tree e4b1f5484324bb183d98d0cb16c950f2932bcf8d
parent ca4f403e4cf7c3533e9743636e1f9bdb267de74b
author Ivan Furnadjiev <ivan@eclipsesource.com> 1403616510 +0300
committer Ivan Furnadjiev <ivan@eclipsesource.com> 1403616510 +0300

Don't fire tree expand/collapse event with null item

Item could be disposed, when expand/collapse notify operation is
processed in GridOperationHandler.

Drop expand/collapse event if item is null (already disposed).