Android example source code file (PowerProfile.java)

This example Android source code file (PowerProfile.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, arraylist, attr_name, content, double, hashmap, io, object, only, power_bluetooth_active, power_cpu_active, power_radio_on, power_radio_scanning, powerprofile, runtimeexception, string, tag_device, util, utilities, utils

The PowerProfile.java Android example source code

/*
 * Copyright (C) 2009 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.internal.os;


import android.content.Context;
import android.content.res.XmlResourceParser;

import com.android.internal.util.XmlUtils;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;

/**
 * Reports power consumption values for various device activities. Reads values from an XML file.
 * Customize the XML file for different devices.
 * [hidden]
 */
public class PowerProfile {

    /**
     * No power consumption, or accounted for elsewhere.
     */
    public static final String POWER_NONE = "none";

    /**
     * Power consumption when CPU is in power collapse mode.
     */
    public static final String POWER_CPU_IDLE = "cpu.idle";

    /**
     * Power consumption when CPU is in power collapse mode.
     */
    public static final String POWER_CPU_ACTIVE = "cpu.active";

    /**
     * Power consumption when WiFi driver is scanning for networks.
     */
    public static final String POWER_WIFI_SCAN = "wifi.scan";

    /**
     * Power consumption when WiFi driver is on.
     */
    public static final String POWER_WIFI_ON = "wifi.on";

    /**
     * Power consumption when WiFi driver is transmitting/receiving.
     */
    public static final String POWER_WIFI_ACTIVE = "wifi.active";

    /**
     * Power consumption when GPS is on.
     */
    public static final String POWER_GPS_ON = "gps.on";

    /**
     * Power consumption when Bluetooth driver is on.
     */
    public static final String POWER_BLUETOOTH_ON = "bluetooth.on";

    /**
     * Power consumption when Bluetooth driver is transmitting/receiving.
     */
    public static final String POWER_BLUETOOTH_ACTIVE = "bluetooth.active";

    /**
     * Power consumption when Bluetooth driver gets an AT command.
     */
    public static final String POWER_BLUETOOTH_AT_CMD = "bluetooth.at";

    /**
     * Power consumption when screen is on, not including the backlight power.
     */
    public static final String POWER_SCREEN_ON = "screen.on";

    /**
     * Power consumption when cell radio is on but not on a call.
     */
    public static final String POWER_RADIO_ON = "radio.on";

    /**
     * Power consumption when cell radio is hunting for a signal.
     */
    public static final String POWER_RADIO_SCANNING = "radio.scanning";

    /**
     * Power consumption when talking on the phone.
     */
    public static final String POWER_RADIO_ACTIVE = "radio.active";

    /**
     * Power consumption at full backlight brightness. If the backlight is at
     * 50% brightness, then this should be multiplied by 0.5
     */
    public static final String POWER_SCREEN_FULL = "screen.full";

    /**
     * Power consumed by the audio hardware when playing back audio content. This is in addition
     * to the CPU power, probably due to a DSP and / or amplifier.
     */
    public static final String POWER_AUDIO = "dsp.audio";

    /**
     * Power consumed by any media hardware when playing back video content. This is in addition
     * to the CPU power, probably due to a DSP.
     */
    public static final String POWER_VIDEO = "dsp.video";

    public static final String POWER_CPU_SPEEDS = "cpu.speeds";

    static final HashMap<String, Object> sPowerMap = new HashMap();

    private static final String TAG_DEVICE = "device";
    private static final String TAG_ITEM = "item";
    private static final String TAG_ARRAY = "array";
    private static final String TAG_ARRAYITEM = "value";
    private static final String ATTR_NAME = "name";

    public PowerProfile(Context context) {
        // Read the XML file for the given profile (normally only one per
        // device)
        if (sPowerMap.size() == 0) {
            readPowerValuesFromXml(context);
        }
    }

    private void readPowerValuesFromXml(Context context) {
        int id = com.android.internal.R.xml.power_profile;
        XmlResourceParser parser = context.getResources().getXml(id);
        boolean parsingArray = false;
        ArrayList<Double> array = new ArrayList();
        String arrayName = null;

        try {
            XmlUtils.beginDocument(parser, TAG_DEVICE);

            while (true) {
                XmlUtils.nextElement(parser);

                String element = parser.getName();
                if (element == null) break;
                
                if (parsingArray && !element.equals(TAG_ARRAYITEM)) {
                    // Finish array
                    sPowerMap.put(arrayName, array.toArray(new Double[array.size()]));
                    parsingArray = false;
                }
                if (element.equals(TAG_ARRAY)) {
                    parsingArray = true;
                    array.clear();
                    arrayName = parser.getAttributeValue(null, ATTR_NAME);
                } else if (element.equals(TAG_ITEM) || element.equals(TAG_ARRAYITEM)) {
                    String name = null;
                    if (!parsingArray) name = parser.getAttributeValue(null, ATTR_NAME);
                    if (parser.next() == XmlPullParser.TEXT) {
                        String power = parser.getText();
                        double value = 0;
                        try {
                            value = Double.valueOf(power);
                        } catch (NumberFormatException nfe) {
                        }
                        if (element.equals(TAG_ITEM)) {
                            sPowerMap.put(name, value);
                        } else if (parsingArray) {
                            array.add(value);
                        }
                    }
                }
            }
            if (parsingArray) {
                sPowerMap.put(arrayName, array.toArray(new Double[array.size()]));
            }
        } catch (XmlPullParserException e) {
            throw new RuntimeException(e);
        } catch (IOException e) {
            throw new RuntimeException(e);
        } finally {
            parser.close();
        }
    }

    /**
     * Returns the average current in mA consumed by the subsystem 
     * @param type the subsystem type
     * @return the average current in milliAmps.
     */
    public double getAveragePower(String type) {
        if (sPowerMap.containsKey(type)) {
            Object data = sPowerMap.get(type);
            if (data instanceof Double[]) {
                return ((Double[])data)[0];
            } else {
                return (Double) sPowerMap.get(type);
            }
        } else {
            return 0;
        }
    }
    
    /**
     * Returns the average current in mA consumed by the subsystem for the given level.
     * @param type the subsystem type
     * @param level the level of power at which the subsystem is running. For instance, the
     *  signal strength of the cell network between 0 and 4 (if there are 4 bars max.)
     *  If there is no data for multiple levels, the level is ignored.
     * @return the average current in milliAmps.
     */
    public double getAveragePower(String type, int level) {
        if (sPowerMap.containsKey(type)) {
            Object data = sPowerMap.get(type);
            if (data instanceof Double[]) {
                final Double[] values = (Double[]) data;
                if (values.length > level && level >= 0) {
                    return values[level];
                } else if (level < 0) {
                    return 0;
                } else {
                    return values[values.length - 1];
                }
            } else {
                return (Double) data;
            }
        } else {
            return 0;
        }
    }

    public int getNumSpeedSteps() {
        Object value = sPowerMap.get(POWER_CPU_SPEEDS);
        if (value != null && value instanceof Double[]) {
            return ((Double[])value).length;
        }
        return 1; // Only one speed
    }
}