trying to get current point on a patch in the axes

Hi I wrote the next code:

set(worldAxes,'ButtonDownFcn',@mouseCB5); 

 % using this line I call the next function (worldAxes is the name i gave to my axes

 function [] = mouseCB5 (hObject,event)

    XY1 = get(hObject,'CurrentPoint');
    xPosition = XY1(1,1);
    yPosition = XY1(1,2);
    fprintf('x=%f Y=%f \n',xPosition,yPosition)
   end

what I want is whenever i press the left button of the mouse somewhere in the axes area, I will get the position of the cursor in the axes.

when the cursor is somewhere on an empty place in the axes area, every thing is fine.

however ,once the cursor is over a patch object (a square) I do not get the current position

it just wouldn't work

Answer 1

[Geoff Hayes]

Ehud - I think that what you want to do is to attach this callback to both your axes (like you are doing now) and to the patch object. Suppose we have the following code to create the patch

 figure;
 t      = 0:pi/5:2*pi;
 hPatch = patch(sin(t),cos(t),'y');
 axis equal;

which will give us a yellow decagon. As before we assign the callback to the axes and (now) to the patch object too

 set(gca,'ButtonDownFcn',@mouseCB5); 
 set(hPatch,'ButtonDownFcn',@mouseCB5);

In the above, we use gca to get the handle to the current axes. Now if we were to run your code, it would work when we click outside of the patch but will crash when we click within it because a patch object doesn't have a current point property like the axes. So we have to adjust your callback to handle whether you are clicking within a patch object or the axes

 function [] = mouseCB5 (hObject,event)

    % get the type of object
    type = get(hObject,'Type');

    if strcmpi(type,'axes')
        XY1 = get(hObject,'CurrentPoint');
    elseif strcmpi(type,'patch')
        XY1 = get(get(hObject,'Parent'),'CurrentPoint');
    else
        fprintf('unhandled object type!\n');
        return;
    end

    xPosition = XY1(1,1);
    yPosition = XY1(1,2);
    fprintf('x=%f Y=%f \n',xPosition,yPosition)

 end

Note how we get the type of the object being clicked. If it is the axes then we do as before and get the current point. If the type of object being clicked is the patch object, then we get its parent (which is the axes) and grab the parent/axes current point.

Try the above and see what happens!

[Harald Hentschke]

Works, perfect! Best solution if you want to avoid resorting to ginput or the data cursors