#304 CombinedPlots do not respect the isXXPannable() flag of subplots

[Boente]

A CombinedXXPlot does not respect the isYYPannable() flag.

CombinedRangePlot.isDomainPannable() now returns:
true: if at least one subplot returns true for isDomainPannable()
false: if subplots are not empty and no suplot returns true for isDomainPannable()
true/false: if subplots are empty the value of XYPlot.isDomainPannable() is returned

Additionally the pan methods also checks if the subplot is pannable.

[David Gilbert]

Thanks for the patch. I've committed something close to what you have, but with a few changes (let me know if it misses something):

http://sourceforge.net/p/jfreechart/code/3257/

There didn't seem much point to return the value of the flag from the parent plot if it has no subplots, since this value won't be used anywhere (so now it just returns false). For the same reason, I have also overridden the setter to set the flag on all the subplots.

However, note that there is a different approach in JFreeChart-FSE (on GitHub) where the parent flag is used and will cause panning on all subplots simultaneously (if not set, then panning happens on a single subplot if the subplot flag allows it).