how to get string for empty Edit Text in Matlab GUI ?

Hi,

I inserted an Edit Text in a Matlab GUI, and I would like to perform some actions when nothing is in the Edit Text (Edit Text empty). I have the following:

 extractPass=get(handles.inputPassword_txt,'string');

The problem is that, when the Edit Text is empty, isempty(extractPass)= 0. I was expecting isempty(extractPass)=1 when the Edit Text is empty.

What do I need to write to know when the Edit Text is empty ?

Thanks.

Answer 1

[per isakson]

With R2012a I fail to reproduce your problem. Try

    class( extractPass )
    double( extractPass )

to find out what get returns

[MatlabFan]

Thank you for assisting me isakon.

>>class(extractPass) ans = cell

What I am trying to achieve is to perform some actions when the edit text is empty. Apparently, when I create an edit text box and insert nothing into then

isempty(get(handles.inputPassword_txt,'string'))

returns a value of 0. It is weird.

[Walter Roberson]

What does

size(extractPass)

show? I'm going to guess it shows 1 x 1, and that extractPass{1,1} is going to be empty.

[per isakson]

I think cell indicates that it is a multi-line edit box. Check the on-line help.

Try

    size( extractPass )
    isempty( char( extractPass ) )

[MatlabFan]

 isempty( char( extractPass ) )

Error using char

Cell elements must be character arrays.

 size( extractPass )

ans=

2 x 1

extractPass{1,1}

ans=

0

[per isakson]

I made a little experiment:

    >> ohe = uicontrol( 'Style', 'edit', 'max', 3,'min',1 )
    ohe =
        0.0023
    >> set(ohe,'String', {'abc','dfg'})

deleted the strings in the editbox interactively and

    >> str=get(ohe,'String')
    str = 
        {''}
    >> isempty( char( str ) ) 
    ans =
         1

or better

    isempty( [str{:}] )

the char doesn't hurt if str is character, but if str not a scalar it might. Matlab is sometimes tiresome!

[MatlabFan]

Thank you very much for your help Isakon. I appreciate that. It still doesn't solve the problem though.

[per isakson]

You have a < 2x1 cell> array of strings (or something else). Try this

    extractPass{1}
    extractPass{2}

    whos extractPass

    for ii = 1 : numel( extractPass )
        class( extractPass{ii} )
        isempty( extractPass{ii} )
    end

or use the variable editor to find out what is in the cells.

Do you have a squeezed scroll bar to the right end of the edit box?

If nothing helps restart Matlab!