[RFC] branchview-NG

[Dirkjan Ochtman]

Hello all,

As some of you may have noticed, I've been working on an update for the 
old branchview extension. Matt mentioned he liked the idea save for some 
crappy implementation details, so I've been trying to reimplement the 
idea without all of the crap that came with the old implementation. This 
work is now more or less finished, so I was wondering if this could now 
be included in mainline Mercurial as an addition to the web interface.

I worked from the old branchview code, but was able to replace pretty 
much all the bits there (especially the dirty HTML drawing library and 
the blob of bzr code that was trying to do some topology sorting.)

My example is here: http://hg.xavamedia.nl/mercurial/graph/graph.

Review the tip changeset to see how it's implemented. Basically, this 
uses an adaptation of the (linear) graphlog algorithm to come up with 
the graph, which is then converted to a JSON representation by a new 
webcommand. A JavaScript class is included that draws the graph on a 
browser canvas, which should work (and was tested) in Firefox, Safari 
and Opera. For IE users, I've included ExplorerCanvas, an open source 
(Apache 2.0) JavaScript library that exposes a canvas API based on IE's 
VML implementation, which appears to work alright.

This means it works in all 4 major browsers, although the spacing isn't 
perfect in IE (and the positioning could be a little in places in other 
browsers, but I'm hoping others will step in and help improving that). 
I've only added links and a template in the coal style for now, will add 
the other ones if this is accepted. So, I'd like to know what you think!

Cheers,

Dirkjan