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      1 /*
      2 * Copyright 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.example.android.system.runtimepermissions.camera;
     18 
     19 import com.example.android.common.logger.Log;
     20 import com.example.android.system.runtimepermissions.R;
     21 
     22 import android.hardware.Camera;
     23 import android.os.Bundle;
     24 import android.support.v4.app.Fragment;
     25 import android.view.LayoutInflater;
     26 import android.view.View;
     27 import android.view.ViewGroup;
     28 import android.widget.FrameLayout;
     29 import android.widget.Toast;
     30 
     31 /**
     32  * Displays a {@link CameraPreview} of the first {@link Camera}.
     33  * An error message is displayed if the Camera is not available.
     34  * <p>
     35  * This Fragment is only used to illustrate that access to the Camera API has been granted (or
     36  * denied) as part of the runtime permissions model. It is not relevant for the use of the
     37  * permissions API.
     38  * <p>
     39  * Implementation is based directly on the documentation at
     40  * http://developer.android.com/guide/topics/media/camera.html
     41  */
     42 public class CameraPreviewFragment extends Fragment {
     43 
     44     private static final String TAG = "CameraPreview";
     45 
     46     /**
     47      * Id of the camera to access. 0 is the first camera.
     48      */
     49     private static final int CAMERA_ID = 0;
     50 
     51     private CameraPreview mPreview;
     52     private Camera mCamera;
     53 
     54     public static CameraPreviewFragment newInstance() {
     55         return new CameraPreviewFragment();
     56     }
     57 
     58     @Override
     59     public View onCreateView(LayoutInflater inflater, ViewGroup container,
     60             Bundle savedInstanceState) {
     61 
     62         // Open an instance of the first camera and retrieve its info.
     63         mCamera = getCameraInstance(CAMERA_ID);
     64         Camera.CameraInfo cameraInfo = null;
     65 
     66         if (mCamera != null) {
     67             // Get camera info only if the camera is available
     68             cameraInfo = new Camera.CameraInfo();
     69             Camera.getCameraInfo(CAMERA_ID, cameraInfo);
     70         }
     71 
     72         if (mCamera == null || cameraInfo == null) {
     73             // Camera is not available, display error message
     74             Toast.makeText(getActivity(), "Camera is not available.", Toast.LENGTH_SHORT).show();
     75             return inflater.inflate(R.layout.fragment_camera_unavailable, null);
     76         }
     77 
     78         View root = inflater.inflate(R.layout.fragment_camera, null);
     79 
     80         // Get the rotation of the screen to adjust the preview image accordingly.
     81         final int displayRotation = getActivity().getWindowManager().getDefaultDisplay()
     82                 .getRotation();
     83 
     84         // Create the Preview view and set it as the content of this Activity.
     85         mPreview = new CameraPreview(getActivity(), mCamera, cameraInfo, displayRotation);
     86         FrameLayout preview = (FrameLayout) root.findViewById(R.id.camera_preview);
     87         preview.addView(mPreview);
     88 
     89         return root;
     90     }
     91 
     92     @Override
     93     public void onPause() {
     94         super.onPause();
     95         // Stop camera access
     96         releaseCamera();
     97     }
     98 
     99     /** A safe way to get an instance of the Camera object. */
    100     public static Camera getCameraInstance(int cameraId) {
    101         Camera c = null;
    102         try {
    103             c = Camera.open(cameraId); // attempt to get a Camera instance
    104         } catch (Exception e) {
    105             // Camera is not available (in use or does not exist)
    106             Log.d(TAG, "Camera " + cameraId + " is not available: " + e.getMessage());
    107         }
    108         return c; // returns null if camera is unavailable
    109     }
    110 
    111     private void releaseCamera() {
    112         if (mCamera != null) {
    113             mCamera.release();        // release the camera for other applications
    114             mCamera = null;
    115         }
    116     }
    117 }
    118