




Gets and sets the checkbox status of an item in a tree-view.
The function 
tree-view-item-checkbox-status
 retrieves the checkbox status of 
item
 in 
tree-view
. 
(setf tree-view-item-checkbox-status) 
sets the checkbox status of 
item
 in 
tree-view
. The 
status
 must be an non-negative integer smaller than the number of images in 
tree-view
's 
state-image-list
.