/*
* Copyright (C) 2008 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;
import android.app.ActivityManagerNative;
import android.content.Context;
import android.content.Intent;
import android.os.Handler;
import android.os.Message;
import android.os.PowerManager;
import android.os.PowerManager.WakeLock;
import android.os.UEventObserver;
import android.util.Slog;
import android.media.AudioManager;
import java.io.FileReader;
import java.io.FileNotFoundException;
/**
* <p>HeadsetObserver monitors for a wired headset.
*/
class HeadsetObserver extends UEventObserver {
private static final String TAG = HeadsetObserver.class.getSimpleName();
private static final boolean LOG = true;
private static final String HEADSET_UEVENT_MATCH = "DEVPATH=/devices/virtual/switch/h2w";
private static final String HEADSET_STATE_PATH = "/sys/class/switch/h2w/state";
private static final String HEADSET_NAME_PATH = "/sys/class/switch/h2w/name";
private static final int BIT_HEADSET = (1 << 0);
private static final int BIT_HEADSET_NO_MIC = (1 << 1);
private static final int SUPPORTED_HEADSETS = (BIT_HEADSET|BIT_HEADSET_NO_MIC);
private static final int HEADSETS_WITH_MIC = BIT_HEADSET;
private int mHeadsetState;
private int mPrevHeadsetState;
private String mHeadsetName;
private final Context mContext;
private final WakeLock mWakeLock; // held while there is a pending route change
public HeadsetObserver(Context context) {
mContext = context;
PowerManager pm = (PowerManager)context.getSystemService(Context.POWER_SERVICE);
mWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "HeadsetObserver");
mWakeLock.setReferenceCounted(false);
startObserving(HEADSET_UEVENT_MATCH);
init(); // set initial status
}
@Override
public void onUEvent(UEventObserver.UEvent event) {
if (LOG) Slog.v(TAG, "Headset UEVENT: " + event.toString());
try {
update(event.get("SWITCH_NAME"), Integer.parseInt(event.get("SWITCH_STATE")));
} catch (NumberFormatException e) {
Slog.e(TAG, "Could not parse switch state from event " + event);
}
}
private synchronized final void init() {
char[] buffer = new char[1024];
String newName = mHeadsetName;
int newState = mHeadsetState;
mPrevHeadsetState = mHeadsetState;
try {
FileReader file = new FileReader(HEADSET_STATE_PATH);
int len = file.read(buffer, 0, 1024);
newState = Integer.valueOf((new String(buffer, 0, len)).trim());
file = new FileReader(HEADSET_NAME_PATH);
len = file.read(buffer, 0, 1024);
newName = new String(buffer, 0, len).trim();
} catch (FileNotFoundException e) {
Slog.w(TAG, "This kernel does not have wired headset support");
} catch (Exception e) {
Slog.e(TAG, "" , e);
}
update(newName, newState);
}
private synchronized final void update(String newName, int newState) {
// Retain only relevant bits
int headsetState = newState & SUPPORTED_HEADSETS;
int newOrOld = headsetState | mHeadsetState;
int delay = 0;
// reject all suspect transitions: only accept state changes from:
// - a: 0 heaset to 1 headset
// - b: 1 headset to 0 headset
if (mHeadsetState == headsetState || ((newOrOld & (newOrOld - 1)) != 0)) {
return;
}
mHeadsetName = newName;
mPrevHeadsetState = mHeadsetState;
mHeadsetState = headsetState;
if (headsetState == 0) {
Intent intent = new Intent(AudioManager.ACTION_AUDIO_BECOMING_NOISY);
mContext.sendBroadcast(intent);
// It can take hundreds of ms flush the audio pipeline after
// apps pause audio playback, but audio route changes are
// immediate, so delay the route change by 1000ms.
// This could be improved once the audio sub-system provides an
// interface to clear the audio pipeline.
delay = 1000;
} else {
// Insert the same delay for headset connection so that the connection event is not
// broadcast before the disconnection event in case of fast removal/insertion
if (mHandler.hasMessages(0)) {
delay = 1000;
}
}
mWakeLock.acquire();
mHandler.sendMessageDelayed(mHandler.obtainMessage(0,
mHeadsetState,
mPrevHeadsetState,
mHeadsetName),
delay);
}
private synchronized final void sendIntents(int headsetState, int prevHeadsetState, String headsetName) {
int allHeadsets = SUPPORTED_HEADSETS;
for (int curHeadset = 1; allHeadsets != 0; curHeadset <<= 1) {
if ((curHeadset & allHeadsets) != 0) {
sendIntent(curHeadset, headsetState, prevHeadsetState, headsetName);
allHeadsets &= ~curHeadset;
}
}
}
private final void sendIntent(int headset, int headsetState, int prevHeadsetState, String headsetName) {
if ((headsetState & headset) != (prevHeadsetState & headset)) {
// Pack up the values and broadcast them to everyone
Intent intent = new Intent(Intent.ACTION_HEADSET_PLUG);
intent.addFlags(Intent.FLAG_RECEIVER_REGISTERED_ONLY);
int state = 0;
int microphone = 0;
if ((headset & HEADSETS_WITH_MIC) != 0) {
microphone = 1;
}
if ((headsetState & headset) != 0) {
state = 1;
}
intent.putExtra("state", state);
intent.putExtra("name", headsetName);
intent.putExtra("microphone", microphone);
if (LOG) Slog.v(TAG, "Intent.ACTION_HEADSET_PLUG: state: "+state+" name: "+headsetName+" mic: "+microphone);
// TODO: Should we require a permission?
ActivityManagerNative.broadcastStickyIntent(intent, null);
}
}
private final Handler mHandler = new Handler() {
@Override
public void handleMessage(Message msg) {
sendIntents(msg.arg1, msg.arg2, (String)msg.obj);
mWakeLock.release();
}
};
}