Pan object support for uiaxes for callback functionality following that of "Zoom" (ActionPreCallback / ActionPostCallback)

I am working on an app component that requires ActionPreCallback and ActionPostCallback functions for both zoom and pan.

Since this project is based on an old GUIDE application, I need at least similar functionality that Axes provides with uiaxes.

In the original implementation using Axes, the callbacks can be assigned using zoom and pan objects following (Enable pan mode - MATLAB (mathworks.com), Enable zoom mode - MATLAB (mathworks.com)). However, according to the documentation under the 2023a version history notes, when using uiaxes, a zoom or pan object is not returned.

Following this thread (Cannot get zoom post-callback to work on UIAxes - MATLAB Answers - MATLAB Central (mathworks.com)), I am able to set the callback for zoom because a zoom object is returned, contrary to the documentation. On the other hand, the equivalent approach with pan returns the following error when calling "hp = pan(app.UIAxes)":

"Error using uigetmodemanager

First argument must be a figure handle

Error in getuimode (line 12)

hManager = uigetmodemanager(hFig);

Error in pan>locGetMode (line 347)

hMode = getuimode(hFig,'Exploration.Pan');

Error in pan>locGetObj (line 277)

hMode = locGetMode(hFig);

Error in pan (line 229)

out = locGetObj(arg1);"

Attempted solutions:

• I have tried adding a value changed callback to app.UIAxes.XAxis.LimitsChangedFcn, but this does not provide the necessary pre and post action callbacks which I need for this project.

My question is: how can I get pre and post action callback functionality for panning using a uiaxes?

Answer 1

[Githin George]

Hello Josiah,

It is my understanding that you are trying to replicate the “ActionPreCallback” and “ActionPostCallback” functionality of “pan” action for a MATLAB “uiaxes” like that of a MATLAB “axis” object.

You can use the following workaround to add a listener to the “PreSet” and “PostSet” event for properties like “XLim” or “YLim” of the “uiaxes”. Since these properties are set during a “pan” action, you will be able to implement the logic within the listener functions. An example code is provided below.

function startupFcn(app) 
    addlistener(app.UIAxes, 'YLim', 'PostSet', @(src,evnt)postFun(src,evnt,app)); 
    addlistener(app.UIAxes, 'YLim', 'PreSet', @(src,evnt)preFun(src,evnt,app)); 
end 

Note that the above workaround requires the listener functions to be external to the application.

Please refer to the documentation link for “addlistener” function below.

https://www.mathworks.com/help/matlab/ref/handle.addlistener.html

I hope this helps.