/*
* Copyright (C) 2012 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.server.power;
/**
* Low-level screen on blocker mechanism which is used to keep the screen off
* or the contents of the screen hidden until the window manager is ready to show new content.
*/
interface ScreenOnBlocker {
/**
* Acquires the screen on blocker.
* Prevents the screen from turning on.
*
* Calls to acquire() nest and must be matched by the same number
* of calls to release().
*/
void acquire();
/**
* Releases the screen on blocker.
* Allows the screen to turn on.
*
* It is an error to call release() if the screen on blocker has not been acquired.
* The system may crash.
*/
void release();
}