tk4.2 User Commands - focusNext
NAME
tk_focusNext, tk_focusPrev, tk_focusFollowsMouse - Utility
procedures for managing the input focus.
SYNOPSIS
tk_focusNext window
tk_focusPrev window
tk_focusFollowsMouse
DESCRIPTION
tk_focusNext is a utility procedure used for keyboard
traversal. It returns the ``next'' window after window 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 chil-
dren (recursively), followed by its next sibling. Top-level
windows other than window are skipped, so that tk_focusNext
never returns a window in a different top-level from window.
After computing the next window, tk_focusNext examines the
window's - takefocus option to see whether it should be
skipped. If so, tk_focusNext continues on to the next win-
dow in the focus order, until it eventually finds a window
that will accept the focus or returns back to window.
tk_focusPrev is similar to tk_focusNext except that it
returns the window just before window in the focus order.
tk_focusFollowsMouse changes the focus model for the appli-
cation 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 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 tk_focusFollowsMouse.
KEYWORDS
focus, keyboard traversal, top-level