1 /** 2 * Copyright (c) 2010, Google Inc. 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 package com.android.mail.utils; 17 18 import android.content.Context; 19 import android.content.Intent; 20 import android.content.pm.PackageManager; 21 import android.content.pm.ResolveInfo; 22 import android.net.Uri; 23 import android.text.TextUtils; 24 import android.webkit.MimeTypeMap; 25 26 import com.google.common.annotations.VisibleForTesting; 27 import com.google.common.collect.ImmutableSet; 28 29 import java.util.List; 30 import java.util.Set; 31 32 /** 33 * Utilities for working with different content types within Mail. 34 */ 35 public class MimeType { 36 private static final String LOG_TAG = LogTag.getLogTag(); 37 38 public static final String ANDROID_ARCHIVE = "application/vnd.android.package-archive"; 39 private static final String TEXT_PLAIN = "text/plain"; 40 @VisibleForTesting 41 static final String GENERIC_MIMETYPE = "application/octet-stream"; 42 43 @VisibleForTesting 44 private static final Set<String> EML_ATTACHMENT_CONTENT_TYPES = ImmutableSet.of( 45 "message/rfc822", "application/eml"); 46 public static final String EML_ATTACHMENT_CONTENT_TYPE = "message/rfc822"; 47 private static final String NULL_ATTACHMENT_CONTENT_TYPE = "null"; 48 49 /** 50 * Returns whether or not an attachment of the specified type is installable (e.g. an apk). 51 */ 52 public static boolean isInstallable(String type) { 53 return ANDROID_ARCHIVE.equals(type); 54 } 55 56 /** 57 * Returns whether or not an attachment of the specified type is viewable. 58 */ 59 public static boolean isViewable(Context context, Uri contentUri, String contentType) { 60 // The provider returns a contentType of "null" instead of null, when the 61 // content type is not known. Changing the provider to return null, 62 // breaks other areas that will need to be fixed in a later CL. 63 // Bug 2922948 has been written up to track this 64 if (contentType == null || contentType.length() == 0 || 65 NULL_ATTACHMENT_CONTENT_TYPE.equals(contentType)) { 66 LogUtils.d(LOG_TAG, "Attachment with null content type. '%s", contentUri); 67 return false; 68 } 69 70 final Intent mimetypeIntent = new Intent(Intent.ACTION_VIEW); 71 mimetypeIntent.setFlags(Intent.FLAG_GRANT_READ_URI_PERMISSION 72 | Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET); 73 74 if (contentUri != null) { 75 Utils.setIntentDataAndTypeAndNormalize(mimetypeIntent, contentUri, contentType); 76 } else { 77 Utils.setIntentTypeAndNormalize(mimetypeIntent, contentType); 78 } 79 80 PackageManager manager; 81 // We need to catch the exception to make CanvasConversationHeaderView 82 // test pass. Bug: http://b/issue?id=3470653. 83 try { 84 manager = context.getPackageManager(); 85 } catch (UnsupportedOperationException e) { 86 return false; 87 } 88 final List<ResolveInfo> list = manager.queryIntentActivities(mimetypeIntent, 89 PackageManager.MATCH_DEFAULT_ONLY); 90 if (list.size() == 0) { 91 // This logging will help track down bug 7092215. Once that bug is resolved, remove 92 // this. 93 LogUtils.w(LOG_TAG, "Unable to find supporting activity. " + 94 "mime-type: %s, uri: %s, normalized mime-type: %s normalized uri: %s", 95 contentType, contentUri, mimetypeIntent.getType(), mimetypeIntent.getData()); 96 } 97 return list.size() > 0; 98 } 99 100 /** 101 * Extract and return filename's extension, converted to lower case, and not including the "." 102 * 103 * @return extension, or null if not found (or null/empty filename) 104 */ 105 private static String getFilenameExtension(String fileName) { 106 String extension = null; 107 if (!TextUtils.isEmpty(fileName)) { 108 int lastDot = fileName.lastIndexOf('.'); 109 if ((lastDot > 0) && (lastDot < fileName.length() - 1)) { 110 extension = fileName.substring(lastDot + 1).toLowerCase(); 111 } 112 } 113 return extension; 114 } 115 116 117 /** 118 * Returns the mime type of the attachment based on its name and 119 * original mime type. This is an workaround for bugs where Gmail 120 * server doesn't set content-type for certain types correctly. 121 * 1) EML files -> "message/rfc822". 122 * @param name name of the attachment. 123 * @param mimeType original mime type of the attachment. 124 * @return the inferred mime type of the attachment. 125 */ 126 public static String inferMimeType(String name, String mimeType) { 127 final String extension = getFilenameExtension(name); 128 if (TextUtils.isEmpty(extension)) { 129 // Attachment doesn't have extension, just return original mime 130 // type. 131 return mimeType; 132 } else { 133 final boolean isTextPlain = TEXT_PLAIN.equalsIgnoreCase(mimeType); 134 final boolean isGenericType = 135 isTextPlain || GENERIC_MIMETYPE.equalsIgnoreCase(mimeType); 136 137 String type = null; 138 if (isGenericType || TextUtils.isEmpty(mimeType)) { 139 type = MimeTypeMap.getSingleton().getMimeTypeFromExtension(extension); 140 } 141 if (!TextUtils.isEmpty(type)) { 142 return type; 143 } if (extension.equals("eml")) { 144 // Extension is ".eml", return mime type "message/rfc822" 145 return EML_ATTACHMENT_CONTENT_TYPE; 146 } else { 147 // Extension is not ".eml", just return original mime type. 148 return !TextUtils.isEmpty(mimeType) ? mimeType : GENERIC_MIMETYPE; 149 } 150 } 151 } 152 153 /** 154 * Checks the supplied mime type to determine if it is a valid eml file. 155 * Valid mime types are "message/rfc822" and "application/eml". 156 * @param mimeType the mime type to check 157 * @return {@code true} if the mime type is one of the valid mime types. 158 */ 159 public static boolean isEmlMimeType(String mimeType) { 160 return EML_ATTACHMENT_CONTENT_TYPES.contains(mimeType); 161 } 162 } 163