Problem with a callback function that checks user input

I have an edit box and I want that another uicontrol changes its color depending on user input. I have defined a callback function that should control that, but my problem is when the user input a negative value between the valid range because takes "-" as an invalid input.

function check(hObject,~)
    inp = get(hObject,'String');
    if ~isempty(strfind(inp,','))
        warndlg('Invalid input. No commas are allowed','Warning');
        set(tex,'BackgroundColor',[.91 .88 .88]);
    elseif ~isempty(regexp(inp,'\D','once'))
        warndlg('Invalid input. Only numbers are allowed','Warning');
        set(tex,'BackgroundColor',[.91 .88 .88]);
    elseif str2num(inp)<-360 || str2num(inp)>360
        warndlg('RANGE ERROR. Valid values are between -360° and 360°','Warning');
        set(tex,'BackgroundColor',[.91 .88 .88]);
    elseif str2num(inp)>-360 && str2num(inp)<360
        set(tex,'BackgroundColor',[.88 .91 .88])
    end
end

So what can I do to solve this?

Answer 1

[Geoff Hayes]

isdapi - why not first convert the input to a number and then decide what to do? If the string contains invalid characters, then the conversion will result in an empty matrix. For example, you could do

 inp = str2num(get(hObject, 'String'));

 if isempty(inp)
     % input is invalid
 elseif inp < -360 || inp > 360
     % input is invalid
 else
     % input is valid
 end

Try the above and see what happens!

Answer 2

[isdapi]

Thanks!