Android: Ensure mTopBarMode is initialised

Otherwise loading calc.pdf and clicking buttons causes a null
pointer exception.

1 files changed, 1 insertions, 1 deletions

diff --git a/android/src/com/artifex/mupdfdemo/MuPDFActivity.java b/android/src/com/artifex/mupdfdemo/MuPDFActivity.java
index 7cca742b..2c10b248 100644
--- a/android/src/com/artifex/mupdfdemo/MuPDFActivity.java
+++ b/android/src/com/artifex/mupdfdemo/MuPDFActivity.java
@@ -65,7 +65,7 @@ public class MuPDFActivity extends Activity
 	private ImageButton mAnnotButton;
 	private ViewAnimator mTopBarSwitcher;
 	private ImageButton  mLinkButton;
-	private TopBarMode   mTopBarMode;
+	private TopBarMode   mTopBarMode = TopBarMode.Main;
 	private AcceptMode   mAcceptMode;
 	private ImageButton  mSearchBack;
 	private ImageButton  mSearchFwd;