GitLab

(tree-widget-theme-name): Ignore parent themes.
(tree-widget-set-parent-theme): New function.
(tree-widget-set-theme): Use it.
(tree-widget-set-image-properties): Move definition.  Does nothing
if image properties have already been set.
(tree-widget-image-properties): Move definition.  Receive an image
name.  Set the :pointer property.
(tree-widget-lookup-image): Doc fix.  Search in parent themes.
Don't set the :pointer image property.
(tree-widget-convert-widget): New function.  Handle :dynargs
compatibility here.
(tree-widget): Use it to :convert-widget.  Add the :expander-p
predicate to control when the :expander function is entered.
Thanks to Ken Manheimer <ken.manheimer@gmail.com> for the idea.
(tree-widget-value-create): Handle :expander-p.  widget-apply
:expander.
(tree-widget-expander-p): New function.  Default value of the
:expander-p property.