How do I put a waitbar in an existing figure in MATLAB 7.8 (R2009a)?

I would like to put a waitbar in an existing figure, such as a GUI figure, instead of having it appear in a separate window.

[Aurelien Queffurust]

I would really appreciate to see this question/answer as a Technical Note on the technical support web site.

Thanks,

Aurélien

Answer 1

[Doug Hull]

To put a waitbar in an existing figure, you must transfer all the elements of a waitbar out of the default separate figure window and put it them on the existing figure.

Specifically, you must assign the parent of all these elements to be a handle to your existing figure rather than the handle to the separate figure. See the following code as an example of how to do this:

%grabs a handle 'f' to a figure. 
f = figure;  

% Creates a WAITBAR in a new figure (by default) 
h = waitbar(0,'Please wait...'); %   
% The child of the waitbar is an axes object.  Grab the axes 
% object 'c' and set its parent to be your figure f so that it now 
% resides on figure f rather than on the old default figure. 

c = get(h,'Children'); 
set(c,'Parent',f);  % Set the position of the WAITBAR on your figure 
set(c,'Units','Normalized','Position',[.5 .5 .3 .05]);  

% Close the default figure 
close(h);  

% The above steps only need to occur once to place the waitbar on the figure. 
% Now when you go to use the WAITBAR you can just call the waitbar with two 
% inputs: waitbar(x,h) where x is how much of the bar you want filled and f 
% is the handle to your figure. 

steps = 1000; 

for step = 1:steps     
  % computations take place here     
  waitbar(step / steps,f)     
  pause(.01) 
end

[Aurelien Queffurust]

Hi Dough,

This code works fine in R2010b but fails in R2011a :

It returns the error message :

??? Error using ==> waitbar>extractHandles at 280

Couldn't find waitbar handles.

Error in ==> waitbar at 89

handles = extractHandles(whichbar);

Error in ==> Untitled at 25

waitbar(step / steps,f)

The waitbar code has changed in 11a .

[Walter Roberson]

I do not have 2011a to look at the code with, but I would _speculate_ that it might be necessary to set the figure Tag to 'TMWWaitbar'

Answer 2

[Jelle]

Hello,

I have a problem with this function when i want to update the message corresponding to the waitbar. When the waitbar has an own figure this command works fine:

waitbar(x,figurehandle,'updated message')

But when figurehandle corresponds to the figure where the waitbar is placed in, then the update message function does not work anymore. This error is shown:

??? Error using ==> waitbar at 106
Improper arguments for waitbar.

Caused by:
    Error using ==> set
    Conversion to double from cell is not possible.

How can I solve this problem?

Kind regards,

Jelle

[Walter Roberson]

I just looked at the waitbar code as of 2008b, and it is definitely not designed for the possibility that the figure might have a line, patch, or axes other than those that belong to the waitbar. In narrow situations, though, the crash wouldn't happen until it went to update the message.