CheckBattery.cpp

/*
 * Copyright (C) 2014 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.
 */

#define LOG_TAG "VoldCheckBattery"
#include <cutils/log.h>

#include <binder/IServiceManager.h>
#include <batteryservice/IBatteryPropertiesRegistrar.h>

using namespace android;

namespace
{
    // How often to check battery in seconds
    const int CHECK_PERIOD = 30;
    const String16 serviceName("batteryproperties");

    sp<IBinder> bs;
    sp<IBatteryPropertiesRegistrar> interface;

    bool singletonInitialized = false;
    time_t last_checked = {0};
    int battery_ok = 1;
}

extern "C" int is_battery_ok()
{
    time_t now = time(NULL);
    if (now == -1 || difftime(now, last_checked) < 5) {
        return battery_ok;
    }
    last_checked = now;

    if (!singletonInitialized) {
        bs = defaultServiceManager()->checkService(serviceName);
        if (bs == NULL) {
            SLOGE("No batteryproperties service!");
            return 1;
        }

        interface = interface_cast<IBatteryPropertiesRegistrar>(bs);
        if (interface == NULL) {
            SLOGE("No IBatteryPropertiesRegistrar interface");
            return 1;
        }

        singletonInitialized = true;
    }

    BatteryProperty val;
    status_t status = interface->getProperty(android::BATTERY_PROP_CAPACITY,
                                             &val);
    if (status == NO_ERROR) {
        SLOGD("Capacity is %d", val.valueInt);
        battery_ok = val.valueInt > 5 ? 1 : 0;
    } else {
        SLOGE("Failed to get battery charge");
        battery_ok = 1;
    }

    return battery_ok;
}