Start/stop button Matlab App

I have an app that outputs a predetermined set of data in the background and plots the inputs at the same time. The program begins when I press the start button. The 'start' button then becomes a 'stop' button. I want the button to display 'start' again when all the data has been outputted. How do I do this?

I thought about pausing for the amount of time that the data takes to run, but that would that stop the program from plotting?

% Button pushed function: STARTButton

function STARTButtonPushed(app, event)

if app.ButtonState==0

app.FileName = [num2str(app.LowV.Value),'-',num2str(app.HighV.Value), 'akV_',num2str(app.AMTFrequency.Value), 'Hz_', num2str(app.Fill.Value), 'ml',app.Filename.Value];

app.ButtonState=1;

app.STARTButton.Text = 'Stop';

app.File=fopen(app.FileName,'a');

fprintf(app.File,'%s\n','Time[s] Low voltage[kV] HASEL[kV] High voltage[kV] Force[N] Displacement[mm]');

% Charging

% trek voltage signals

lowV = (app.LowV.Value*1000/app.Amplification)*ones(5*app.SamplingRate,1);

highV = (app.HighV.Value*1000/app.Amplification)*ones(7*app.SamplingRate,1);

noV = 0*ones(app.SamplingRate,1);

trekV = [lowV; highV; noV];

% relay 1

Relay1on = 5*ones(4*app.SamplingRate,1);

Relay1off = 0*ones(9*app.SamplingRate,1);

Relay1 = [Relay1on; Relay1off];

% relay 2

Relay2on = 5*ones(11*app.SamplingRate,1);

Relay2off = 0*ones(2*app.SamplingRate,1);

Relay2 = [Relay2on; Relay2off];

% AMT signal

app.AMTtime = linspace(0,app.Cycles.Value/app.AMTFrequency.Value,app.SamplingRate*app.Cycles.Value/app.AMTFrequency.Value)';

AMTstart = app.MinForce.Value*ones(size(Relay2));

amplitude = (app.MinForce.Value - app.MaxForce.Value)/2;

offset = (app.MinForce.Value + app.MaxForce.Value)/2;

AMTon = (offset + amplitude*cos(2*pi*app.AMTFrequency.Value*app.AMTtime))/app.ForceConversion;

AMT = [AMTstart; AMTon];

Relay1 = [Relay1; zeros(size(AMTon))];

Relay2 = [Relay2; zeros(size(AMTon))];

trekV = [trekV; zeros(size(AMTon))];

queueOutputData(app.Session, [trekV,Relay1,Relay2,AMT]);

% zero everything

queueOutputData(app.Session, zeros(app.SamplingRate,4));

startBackground(app.Session);

%once this data has been outputted then I want the button to say 'stop'

else

app.ButtonState=0;

app.STARTButton.Text = 'Start';

stop(app.session)

% discharge capacitors

Relay1 = 5*ones(app.SamplingRate,1);

Relay2 = Relay1;

trekV = zeros(app.SamplingRate,1);

AMT = trekV;

queueOutputData(app.Session, [trekV,Relay1,Relay2,AMT]);

startBackground(app.session)

pause(2)

stop(app.Session);

pause(2)

fclose(app.File);

% delete(lh1)

end

[Thomas Satterly]

I think you either need some way of determining the state of your background application or pass along a callback method in the "startBackground" call that's called once it's finished. I would recommend a callback method, as continuously checking for the state from the caller is wasteful.