Add notification channel settings.

If a user has set a preference at an app wide level, it cannot be
undone at a channel level, but channels can be more restrictive.

Tests: changing settings for apps and channels.

Change-Id: I7907b8179ffc24d68197c917f182e63d8e1ff7a7

src/com/android/settings/notification/DefaultNotificationTonePreference.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.notification;
+
+
+import com.android.settings.DefaultRingtonePreference;
+import com.android.settings.Utils;
+
+import android.content.ContentResolver;
+import android.content.Context;
+import android.content.Intent;
+import android.database.Cursor;
+import android.database.sqlite.SQLiteException;
+import android.media.Ringtone;
+import android.media.RingtoneManager;
+import android.os.AsyncTask;
+import android.os.UserHandle;
+import android.os.UserManager;
+import android.net.Uri;
+import android.provider.MediaStore;
+import android.provider.OpenableColumns;
+import android.util.AttributeSet;
+
+import static android.content.ContentProvider.getUriWithoutUserId;
+
+public class DefaultNotificationTonePreference extends DefaultRingtonePreference {
+    private Uri mRingtone;
+
+    public DefaultNotificationTonePreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    @Override
+    protected Uri onRestoreRingtone() {
+        return mRingtone;
+    }
+
+    @Override
+    public void onPrepareRingtonePickerIntent(Intent ringtonePickerIntent) {
+        super.onPrepareRingtonePickerIntent(ringtonePickerIntent);
+        ringtonePickerIntent.putExtra(RingtoneManager.EXTRA_RINGTONE_EXISTING_URI,
+                mRingtone);
+    }
+
+    public void setRingtone(Uri ringtone) {
+        mRingtone = ringtone;
+        updateRingtoneName(mRingtone);
+    }
+
+    private void updateRingtoneName(final Uri uri) {
+        AsyncTask ringtoneNameTask = new AsyncTask<Object, Void, CharSequence>() {
+            @Override
+            protected CharSequence doInBackground(Object... params) {
+                return Ringtone.getTitle(mUserContext, uri, false /* followSettingsUri */,
+                        true /* allowRemote */);
+            }
+
+            @Override
+            protected void onPostExecute(CharSequence name) {
+                setSummary(name);
+            }
+        };
+        ringtoneNameTask.execute();
+    }
+}