1 /* 2 * Copyright (C) 2013 Google Inc. 3 * Licensed to The Android Open Source Project. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package com.android.mail.browse; 19 20 import android.content.AsyncTaskLoader; 21 import android.content.ContentResolver; 22 import android.content.Context; 23 import android.content.Intent; 24 import android.net.Uri; 25 26 import com.android.emailcommon.TempDirectory; 27 import com.android.emailcommon.internet.MimeMessage; 28 import com.android.emailcommon.mail.MessagingException; 29 import com.android.mail.utils.LogTag; 30 import com.android.mail.utils.LogUtils; 31 32 import java.io.File; 33 import java.io.FileNotFoundException; 34 import java.io.IOException; 35 import java.io.InputStream; 36 37 /** 38 * Loader that builds a ConversationMessage from an EML file Uri. 39 */ 40 public class EmlMessageLoader extends AsyncTaskLoader<ConversationMessage> { 41 private static final String LOG_TAG = LogTag.getLogTag(); 42 43 private Uri mEmlFileUri; 44 private ConversationMessage mMessage; 45 46 public EmlMessageLoader(Context context, Uri emlFileUri) { 47 super(context); 48 mEmlFileUri = emlFileUri; 49 } 50 51 @Override 52 public ConversationMessage loadInBackground() { 53 final Context context = getContext(); 54 TempDirectory.setTempDirectory(context); 55 final ContentResolver resolver = context.getContentResolver(); 56 final InputStream stream; 57 try { 58 stream = resolver.openInputStream(mEmlFileUri); 59 } catch (FileNotFoundException e) { 60 LogUtils.e(LOG_TAG, e, "Could not find eml file at uri: %s", mEmlFileUri); 61 return null; 62 } 63 64 final MimeMessage mimeMessage; 65 final ConversationMessage convMessage; 66 try { 67 mimeMessage = new MimeMessage(stream); 68 convMessage = new ConversationMessage(context, mimeMessage, mEmlFileUri); 69 } catch (IOException e) { 70 LogUtils.e(LOG_TAG, e, "Could not read eml file"); 71 return null; 72 } catch (MessagingException e) { 73 LogUtils.e(LOG_TAG, e, "Error in parsing eml file"); 74 return null; 75 } finally { 76 try { 77 stream.close(); 78 } catch (IOException e) { 79 return null; 80 } 81 82 // delete temp files created during parsing 83 final File[] cacheFiles = TempDirectory.getTempDirectory().listFiles(); 84 for (final File file : cacheFiles) { 85 if (file.getName().startsWith("body")) { 86 file.delete(); 87 } 88 } 89 90 } 91 92 return convMessage; 93 } 94 95 /** 96 * Called when there is new data to deliver to the client. The 97 * super class will take care of delivering it; the implementation 98 * here just adds a little more logic. 99 */ 100 @Override 101 public void deliverResult(ConversationMessage result) { 102 if (isReset()) { 103 // An async query came in while the loader is stopped. We 104 // don't need the result. 105 if (result != null) { 106 onReleaseResources(result); 107 } 108 return; 109 } 110 ConversationMessage oldMessage = mMessage; 111 mMessage = result; 112 113 if (isStarted()) { 114 // If the Loader is currently started, we can immediately 115 // deliver its results. 116 super.deliverResult(result); 117 } 118 119 // At this point we can release the resources associated with 120 // 'oldMessage' if needed; now that the new result is delivered we 121 // know that it is no longer in use. 122 if (oldMessage != null && oldMessage != mMessage) { 123 onReleaseResources(oldMessage); 124 } 125 } 126 127 /** 128 * Handles a request to start the Loader. 129 */ 130 @Override 131 protected void onStartLoading() { 132 if (mMessage != null) { 133 // If we currently have a result available, deliver it immediately. 134 deliverResult(mMessage); 135 } 136 137 if (takeContentChanged() || mMessage == null) { 138 // If the data has changed since the last time it was loaded 139 // or is not currently available, start a load. 140 forceLoad(); 141 } 142 } 143 144 /** 145 * Handles a request to stop the Loader. 146 */ 147 @Override protected void onStopLoading() { 148 // Attempt to cancel the current load task if possible. 149 cancelLoad(); 150 } 151 152 /** 153 * Handles a request to cancel a load. 154 */ 155 @Override 156 public void onCanceled(ConversationMessage result) { 157 super.onCanceled(result); 158 159 // At this point we can release the resources associated with 160 // the message, if needed. 161 if (result != null) { 162 onReleaseResources(result); 163 } 164 } 165 166 /** 167 * Handles a request to completely reset the Loader. 168 */ 169 @Override 170 protected void onReset() { 171 super.onReset(); 172 173 // Ensure the loader is stopped 174 onStopLoading(); 175 176 // At this point we can release the resources associated with 177 // the message, if needed. 178 if (mMessage != null) { 179 onReleaseResources(mMessage); 180 mMessage = null; 181 } 182 } 183 184 185 /** 186 * Helper function to take care of releasing resources associated 187 * with an actively loaded data set. 188 */ 189 protected void onReleaseResources(ConversationMessage message) { 190 // if this eml message had attachments, start a service to clean up the cache files 191 if (message.attachmentListUri != null) { 192 final Intent intent = new Intent(Intent.ACTION_DELETE); 193 intent.setClass(getContext(), EmlTempFileDeletionService.class); 194 intent.setData(message.attachmentListUri); 195 196 getContext().startService(intent); 197 } 198 } 199 } 200