diff --git a/.idea/misc.xml b/.idea/misc.xml
index 1d6606a..b0a270f 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,5 +1,32 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
+  <component name="EntryPointsManager">
+    <entry_points version="2.0" />
+  </component>
+  <component name="NullableNotNullManager">
+    <option name="myDefaultNullable" value="android.support.annotation.Nullable" />
+    <option name="myDefaultNotNull" value="android.support.annotation.NonNull" />
+    <option name="myNullables">
+      <value>
+        <list size="4">
+          <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.Nullable" />
+          <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nullable" />
+          <item index="2" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.Nullable" />
+          <item index="3" class="java.lang.String" itemvalue="android.support.annotation.Nullable" />
+        </list>
+      </value>
+    </option>
+    <option name="myNotNulls">
+      <value>
+        <list size="4">
+          <item index="0" class="java.lang.String" itemvalue="org.jetbrains.annotations.NotNull" />
+          <item index="1" class="java.lang.String" itemvalue="javax.annotation.Nonnull" />
+          <item index="2" class="java.lang.String" itemvalue="edu.umd.cs.findbugs.annotations.NonNull" />
+          <item index="3" class="java.lang.String" itemvalue="android.support.annotation.NonNull" />
+        </list>
+      </value>
+    </option>
+  </component>
   <component name="ProjectRootManager" version="2" languageLevel="JDK_1_7" assert-keyword="true" jdk-15="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
diff --git a/KeyboardUtils.java b/KeyboardUtils.java
deleted file mode 100644
index 33b94aa..0000000
--- a/KeyboardUtils.java
+++ /dev/null
@@ -1,108 +0,0 @@
-package com.ravindu1024.utils;
-
-import android.app.Activity;
-import android.graphics.Rect;
-import android.view.View;
-import android.view.ViewGroup;
-import android.view.ViewTreeObserver;
-import android.content.Context;
-
-import java.util.HashMap;
-
-/**
- * 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
-{
-    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
-    {
-        void onToggleSoftKeyboard(boolean isVisible);
-    }
-
-
-    @Override
-    public void onGlobalLayout()
-    {
-        Rect r = new Rect();
-        mRootView.getWindowVisibleDisplayFrame(r);
-
-        int heightDiff = mRootView.getRootView().getHeight() - (r.bottom - r.top);
-        float dp = heightDiff/ mScreenDensity;
-        boolean isVisible = dp > MAGIC_NUMBER;
-
-        if (mCallback != null && (prevValue == null || isVisible != prevValue)) {
-            prevValue = isVisible;
-            mCallback.onToggleSoftKeyboard(isVisible);
-        }
-    }
-
-
-    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))
-        {
-            KeyboardUtils k = sListenerMap.get(listener);
-            k.removeListener();
-
-            sListenerMap.remove(listener);
-        }
-    }
-
-    public static void removeAllKeyboardToggleListeners()
-    {
-        for(SoftKeyboardToggleListener l : sListenerMap.keySet())
-            sListenerMap.get(l).removeListener();
-
-        sListenerMap.clear();
-    }
-
-    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)
-    {
-        InputMethodManager inputMethodManager = (InputMethodManager) activeView.getContext().getSystemService(Context.INPUT_METHOD_SERVICE);
-        inputMethodManager.hideSoftInputFromWindow(activeView.getWindowToken(), 0);
-    }
-
-    private void removeListener()
-    {
-        mCallback = null;
-
-        mRootView.getViewTreeObserver().removeOnGlobalLayoutListener(this);
-    }
-
-    private KeyboardUtils(Activity act, SoftKeyboardToggleListener listener)
-    {
-        mCallback = listener;
-
-        mRootView = ((ViewGroup) act.findViewById(android.R.id.content)).getChildAt(0);
-        mRootView.getViewTreeObserver().addOnGlobalLayoutListener(this);
-
-        mScreenDensity = act.getResources().getDisplayMetrics().density;
-    }
-
-}