Close GUI menu after discrete time period or user keystroke

I'm making an n-back test using MATLAB 7.10.0, and I need to acquire either or both keystrokes 'A' and 'S' from the user within 2.5s. If 2.5s passes without any keystrokes pressed, then the program will set the response to 0.

Simple algorithm: 1) Ask user for data 2) Start timer, t = 0s 3) Acquire keystrokes from the user and store ASCII equivalent as answer. 4) End timer, t = 2.5s 5) If no keystrokes, then answer = 0.

I've looked online and through the Product Documentation, but nothing is coming up -- although I'm sure it's possible.

Thanks in advance.

EDIT: In the same vein, rather than keystrokes as the input, I'd actually like to use the menu function, with three buttons: 'A', 'S', and 'A+S'. But the problem is closing the menu after a discrete time period.

WHAT I REALLY NEED TO KNOW: 1) Time the input period 2) Acquire specific keystroke 3) Close the menu using code -- 'close' fn doesn't work with menu.

Answer 1

[Oleg Komarov]

EDITED

% Create timer object that stops after 2.5 seconds

f = 'h = findobj(0,''Name'',''GETKEY''); if h; uiresume(h); end';
t = timer('StartDelay',2.5,'TasksToExecute',1,'TimerFcn',f);

% Accepted keys are 'A'or 'a' for rist position and 'S' or 's' for second position

keys = false(1,2);
vec  = {'A' 'S'};

% Start timer

start(t)

% Run till timer executes

while strcmp(get(t,'Running'),'on')
    % Acquire keystroke
    key = getkey;
    % Check if already pressed
    keys = keys | strcmpi(key,vec);
    % If both pressed before the timer stops exit the loop
    if all(keys)
        break
    end
end
disp(keys)

Link to getkey. You may want to make it invisible.

[Robert]

Thank you for the help. That is very good. Is it possible to close the menu function with code provided that someone hasn't clicked the GUI button?

[Robert]

Actually, could you explain what you're doing here?

keys = keys | ismembc([65 83 97 115], key);

It yields an error message when executed.

[Robert]

Also, getkey prevents the loop from closing until a key is pressed even though the timer has stopped. Any ideas on how to fix this problem?

[Walter Roberson]

ismembc() is an internal routine used by ismember(); some people prefer to code ismembc() because it is faster, whereas unless there is strong reason I prefer to code ismember() for clarity.

I think Oleg has miscoded the call: getkey() is going to be a single value, but ismembc() is going to return a logical array as long as its first argument, 4, which is not going to work when or'd (|) against the array false(1,2) used to initialize keys.

[Oleg Komarov]

Yeah, I just noticed when writing that it could be case insensitive and modified inappropriately. Now it should be fine for the dimension mismatch. Haven't looked yet into getkey issue.

[Walter Roberson]

Oleg, did you perhaps want strcmpi(key, {'a', 's'}) instead of 'a' and 'b' ?

[Oleg Komarov]

@Walter: Thanks, corrected.

@Robert: now my edited script takes care of closing getkey (no modification needed).

[Robert]

Oleg, your updated code is nearly perfect: strcmpi(key,vec) should be strcmpi(char(key),vec). If you make that change, it works like a charm.

[Robert]

When I run the above code in the Command Window it executes perfectly. But when I try executing it from an .m file script, I get the error:

??? Error using ==> subsindex

Function 'subsindex' is not defined for values of class

'timer'.

When I try executing it as a function keys = timedKey, I get the error:

??? Error while evaluating TimerFcn for timer 'timer-62'

Undefined function or variable 't'.

??? Error using ==> delete

Invalid handle object.

Error in ==> getkey at 73

delete(fh) ;

Error in ==> timedKeys at 21

key = getkey;

[Robert]

Let me clarify... I'm trying to write this code to a function, which -- in the main script -- will be looped for i = 1:n. But for some reason Matlab doesn't recognize 't' although it is defined. This causes the program to be caught in the loop until a key is pressed. Normally I'd figure it out on my own, but I'm not familiar with the timer function, and what I've tried has been unsuccessful.

[Oleg Komarov]

I'll try to test it within a function foo and come back to you.

[Oleg Komarov]

I erased stop(t) from f.

[Robert]

Thank you, friend. That works great!

[Oleg Komarov]

If yout hink my answer solved your problem please accept it.

Answer 2

[Robert]

I solved the problem by making a function getkey2, which combines Oleg's suggestion, my code, and the getkey function. Here it is if anyone is interested.

function ch = getkey2(m)
if nargin == 1,
    if strcmp(lower(m),'non-ascii'),
        callstr = ['set(gcbf,''Userdata'',get(gcbf,''Currentkey'')) ; uiresume '] ;
    else
        error('Argument should be the string ''non-ascii''') ;
    end
else
    callstr = ['set(gcbf,''Userdata'',double(get(gcbf,''Currentcharacter''))) ; uiresume '] ;
end

% Set up the figure
% May be the position property  should be individually tweaked to avoid visibility
fh = figure('keypressfcn',callstr, ...
    'windowstyle','modal',...
    'position',[0 0 1 1],...
    'Name','GETKEY', ...
    'userdata','timeout') ;
try
  % Create timer object that stops after 2.5 seconds

    t = timer('StartDelay',0.5,'TasksToExecute',1,'TimerFcn','stop(t)');

    % Accepted keys are 'ASas' ASCII values [65 83 97 115]

    keys = zeros(1,2);

    % Start timer

    start(t)
    % Run till timer executes
    vec = [65 83];
    while strcmp(get(t,'Running'),'on')
        ch = get(fh,'Userdata') ;
    end
    if isempty(ch),
        ch = NaN ;
    end
catch
    % Something went wrong, return and empty matrix.
    ch = [] ;
end

delete(fh) ;

[Robert]

Actually this doesn't work yet... Any other ideas?

[Walter Roberson]

What do you do with vec() ?

You get values and assign them in to ch, but as long as the timer is running, you risk overwriting ch with the next value read.

[Oleg Komarov]

Recheck my script, I have modified it to close getkey if nothing happens in x seconds and fixed the other error.

It is case insensitive, wether you press 'A' or 'a'. But you can use strcmp instead of strcmpi to make it case sensitive.

[Robert]

vec() was a lazy residual part of earlier code. At some point, getkey2 worked, but now it's not. I'll look at Oleg's code soon, as I'm sure that's the most concise option.

[Oleg Komarov]

Fixing one last thing, if you have typed both A and S it exits the loop and when the timer stops later it calls uiresume but at that point no getkey figure exists thus it creates and empty one.

[Oleg Komarov]

Ok now it should work properly.