Apache Cordova App Reloader

Apache Cordova 

简介

cordova.apache.org

Cordova项目将mobile app变成了一件很web的事情。使用js，html来生成native的mobile app.

其核心是提供了一个带有plugin的“浏览器”。plugin处理了native的api，比如获取device信息，照相等。

cordova源码(Android)： https://github.com/apache/cordova-android

装载

cordova android 中，使用一个加强的Android WebView来封装应用。

核心类：

https://github.com/apache/cordova-android/blob/master/framework/src/org/apache/cordova/CordovaActivity.java

https://github.com/apache/cordova-android/blob/master/framework/src/org/apache/cordova/CordovaWebView.java

核心方法：

loadUrl － 用户可以指定一个位置，当这个网络里面的js调用了cordova.js 提供的API时，在容器里，它就能成功调用。

日前，我写了一个方法，可以在android上，长按 back键，弹出对话框，选择load另外一个网址。

package com.foo;import android.content.Context;import android.util.AttributeSet;import android.util.Log;import android.view.KeyEvent;import android.widget.Toast;import org.apache.cordova.*;import java.util.Timer;import java.util.TimerTask;import android.view.MotionEvent;import android.app.AlertDialog;import android.webkit.WebView;import android.webkit.WebViewClient;import android.content.Context;import android.content.DialogInterface;/** * when press screen for a long time, give a choice to exit. *  */public class ReloadAppOptionWebView extends CordovaWebView {private boolean isBackLongPress = false;private final int TOAST_MSG_DURATION = 3000;private CordovaInterface xCordova;    private static Context context;    private static String currentAppUrl;public ReloadAppOptionWebView(Context context) {super(context);        this.context=context;}public ReloadAppOptionWebView(Context context, AttributeSet attrs) {super(context, attrs);        this.context=context;}public ReloadAppOptionWebView(Context context, AttributeSet attrs,int defStyle) {super(context, attrs, defStyle);        this.context=context;}public ReloadAppOptionWebView(Context context, AttributeSet attrs,int defStyle, boolean privateBrowsing) {super(context, attrs, defStyle, privateBrowsing);        this.context=context;}/** * store the current app url, use it when reloading this app afterward  */    @Override    public void loadUrl(String url){        super.loadUrl(url);        this.currentAppUrl=url;    }@Overridepublic boolean onKeyLongPress(int keyCode, KeyEvent event) {if ((keyCode == KeyEvent.KEYCODE_BACK)) {if (event.getRepeatCount() == 1) {toastMessage("Press again to load the original app.",TOAST_MSG_DURATION);shiftBackLongPressFlagWithTimer(TOAST_MSG_DURATION);}return true;}return super.onKeyLongPress(keyCode, event);}/** * Detect actions of BACK key reload the app if clicks of BACK happens * during Reload App Window */@Overridepublic boolean onKeyDown(int keyCode, KeyEvent event) {if ((keyCode == KeyEvent.KEYCODE_BACK) && (isBackLongPress)) {if (event.getRepeatCount() == 0) {// user click back again during Reload App Window// super.loadUrl(Config.getStartUrl());                popUpChoices(context);}return true;} else if (keyCode == KeyEvent.KEYCODE_BACK) {event.startTracking();return true;}return super.onKeyDown(keyCode, event);}/** * During Reload App Window, all keyup actions are blocked. */@Overridepublic boolean onKeyUp(int keyCode, KeyEvent event) {if (isBackLongPress) {return true;}return super.onKeyUp(keyCode, event);}public void toastMessage(String msg, int duration) {Toast.makeText(this.getContext(), msg, duration).show();}/** * Reload App Window */private void shiftBackLongPressFlagWithTimer(int sleepTime) {Timer tExit = null;if (isBackLongPress == false) {// open Reload Option WindowisBackLongPress = true;tExit = new Timer();tExit.schedule(new TimerTask() {@Overridepublic void run() {// close Reload Option Window since no BACK Key event// happens.isBackLongPress = false;}}, sleepTime);}}    // popup alert     private void popUpChoices(Context context){        AlertDialog.Builder alert = new AlertDialog.Builder(context);         // more icon http://androiddrawableexplorer.appspot.com/        alert.setIcon(android.R.drawable.ic_menu_directions);        alert.setTitle("TestApp");        WebView wv = new WebView(context);        //TODO add app options directly        wv.loadUrl("file:///android_asset/www/mini_applist.html");        wv.setWebViewClient(new WebViewClient() {            @Override            public boolean shouldOverrideUrlLoading(WebView view, String url) {                view.loadUrl(url);                return true;            }        });        alert.setView(wv);        alert.setPositiveButton("Reload", new DialogInterface.OnClickListener() {            @Override            public void onClick(DialogInterface dialog, int id) {                dialog.dismiss();                loadUrl(currentAppUrl);            }        });        alert.setNeutralButton("Home", new DialogInterface.OnClickListener() {            @Override            public void onClick(DialogInterface dialog, int id) {                dialog.dismiss();                loadUrl(Config.getStartUrl());            }        });        alert.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {            @Override            public void onClick(DialogInterface dialog, int id) {                dialog.dismiss();            }        });        alert.show();    }}