title: How to use touchmove correctly on Android with Titanium SDK / Appcellerator
body: <p>I'm finding that touchmove events seem to behave in ways I didn't expect. There seem to be multiple coordinate systems I have to deal with. I read through this ticket: <a href="https://jira.appcelerator.org/browse/TIMOB-1277" rel="nofollow">https://jira.appcelerator.org/browse/TIMOB-1277</a> but it doesn't seem there is a clear solution.</p>
  
  <p>I tried the suggestion Vishal Duggal gave of using convertPointToView, but while it seems to work in some instances, in others it seems to mess things up more. Sometimes convertPointToView returns null even though none of my elements are being removed from the view hierarchy. Does every element have its own coordinate system? I looked at this documentation: <a href="http://docs.appcelerator.com/titanium/3.0/#!/guide/Layouts,_Positioning,_and_the_View_Hierarchy" rel="nofollow">http://docs.appcelerator.com/titanium/3.0/#!/guide/Layouts,_Positioning,_and_the_View_Hierarchy</a>, but it doesn't seem to explain anything about how the coordinate systems work. </p>
  
  <p>Sometimes convertPointToView seems to return incorrect values too. Comparing the values I get from e.x vs what come out of convertPointToView, it seems to sometimes jump to a high number when e.x seems to have the correct value.</p>
  
  <p>Does anyone have any good reference I can read about this?</p>
  
  <p>My basic question is: what are the best practices around using touch events? And most importantly, how do I ensure the coordinates I get from a touch event object continue to make sense even if the object I'm touching is moving (in response to the touch)?</p>