core/java/android/provider/TimeZoneRulesDataContract.java

/*
 * Copyright (C) 2017 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 android.provider;

import android.annotation.SystemApi;
import android.net.Uri;

/**
 * A set of constants for implementing a time zone data content provider, which is used by the time
 * zone updater application.
 *
 * @hide
 */
@SystemApi
public final class TimeZoneRulesDataContract {

    private TimeZoneRulesDataContract() {}

    /**
     * The authority that <em>must</em> be used for the time zone data content provider.
     * To be accepted by the time zone updater application it <em>must</em> be exposed by the
     * package specified in the config_timeZoneRulesDataPackage config value.
     */
    public static final String AUTHORITY = "com.android.timezone";

    /** A content:// style uri to the authority for the time zone data content provider */
    private static final Uri AUTHORITY_URI = Uri.parse("content://" + AUTHORITY);

    /**
     * Defines fields exposed through the {@link Operation#CONTENT_URI} for describing a time zone
     * distro operation.
     */
    public static final class Operation {

        /** Not instantiable. */
        private Operation() {
        }

        /**
         * The content:// style URI for determining what type of update is available.
         *
         * <p>The URI can be queried using
         * {@link android.content.ContentProvider#query(Uri, String[], String, String[], String)};
         * the result will be a cursor with a single row. If the {@link Operation#COLUMN_TYPE}
         * column is {@link Operation#TYPE_INSTALL} then
         * {@link android.content.ContentProvider#openFile(Uri, String)} can be used with "r" mode
         * to obtain the binary data.
         */
        public static final Uri CONTENT_URI = Uri.withAppendedPath(AUTHORITY_URI, "operation");

        /**
         * The {@code String} column of the {@link #CONTENT_URI} that provides an int specifying
         * the type of operation to perform. See {@link #TYPE_NO_OP},
         * {@link #TYPE_UNINSTALL} and {@link #TYPE_INSTALL}.
         */
        public static final String COLUMN_TYPE = "type";

        /**
         * An operation type used when the current time zone rules on device should be replaced by
         * a new set obtained via the {@link android.content.ContentProvider#openFile(Uri, String)}
         * method.
         */
        public static final String TYPE_INSTALL = "INSTALL";

        /**
         * An operation type used when the current time zone rules on device should be uninstalled,
         * returning to the values held in the system partition.
         */
        public static final String TYPE_UNINSTALL = "UNINSTALL";

        /**
         * An operation type used when the time zone rules on device should be left as they are.
         * This is not expected to be used in normal operation but a safe result in the event of an
         * error that cannot be recovered from.
         */
        public static final String TYPE_NO_OP = "NOOP";

        /**
         * The {@code nullable int} column of the {@link #CONTENT_URI} that describes the major
         * version of the distro to be installed.
         * Only non-null if {@link #COLUMN_TYPE} contains {@link #TYPE_INSTALL}.
         */
        public static final String COLUMN_DISTRO_MAJOR_VERSION = "distro_major_version";

        /**
         * The {@code nullable int} column of the {@link #CONTENT_URI} that describes the minor
         * version of the distro to be installed.
         * Only non-null if {@link #COLUMN_TYPE} contains {@link #TYPE_INSTALL}.
         */
        public static final String COLUMN_DISTRO_MINOR_VERSION = "distro_minor_version";

        /**
         * The {@code nullable String} column of the {@link #CONTENT_URI} that describes the IANA
         * rules version of the distro to be installed.
         * Only non-null if {@link #COLUMN_TYPE} contains {@link #TYPE_INSTALL}.
         */
        public static final String COLUMN_RULES_VERSION = "rules_version";

        /**
         * The {@code nullable int} column of the {@link #CONTENT_URI} that describes the revision
         * number of the distro to be installed.
         * Only non-null if {@link #COLUMN_TYPE} contains {@link #TYPE_INSTALL}.
         */
        public static final String COLUMN_REVISION = "revision";
    }
}