title: How android is scaling PNGs
body: <p>I'm new in android. And I'm curuous how android is scaling it's PNGs.
  For example in ...<strong>\sdk\platforms\android-19\data\res\drawable-xhdpi</strong> there is a <strong>popup_inline_error_holo_light_am.9.png</strong>. (Sorry I don't have needed reputation to post the image)</p>
  
  <p>First I don't understand the black and red lines on the edges of the PNG.
  Second for example when you call <strong><em>EditText.setError("Some kind of error")</em></strong>, the PNG will auto scale it self so it can contain all the error message, but the red "arrow/pointer", that points up, of the PNG won't stretch and will stay the same. The other thing is that the black and red lines from the PNG doesn't show when the error popup in the application.</p>
  
  <p>How is this happening ?</p>