title: Picking (pick_event) the correct artist on tkinter canvas?
body: <p>I am trying to use the pick_event in matplotlib within the tkinter framework. I have a problem with picking the right artist on the plot. I have multiple annotated artist on the plots with arrows connecting the annotated points, and I am trying to move the annotations around because they overlap and are not readable. I can move them in some cases with mouse_motion without any issues. The problem is sometimes clicking an artist generates event from an earlier moved artist and then the older artist starts moving and I can see in my pick_event function that indeed the older artist was the one that generated the last event. Sometimes 3 artists produce events on clicking sometimes more, irrespective of their positions on the graph. How can I make sure to only move the artist which is clicked? I know their is a hierarchy in pick_event. <strong>Can somebody show me a snippet where annotations can be picked correctly?</strong> I assume when annotations are close by there can be a confusion as to which one is clicked but if the annotations are far away from each other they should be distinguishable. </p>
  
  <p>Any pointers are welcome.</p>