Add pan and zoom control to log statistics

[GoogleCodeExporter]

In work I am trying to use the by-author commit stats to work out who was
working on which project and when. It is not as easy as I had hoped, and
here’s why. Although the complete information for a project is available if
you use show-all in the log dialog, we restrict the number of data points
in the graph to give a sensible view, so for a project that lasts a couple
of years you get a very ‘smoothed’ graph showing that 300 commits were made
in Q2 of 2008, but not that it all took place in weeks 18, 19, and 24.

One way round this is to allow a pan and zoom on the time axis of the graph
so you can select a horizontal scale which shows the right level of detail
and use a horizontal scroll bar to traverse the (very) long graph.

A separate zoom control for height would be useful as well for pulling
detail out of low points on the graph.

Original issue reported on code.google.com by simon.to...@gmail.com on 19 Apr 2010 at 9:25

[GoogleCodeExporter]

Google maps has a good UI for this sort of thing. The scroll wheel controls the 
zoom
level, using the current mouse position as the centre for zooming in. Left 
dragging
performs the pan action in 2-D if required.

Original comment by simon.to...@gmail.com on 19 Apr 2010 at 9:26