Re: Function handle with arguments for GUI callback

[Michael Goffioul]

On Mon, Mar 11, 2013 at 2:13 PM, Arnaud Miege <address@hidden> wrote:

On 11 March 2013 17:34, Michael Goffioul <address@hidden> wrote:

Using a cell array is the right approach. It is supported. What error do you get and what code are you using? Also please note that a GUI callback always get the object handle and an event data as first 2 arguments. Whatever arguments you specify in the cell array starts at position 3 in the callback argument list.

Michael.

Thanks, I have made some progress since my initial email.

In my main function, I create a variable called "gui" as the output of a sub-function called create_interface:

gui = create_interface;

In the sub-function create_interface, I add various fields to the gui structure which are handles to the various UI components, such as:

% Add pop-up menus for dimension choice of each input

strings = {'Nominal dimensions|Measurement file'};

width = [0.5 0.5 0.5];

gui.dim_choices = cell(size(gui.inputs_txt));

for k=1:length(gui.inputs_txt)

gui.dim_choices{k} = uicontrol('Style','popupmenu','String',strings,...

        'Units','normalized','Position',[0.23 y_pos(k) width(k) 0.1],...

        'BackgroundColor','w','Parent',gui.inputs_panel,'Callback',...

address@hidden,num2str(k),gui});

end

I have worked out that the first argument to the function handle callback needs to be converted to a string. I am also passing the gui structure as a second argument because I couldn't figure out a way of using the second default argument (eventdata - there doesn't seem to be much documentation about it).

This is standard Matlab behavior:

http://www.mathworks.com/help/matlab/creating_guis/writing-code-for-callbacks.html

(look for  "Use Cell Arrays with Strings")

 

However, if I start using the index k (which has a sensible value between 1 and 3), as in:

function update_browse_btn(src,data,k,gui)

% Called when user activates popup menu 

disp(['k = ' num2str(k)]);

        val = get(src,'Value')

gui.browse_btns(k,1)

end

I get the following error:

>> k = 1

val =  2

error: update_browse_btn: A(I,J): row index out of bounds; value 49 out of bound

 3

error: called from:

error:   <path_to_my_file> at line 185, colu

mn 3

I can't then close the GUI, I need to click on the console to activate it, which triggers the following error message:

error: octave_base_value::convert_to_str_internal (): wrong type argument `<unkn

own type>'

error: octave_base_value::convert_to_str_internal (): wrong type argument `<unkn

own type>'

error: octave_base_value::convert_to_str_internal (): wrong type argument `<unkn

own type>'

error: octave_base_value::double_value (): wrong type argument `<unknown type>'

error: octave_base_value::convert_to_str_internal (): wrong type argument `<unkn

own type>'

error: octave_base_value::convert_to_str_internal (): wrong type argument `<unkn

own type>'

error: octave_base_value::convert_to_str_internal (): wrong type argument `<unkn

own type>'

I then need to press Enter to regain control and close the figure with the close command.

The syntax gui.browse_btns{k} results in a similar behaviour.

As the object is a cell array, you need to index it with {}, but from what you saying, it doesn't work either. Does it change anything if you do an assignment instead:

x = gui.browse_btns{k}

x

Michael.