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pythonpygtkgtktreeview

How to update TreeModel after moving subtree

I have a custom GenericTreeModel, that works just fine. Now I want the user to be able to rearrange the nodes using drag and drop, so I move a node to its new parent in the data model. However then, the TreeModel wants to be notified using methods like row_has_child_toggled, row_deleted and row_inserted.

So apparently there is no row_moved and calling row_deleted (for the original path) and row_inserted (for the new path) seems not to be enough. So I thought I may have to recursively issue these changes.

Consider the following example:

* A (0,)
* B (1,)
  * C (1,0)
    * D (1,0,0)

Now, if I move C to A, the following things have happened:

row_delete( (1,0) ) # C
row_delete( (1,0,0) ) # D
row_inserted( (0,0) ) # C'
row_inserted( (0,0,0) ) # D'
child_toggle( (0,) ) # A
child_toggle( (1,) ) # B
child_toggle( (0,1) ) # C'

However, gtk still complains about inconsistent state of the model. Two things come to my mind:

  • maybe the order of calling these functions is relevant (if so any idea how?)
  • technically child_toggle( (1,0) ) also happens, however the row is a) already deleted and b) row_has_child_toggled needs a tree_iter reference, which I can't get as it doesn't exist any more.

Maybe I am following a totally wrong approach here, so what’s the best way to go about this?

Solution

  • Figured it out: Removing a subtree works fine by removing the subtree’s root node row (notify the model that the path is gone and conditionally toggling parent.has_child). Same goes for insertion of a new subtree, so I don't need to tell the model stuff recursively.

    However the combination is critical, so

    1. first remove, notify model
    2. then insert and notify model again.