Histogram: tool tip improvement

[nikicat]

This patch adds series' label to histogram tool tip and corrects value for stacked graphs.

[bobrik]

If series has no "alias" then you end up with empty space after "=". I think showing query in this case is better:

diff --git a/panels/histogram/module.js b/panels/histogram/module.js
index 60b823f..859651f 100644
--- a/panels/histogram/module.js
+++ b/panels/histogram/module.js
@@ -418,7 +418,8 @@ angular.module('kibana.histogram', [])
             "<div style='vertical-align:middle;display:inline-block;background:"+
             item.series.color+";height:15px;width:15px;border-radius:10px;'></div> "+
             item.datapoint[1].toFixed(0) + " @ " +
-            moment(item.datapoint[0]).format('MM/DD HH:mm:ss'));
+            moment(item.datapoint[0]).format('MM/DD HH:mm:ss') + " = " +
+            (item.series.info.alias || item.series.info.query));
         } else {
           $("#pie-tooltip").remove();
         }

You are right about stacked graphs, but I thin it should be separate pull request.

What do you think?

[nikicat]

As I see you've opened pull request for it. I think it's useful too.

[spalger]

Thanks for pointing this out, I think it makes the tooltip more useful.

In regards to the value within a stacked plot: I expected the same behavior you did at first, but after a bit of research it seems that stacked/area plots are designed to show cumulative totals, not just a way to prevent things from overlapping. Because of this, I feel like the current behavior is probably correct.

Closing this for now since #439 will likely be merged soon.

[nikicat]

I could make a similar patch, but with toggle in a settings panel. Is it OK?

[bobrik]

I vote for setting (maybe even enabled by default) for this. This is definitely not obvious.