LongDef.kt

/*
 * 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 androidx.annotation

/**
 * Denotes that the annotated long element represents
 * a logical type and that its value should be one of the explicitly
 * named constants. If the LongDef#flag() attribute is set to true,
 * multiple constants can be combined.
 *
 * Example:
 * ```
 * @Retention(SOURCE)
 * @LongDef({NAVIGATION_MODE_STANDARD, NAVIGATION_MODE_LIST, NAVIGATION_MODE_TABS})
 * public @interface NavigationMode {}
 * public static final long NAVIGATION_MODE_STANDARD = 0;
 * public static final long NAVIGATION_MODE_LIST = 1;
 * public static final long NAVIGATION_MODE_TABS = 2;
 * ...
 * public abstract void setNavigationMode(@NavigationMode long mode);
 * @NavigationMode
 * public abstract long getNavigationMode();
 * ```
 *
 * For a flag, set the flag attribute:
 * ```
 * @LongDef(
 *     flag = true,
 *     value = {NAVIGATION_MODE_STANDARD, NAVIGATION_MODE_LIST, NAVIGATION_MODE_TABS}
 * )
 * ```
 *
 * @see IntDef
 */
@Retention(AnnotationRetention.SOURCE)
@Target(AnnotationTarget.ANNOTATION_CLASS)
public annotation class LongDef(
    /** Defines the allowed constants for this element  */
    vararg val value: Long = [],
    /** Defines whether the constants can be used as a flag, or just as an enum (the default)  */
    val flag: Boolean = false,
    /**
     * Whether any other values are allowed. Normally this is
     * not the case, but this allows you to specify a set of
     * expected constants, which helps code completion in the IDE
     * and documentation generation and so on, but without
     * flagging compilation warnings if other values are specified.
     */
    val open: Boolean = false
)