added highlight to element on hover by decreasing the opacity of the bac...

...kground elements using a global higlight function

@jebeck can you look at it, i think its ready but i'd like to hear what you think of the code and the resulting interaction.
Background:
If you're hovering over a bolus, it looks for a carb event within 5 minutes
on either side. If there is, the linked tool tip appears. If there isn't,
you only get the single tool tip. Same thing vice versa.

May thoughts on Jana's question:

   1. Should we keep the code for 5 minutes on either side tool tips? (May
   be helpful for MDI.) BA: I'm fine with this.
   2. Should we make the join by join key rather than by timestamp? BA: Ok
   with column-circle as forcing function (see below).
   3. How does this affect column and circle? Column-circle will be forcing
   function for join key.




-- 
*Brandon Arbiter*
VP, Product and Business Development

*Tidepool *An open source, not-for-profit effort to build an open data
platform and better applications that reduce the burden of Type 1 Diabetes
and accelerate the commercialization of closed-loop systems.

*Phone :* 917 536 0505
*Email : *brandon@tidepool.org
*Web : *Tidepool.org <http://tidepool.org/>


On Thu, Jun 26, 2014 at 8:23 AM, Jana Beck <notifications@github.com> wrote:

> In js/plot/bolus.js:
>
> > @@ -99,8 +100,10 @@ module.exports = function(pool, opts) {
> >        var bolusGroups = boluses.enter()
> >          .append('g')
> >          .attr({
> > -          'class': 'd3-bolus-group',
> > -          'id': function(d) { return 'bolus_group_' + d.id; }
> > +          class: function(d) {
> > +            return 'd3-bolus-group d3-wizard-' + Date.parse(d.normalTime);
>
> @brandonarbiter <https://github.com/brandonarbiter> @HowardLook
> <https://github.com/HowardLook> how do you feel about this, approximate
> time matching for generating "combo" tooltips for bolus and basals? Get rid
> of it, or keep it around because it may be useful one day for manual
> logging data sources?
>
> —
> Reply to this email directly or view it on GitHub
> <https://github.com/tidepool-org/tideline/pull/138/files#r14246962>.
>