1 /*
2  * Copyright (C) 2023 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.DeviceAsWebcam;
18 
19 import android.hardware.camera2.CameraManager;
20 
21 import androidx.annotation.Nullable;
22 import androidx.core.util.Preconditions;
23 
24 import java.util.regex.Pattern;
25 
26 /**
27  * An identifier composed by a pair of camera device id and its underlying physical camera id.
28  */
29 public class CameraId {
30     private static final String CAMERA_ID_SPLITTER = "-";
31     public final String mainCameraId;
32     @Nullable
33     public final String physicalCameraId;
34     private final String identifier;
35 
36     /**
37      * Constructor
38      *
39      * @param mainCameraId     the main camera id retrieved via
40      *                         {@link CameraManager#getCameraIdList()}.
41      * @param physicalCameraId the physical camera id if the main camera is a logical camera. This
42      *                         can be {@code null}.
43      */
CameraId(String mainCameraId, @Nullable String physicalCameraId)44     public CameraId(String mainCameraId, @Nullable String physicalCameraId) {
45         Preconditions.checkNotNull(mainCameraId, "The specified id can't be null!");
46         this.mainCameraId = mainCameraId;
47         this.physicalCameraId = physicalCameraId;
48         identifier = createIdentifier(mainCameraId, physicalCameraId);
49     }
50 
51     @Override
hashCode()52     public int hashCode() {
53         return identifier.hashCode();
54     }
55 
56     @Override
equals(Object obj)57     public boolean equals(Object obj) {
58         if (this == obj) {
59             return true;
60         }
61 
62         if (!(obj instanceof CameraId dest)) {
63             return false;
64         }
65 
66         return identifier.equals(dest.identifier);
67     }
68 
69     @Override
toString()70     public String toString() {
71         return identifier;
72     }
73 
74     /**
75      * Creates an identifier string to represent the camera.
76      */
createIdentifier(String cameraId, @Nullable String physicalCameraId)77     public static String createIdentifier(String cameraId, @Nullable String physicalCameraId) {
78         return cameraId + CAMERA_ID_SPLITTER + physicalCameraId;
79     }
80 
81     /**
82      * Returns the CameraId restored from the specified identifier.
83      *
84      * <p>The identifier should be created by the {@link #createIdentifier(String, String)}
85      * function. If the identifier format is not matched, {@code null} will be returned by this
86      * function.
87      */
88     @Nullable
fromCameraIdString(@ullable String identifier)89     public static CameraId fromCameraIdString(@Nullable String identifier) {
90         if (identifier == null) {
91             return null;
92         }
93 
94         String idPattern = "\\d+" + CAMERA_ID_SPLITTER + "(?:\\d+|null)";
95         if (!Pattern.matches(idPattern, identifier)) {
96             return null;
97         }
98 
99         int index = identifier.indexOf(CAMERA_ID_SPLITTER);
100         String mainCameraId = identifier.substring(0, index);
101         String physicalCameraId = identifier.substring(index + CAMERA_ID_SPLITTER.length());
102 
103         return new CameraId(mainCameraId,
104                 physicalCameraId.equals("null") ? null : physicalCameraId);
105     }
106 }
107