/*
 * Copyright (C) 2022 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.systemui.smartspace

/**
 * A {@link SmartspacePrecondition} captures the conditions that must be met for Smartspace to be
 * used in a particular setting.
 */
interface SmartspacePrecondition {
    /**
     * A callback for receiving updates when conditions have changed.
     */
    interface Listener {
        fun onCriteriaChanged()
    }

    /**
     * Adds a listener to receive future updates. {@link Listener#onCriteriaChanged} will be called
     * immediately upon adding.
     */
    fun addListener(listener: Listener)

    /**
     * Removes a listener from receiving future updates.
     */
    fun removeListener(listener: Listener)

    /**
     * Returns whether all conditions have been met.
     */
    fun conditionsMet(): Boolean
}