Appdesigner: Using axes toolbar to zoom and pan while using drawpolyline without getting new points

Currently I am building an App in AppDesigner where I want the user to be able to draw a line on an image in an UIAxes while being able to zoom in and out and pan on the image. For the interactivity with the image I am so far relying on the standard Matlab axes toolbar. Sadly after having started a drawpolyline, every click on the image to zoom in gets me a new point for the polyline and every click to do a movement of the image also gives me a new point for the polyline.

When I try the same in Matlab with a figure it works as intended. So while using the axes toolbar during drawing a polyline no new points get added. But in AppDesigner sadly the behaviour is different. Every click from the axis toolbar gives me a new point on the polyline.

Matlab code (intended behaviour):

image(peaks,'CDataMapping','scaled','Interpolation','bilinear');
b=drawpolyline;

AppDesigner code (unintended behaviour):

function Button_4Pushed(app, event)
    image(app.UIAxes_2,peaks,'CDataMapping','scaled','Interpolation','bilinear');
end
function Button2Pushed(app, event)
    b=drawpolyline(app.UIAxes_2);
end

How can I prevent in AppDesigner new points being added to a polyline while I use the axes toolbar?

Answer 1

[Gayathri]

Hi @Matthias La,

I understand that when trying to zoom the image or use pan in between drawing a polyline in MATLAB R2020b version, you are getting extra points on the polyline which is not desired. I was able to reproduce the issue at my end.

To resolve it, consider upgrading to MATLAB R2022a or a later version, where this issue has been addressed. In these versions, you can zoom the image without inadvertently adding extra points to the polyline.

Hope you find this information helpful.