diff --git a/app/src/main/java/acr/browser/lightning/utils/KeyboardHelper.java b/app/src/main/java/acr/browser/lightning/utils/KeyboardHelper.java
deleted file mode 100644
index d6ed3ec..0000000
--- a/app/src/main/java/acr/browser/lightning/utils/KeyboardHelper.java
+++ /dev/null
@@ -1,67 +0,0 @@
-package acr.browser.lightning.utils;
-
-import android.graphics.Rect;
-import android.support.annotation.NonNull;
-import android.view.View;
-import android.view.ViewTreeObserver;
-
-class KeyboardHelper {
-
-    interface KeyboardListener {
-        /**
-         * Called when the visibility of the keyboard changes.
-         * Parameter tells whether the keyboard has been shown
-         * or hidden.
-         *
-         * @param visible true if the keyboard has been shown,
-         *                false otherwise.
-         */
-        void keyboardVisibilityChanged(boolean visible);
-    }
-
-    @NonNull private final View mView;
-    private int mLastRight = -1;
-    private int mLastBottom = -1;
-
-    /**
-     * Constructor
-     *
-     * @param view the view to listen on, should be
-     *             the {@link android.R.id#content} view.
-     */
-    public KeyboardHelper(@NonNull View view) {
-        mView = view;
-    }
-
-    /**
-     * Registers a {@link KeyboardListener} to receive
-     * callbacks when the keyboard is shown for the specific
-     * view. The view used should be the content view as it
-     * will receive resize events from the system.
-     *
-     * @param listener the listener to register to receive events.
-     */
-    public void registerKeyboardListener(@NonNull final KeyboardListener listener) {
-        mView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
-            @Override
-            public void onGlobalLayout() {
-                Rect rect = new Rect();
-                if (mLastBottom == -1) {
-                    mLastBottom = rect.bottom;
-                }
-                if (mLastRight == -1) {
-                    mLastRight = rect.right;
-                }
-                mView.getWindowVisibleDisplayFrame(rect);
-                if (mLastRight == rect.right && rect.bottom < mLastBottom) {
-                    listener.keyboardVisibilityChanged(true);
-                } else if (mLastRight == rect.right && rect.bottom > mLastBottom) {
-                    listener.keyboardVisibilityChanged(false);
-                }
-                mLastBottom = rect.bottom;
-                mLastRight = rect.right;
-            }
-        });
-    }
-
-}