Emitted when a change has occured to the menu.
The only changes that can occur to a menu is that items are removed or added. Items may not change (except by being removed and added back in the same location). This signal is capable of describing both of those changes (at the same time).
The signal means that starting at the index
removed items were removed and
added items were
added in their place. If
removed is zero then only items were added. If
added is zero then only items were removed.
As an example, if the menu contains items a, b, c, d (in that order) and the signal (2, 1, 3) occurs then the new composition of the menu will be a, b, _, _, _, d (with each _ representing some new item).
Signal handlers may query the model (particularly the added items) and expect to see the results of the modification that is being reported. The signal is emitted after the modification.
the position of the change
the number of items removed
the number of items added