Adding a utility class for listening disable rotation changes

/*

 * Copyright (C) 2018 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.shared.system;

import android.content.Context;

import android.os.RemoteException;

import android.util.Log;

import android.view.IRotationWatcher;

import android.view.WindowManagerGlobal;

public abstract class RotationWatcher {

    private static final String TAG = "RotationWatcher";

    private final Context mContext;

    private final IRotationWatcher mWatcher = new IRotationWatcher.Stub() {

        @Override

        public void onRotationChanged(int rotation) {

            RotationWatcher.this.onRotationChanged(rotation);

        }

    };

    private boolean mIsWatching = false;

    public RotationWatcher(Context context) {

        mContext = context;

    }

    protected abstract void onRotationChanged(int rotation);

    public void enable() {

        if (!mIsWatching) {

            try {

                WindowManagerGlobal.getWindowManagerService().watchRotation(mWatcher,

                        mContext.getDisplay().getDisplayId());

                mIsWatching = true;

            } catch (RemoteException e) {

                Log.w(TAG, "Failed to set rotation watcher", e);

            }

        }

    }

    public void disable() {

        if (mIsWatching) {

            try {

                WindowManagerGlobal.getWindowManagerService().removeRotationWatcher(mWatcher);

                mIsWatching = false;

            }  catch (RemoteException e) {

                Log.w(TAG, "Failed to remove rotation watcher", e);

            }

        }

    }

}