When using GUIDE, in a callback function such as
function checkbox_Callback(hObject, eventdata, handles)
will
guidata(hObject)
and
guidata(handles.output)
return the same struct?
Similarly, will
guidata(hObject, handles)
and
guidata(handles.output, handles)
save changes made to the handles struct to the same "place"?
In other words, is using hObject versus handles.output for guidata equivalent?
handles.output returns a "handle to the main interface" - see http://www.matlabtips.com/guide-me-in-the-guide/.
Yes, because the guidata function includes the following call
fig = getParentFigure(h)
to ensure that it is operating on a figure handle even if you supply it with the handle of a figure child element (e.g. a checkbox handle).
The handles structure is stored in the application data of the figure (i.e. the data that the guidata function updates) so subsequent callbacks will receive your updated handles structure.