Hi Irene,
As it is now, the MouseTracker element only detects mouse movement, it does not detect mouse clicks at all. The content of the corresponding callback command is therefore run only when the cursor moves, and so your x/y variables are only updated on mouse movement, not on mouse click.
Which means that what you log upon selection is not technically the mouse coordinates when the click happens but the mouse coordinates resulting from the latest movement. Because there typically is no mouse movement whatsoever with touchscreen devices (unless a mouse is plugged in, of course), I don’t understand how your x/y variables can ever be instantiated at all. Maybe the slight finger swipe that can come with tapping the screen is interpreted as a mouse movement…
As I said, I don’t know what is happening exactly, so I don’t know how the different problems can be related. What I can say, however, is that the code from my previous message will effectively update clickx and clicky upon click, and no longer upon movement.
I’m sorry, I wish I could give your more insight into this problem
Jeremy