重写滑动监听的 WebView

package com.chitty.views;

import android.content.Context;
import android.util.AttributeSet;
import android.webkit.WebView;

/**
 * Created by chitty on 2017/8/29.
 * 重写滑动监听的 WebView 
 */

public class NewWebView extends WebView {
    
    

        private OnScrollChangeListener mOnScrollChangeListener;

        public NewWebView(Context context, AttributeSet attrs) {
            super(context, attrs);
        }

        @Override
        protected void onScrollChanged(int l, int t, int oldl, int oldt) {
            super.onScrollChanged(l, t, oldl, oldt);
            // webview的高度
            float webcontent = getContentHeight() * getScale();
            // 当前webview的高度
            float webnow = getHeight() + getScrollY();
            if (Math.abs(webcontent - webnow) < 1) {
                //处于底端
                mOnScrollChangeListener.onPageEnd(l, t, oldl, oldt);
            } else if (getScrollY() == 0) {
                //处于顶端
                mOnScrollChangeListener.onPageTop(l, t, oldl, oldt);
            } else {
                mOnScrollChangeListener.onScrollChanged(l, t, oldl, oldt);
            }
        }

    public void setOnScrollChangeListener(OnScrollChangeListener listener) {
        this.mOnScrollChangeListener = listener;
    }

    public interface OnScrollChangeListener {
    
    

        public void onPageEnd(int l, int t, int oldl, int oldt);

        public void onPageTop(int l, int t, int oldl, int oldt);

        public void onScrollChanged(int l, int t, int oldl, int oldt);

    }

}