cla reset stops UIAxesButtonDown from working

Hello. I have a UIAxes that I plot on and I want to manually be able to add text where ever I click on the graph. I am using the following to do this UIAxesButtonDown(app, event) defined as:

ax=app.UIAxes;              
%set(ax, 'hittest', 'off');
cursorPos = ax.CurrentPoint(1,1:2);
app.curX=(cursorPos(1));                   % Current Mouse Coords defined as a public property
app.curY=(cursorPos(2));                   % Current Mouse Coords defined as a public property

This works and indeed after I have plotted a graph Im able to place the text where I click on the graph. (see the function myAddText below)

However, if I clear the UIAxes by

Cla(ax,’reset’)

Then this is where it stops working. I have played about with hittest etc and still no luck.

If I use the following instead to clear the UIAxes, it all works again

ax=app.UIAxes;
b=ax.Children
n=numel(b)
for i=1:n
    delete(b(i))             
end

So my questions are:

1: What is it with cla 'reset' that stops it working and how can I correct it

2: Is my alternative way of clearing the UIAxes good for removing all graphics objects on the UIAxes so I actually don't need cla 'reset;

function  myAddText(app)             
ax=app.UIAxes; 
x=app.curX;% SavedMouse Coords
y=app.curY; % SavedMouse Coords           
txt=app.AddTitleEditField.Value;
txt=horzcat('\leftarrow',txt);
text(ax,x,y,txt,'Color',cl,'FontSize',12,'Interpreter', 'tex','HorizontalAlignment','left','VerticalAlignment','middle');

Answer 1

[Cameron]

cla(ax,'reset')

Resets the ButtonDownFcn callback. I haven't tested this out, but can you just use this:

myFun = ax.ButtonDownFcn;
cla(ax,'reset')
ax.ButtonDownFcn = myFun;

[Jason]

Yes that works, thanks.

Can you comment on my alternative way to do it.

[Image Analyst]

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Answer 2

[Image Analyst]

If yoiu just want to clear the axes without disconnecting your callback function why not call cla without 'reset':

cla(app.UIAxes);

[Jason]

Hi I.A. Well I guess its historic, Im usually working with images, and load up upto 500 at a time - and repeat this say 20 times throught the day. When I used to exclude the 'reset' option, I believe I had some kind of memory leak with something being left on the axes everytime. It ended up with my matlab session freezing and needed to be closed. When I started to sue the 'reset' option I never had any problems.