相机在未经相机许可的情况下正常工作

Question

I've not included the camera permission neither in manifest nor by programmatically but still my app opens the camera. What I was thinking till now was that the camera permission is used to open the camera, but here its totally different. So need some help to know, why camera works without giving permissions. Every help is appreciated. Here's my code

MainActivity.java

public class MainActivity extends AppCompatActivity {

    private static final int REQUEST_CAMERA = 1;
    private static final int SELECT_FILE = 2;
    String userChoosenTask;
    ImageView ivImage;
    Button btselect;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ivImage = (ImageView) findViewById(R.id.ivImage);
        btselect = (Button) findViewById(R.id.btnSelectPhoto);
        btselect.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                selectImage();
            }
        });
    }

    private void selectImage() {
        final CharSequence[] items = {"Take Photo", "Choose from Library", "Cancel"};
        AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
        builder.setTitle("Add Photo!");
        builder.setItems(items, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int item) {
                boolean result = Utility.checkPermission(MainActivity.this);

                if (items[item].equals("Take Photo")) {
                    userChoosenTask = "Take Photo";
                    if (result)
                        cameraIntent();
                } else if (items[item].equals("Choose from Library")) {
                    userChoosenTask = "Choose from Library";
                    if (result)
                        galleryIntent();
                } else if (items[item].equals("Cancel")) {
                    dialog.dismiss();
                }
            }
        });
        builder.show();
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        switch (requestCode) {
            case Utility.MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE:
                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    if (userChoosenTask.equals("Take Photo"))
                        cameraIntent();
                    else if (userChoosenTask.equals("Choose from Library"))
                        galleryIntent();
                } else {
//code for deny
                }
                break;
        }
    }

    private void cameraIntent() {
        Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        startActivityForResult(intent, REQUEST_CAMERA);
    }

    private void galleryIntent() {
        Intent intent = new Intent();
        intent.setType("image/*");
        intent.setAction(Intent.ACTION_GET_CONTENT);
        startActivityForResult(Intent.createChooser(intent, "Select File"), SELECT_FILE);
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (resultCode == Activity.RESULT_OK) {
            if (SELECT_FILE == requestCode)
                onSelectFromGalleryResult(data);
            else if (requestCode == REQUEST_CAMERA)
                onCaptureImageResult(data);
        }
    }

    @SuppressWarnings("deprecation")
    private void onSelectFromGalleryResult(Intent data) {
        Bitmap bm = null;
        if (data != null) {
            try {
                bm = MediaStore.Images.Media.getBitmap(getApplicationContext().getContentResolver(), data.getData());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        ivImage.setImageBitmap(bm);
    }

    private void onCaptureImageResult(Intent data) {
        Bitmap thumbnail = (Bitmap) data.getExtras().get("data");

        // CALL THIS METHOD TO GET THE URI FROM THE BITMAP
        Uri tempUri = getImageUri(getApplicationContext(), thumbnail);

        // CALL THIS METHOD TO GET THE ACTUAL PATH
        File finalFile = new File(getRealPathFromURI(tempUri));
        Bitmap finalimg = ExifUtil.rotateBitmap(finalFile.toString(), thumbnail);
        ivImage.setImageBitmap(thumbnail);
    }

    public Uri getImageUri(Context inContext, Bitmap inImage) {
        ByteArrayOutputStream bytes = new ByteArrayOutputStream();
        inImage.compress(Bitmap.CompressFormat.JPEG, 100, bytes);
        String path = MediaStore.Images.Media.insertImage(inContext.getContentResolver(), inImage, "Title", null);
        return Uri.parse(path);
    }

    public String getRealPathFromURI(Uri uri) {
        Cursor cursor = getContentResolver().query(uri, null, null, null, null);
        cursor.moveToFirst();
        int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA);
        return cursor.getString(idx);
    }
}

ExifUtil.java

public class ExifUtil {

    public static Bitmap rotateBitmap(String src, Bitmap bitmap) {
        try {
            int orientation = getExifOrientation(src);

            if (orientation == 1) {
                return bitmap;
            }

            Matrix matrix = new Matrix();
            switch (orientation) {
            case 2:
                matrix.setScale(-1, 1);
                break;
            case 3:
                matrix.setRotate(180);
                break;
            case 4:
                matrix.setRotate(180);
                matrix.postScale(-1, 1);
                break;
            case 5:
                matrix.setRotate(90);
                matrix.postScale(-1, 1);
                break;
            case 6:
                matrix.setRotate(90);
                break;
            case 7:
                matrix.setRotate(-90);
                matrix.postScale(-1, 1);
                break;
            case 8:
                matrix.setRotate(-90);
                break;
            default:
                return bitmap;
            }

            try {
                Bitmap oriented = Bitmap.createBitmap(bitmap, 0, 0, bitmap.getWidth(), bitmap.getHeight(), matrix, true);
                bitmap.recycle();
                return oriented;
            } catch (OutOfMemoryError e) {
                e.printStackTrace();
                return bitmap;
            }
        } catch (IOException e) {
            e.printStackTrace();
        } 

        return bitmap;
    }

    private static int getExifOrientation(String src) throws IOException {
        int orientation = 1;

        try {
            /**
             * if your are targeting only api level >= 5
             * ExifInterface exif = new ExifInterface(src);
             * orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, 1);
             */
            if (Build.VERSION.SDK_INT >= 5) {
                Class<?> exifClass = Class.forName("android.media.ExifInterface");
                Constructor<?> exifConstructor = exifClass.getConstructor(new Class[] { String.class });
                Object exifInstance = exifConstructor.newInstance(new Object[] { src });
                Method getAttributeInt = exifClass.getMethod("getAttributeInt", new Class[] { String.class, int.class });
                Field tagOrientationField = exifClass.getField("TAG_ORIENTATION");
                String tagOrientation = (String) tagOrientationField.get(null);
                orientation = (Integer) getAttributeInt.invoke(exifInstance, new Object[] { tagOrientation, 1});
            }
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SecurityException e) {
            e.printStackTrace();
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        } catch (InstantiationException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        }

        return orientation;
    }
}

Utility.java

public class Utility {
    public static final int MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE = 123;
    @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
    public static boolean checkPermission(final Context context)
    {
        int currentAPIVersion = Build.VERSION.SDK_INT;
        if(currentAPIVersion>=android.os.Build.VERSION_CODES.M)
        {
            if (ContextCompat.checkSelfPermission(context, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
                if (ActivityCompat.shouldShowRequestPermissionRationale((Activity) context, Manifest.permission.READ_EXTERNAL_STORAGE)) {
                    AlertDialog.Builder alertBuilder = new AlertDialog.Builder(context);
                    alertBuilder.setCancelable(true);
                    alertBuilder.setTitle("Permission necessary");
                    alertBuilder.setMessage("External storage permission is necessary");
                    alertBuilder.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
                        @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
                        public void onClick(DialogInterface dialog, int which) {
                            ActivityCompat.requestPermissions((Activity) context, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);
                        }
                    });
                    AlertDialog alert = alertBuilder.create();
                    alert.show();
                } else {
                    ActivityCompat.requestPermissions((Activity) context, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);
                }
                return false;
            } else {
                return true;
            }
        } else {
            return true;
        }
    }
}

AndroidManifest.xml

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.takeimagedemo">

    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
</manifest>

Answer 1

You don't require camera permission has you are just launching camera application via Intent.For launching any application you don't require any permission. You required camera permission when you are directly accessing camera resources or using camera apis.

android.permission.READ_EXTERNAL_STORAGE & 
android.permission.WRITE_EXTERNAL_STORAGE

these above permission required just because you are storing captured imaged in sd card or phone memory.

I hope these would help you.

Answer 2

In this example two things are noted there:

First: A Note on Permissions:
Although your application is leveraging the Camera, it is not required to have the android.permission.CAMERA permission since it is not directly accessing the camera. Instead, it's just launching the Camera application via Intent.

It seems you only need the permission to access the camera primitives directly, and not via the Intent.

Note that the same URL above also points out that you should declare the feature to prevent users without cameras from seeing your app in the market.