How to update date and time in matlab gui - matlab

Question

function demo1()
H.f = figure('Name','DEMO1');
set(H.f,'Units','Pixels','Position',get(0,'ScreenSize'));% adjust figure size as per the screen size
H.pb1 = uicontrol('style','push',...
'units','pixels',...
'position',[400 800 280 30],...
'fontsize',14,...
'string', datestr(now)); % datestr(now) is used to get current date and time
end
how i can get the real time clock in gui

Answer 1

This is not really an easy task to perform and you may want to think about your design. This could be wrapped in a class, but not necessarily. In case you do not want to do this you may be able to modify the underlying Java objects, but that seems to be overworking this. I have instead structured this in a more C-style manner with placing all data in a struct and writing functions taking the struct as an argument. However, since matlab does not support passing memory locations you need to return the struct after modifying it.
I have chosen to use a timer object for this. You need to store the timer object somewhere since it needs to be deleted when you are not using it anymore. Further, I have added some code for using a start function and stop function as well. For the timer object. This for seeing that the object actually gets finished during development phase. This is not needed for the final project. Further, you may want to handle the case where the window is closed. This will cause the current implementation to crash since the timer is independent of the figure and does not stop when the figure is closed. You probably want to call stop_timer on closing the figure. Anyway here is the code:
function test()
h.f = figure('Name','DEMO1');
set(h.f,'Units','Pixels','Position',get(0,'ScreenSize'));% adjust figure size as per the screen size
h.pb1 = uicontrol('style','push',...
'units','pixels',...
'position',[400 800 280 30],...
'fontsize',14,...
'string', datestr(now)); % datestr(now) is used to get current date and time
h = start_clock(h);
pause on;
pause(15);
pause off;
h = stop_clock(h);
end
function obj = start_clock(obj)
%TasksToExecute calls the timer object N times
t = timer('StartDelay', 0, 'Period', 1,... % 'TasksToExecute', inf, ...
'ExecutionMode', 'fixedRate');
t.StartFcn = {#my_callback_fcn, 'My start message'};
t.StopFcn = { #my_callback_fcn, 'My stop message'};
t.TimerFcn = {#set_time, obj};
obj.t = t;
start(obj.t);
end
function obj = stop_clock(obj)
stop(obj.t);
delete(obj.t);
end
function set_time(obj, event, arg)
arg.pb1.String = datestr(now);
end
function my_callback_fcn(obj, event, arg)
txt1 = ' event occurred at ';
txt2 = arg;
event_type = event.Type;
event_time = datestr(event.Data.time);
msg = [event_type txt1 event_time];
disp(msg)
disp(txt2)
end