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      1 /*
      2  * Copyright (C) 2018 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.server.usb;
     18 
     19 /**
     20  * Detects and reports ALSA jack state and events.
     21  */
     22 public final class UsbAlsaJackDetector implements Runnable {
     23     private static final String TAG = "UsbAlsaJackDetector";
     24 
     25     private static native boolean nativeHasJackDetect(int card);
     26     private native boolean nativeJackDetect(int card);
     27     private native boolean nativeOutputJackConnected(int card);
     28     private native boolean nativeInputJackConnected(int card);
     29 
     30     private boolean mStopJackDetect = false;
     31     private UsbAlsaDevice mAlsaDevice;
     32 
     33     /* use startJackDetect to create a UsbAlsaJackDetector */
     34     private UsbAlsaJackDetector(UsbAlsaDevice device) {
     35         mAlsaDevice = device;
     36     }
     37 
     38     /** If jack detection is detected on the given Alsa Device,
     39      * create and return a UsbAlsaJackDetector which will update wired device state
     40      * each time a jack detection event is registered.
     41      *
     42      * @returns UsbAlsaJackDetector if jack detect is supported, or null.
     43      */
     44     public static UsbAlsaJackDetector startJackDetect(UsbAlsaDevice device) {
     45         if (!nativeHasJackDetect(device.getCardNum())) {
     46             return null;
     47         }
     48         UsbAlsaJackDetector jackDetector = new UsbAlsaJackDetector(device);
     49 
     50         // This thread will exit once the USB device disappears.
     51         // It can also be convinced to stop with pleaseStop().
     52         new Thread(jackDetector, "USB jack detect thread").start();
     53         return jackDetector;
     54     }
     55 
     56     public boolean isInputJackConnected() {
     57         return nativeInputJackConnected(mAlsaDevice.getCardNum());
     58     }
     59 
     60     public boolean isOutputJackConnected() {
     61         return nativeOutputJackConnected(mAlsaDevice.getCardNum());
     62     }
     63 
     64     /**
     65      * Stop the jack detect thread from calling back into UsbAlsaDevice.
     66      * This doesn't force the thread to stop (which is deprecated in java and dangerous due to
     67      * locking issues), but will cause the thread to exit at the next safe opportunity.
     68      */
     69     public void pleaseStop() {
     70         synchronized (this) {
     71             mStopJackDetect = true;
     72         }
     73     }
     74 
     75     /**
     76      * Called by nativeJackDetect each time a jack detect event is reported.
     77      * @return false when the jackDetect thread should stop.  true otherwise.
     78      */
     79     public boolean jackDetectCallback() {
     80         synchronized (this) {
     81             if (mStopJackDetect) {
     82                 return false;
     83             }
     84             mAlsaDevice.updateWiredDeviceConnectionState(true);
     85         }
     86         return true;
     87     }
     88 
     89     /**
     90      * This will call jackDetectCallback each time it detects a jack detect event.
     91      * If jackDetectCallback returns false, this function will return.
     92      */
     93     public void run() {
     94         nativeJackDetect(mAlsaDevice.getCardNum());
     95     }
     96 }
     97 
     98