Android 监听键盘弹出和隐藏

package jp.co.eposcard.eposcardapp.common;

import android.app.Activity;
import android.graphics.Rect;
import android.view.View;
import android.view.ViewTreeObserver;

public class EPSoftKeyBoardListener {
    private View rootView;
    private int rootViewVisibleHeight;
    private OnSoftKeyBoardChangeListener onSoftKeyBoardChangeListener;

    public EPSoftKeyBoardListener(Activity activity) {

        rootView = activity.getWindow().getDecorView();

        rootView.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {

                Rect r = new Rect();
                rootView.getWindowVisibleDisplayFrame(r);

                int visibleHeight = r.height();
                if (rootViewVisibleHeight == 0) {
                    rootViewVisibleHeight = visibleHeight;
                    return;
                }

                if (rootViewVisibleHeight == visibleHeight) {
                    return;
                }

                if (rootViewVisibleHeight - visibleHeight > 200) {
                    if (onSoftKeyBoardChangeListener != null) {
                        onSoftKeyBoardChangeListener.keyBoardShow(rootViewVisibleHeight - visibleHeight);
                    }
                    rootViewVisibleHeight = visibleHeight;
                    return;
                }

                if (visibleHeight - rootViewVisibleHeight > 200) {
                    if (onSoftKeyBoardChangeListener != null) {
                        onSoftKeyBoardChangeListener.keyBoardHide(visibleHeight - rootViewVisibleHeight);
                    }
                    rootViewVisibleHeight = visibleHeight;
                    return;
                }

            }
        });
    }

    private void setOnSoftKeyBoardChangeListener(OnSoftKeyBoardChangeListener onSoftKeyBoardChangeListener) {
        this.onSoftKeyBoardChangeListener = onSoftKeyBoardChangeListener;
    }

    public interface OnSoftKeyBoardChangeListener {
        void keyBoardShow(int height);

        void keyBoardHide(int height);
    }

    public static void setListener(Activity activity, OnSoftKeyBoardChangeListener onSoftKeyBoardChangeListener) {
        EPSoftKeyBoardListener softKeyBoardListener = new EPSoftKeyBoardListener(activity);
        softKeyBoardListener.setOnSoftKeyBoardChangeListener(onSoftKeyBoardChangeListener);
    }
}