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      1 /*
      2  * Copyright (C) 2017 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.settingslib.license;
     18 
     19 import android.content.Context;
     20 import android.support.annotation.VisibleForTesting;
     21 import android.util.Log;
     22 
     23 import com.android.settingslib.utils.AsyncLoader;
     24 
     25 import java.io.File;
     26 import java.util.ArrayList;
     27 import java.util.List;
     28 
     29 /**
     30  * LicenseHtmlLoader is a loader which loads a license html file from default license xml files.
     31  */
     32 public class LicenseHtmlLoader extends AsyncLoader<File> {
     33     private static final String TAG = "LicenseHtmlLoader";
     34 
     35     private static final String[] DEFAULT_LICENSE_XML_PATHS = {
     36             "/system/etc/NOTICE.xml.gz",
     37             "/vendor/etc/NOTICE.xml.gz",
     38             "/odm/etc/NOTICE.xml.gz",
     39             "/oem/etc/NOTICE.xml.gz"};
     40     private static final String NOTICE_HTML_FILE_NAME = "NOTICE.html";
     41 
     42     private Context mContext;
     43 
     44     public LicenseHtmlLoader(Context context) {
     45         super(context);
     46         mContext = context;
     47     }
     48 
     49     @Override
     50     public File loadInBackground() {
     51         return generateHtmlFromDefaultXmlFiles();
     52     }
     53 
     54     @Override
     55     protected void onDiscardResult(File f) {
     56     }
     57 
     58     private File generateHtmlFromDefaultXmlFiles() {
     59         final List<File> xmlFiles = getVaildXmlFiles();
     60         if (xmlFiles.isEmpty()) {
     61             Log.e(TAG, "No notice file exists.");
     62             return null;
     63         }
     64 
     65         File cachedHtmlFile = getCachedHtmlFile();
     66         if (!isCachedHtmlFileOutdated(xmlFiles, cachedHtmlFile)
     67                 || generateHtmlFile(xmlFiles, cachedHtmlFile)) {
     68             return cachedHtmlFile;
     69         }
     70 
     71         return null;
     72     }
     73 
     74     @VisibleForTesting
     75     List<File> getVaildXmlFiles() {
     76         final List<File> xmlFiles = new ArrayList();
     77         for (final String xmlPath : DEFAULT_LICENSE_XML_PATHS) {
     78             File file = new File(xmlPath);
     79             if (file.exists() && file.length() != 0) {
     80                 xmlFiles.add(file);
     81             }
     82         }
     83         return xmlFiles;
     84     }
     85 
     86     @VisibleForTesting
     87     File getCachedHtmlFile() {
     88         return new File(mContext.getCacheDir(), NOTICE_HTML_FILE_NAME);
     89     }
     90 
     91     @VisibleForTesting
     92     boolean isCachedHtmlFileOutdated(List<File> xmlFiles, File cachedHtmlFile) {
     93         boolean outdated = true;
     94         if (cachedHtmlFile.exists() && cachedHtmlFile.length() != 0) {
     95             outdated = false;
     96             for (File file : xmlFiles) {
     97                 if (cachedHtmlFile.lastModified() < file.lastModified()) {
     98                     outdated = true;
     99                     break;
    100                 }
    101             }
    102         }
    103         return outdated;
    104     }
    105 
    106     @VisibleForTesting
    107     boolean generateHtmlFile(List<File> xmlFiles, File htmlFile) {
    108         return LicenseHtmlGeneratorFromXml.generateHtml(xmlFiles, htmlFile);
    109     }
    110 }
    111