Getting user input in a time interval in matlab

Question

I'm trying to write a script which gets user input for a specified time interval. I wrote a simple script as below:

timeEllapsed=0;
Count=0;
while 1
  tic
  input('press enter');
  timeEllapsed=timeEllapsed+toc;
  Count=Count+1;
  if(timeEllapsed>5)
    break;
  end
end
disp ('result is:') 
disp(Count)

This script gets user input, when the time between first and last input less than 5 seconds. But this script waits indefinitely if user doesn't enter any input as expected. Is there any way to get user input for exactly given time interval? Thanks in advance!

Answer 1

Source : http://www.mathworks.com/matlabcentral/answers/96229-how-can-i-have-a-dialog-box-or-user-prompt-with-a-time-out-period

function varargout = timeoutDlg(dlg, delay, varargin)
% Dialog function with timeout property
% dlg is a handle to the dialog function to be called
% delay is the length of the delay in seconds
% other input arguments as required by the dialog
% EXAMPLE FUNCTION-CALL
% To display an input dialog box (REFER MATLAB HELP DOC) with a 
% timeout = 6 second say, the function call would be:
%
% [matrix_size_value, colormap_string] = timeoutdlg(@inputdlg, 6, ...
%                                {'Enter matrix size:','Enter colormap name:'}, ...
%                                'Input for peaks function', 1, {'20','hsv'})
% Setup a timer to close the dialog in a moment
f1 = findall(0, 'Type', 'figures');
t = timer('TimerFcn', {@closeit f1}, 'StartDelay', delay);
start(t);
% Call the dialog
retvals = dlg(varargin{:});
if numel(retvals) == nargout
      varargout = retvals(:);
else
      varargout = cell(1, nargout);
end
% Delete the timer
if strcmp(t.Running, 'on')
       stop(t);
end
delete(t);
function closeit(src, event, f1)
disp('Time out!');
f2 = findall(0, 'Type', 'figure');
fnew = setdiff(f2, f1);
if ishandle(fnew);
      close(fnew);
end

Answer 2

This is a self contained solution...

function output = timeinput(t,default_string)
% TIMEINPUT
% Input arguments:  
% t - time delay
% default_string - string which is returned if nothing is entered
%
% Examples:
% If a string is expected
%   x = timeinput(20,'no input')
% If a number is expected
%   x = str2num(timeinput(20,'1'))
%    

if nargin == 1
   default_string = '';
end
% Creating a figure
h = figure('CloseRequestFcn','','Position',[500 500 200 50],'MenuBar','none',...
    'NumberTitle','off','Name','Please insert...');
% Creating an Edit field
hedit = uicontrol('style','edit','Units','pixels','Position',[10 15 180 20],'callback','uiresume','string',default_string);
% Defining a Timer object
T = timer('Name','mm', ...
   'TimerFcn','uiresume', ...
   'StartDelay',t, ...
   'ExecutionMode','singleShot');
% Starting the timer
start(T)
uiwait(h)
% Defining the return value
output = get(hedit,'String');
% Deleting the figure
delete(h)
% Stopping and Deleting the timer
stop(T)
delete(T)

To run a 5 seconds timeout input, just write:

x = timeinput(5,'no input')

https://www.mathworks.com/matlabcentral/answers/95301-how-can-i-implement-a-timer-dependent-input-request-in-matlab