so that -B<focusNext> never returns a window in a different top-level -from I<$widget>. - -After computing the next window, B<focusNext> examines the -window's B<-takefocus> option to see whether it should be skipped. -If so, B<focusNext> continues on to the next window in the focus -order, until it eventually finds a window that will accept the focus -or returns back to I<$widget>. - -B<focusPrev> is similar to B<focusNext> except that it -sets the focus to the window just before I<$widget> in the focus order. - -=item I<$widget>-E<gt>B<focusFollowsMouse> - -B<focusFollowsMouse> changes the focus model for the application -to an implicit one where the window under the mouse gets the focus. -After this procedure is called, whenever the mouse enters a window -Tk will automatically give it the input focus. -The B<focus> command may be used to move the focus to a window -other than the one under the mouse, but as soon as the mouse moves -into a new window the focus will jump to that window. -Note: at present there is no built-in support for returning the -application to an explicit focus model; to do this you'll have -to write a script that deletes the bindings created by -B<focusFollowsMouse>. - -=back - -=head1 QUIRKS - -When an internal window receives the input focus, Tk doesn't actually -set the X focus to that window; as far as X is concerned, the focus -will stay on the top-level window containing the window with the focus. -However, Tk generates FocusIn and FocusOut events just as if the X -focus were on the internal window. This approach gets around a -number of problems that would occur if the X focus were actually moved; -the fact that the X focus is on the top-level is invisible unless -you use C code to query the X server directly. - -=head1 CAVEATS - -Note that for the B<Canvas> widget, the call to B<focus> has to be -fully qualified. This is because there is already a focus method for -the B<Canvas> widget, which sets the focus on individual canvas tags. - -S< >I<$canvas>-E<gt>B<Tk::focus> - - -=head1 KEYWORDS - -events, focus, keyboard, top-level, window manager - -=cut - |