How to handle check-able tree-view nodes that act as both a group and an item
I need to create a tree-view which allows users to select nodes (using a checkbox). The tree-view contains two types of node, "group" and "item". A "group" node can contain both "group" and "item" nodes. An item node can't contain other nodes. Crucially selecting a group node should automatically select all node below it (to the bottom of the tree).
However, due to this last criteria I can't figure out the following behaviour (I make reference to the attached diagram).
- The user selects Group A
- Now Group A, Group B, Item 1 and Item 2 are now checked.
- The user then deselects Item 1
What should the state of Group A be (checked, unchecked or indeterminate)?
