I have a GtkTreeView in which I would like to enable dragging and nesting. In my tree not every item can host children; the tree maps files and directories, and therefore only the rows that map directories can be the targets of drop operations.
I am fine at managing every step via code, but so far I have not found any attack point in GTK4 for doing that. What signals should I use for allowing/forbidding the user to drop a row inside another row?