Can't Create Child Tree Item On "item_collapsed" Signal

[509dave16]

Godot Version

4.2

Question

I attempt to attach additional child tree items to a parent tree item when the parent expands(i.e. “item_collapsed”). But I get the error: scene/gui/tree.cpp:4291 - Condition "blocked > 0" is true. Returning: nullptr.

Does this mean it’s not possible?

“item_collapsed” Callback

func _on_tree_item_collapsed(item: TreeItem):
	var metadata = item.get_metadata(0)
	var should_attach_leaf_items = \
		typeof(metadata) != TYPE_NIL \
		&& item.collapsed == false \
		&& metadata["processed"] == false
	if should_attach_leaf_items:
		metadata["processed"] = true
		item.set_metadata(0, metadata)
		attach_leaf_tree_items(global_tree, item, metadata)

Section from “attach_leaf_tree_items” where “create_item” attempted

func attach_leaf_tree_items(tree: Tree, parent: TreeItem, definition: Dictionary):
	var variants = get_variants(definition)
	# This is for all variants after "None"
	for variant in variants:
		var item = tree.create_item(parent)
....

[mrcdk]

It may not let you at the same time. Try with call_deferred():

attach_leaf_tree_items.call_deferred(global_tree, item, metadata)

[509dave16]

That worked, @mrcdk ! No more “blocked” errors. You made my day !! I didn’t think it was going to be possible to add more child tree items on parent tree item expansion.