Enable / Disable specific listbox item

Is there a way to disable an item in a listbox. Basically I want to have a listbox that displays a number of available items for selection but want a subset of these items to be greyed out (disabled).

I can (of course) just check for the forbidden item AFTER the user has selected it and tell him that this item is unavailable. But that seems in elegant. Alternatively, I could simply not list forbidden items to begin with but.... also inelegant.

Ideas?

Thanks!

Dan

Answer 1

[Image Analyst]

You can't do that. The workarounds are the two you listed.

Answer 2

[Robert Cumming]

By using this FEX you can make it look like things are disabled:

function test
  myStr{1} = 'Allowed';
  myStr{2} = str2html ( 'Not Allowed', 'italic', true, 'colour', '#A0A0A0'  );
  myStr{3} = 'Allowed';
  myStr{4} = 'Allowed';
  myStr{5} = 'Allowed';
  allowed = [1 0 1 1 1]; % flags of items allowed or not.
  uicontrol ( 'style', 'listbox', 'position', [0 0 400 200], 'String', myStr, 'Callback', {@checkcb allowed} )
end
function checkcb ( obj, event, allowed )
  if allowed(obj.Value) == 0
    errordlg ( 'Not allowed' );
    obj.Value = find ( allowed, 1, 'first' );
  end
end

See example image:

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[Dan]

Intriguing..... I'll give it a shot! thanks!

[Afifa Shaikh]

Matlab is not able to recognize the keyword 'str2html'

Undefined function or variable 'str2html'.

[Andy]

See file exchange

https://uk.mathworks.com/matlabcentral/fileexchange/46755-str2html?s_tid=srchtitle