How to cancel a tkinter key bind event-CodePudding

I have a tkinter treeview. I am responding to a click on an item. If the item is not unique i want to cancel the selection and stay on the current item.

The code I am using is:

def select_item(self, event, *args) -> None:
    item = self.index.identify_row(event.y)
    current_idx = self.index.index(item)
    if item:
        if self.current_item_index >= 0:
            if self.save_item(self.current_item_index):
                print("UNIQUE")
                self.current_item_index = current_idx
                self.load_item(current_idx)
            else:
                print("NOT UNIQUE", self.current_item_index)
                child_id = self.index.get_children()[self.current_item_index]
                self.index.focus(child_id)
                self.index.selection_set(child_id)

However, even after the test fails and I refocus on the current item, instead of the new selection, the new item is still selected.

For example; say I am currently editing the fourth item in the tree view. If the associated data is not unique, then if someone selects, say the seventh item, i want to ignore that selection and stay on the fourth item.

CodePudding user response：

If your bound function returns the string "break", any further processing of the event will be cancelled. This includes cancelling the default behavior of the event.