How to undo a plot for multiple times?

I want to delete a scatter plot's items for multiple times. My code is like

 Function plot_callbacks (hObject, eventdata, handles)
figure (5)
scatter(x,y,'x')
hold on
scatitem = get(gca, 'Children');
handles.scatitem = scatitem;
guidata(hObject,handles)

Function undo_callbacks (hObject, eventdata, handles)
scatitem = handles.scatitem;
should_continue = true
while true
delete(scatitem(1))
scatitem(1) = []
should_continue = 0
end

In the second callback function, the line

 delete(scatitem(1))

, just by it-self, deletes the last item, but just for one time. By the second function, I am trying to do the deletion for several times.

Does anyone know where did I write the code incorrectly? How can I make it working?

Answer 1

[Walter Roberson]

function undo_callbacks (hObject, eventdata, handles)
scatitem = handles.scatitem;
number_to_delete = 3;   %for example
delete(scatitem(1:number_to_delete))
scatitem(1:number_to_delete) = [];
handles.scatitem = scatitem;
guidata(hObject, handles);
end

If you only want to undo one per call, change the 3 to 1.

The difference compared to your code is that my code updates handles.scatitem . You were trying to delete the same child every time

[Ali Y.]

Thank you very much, Wlater.