<s>Do you know if there's a performance impact on very large notes?</s> (sorry just saw that Caleb already checked that) Also the notes sometimes are giant blobs of HTML, when it's imported from the web clipper or Evernote. Could you check that it works with these too (in particular that it doesn't freeze)?

Check that the element exist

Please check that the element exist

Please add a detailed comment to explain what this class does.

onSomething

onSomething

All callbacks should be written as `onSomething`. If the onSomething notation doesn't make sense it's probably because you shouldn't make it a callback.

Please could you try to write this without refs? Using refs make it hard to follow the code. For example I can't tell if the timeout is properly cleared when the component unmount, and I have no idea if the state logic makes sense (i.e. stuff being updated when the state changes). I use refs too, but it has to be a last desperate attempt to get things working, and it should be documented.