These caches, well, cache the result of the :layout and :fit callbacks on
widgets.
Clearing caches is done by recording dependencies between a widget. When a call
to base.fit_widget() or base.layout_widget() recursively causes another call to
such a function, this means that the earlier widget depends on the later widget.
This dependency is recorded and when the later widget emits
widget::layout_changed, the caches of all the widgets involved are cleared.
Signed-off-by: Uli Schlachter <psychon@znc.in>
Having two modules named "base" is confusing and "wibox.layout" doesn't contain
much useful stuff. This is a first step for removing wibox.layout by moving a
function which should only ever be used internally in awesome.
Signed-off-by: Uli Schlachter <psychon@znc.in>