MATLAB: Is this a switchyarding case

checkboxswitchyard

I have a figure with 4 checkboxes. I want to fill a 1×4 array with values of 1 if the checkbox is selected. What I've written below somewhat works, but only allows one value of chkbxvals to change and won't keep any previous values. All four checkboxes use the same callback.
So for example, if the user clicks on all four boxes, I want chkbxvals = [1 1 1 1]. If the user unchecks the first box, chkbxvals = [0 1 1 1]. If none are selected, then chkbxvals = [0 0 0 0]; and so on…
I know the long way to do this is to create 16 loops to cover all possible situations, but I feel as though there may be a more compact way to do it.
function input_chkbx_Callback(gcf,eventdata,handles,chkbxval)
chkbxvals = [0 0 0 0];
switch chkbxval
    case 1
        chkbxvals(1) = 1;
    case 2
        chkbxvals(2) = 1;
    case 3
        chkbxvals(3) = 1;
    case 4
        chkbxvals(4) = 1;
end
Thanks!

Best Answer

Here is an example.
function [] = Check_examp()
% Print to screen the users checkbox choices.
S.fh = figure('units','pixels',...
              'position',[500 500 200 220],...
              'menubar','none',...
              'name','Check_boxes',...
              'numbertitle','off',...
              'resize','off');
S.ch(1) = uicontrol('style','check',...
                    'unit','pix',...
                    'position',[10 60 180 20],...
                    'fontsize',14,...
                    'string','checkbox1');
S.ch(2) = uicontrol('style','check',...
                    'unit','pix',...
                    'position',[10 100 180 20],...
                    'fontsize',14,...
                    'string','checkbox2');
S.ch(3) = uicontrol('style','check',...
                    'unit','pix',...
                    'position',[10 140 180 20],...
                    'fontsize',14,...
                    'string','checkbox3');
S.ch(4) = uicontrol('style','check',...
                    'unit','pix',...
                    'position',[10 180 180 20],...
                    'fontsize',14,...
                    'string','checkbox4');                
S.pb = uicontrol('style','push',...
                 'units','pix',...
                 'position',[10 10 180 40],...
                 'fontsize',14,...
                 'string','Get Boxes',...
                 'callback',{@pb_call,S});
function [] = pb_call(varargin)
% Callback for pushbutton, gets checkbox choices.
S = varargin{3};  % Get the structure.
V = cell2mat(get(S.ch(4:-1:1),'value'))  % Get the users choice.
.
.
.
Note that if you are using GUIDE, you should modify the code in the callback by getting the handles to the checkboxes into a single vector when querying their value property. Something like:
S =[handles.ch1,handles.ch2,handles.ch3,handles.ch4];
V = cell2mat(get(S,'value'))
Also, note that I put the code in the callback to a pushbutton, but you can put it anywhere.
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