Help using guidata in a script

Hi everyone,

i have a quick question about the use of guidata.

Say i have a script like that:

random code [handles, movie] = timelapse(selection, handles] guidata(gcbo, handles) random code

do i really need to use guidata in this case or does my function already return the current handle structure? Thank you guys!

Answer 1

[OCDER]

If you pass handles as input and also output, you don't need guidata

Use guidata only to store/retrieve the GUI's data.

https://www.mathworks.com/help/matlab/ref/guidata.html

function [handles, movie] = myFcn(CurFigHandle)
handles = guidata(CurFigHandle);  %In this case, use guidata to retrieve handles, since it was not an input
movie = handles.movie; 

function [handles, movie] = myFcn(handles)
movie = handles.movie;
%No guidata required, since handles was passed as the input.

In GUIDE, the handles is pretty much always passed as the 3rd input to a callback function, so no need to use guidata to "retrieve" handle. You do need to use guidata to "store" any changes to handles though.

function pushbutton_callback(hObject, events, handles)
movie = handles.movie;
handles.movie = movie(1:end-1); %Changes made!
guidata(hObject, handles); %save modified handles

[Julian]

Thank you, that was very helpful!