Merge "Create SdkLevelUtil for Mainline"

/*

 * Copyright (C) 2020 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.net.wifi.util;

import android.os.Build;

/**

 * Utility to check the SDK version of the device that the code is running on.

 *

 * This can be used to disable new Wifi APIs added in Mainline updates on older SDK versions.

 *

 * @hide

 */

public class SdkLevelUtil {

    /** This class is instantiable to allow easy mocking. */

    public SdkLevelUtil() { }

    /** Returns true if the Android platform SDK is at least "S", false otherwise. */

    public boolean isAtLeastS() {

        // TODO(b/167575586): after S SDK finalization, this method should just be

        //  `return Build.VERSION.SDK_INT >= Build.VERSION_CODES.S;`

        // at least S: return true

        // this condition only evaluates to true after S SDK finalization when VERSION_CODES.S

        // is set to something like "31", before SDK finalization the value is "10000"

        // Note that Build.VERSION_CODES.S is inlined at compile time. If it's inlined to 10000,

        // this condition never evaluates to true.

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.S) {

            return true;

        }

        // Assume for now that S = R + 1

        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.R) {

            return true;

        }

        // R: check CODENAME

        // Before S SDK finalization, SDK_INT = R = 30 i.e. remains on the previous version

        if (Build.VERSION.SDK_INT == Build.VERSION_CODES.R) {

            // CODENAME = "REL" on R release builds

            // CODENAME = "S" on S development builds

            return "S".equals(Build.VERSION.CODENAME);

        }

        // older than R: return false

        return false;

    }

}