@Dongze - is there a reason why you want to stop the timer via a double-click of a button that says "Start Countdown"? Perhaps you can use a different button to pause/stop the timer. If though you really want to do this with a double-click, you could try the following
function [] = pb_call(varargin)
% not keen on using a persistent/static but...
persistent firstButtonPressTime
S = varargin{3};
if (strcmpi(S.tmr.Running,'on'))
% if timer is running, then save the current time or compare against
% the last saved time
if isempty(firstButtonPressTime)
firstButtonPressTime = now;
else
currentTime = now;
% determine the delta in seconds
xDeltaInSeconds = (currentTime - firstButtonPressTime) * 24 * 60 * 60;
% stop timer if two consecutive button presses are less than 0.5
% seconds apart
if xDeltaInSeconds < 0.5
firstButtonPressTime = [];
stop(S.tmr);
else
firstButtonPressTime = currentTime;
end
end
else
set(S.tmr,'TasksToExecute',str2double(get(S.tx,'string')))
start(S.tmr);
end
