Returning a value from a function after click in figure

I would like to return a value from a function, based on the type of click that was used.

I have the following codes:

figure
i = 0;
plot(rand(5))
val = set(gca,'buttondownfcn',@mybttnfcn)

and

 function value =  mybttnfcn(h,~)

    hf = get(h,'parent');
    b = get(hf,'selectiontype');
    if strcmpi(b,'normal')
        value = 1;
        disp(value)
    elseif strcmpi(b,'alt')
        value = -1;
        disp(value)
    else
        value = 0;
        disp(value)
 end

I would want to capture the 'value' from the function, into a variable where the call happens. Thanks!

Answer 1

[Walter Roberson]

Callbacks cannot return values (except for position constraints functions). You need to get the value out a different way.

https://www.mathworks.com/help/matlab/creating_guis/share-data-among-callbacks.html

[Markus Toivonen]

Would it be possible to do this in one function?

h = figure;
i = 0;

plot(rand(5))

b = get(h,'selectiontype');
if strcmpi(b,'normal')
    value = 1;
elseif strcmpi(b,'alt')
    value = -1;
else
    value = 0;
end

Currently, it does not react to clicks. I guess due to the lack of "ButtonDownFcn"?

[Walter Roberson]

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