谈一谈RingtonePickerActivity

Ringtone 的两中类型三种形式

两种类型

指的是：external.db和internal.db中对应的MediaStore.Audio.Media.EXTERNAL_CONTENT_URI和MediaStore.Audio.Media.EXTERNAL_CONTENT_URI

三种形式

1 最常见的uri形式

content://media/external/audio/media/id 和 content://media/internal/audio/media/id
id就是其在MediaProvider中对应的数据库中的id

MediaStore.Audio.Media.EXTERNAL_CONTENT_URI---content://media/external/audio/media/id对应的数据库：/data/data/com.android.providers.media/databases/external.dbMediaStore.Audio.Media.EXTERNAL_CONTENT_URI---content://media/internal/audio/media/id对应的数据库：/data/data/com.android.providers.media/databases/internal.db

authority是media

2 Settings数据库中的uri形式

content://setting/system/***

Settings.System.DEFAULT_NOTIFICATION_URI----content://setting/system/notification_soundSettings.System.DEFAULT_RINGTONE_URI------content://settings/system/ringtoneSettings.System.DEFAULT_ALARM_ALERT_URI-----content://settings/system/alarm_alert

authority是settings

android M以前对应的数据库data\data\com.android.providers.settings\databases\这个目录下的Settings.db （如android L）

android M SettingsProvider数据库的变化，变化如下，之前系统修改的数据最后是存储在data/data/com.android.providers.settings/databases目录下，现在该目录下存放了一个backup数据库，里面的数据不是当前系统设置的全部数据，只有一部分内容，另一个是journal数据库，无数据。现在的数据库真正的数据存储目录在data/system/users/userId（我们没开启多用户，userid为0），数据存储形式不是以db的形式，如下截图，为数据三个表分别对应system，secure和global，查看相应数据可以导出对应的xml。

settings_system.xml中存储的就有content://setting/system/..，存储的value是第一种形式，所以其本质是把第一种数据uri形式存储在settings_system.xml中。

3 Android 4.4以后增加了document uri

content://com.android.providers.media.documents/document/audio%3A82482
content://com.android.providers.downloads.documents/document/audio%3A82556
content://com.android.externalstorage.documents//document/audio%8N584645

authority是com.android.providers.*.documents
其DocumentsContract.getDocumentId(uri)进行String串的处理获取id转化为第一种形式，本质上是对第一种形式的包装

  if (isMediaDocument(uri)) {       final String docId = DocumentsContract.getDocumentId(uri);       final String[] split = docId.split(":");       final String id = split[1];       Uri contentUri = ContentUris.withAppendedId(               Uri.parse("content://media/external/audio/media/"), Long.valueOf(id));       return contentUri;       ...

不管那种类型或形式都是下面这种格式：

content://authority/path/id

返回给RingtonePickerActivity的uri处理

返回给RingtonePickerActivity的uri如果不是第三中形式需要对uri处理转化为第一种形式

authority是settings

通过访问settings_system.xml获取对应的value，也就是存储的第一种形式的content uri的String形式

String uriString = Settings.System.getString(         context.getContentResolver(), Settings.System.RINGTONE.toString());

authority是com.android.providers…

返回给RingtonePickerActivity的uri如果不是第三中形式需要对uri处理转化为第一种形式 authority是com.android.providers…
这种有三种，需要分别处理如下：

    /**     * Gets the content:// URI from the given corresponding path to a file     *     * @param context     * @param path     * @return content Uri     */    private static Uri getContentUriWithPath(ContentResolver resolver, String path) {        Cursor cursor = null;        String filePath = path;        try {            cursor = resolver.query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,                    new String[] { MediaStore.Audio.Media._ID },                    MediaStore.Audio.Media.DATA + "=? ",                    new String[] { filePath }, null);            if (cursor != null && cursor.moveToFirst()) {                int id = cursor.getInt(cursor.getColumnIndex(                        MediaStore.MediaColumns._ID));                Uri baseUri = Uri.parse("content://media/external/audio/media");                return Uri.withAppendedPath(baseUri, "" + id);            } else {                if (filePath != null) {                    ContentValues values = new ContentValues();                    values.put(MediaStore.Audio.Media.DATA, filePath);                    return resolver.insert(MediaStore.                            Audio.Media.EXTERNAL_CONTENT_URI, values);                } else {                    return null;                }           }        }finally {            if (cursor != null)                cursor.close();        }    }    public static String getDataColumn(ContentResolver resolver, Uri uri, String selection,                                       String[] selectionArgs) {        Cursor cursor = null;        final String column = "_data";        final String[] projection = { column };        try {            cursor = resolver.query(uri, projection, selection, selectionArgs,                    null);            if (cursor != null && cursor.moveToFirst()) {                final int index = cursor.getColumnIndexOrThrow(column);                //Log.d(TAG, "cursor.getString(index) =  " + cursor.getString(index));                return cursor.getString(index);            }        } finally {            if (cursor != null)                cursor.close();        }        return null;      }    private Uri getContentUri(ContentResolver resolver, Uri uri){        if (DocumentsContract.isDocumentUri(this, uri)) {            if (isMediaDocument(uri)) {                final String docId = DocumentsContract.getDocumentId(uri);                final String[] split = docId.split(":");                final String id = split[1];                Uri contentUri = ContentUris.withAppendedId(                        Uri.parse("content://media/external/audio/media/"), Long.valueOf(id));                return contentUri;            }else if (isExternalStorageDocument(uri)){                //Log.d(TAG, "****ExternalStorageDocument****");                final String docId = DocumentsContract.getDocumentId(uri);                //Log.d(TAG, "getContentUri: docId =  " + docId);                final String[] split = docId.split(":");                final String type = split[0];                String path = null;                if ("primary".equalsIgnoreCase(type)) {                    path = Environment.getExternalStorageDirectory() + "/" + split[1];                    //Log.d(TAG, "getContentUri: primary   path =  " + path);                }else{                    path = "/storage/" + split[0] + "/" + split[1];                    //Log.d(TAG, "getContentUri: path =  " + path);                }                return getContentUriWithPath(resolver,path);            }else if (isDownloadsDocument(uri)){                Log.d(TAG, "****DownloadsDocument****");                final String id = DocumentsContract.getDocumentId(uri);                //Log.d(TAG, "getContentUri ,getDocumentId: Id =  " + id);                final Uri downloadsUri = ContentUris.withAppendedId(                        Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));                //Log.d(TAG, "downloadsUri:" + downloadsUri.toString());                String path = getDataColumn(resolver, downloadsUri, null, null);                return getContentUriWithPath(resolver,path);            }        }        return uri;    }        /**     * @param uri The Uri to check.     * @return Whether the Uri authority is ExternalStorageProvider.     */    public static boolean isExternalStorageDocument(Uri uri) {        return "com.android.externalstorage.documents".equals(uri.getAuthority());    }    /**     * @param uri The Uri to check.     * @return Whether the Uri authority is DownloadsProvider.     */    public static boolean isDownloadsDocument(Uri uri) {        return "com.android.providers.downloads.documents".equals(uri.getAuthority());    }    /**     * @param uri The Uri to check.     * @return Whether the Uri authority is MediaProvider.     */    public static boolean isMediaDocument(Uri uri) {        return "com.android.providers.media.documents".equals(uri.getAuthority());    }

RingtonePickerActivity的默认铃声

/platform/build / target/product/full_base.mk

PRODUCT_PROPERTY_OVERRIDES := \    ro.config.ringtone=Ring_Synth_04.ogg \    ro.config.notification_sound=pixiedust.ogg    ......

RingtonePickerActivity的初始铃声列表

/platform/build / target/product/full_base.mk中会copy一部分internal ringtone

$(call inherit-product-if-exists, frameworks/base/data/sounds/AllAudio.mk)

AllAudio.mk会把audio资源copy到系统Ringtones、Notifications、Alarms目录下，也可在vendor下定制自己的铃声列表和默认铃声

在MediaScanner扫描文件时，判断到如果文件的路径含有Ringtones，则认为它是铃声，并将其在database的is_ringtone这个属性的栏位置为1，RingtonePickerActivity的初始铃声列表就是这些is_ringtone属性为1的资源

铃声列表查询铃声时，使用的过滤条件就是is_ringtone 为1的铃声，所以会将所有is_ringtone 为1的铃声过滤出来，Hangouts Call /Hangouts Message在应用的Ringtones目录中且is_ringtone 属性为1，也会在“铃声列表“中被过滤出来因此Hangouts Call.ogg /Hangouts Message.ogg会出现在ringtones中，出现在Notification中是同样的原因。
可以去除Hangouts Call /Hangouts Message显示在初始铃声列表：
frameworks / base/media/java/android/media/MediaScanner.java

//ADD BEGINprivate static final String SYS_RINGTONES_DIR = "system/media/audio/ringtones/";private static final String SYS_NOTIFICATIONS_DIR =         "system/media/audio/notifications/";//ADD END......public Uri doScanFile(String path, String mimeType, long lastModified,        long fileSize, boolean isDirectory, boolean scanAlways, boolean noMedia) {     Uri result = null;     try {     ...         if (entry != null && (entry.mLastModifiedChanged || scanAlways)) {             if (noMedia) {                 result = endFile(entry, false, false, false, false, false);             } else {                 String lowpath = path.toLowerCase(Locale.ROOT);                 //MOD BEGIN                 boolean ringtones = (lowpath.indexOf(SYS_RINGTONES_DIR) > 0);                 boolean notifications = (lowpath.indexOf(SYS_NOTIFICATIONS_DIR) > 0);                 //MOD END                 boolean alarms = (lowpath.indexOf(ALARMS_DIR) > 0);                 boolean podcasts = (lowpath.indexOf(PODCAST_DIR) > 0);                 boolean music = (lowpath.indexOf(MUSIC_DIR) > 0) ||                            (!ringtones && !notifications && !alarms && !podcasts);                 ......