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Daniel
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'FocusGainedCallback' doesn't work once figure has axes 2015b

Asked by Daniel
on 18 May 2016
Latest activity Commented on by Arabarra on 1 Mar 2017
I am using this article by Yair to add a 'FocusGainedCallback' onto a MATLAB figure.
The following code works correctly.
plotFigHandle = figure();
jFrame = get(plotFigHandle,'JavaFrame');
jAxis = jFrame.getAxisComponent;
set(jAxis.getComponent(0),'FocusGainedCallback', @(caller, event) disp('This works great'));
However, as soon as I add a MATLAB axis using the axes() command, the functionality stops working.
plotFigHandle = figure();
% adding axes will make this code not function
axes('Parent',plotFigHandle);
jFrame = get(plotFigHandle,'JavaFrame');
jAxis = jFrame.getAxisComponent;
set(jAxis.getComponent(0),'FocusGainedCallback', @(caller, event) disp('This works great'));
My question is how to I keep the FocusGainedCallback even after I add an axes to my MATLAB figure?

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1 Answer

Answer by Arabarra on 16 Feb 2017

Hi Fabio, the code below (I've pasted it to the Yair's article you mention) did work for me in R2016b, but it's mainly created by trial and error. At least it works if a single axis is defined in the figure. In any case, if you have come across a better solution for the general case, please let me know.
Daniel
hFig = figure;
h = axes(hFig);
plot(rand(100,1),'Parent',h);
jFig = get(hFig, 'JavaFrame');
jAxis = jFig.getAxisComponent;
n = jAxis.getComponentCount;
disp(n);
jAxis.grabFocus();
drawnow; % will not work without this
n = jAxis.getComponentCount;
disp(n);
set(jAxis.getComponent(n-1),'FocusGainedCallback',@(x,y)disp('in focus'));
set(jAxis.getComponent(n-1),'FocusLostCallback',@(x,y)disp('... out'));

  1 Comment

damn... just saw that it only works when the figure gains focus through direct interaction with it. If you click on the axis, the figure does gain focus, but the callback doesn't get triggered.

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