1 /*
2  * Copyright (C) 2015 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.managedprofile;
18 
19 import android.hardware.camera2.CameraDevice;
20 import android.hardware.camera2.CameraManager;
21 import android.os.Handler;
22 import android.util.Log;
23 
24 import java.util.concurrent.CountDownLatch;
25 import java.util.concurrent.TimeUnit;
26 import java.util.concurrent.atomic.AtomicBoolean;
27 
28 /**
29  * A util class to help open camera in a blocking way.
30  */
31 class CameraUtils {
32 
33     private static final String TAG = "CameraUtils";
34 
35     /**
36      * @return true if success to open camera, false otherwise.
37      */
blockUntilOpenCamera(CameraManager cameraManager, Handler handler)38     public static boolean blockUntilOpenCamera(CameraManager cameraManager, Handler handler) {
39         try {
40             String[] cameraIdList = cameraManager.getCameraIdList();
41             if (cameraIdList == null || cameraIdList.length == 0) {
42                 return false;
43             }
44             String cameraId = cameraIdList[0];
45             CameraCallback callback = new CameraCallback();
46             cameraManager.openCamera(cameraId, callback, handler);
47             return callback.waitForResult();
48         } catch (Exception ex) {
49             // No matter what is going wrong, it means fail to open camera.
50             ex.printStackTrace();
51             return false;
52         }
53     }
54 
55     /**
56      * {@link CameraDevice.StateCallback} is called when {@link CameraDevice} changes its state.
57      */
58     private static class CameraCallback extends CameraDevice.StateCallback {
59 
60         private static final int OPEN_TIMEOUT_SECONDS = 5;
61 
62         private final CountDownLatch mLatch = new CountDownLatch(1);
63 
64         private AtomicBoolean mResult = new AtomicBoolean(false);
65 
66         @Override
onOpened(CameraDevice cameraDevice)67         public void onOpened(CameraDevice cameraDevice) {
68             Log.d(TAG, "open camera successfully");
69             mResult.set(true);
70             if (cameraDevice != null) {
71                 cameraDevice.close();
72             }
73             mLatch.countDown();
74         }
75 
76         @Override
onDisconnected(CameraDevice cameraDevice)77         public void onDisconnected(CameraDevice cameraDevice) {
78             Log.d(TAG, "disconnect camera");
79             mLatch.countDown();
80         }
81 
82         @Override
onError(CameraDevice cameraDevice, int error)83         public void onError(CameraDevice cameraDevice, int error) {
84             Log.e(TAG, "Fail to open camera, error code = " + error);
85             mLatch.countDown();
86         }
87 
waitForResult()88         public boolean waitForResult() throws InterruptedException {
89             mLatch.await(OPEN_TIMEOUT_SECONDS, TimeUnit.SECONDS);
90             return mResult.get();
91         }
92     }
93 }
94