addlistener syntax not recognized in R2014b

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Matt J
Matt J on 18 Nov 2014
Answered: Ian Noell on 27 Nov 2014
I've just installed R2014b, and have been testing various pieces of my code library fearful of what the new Graphics System is going to break. One routine I have relies on a File Exchange submission with the following local function,
function localSetupPositionListener(hFig,imAxes)
% helper function to sets up listeners for resizing, so we can detect if
% we would need to change the fontsize
PostPositionListener = handle.listener(hFig,'ResizeEvent',...
{@localPostPositionListener,imAxes});
setappdata(hFig,'KenFigResizeListeners',PostPositionListener);
end
After running the MATLAB Graphics Updater app, this local function gets converted to the following,
function localSetupPositionListener(hFig,imAxes)
% helper function to sets up listeners for resizing, so we can detect if
% we would need to change the fontsize
PostPositionListener = addlistener(hFig,'SizeChanged',...
{@localPostPositionListener,imAxes});
setappdata(hFig,'KenFigResizeListeners',PostPositionListener);
end
But when I run the code, the line that has changed throws an error,
No method 'addlistener' with matching signature found for class 'matlab.ui.Figure'.
Error in TextZoomable>localSetupPositionListener (line 80)
PostPositionListener = addlistener(hFig,'SizeChanged',...
Error in TextZoomable (line 58)
localSetupPositionListener(hFig,hAx);
Any ideas why the error occurs and, as importantly, why the app doesn't catch it (so I can be on the lookout for other instances where it may fail)?
  2 Comments
Matt J
Matt J on 18 Nov 2014
Adam, yes I verified that the original version does not work in R2014b.

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Accepted Answer

matt dash
matt dash on 18 Nov 2014
Addlistener doesn't let you use the cell array syntax on the 3rd argument the way every other callback function works. You must specify a "bare" function handle for the 3rd argument.
  1 Comment
Matt J
Matt J on 18 Nov 2014
Thanks.
You must specify a "bare" function handle for the 3rd argument.
I think you mean it needs to be changed as follows?
PostPositionListener = addlistener(hFig,'SizeChanged',...
@(o,e) localPostPositionListener(o,e,imAxes) );

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More Answers (2)

Ian Noell
Ian Noell on 27 Nov 2014
As matt dash said, addlistener needs a function handle or an anonymous function for the callback. The cell array syntax was supported by handle.listener (although undocumented) but is not for event.listener/addlistener.
I have added a note to the message in the MATLAB Graphics Updater app and updated the submission. You will need to make manual changes to your code to update the callback.

Guillaume
Guillaume on 18 Nov 2014
Which version are you upgrading from?
Your old code gives me the same error in R2013b. The problem in either version is that addlistener / event.listener expects a function handle for the third argument, whereas you're passing a cell array, the purpose of which I'm not sure.
  1 Comment
Matt J
Matt J on 18 Nov 2014
Can't account for that, I'm afraid. The original version works fine for me in R2013b.

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