Optimize Data Library (d3)

[knutole]

I have 1054 files in my data library now, and it's very slow. It seems a lot of operations require a redraw of the entire list of files.

Need to go over the code and make sure there is as little redrawing as possible.

Ops that seem to trigger full redraw:

• clicking "Options"
• clicking "Add layer"
• dbclick for renaming filename
• any random click on the file box
• add layer to layermenu
• rename layer
• _onLayerEdited

Also, opening the Data Library for the first time is very, very slow (over a full second for me). Perhaps we can do this "behind the scenes", so that the experience is much faster for end-user.

Need to rewrite _refresh() in chrome.data.js, see comments.

References:

https://developers.google.com/web/fundamentals/performance/rendering/