Matlab figure 'age'

Question

Here's a question for 'experts in the less documented part of Matlab': is there a (undocumented?) way to determine how long a figure has been open for (i.e. the 'age' of the figure)?

figure; spy;
myfig=gcf;
age=get_age() %shoud output age of figure in some format

Answer 1

You can use the following mechanism:

First, create a small Matlab function as follows, that attaches the CreationTime property to a figure:

function setCreationTime(hFig,varargin)
   hProp = addprop(hFig,'CreationTime');
   hFig.CreationTime = now;
   hProp.SetAccess = 'private'; %make property read-only after setting its initial value

   hProp = addprop(hFig,'Age');
   hProp.GetMethod = @(h,e) etime(datevec(hFig.CreationTime), clock); %compute on-the-fly
   hProp.SetAccess = 'private'; %make property read-only
end

Now assign this function as the default CreateFcn callback function for all new figures from now on:

set(0,'DefaultFigureCreateFcn',@setCreationTime)

That's it - you're done!

For example:

>> newFig = figure;
>> newFig.CreationTime
ans =
      737096.613706748

>> ageInDays = now - newFig.CreationTime
ageInDays = 
       0.01625078368466347
>> ageDuration = duration(ageInDays*24,0,0)
ageDuration = 
  duration
   00:23:24
>> ageString = datestr(ageInDays, 'HH:MM:SS.FFF')
ageString = 
    '00:23:24.068'

>> ageInSecs = newFig.Age
ageInSecs =
    1404.067710354923808