Expanded way to customize the look-and-feel of Pivot applications

[Roger Whitcomb <Ro...@actian.com>]

I have created a new issue https://issues.apache.org/jira/browse/PIVOT-1014 and made some changes for it in the 2.1 ("trunk") code to better be able to modify the default styles (which could include colors, fonts, padding, and other things).  This is a bit of a complicated change, but the result is that all the defaults for every control will (eventually) be defined in the new "terra_theme_defaults.json" file, and the name of this file is gotten from the "TerraTheme_defaults.json" file.  But, since this name can be changed by setting the "org.apache.pivot.wtk.skin.terra.location" system property, the way is now opened to change any of the default colors and styles for any/every control.  Most of the defaults were originally set in code in the "Terra*Skin.java" files, but I am slowly changing these classes to move their defaults into this new JSON file.

A side effect of this change is to highlight any of the skins that may be missing methods to set (esp. colors) from a theme index, which will be added as each file is changed.

Full discussion of the motivation for this change is in the JIRA issue, and I would welcome comments.  I intend for this to go into the 2.1 release, and should be one of the signature improvements for that release.

The possibility of drastic slowdown of applications or windows with lots of controls is disturbing me a bit, so that warrants careful scrutiny going forward.

Thanks,
Roger Whitcomb