Continuous tracking of 'LocationChanged' event of figure

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Hi,
I am trying to glue a (main) figure 1 to a (following) figure 2, so that when the user manually moves the main figure, the following figure moves with it. The intended effect is that they are side by side at every moment. By now, my strategy is to use a listener that listens to the 'LocationChanged' event of main figure and replaces figure 2 according to the changes notified by figure 1. The problem is that 'LocationChanged' seems to get notified only after the user has stopped moving the main figure. At this moment, figure 2 just jumps to the side of the main figure.... is there a way to ensure that the event 'LocationChanged' is issued continuously while the figure is being moved?

Accepted Answer

Sean de Wolski
Sean de Wolski on 28 Mar 2018
It seems to be firing and responding correctly for me (18a, Windows) as I drag fig1 around.
posOffset = [500 0]; % positional offset
fig1 = figure('Units','pixels','Position',[140 140 400 400]);
fig2 = figure('Units','pixels','Position',[fig1.Position(1:2)+posOffset 400 400]);
listener1 = event.listener(fig1, 'LocationChanged', @(~,~)set(fig2, 'Position', fig1.Position+[posOffset 0 0]));
  4 Comments
Matt J
Matt J on 18 May 2021
Strange, though, that the events() command lists such a small subset of the events:
>> events(gcf)
Events for class matlab.ui.Figure:
ObjectBeingDestroyed
PropertyAdded
PropertyRemoved
That would seem to mean that 'LocationChanged' and others are undocumented and aren't to be relied upon for backward compatibility.

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More Answers (1)

Kai Domhardt
Kai Domhardt on 27 Mar 2018
Edited: Kai Domhardt on 28 Mar 2018
If you are just trying to display two plot side by side the subplot function is what you are looking for, without having to track figure locations.
If you really want to move the individual figure you can achieve this with:
function window_motion_test
mainFig = figure();
pause(0.2) % Wait for the figure construction complete.
jFig = get(main_fig, 'JavaFrame'); % get JavaFrame. You might see some warnings.
jWindow = jFig.fHG2Client.getWindow; % before 2011a it could be `jFig.fFigureClient.getWindow`. Sorry I cannot test.
jbh = handle(jWindow,'CallbackProperties'); % Prevent memory leak
set(jbh,'ComponentMovedCallback',{@windowMoved});
followFig = figure();
function windowMoved(src,callbackdata)
jComponent = callbackdata.getComponent;
mainFig_pos = jComponent.getLocation;
mainFig_size = jComponent.getSize;
followFig_width = followFig.Position(3);
followFig_height = followFig.Position(4);
followFig.Position = [mainFig_pos.x + mainFig_size.width,...
mainFig_pos.getY,...
followFig_width,...
followFig_height];
%followFig lower left corner is now attached to
%mainFig lower right corner
end
end
The important part comes from this question on stackoverflow, which in turn references this entry on undocumentedmatlab.
  4 Comments
Arabarra
Arabarra on 28 Mar 2018
well, I just did. It definitively doesn't work in my laptop with any matlab version (2017b,2018a), so maybe it is something system dependent (I'm using OS X Yosemite)... I'll try on windows or linux machines when I have the occasion...

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