Need to extract data and exit function - my function never ends

I have a function which allows me to draw a line over top of a current figure. The function begins by plotting a point and then continuously updates a second point to draw a dynamic line which leads to the current mouse location - which then terminates if the user right clicks. My problem is that when I run this function within another script, that script skips over the function before it finishes - in fact I don't think the function is able to end the way I have it written, but I'm still relatively novice at MATLAB and can't figure out how to fix my code for this problem. I'm also extracting the information for the line by using getappdata and setappdata, which probably isn't the best way to do it. Any help would be greatly appreciated, Thanks.

%% ---------------------------------------------------------

function [x,y] = junk

% axis([0 10 0 10])
hold on
f=gcf;
[x,y] = ginput(1);
hl = line(x,y);
ah = gca;
set(ah, 'DrawMode', 'fast');
set(f,'WindowButtonMotionFcn',@movingLine);

      function [xdat,ydat] = movingLine(src,~)            
           [xn,yn] = disp_point(ah);                     
           xdat = [x,xn];                                    
           ydat = [y,yn];                                     
           set(hl,'XData',xdat,'YData',ydat);                 
           set(f,'WindowButtonDownFcn', @outputLines)
      function [xdat,ydat] = outputLines(src,evnt)
          if strcmp(get(src,'SelectionType'),'alt')      
              xdat = [x,xn];
              ydat = [y,yn];
              set(hl,'Xdata',xdat,'Ydata',ydat)
              setappdata(src, 'hLine', hl);
              set(f, 'WindowButtonDownFcn','')
              set(f, 'WindowButtonMotionFcn','')
          end

      end
      function [x,y] = disp_point(ah)                             
        cp = get(ah,'CurrentPoint');                                   
        x = cp(1,1);y = cp(1,2);                                      
      end
  end

Answer 1

After your line

set(f,'WindowButtonMotionFcn',@movingLine);

add

uiwait(f, 'WindowButtonMotionFcn')

This tells it to wait until f's WindowButtonMotionFcn property changes, which is something that you do in the callback when you got the data you need.

I get an error when I do this, the error is:

"??? Error using ==> uiwait at 57
Second input must be numeric"

Do I need to delve deeper into the handles and be more specific about the location of 'WindowButtonMotionFcn' and that it changes? But what you've said makes sense to me - I'm just not sure how to properly use uiwait, and the documentation for it wasn't much help.

Walter may have meant the waitfor function?

Yup, worked perfectly. Thanks you guys!

Darn, and I even had the waitfor() documentation open when I mis-typed that!