[Rev 01] RFR: 8087980: Add property to disable Monocle cursor

[Johan Vos]

On Wed, 18 Dec 2019 12:52:12 GMT, Dell Green <github.com+12861109+dellgreen at openjdk.org> wrote:

>> Often on embedded systems a cursor is not a valid input modality. On some of these systems, when the javafx toolkit initialises the native hardware cursor, it produces artefacts which can be seen on screen (in the framebuffer for example). This change adds a system property "monocle.cursor.enabled" that can disable the creation of a native cursor in each of the Monocle NativePlatform implementations in favour of a NullCursor which is a no-op implementation of the NativeCursor abstract class that all native cursors have to implement.
>> 
>> NullCursor class already existed and was being returned for some implementations like AndroidPlatform and HeadlessPlatform. This change builds upon that and conditionally returns NullCursor for all platforms.
>> 
>> A system property "monocle.debugcursor" has also been added to turn on logging of which NativeCursor has been selected when the toolkit initialises.
> 
> The pull request has been updated with 1 additional commit.

LGTM

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Marked as reviewed by jvos (Reviewer).

PR: https://git.openjdk.java.net/jfx/pull/5