early draft for 8087516: [JavaFX] Conditional support for GTK 3 on Linux

[David Hill]

Kevin, Phil, anyone else interested.

Here is an early draft of [JavaFX] Conditional support for GTK 3 on Linux <https://bugs.openjdk.java.net/browse/JDK-8087516>

http://cr.openjdk.java.net/~ddhill/8087516.1/

There are some rough edges left, particularly with the GTK 3 side of shaped windows.
Given my time frame, I am interested in feedback on what is there because the core of it is complete.

I have done limited testing on this, some with GTK3 and have not found any problems so far. I have more unit testing planned for next week.

The default GTK version will be GTK2. To use GTK3, use the following:

    -Djdk.gtk.version=3

To enable some really verbose output:

     -Djdk.gtk.verbose=true

This verbosity will be reduced before I commit this - and only a message about the version actually used will be output.

Known issues: Marked with a DAVE for easy cleanup later.
     * shaped windows with GTK3 - need to verify the new region methods
     * debug code that will be used to check that all of the code paths are tested.
     * move the disableGrab back into the main code logic.

-- 
David Hill<David.Hill at Oracle.com>
Java Embedded Development

"A man's feet should be planted in his country, but his eyes should survey the world."
-- George Santayana (1863 - 1952)