diff --git a/KeyboardUtils.java b/KeyboardUtils.java
index 017a190..ebf7d7d 100644
--- a/KeyboardUtils.java
+++ b/KeyboardUtils.java
@@ -13,46 +13,44 @@
  * Based on the following Stackoverflow answer:
  * http://stackoverflow.com/questions/2150078/how-to-check-visibility-of-software-keyboard-in-android
  */
-public class KeyboardUtils implements ViewTreeObserver.OnGlobalLayoutListener
-{
+public class KeyboardUtils implements ViewTreeObserver.OnGlobalLayoutListener {
     private final static int MAGIC_NUMBER = 200;
 
     private SoftKeyboardToggleListener mCallback;
     private View mRootView;
+    private Boolean prevValue = null;
     private float mScreenDensity = 1;
     private static HashMap<SoftKeyboardToggleListener, KeyboardUtils> sListenerMap = new HashMap<>();
 
-    public interface SoftKeyboardToggleListener
-    {
+    public interface SoftKeyboardToggleListener {
         void onToggleSoftKeyboard(boolean isVisible);
     }
 
 
     @Override
-    public void onGlobalLayout()
-    {
+    public void onGlobalLayout() {
         Rect r = new Rect();
         mRootView.getWindowVisibleDisplayFrame(r);
 
         int heightDiff = mRootView.getRootView().getHeight() - (r.bottom - r.top);
-        float dp = heightDiff/ mScreenDensity;
+        float dp = heightDiff / mScreenDensity;
+        boolean isVisible = dp > MAGIC_NUMBER;
 
-        if(mCallback != null)
-            mCallback.onToggleSoftKeyboard(dp > MAGIC_NUMBER);
+        if (mCallback != null && (prevValue == null || isVisible != prevValue)) {
+            prevValue = isVisible;
+            mCallback.onToggleSoftKeyboard(isVisible);
+        }
     }
 
 
-    public static void addKeyboardToggleListener(Activity act, SoftKeyboardToggleListener listener)
-    {
+    public static void addKeyboardToggleListener(Activity act, SoftKeyboardToggleListener listener) {
         removeKeyboardToggleListener(listener);
 
         sListenerMap.put(listener, new KeyboardUtils(act, listener));
     }
 
-    public static void removeKeyboardToggleListener(SoftKeyboardToggleListener listener)
-    {
-        if(sListenerMap.containsKey(listener))
-        {
+    public static void removeKeyboardToggleListener(SoftKeyboardToggleListener listener) {
+        if (sListenerMap.containsKey(listener)) {
             KeyboardUtils k = sListenerMap.get(listener);
             k.removeListener();
 
@@ -60,39 +58,37 @@ public static void removeKeyboardToggleListener(SoftKeyboardToggleListener liste
         }
     }
 
-    public static void removeAllKeyboardToggleListeners()
-    {
-        for(SoftKeyboardToggleListener l : sListenerMap.keySet())
+    public static void removeAllKeyboardToggleListeners() {
+        for (SoftKeyboardToggleListener l : sListenerMap.keySet())
             sListenerMap.get(l).removeListener();
 
         sListenerMap.clear();
     }
 
-    public static void toggleKeyboardVisibility(Context context)
-    {
+    public static void toggleKeyboardVisibility(Context context) {
         InputMethodManager inputMethodManager = (InputMethodManager) context.getSystemService(Context.INPUT_METHOD_SERVICE);
         inputMethodManager.toggleSoftInput(InputMethodManager.SHOW_FORCED, 0);
     }
 
     /**
      * Closes the keyboard
+     *
      * @param activeView the view with the keyboard focus
      */
-    public static void forceCloseKeyboard(View activeView)
-    {
+    public static void forceCloseKeyboard(View activeView) {
         InputMethodManager inputMethodManager = (InputMethodManager) activeView.getContext().getSystemService(Context.INPUT_METHOD_SERVICE);
         inputMethodManager.hideSoftInputFromWindow(activeView.getWindowToken(), 0);
     }
 
-    private void removeListener()
-    {
+    private void removeListener() {
         mCallback = null;
 
-        mRootView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN) {
+            mRootView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
+        }
     }
 
-    private KeyboardUtils(Activity act, SoftKeyboardToggleListener listener)
-    {
+    private KeyboardUtils(Activity act, SoftKeyboardToggleListener listener) {
         mCallback = listener;
 
         mRootView = ((ViewGroup) act.findViewById(android.R.id.content)).getChildAt(0);