com.couchbase.lite.Ordering Maven / Gradle / Ivy

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//
// Copyright (c) 2020, 2017 Couchbase, Inc All rights reserved.
//
// 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.couchbase.lite;

import android.support.annotation.NonNull;

import java.util.ArrayList;
import java.util.List;

import com.couchbase.lite.internal.utils.Preconditions;


/**
 * An Ordering represents a single ordering component in the query ORDER BY clause.
 */
public abstract class Ordering {
    //---------------------------------------------
    // Inner public Class
    //---------------------------------------------

    /**
     * SortOrder represents a single ORDER BY entity. You can specify either ascending or
     * descending order. The default order is ascending.
     */
    public static class SortOrder extends Ordering {
        private final Expression expression;
        private boolean isAscending;

        SortOrder(Expression expression) {
            this.expression = expression;
            this.isAscending = true;
        }

        /**
         * Set the order as ascending order.
         *
         * @return the OrderBy object.
         */
        @NonNull
        public Ordering ascending() {
            this.isAscending = true;
            return this;
        }

        /**
         * Set the order as descending order.
         *
         * @return the OrderBy object.
         */
        @NonNull
        public Ordering descending() {
            this.isAscending = false;
            return this;
        }

        Object asJSON() {
            if (isAscending) { return expression.asJSON(); }

            final List