How do I prevent two simultaneous key presses from tabbing away from my GUI?

I have a gui that allows people to listen to a sentence and then type what they think the sentence said. The problem is, if someone is typing too fast and accidentally presses two keys at the same time, instead of putting both characters in the edit box, it tabs out and goes to the command line in MatLab. How do I prevent this from happening? I'm using the following code to pause while the person types their response until "enter" gets pressed: Any ideas would be helpful

    currkey=0;
    % do not move on until enter key is pressed
    while currkey~=13   %13 is the ascii number for the return character
        pause; % wait for a keypress
        currChar=get(gcf,'CurrentCharacter'); 
        currkey = double(currChar);
        if isempty(currkey)
            currkey=0;
        else
        end
    end

Any ideas?

Answer 1

[Walter Roberson]

Use a WindowKeyPressFcn callback in the figure instead.

[Shae Morgan]

Tips on how to do this? I've never used WindowKeyPressFcn before...also, I am using GUIDE, so will that mess up my handles structure? I'm fairly new to MatLab so any help is appreciated!

Answer 2

[valdal]

With KeyPressFcn and guidata :

 h = uicontrol(...);
 escape = false
 guidata(h,escape)
 set(h, 'KeyPressFcn', @key_pressed);
 while ~escape 
    pause(0.01);
    escape = guidata(h)
 end

 function key_pressed(h, e)
    if strcmp(e.Key, 'return') 
       guidata(h, true)
    end
 end

[Walter Roberson]

Warning: using guidata() like that will destroy your handles structure if you are using GUIDE.