Yeah, I didn't consider the other direction, that makes sense.

--John

On 18/11/2022 18:28, Nir Lisker wrote:
I think that even if a node is set to indeterminate programmatically, its parents should be updated at the very least (unless it's set to be independent). Not updating the children seems reasonable.

On Fri, Nov 18, 2022 at 11:12 AM John Hendrikx <john.hendr...@gmail.com> wrote:


    On 18/11/2022 00:10, Nir Lisker wrote:
    > Hi,
    >
    > I have been working on fixing some issues with the behavior
    > of CheckBoxTreeItem. I stumbled across this situation:
    >
    > When a parent is de/selected, all of its children are set to the
    same
    > state. However, a CheckBoxTreeItem can be set to indeterminate
    > programmatically (the control itself does not allow indeterminate).
    > Should all children also be set to an indeterminate state? If
    so, this
    > will put the tree at an "invalid" state where leaf nodes can be
    > indeterminate as well. OTOH, if not, then we are again at an
    invalid
    > state if all children have the same state, but the parent doesn't.

    I think the indeterminate state is best left up completely to the
    owner
    of the control. You may need information that is not part of the
    tree to
    actually determine if something is indeterminate or not.  A tree
    may be
    filtered, or a tree may represent only "nodes" while "leaves" are
    displayed in a 2nd control as a list.  This means that in theory,
    parent
    nodes could be indeterminate even if all its children are in the same
    state (checked/unchecked) due to filtering, and leaf nodes could be
    indeterminate if they represent a directory while the file
    selection is
    displayed in a separate control.  In Backup software, a directory
    may be
    partially selected if it has a filter associated with it (like
    *.java)
    even if that directory is empty or has only Java files currently...

    Some UI's will even allow you to click on an indeterminate parent
    node
    to check it (checking all children), click again to uncheck it
    (unchecked all children), and click a 3rd time to put it back to an
    indeterminate state (restoring all children to the state they had
    before
    the first click).

    --John

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