MATLAB: Pause program and await keypress

Question

I am writing a program in which at some point a graph is plotted and displayed on screen. The user then needs to press \'y\' or \'n\' to accept or reject the graph. My current s

Answer 1

You don't want to use waitforbuttonpress since it locks the figure gui (no zooming, panning etc).

pause can cause the command window to steal the focus from the figure.

The solution I find to work best is to open the figure with a null keyPressFcn in order to avoid focus problems:

figure('KeyPressFcn',@(obj,evt) 0);

and then wait for CurrentCharacter property change:

waitfor(gcf,'CurrentCharacter');
curChar=uint8(get(gcf,'CurrentCharacter'));

Answer 2

The waitforbuttonpress command is good but is triggered by either a mouse click or a key press. If you want it to trigger only from a key press, you can use the following hack:

while ~waitforbuttonpress
end

Answer 3

Why not using waitforbuttonpress instead?

Documentation: http://www.mathworks.fr/help/techdoc/ref/waitforbuttonpress.html

Answer 4

Wait for buttonpress opens up a figure, which may be unwanted. Use instead

pause('on');
pause;

which lets the user pause until a key is pressed.

Answer 5

Wait for key press or mouse-button click:

Example:

w = waitforbuttonpress;
if w == 0
    disp('Button click')
else
    disp('Key press')
end

for more information visit: http://www.mathworks.com/help/matlab/ref/waitforbuttonpress.html

Answer 6

I'd use the input function:

a = input('Accept this graph (y/n)? ','s')

if strcmpi(a,'y')
    ...
else
    ...
end

Although admittedly it requires two keypresses (y then Enter) rather the one.