[orca] Don't bother checking the mousereview item when mousereview is not active

[Joanmarie Diggs <joanied src gnome org>]

commit d327897b2b4b3522a5376315f91d2abf3e4cf04b
Author: Joanmarie Diggs <jdiggs igalia com>
Date:   Tue Nov 20 20:27:24 2018 -0500

    Don't bother checking the mousereview item when mousereview is not active

 src/orca/mouse_review.py | 7 +++++++
 1 file changed, 7 insertions(+)
---
diff --git a/src/orca/mouse_review.py b/src/orca/mouse_review.py
index 360f943b9..bd5ee3f71 100644
--- a/src/orca/mouse_review.py
+++ b/src/orca/mouse_review.py
@@ -259,6 +259,8 @@ class MouseReviewer:
             i = screen.connect("window-stacking-changed", self._on_stacking_changed)
             self._handlerIds[i] = screen
 
+        self._active = True
+
     def deactivate(self):
         """Deactivates mouse review."""
 
@@ -267,12 +269,17 @@ class MouseReviewer:
             value.disconnect(key)
         self._handlerIds = {}
 
+        self._active = False
+
     def getCurrentItem(self):
         """Returns the accessible object being reviewed."""
 
         if not _mouseReviewCapable:
             return None
 
+        if not self._active:
+            return None
+
         obj = self._currentMouseOver.getObject()
 
         if time.time() - self._currentMouseOver.getTime() > 0.1: