ProgressWebView.java

/**
 * Copyright 2016 JustWayward Team
 * <p>
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.justwayward.reader.view;

import android.content.Context;
import android.graphics.Bitmap;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.view.KeyEvent;
import android.view.View;
import android.webkit.JsPromptResult;
import android.webkit.JsResult;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.LinearLayout;
import android.widget.ProgressBar;

import com.justwayward.reader.R;

import butterknife.Bind;
import butterknife.ButterKnife;

public class ProgressWebView extends LinearLayout {

    @Bind(R.id.web_view)
    WebView mWebView;

    @Bind(R.id.progress_bar)
    ProgressBar mProgressBar;

    private Context mContext;
    private String url;


    public ProgressWebView(Context context) {
        this(context, null);
    }

    public ProgressWebView(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public ProgressWebView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        this.mContext = context;
        initView(context);
    }

    private void initView(Context context) {
        View.inflate(context, R.layout.layout_web_progress, this);
        ButterKnife.bind(this);
    }

    public String getUrl() {
        return url;
    }

    public void setUrl(String url) {
        this.url = url;
    }

    public void loadUrl(String url) {
        if (TextUtils.isEmpty(url)) {
            url = "https://github.com/JustWayward/BookReader";
        }
        initWebview(url);
    }


    private void initWebview(String url) {

        mWebView.addJavascriptInterface(this, "android");

        WebSettings webSettings = mWebView.getSettings();

        webSettings.setJavaScriptEnabled(true);
        // 设置可以访问文件
        webSettings.setAllowFileAccess(true);
        // 设置可以支持缩放
        webSettings.setSupportZoom(true);
        // 设置默认缩放方式尺寸是far
        webSettings.setDefaultZoom(WebSettings.ZoomDensity.MEDIUM);
        // 设置出现缩放工具
        webSettings.setBuiltInZoomControls(false);
        webSettings.setDefaultFontSize(16);

        mWebView.loadUrl(url);

        // 设置WebViewClient
        mWebView.setWebViewClient(new WebViewClient() {
            // url拦截
            @Override
            public boolean shouldOverrideUrlLoading(WebView view, String url) {
                // 使用自己的WebView组件来响应Url加载事件，而不是使用默认浏览器器加载页面
                view.loadUrl(url);
                // 相应完成返回true
                return true;
                // return super.shouldOverrideUrlLoading(view, url);
            }

            // 页面开始加载
            @Override
            public void onPageStarted(WebView view, String url, Bitmap favicon) {
                mProgressBar.setVisibility(View.VISIBLE);
                super.onPageStarted(view, url, favicon);
            }

            // 页面加载完成
            @Override
            public void onPageFinished(WebView view, String url) {
                mProgressBar.setVisibility(View.GONE);
                super.onPageFinished(view, url);
            }

            // WebView加载的所有资源url
            @Override
            public void onLoadResource(WebView view, String url) {
                super.onLoadResource(view, url);
            }

            @Override
            public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
//				view.loadData(errorHtml, "text/html; charset=UTF-8", null);
                super.onReceivedError(view, errorCode, description, failingUrl);
            }

        });

        // 设置WebChromeClient
        mWebView.setWebChromeClient(new WebChromeClient() {
            @Override
            // 处理javascript中的alert
            public boolean onJsAlert(WebView view, String url, String message, final JsResult result) {
                return super.onJsAlert(view, url, message, result);
            }

            @Override
            // 处理javascript中的confirm
            public boolean onJsConfirm(WebView view, String url, String message, final JsResult result) {
                return super.onJsConfirm(view, url, message, result);
            }

            @Override
            // 处理javascript中的prompt
            public boolean onJsPrompt(WebView view, String url, String message, String defaultValue, final JsPromptResult result) {
                return super.onJsPrompt(view, url, message, defaultValue, result);
            }

            // 设置网页加载的进度条
            @Override
            public void onProgressChanged(WebView view, int newProgress) {
                mProgressBar.setProgress(newProgress);
                super.onProgressChanged(view, newProgress);
            }

            // 设置程序的Title
            @Override
            public void onReceivedTitle(WebView view, String title) {
                super.onReceivedTitle(view, title);
            }
        });
        mWebView.setOnKeyListener(new OnKeyListener() {
            @Override
            public boolean onKey(View v, int keyCode, KeyEvent event) {
                if (event.getAction() == KeyEvent.ACTION_DOWN) {
                    if (keyCode == KeyEvent.KEYCODE_BACK && mWebView.canGoBack()) { // 表示按返回键

                        mWebView.goBack(); // 后退

                        // webview.goForward();//前进
                        return true; // 已处理
                    }
                }
                return false;
            }
        });
    }

    public boolean canBack() {
        if (mWebView.canGoBack()) {
            mWebView.goBack();
            return false;
        }
        return true;
    }
}