1 /* 2 * Copyright (C) 2016 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.cts.verifier.usb.accessory; 18 19 import android.app.Activity; 20 import android.hardware.usb.UsbAccessory; 21 import android.hardware.usb.UsbManager; 22 import android.os.Bundle; 23 import androidx.annotation.NonNull; 24 import androidx.annotation.Nullable; 25 26 import java.util.ArrayList; 27 28 /** 29 * Utility to receive callbacks when an USB accessory is attached. 30 */ 31 public class AccessoryAttachmentHandler extends Activity { 32 private static final ArrayList<AccessoryAttachmentObserver> sObservers = new ArrayList<>(); 33 34 /** 35 * Register an observer to be called when an USB accessory connects. 36 * 37 * @param observer The observer that should be called when an USB accessory connects. 38 */ 39 static void addObserver(@NonNull AccessoryAttachmentObserver observer) { 40 synchronized (sObservers) { 41 sObservers.add(observer); 42 } 43 } 44 45 /** 46 * Remove an observer that was added in {@link #addObserver}. 47 * 48 * @param observer The observer to remove 49 */ 50 static void removeObserver(@NonNull AccessoryAttachmentObserver observer) { 51 synchronized (sObservers) { 52 sObservers.remove(observer); 53 } 54 } 55 56 @Override 57 protected void onCreate(@Nullable Bundle savedInstanceState) { 58 super.onCreate(savedInstanceState); 59 60 UsbAccessory accessory = getIntent().getParcelableExtra(UsbManager.EXTRA_ACCESSORY); 61 62 synchronized (sObservers) { 63 ArrayList<AccessoryAttachmentObserver> observers = 64 (ArrayList<AccessoryAttachmentObserver>) sObservers.clone(); 65 66 for (AccessoryAttachmentObserver observer : observers) { 67 observer.onAttached(accessory); 68 } 69 } 70 71 finish(); 72 } 73 74 /** 75 * Callback when an accessory is attached 76 */ 77 interface AccessoryAttachmentObserver { 78 void onAttached(UsbAccessory accessory); 79 } 80 } 81
