/*
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* Copyright (C) 2012 ZXing authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package com.zxing.scanner.camera.open;
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import android.hardware.Camera;
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import android.util.Log;
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/**
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* Abstraction over the {@link Camera} API that helps open them and return their metadata.
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*/
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@SuppressWarnings("deprecation")
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public final class OpenCameraInterface {
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private static final String TAG = OpenCameraInterface.class.getName();
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private OpenCameraInterface() {
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}
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/**
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* For {@link #open(int)}, means no preference for which camera to open.
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*/
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public static final int NO_REQUESTED_CAMERA = -1;
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/**
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* Opens the requested camera with {@link Camera#open(int)}, if one exists.
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*
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* @param cameraId camera ID of the camera to use. A negative value
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* or {@link #NO_REQUESTED_CAMERA} means "no preference", in which case a rear-facing
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* camera is returned if possible or else any camera
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* @return handle to {@link OpenCamera} that was opened
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*/
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public static OpenCamera open(int cameraId) {
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int numCameras = Camera.getNumberOfCameras();
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if (numCameras == 0) {
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Log.w(TAG, "No cameras!");
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return null;
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}
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boolean explicitRequest = cameraId >= 0;
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Camera.CameraInfo selectedCameraInfo = null;
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int index;
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if (explicitRequest) {
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index = cameraId;
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selectedCameraInfo = new Camera.CameraInfo();
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Camera.getCameraInfo(index, selectedCameraInfo);
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} else {
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index = 0;
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while (index < numCameras) {
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Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
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Camera.getCameraInfo(index, cameraInfo);
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CameraFacing reportedFacing = CameraFacing.values()[cameraInfo.facing];
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if (reportedFacing == CameraFacing.BACK) {
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selectedCameraInfo = cameraInfo;
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break;
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}
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index++;
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}
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}
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Camera camera;
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if (index < numCameras) {
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Log.i(TAG, "Opening camera #" + index);
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camera = Camera.open(index);
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} else {
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if (explicitRequest) {
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Log.w(TAG, "Requested camera does not exist: " + cameraId);
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camera = null;
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} else {
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Log.i(TAG, "No camera facing " + CameraFacing.BACK + "; returning camera #0");
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camera = Camera.open(0);
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selectedCameraInfo = new Camera.CameraInfo();
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Camera.getCameraInfo(0, selectedCameraInfo);
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}
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}
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if (camera == null) {
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return null;
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}
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return new OpenCamera(index, camera, CameraFacing.values()[selectedCameraInfo.facing],
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selectedCameraInfo.orientation);
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}
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}
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