android: when in selection, avoid showing the middle handle

editeng sends LOK_CALLBACK_CURSOR_VISIBLE after the text selection is
already created. The effect of this is that after a long push on a word
you get not only the selection overlay + the start/end handles, but also
the middle one, which is not expected. Just check if we're in a
selection already, and if so, don't react to
LOK_CALLBACK_CURSOR_VISIBLE=true.

Change-Id: I939c957feb7889dfb1997fac1051cb4eaa77004c

android/experimental/LOAndroid3/src/java/org/libreoffice/InvalidationHandler.java

@@ -3,6 +3,7 @@ package org.libreoffice;
 import android.content.Intent;
 import android.graphics.RectF;
 import android.net.Uri;
+import android.util.Log;
 
 import org.libreoffice.kit.Document;
 import org.mozilla.gecko.TextSelection;
@@ -211,7 +212,9 @@ public class InvalidationHandler implements Document.MessageCallback {
     private synchronized void cursorVisibility(String payload) {
         if (payload.equals("true")) {
             mTextCursorLayer.showCursor();
-            mTextSelection.showHandle(TextSelectionHandle.HandleType.MIDDLE);
+            if (mState != OverlayState.SELECTION) {
+                mTextSelection.showHandle(TextSelectionHandle.HandleType.MIDDLE);
+            }
         } else if (payload.equals("false")) {
             mTextCursorLayer.hideCursor();
             mTextSelection.hideHandle(TextSelectionHandle.HandleType.MIDDLE);