FileProvider path creation and BitmapFactory.decodefile problems in Android

Question

I am trying to use BitmapFactory.decodefile() in order to create a scaled down version of a camera photo and set it to an imageview in my framelayout. Am following the following instructions from Android Developers: https://developer.android.com/training/camera/photobasics.html In these instructions, files are created and stored inside a fileprovider which holds some meta-data file formatted in xml. Somehow, BitmapFactory.decodefile() can't seem to access this file which stores a picture whose content uri resides inside the fileprovider. The fileprovider is created inside the androidmanifest file as follows:

<provider
android:authorities="mypackagename.fileprovider"
android:name="android.support.v4.content.FileProvider"
android:exported="false" android:grantUriPermissions="true">
<meta-data
android:name="android.support.FILE_PROVIDER_PATHS"
android:resource="@xml/file_paths"  >
</meta-data>
</provider>

the file_paths xml file looks like this:

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
<external-path name="my_images"            path="Android/data/mypackagename/files/Pictures/" />
</paths>

The file name for where the picture will reside is generated via this method:

private File createImageFile() throws IOException {
// Create an image file name
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
String imageFileName = "JPEG_" + timeStamp + "_";
File storageDir = getExternalFilesDir(Environment.DIRECTORY_PICTURES);
File image = File.createTempFile(imageFileName,".jpg",storageDir);

// Save a file: path for use with ACTION_VIEW intents
mCurrentPhotoPath = image.getAbsolutePath();
Log.d("absolute",""+image.getAbsolutePath());
return image;
}

The code starts an intent in order to take a picture with startactivityforresult() like this:

Intent i = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
// Ensure that there's a camera activity to handle the intent
if (i.resolveActivity(getPackageManager()) != null) {
// Create the File where the photo should go
photoFile = null;
try {
photoFile = createImageFile();
} catch (IOException ex) {
// Error occurred while creating the File

}
// Continue only if the File was successfully created
if (photoFile != null) {
Uri photoURI = FileProvider.getUriForFile  (this,"mypackagename.fileprovider",photoFile);

i.putExtra(android.provider.MediaStore.EXTRA_OUTPUT, photoURI);
startActivityForResult(i,TAKE_PICTURE);
}
}

Now, onActivityForResult() method starts, but if I set my if statement like this if(requestCode == TAKE_PICTURE && resultCode == RESULT_OK) it doesn't work. I don't know why. From reading the android reference documents on fileprovider class, I see that I must open the photoUri which is passed as an extra in my intent. According to the docs, I must open It with ContentResolver.openFileDescriptor which will return a ParcelFileDescriptor. Somehow, this is where the picture the camera just took resides. Somehow I need to access the file name from this ParcelFileDescriptor object and pass it to BitmapFactory.decodefile in order to scale down the picture-bitmap and set it on my imageview. I don't know how to go about this

When trying to scale the picture-bitmap I have the following code that returns -1, meaning that "according to the android reference docs for BitmapFactory class" "there was a problem decoding the file". I don't know why there would be a problem. Here's the code that returns -1:

BitmapFactory.decodeFile(mCurrentPhotoPath, bmOptions);

int photoW = bmOptions.outWidth;
int photoH = bmOptions.outHeight;

Both photoW and photoH return -1. Remember that the variable mCurrentPhotoPath was initialized inside the method CreateImageFile() , all the way at the top of this question.

I've also tried,

BitmapFactory.decodeFile(photoFile.getAbsolutePath(), bmOptions);

But still the same result, actually mCurrentPhotoPath and photoFile.getAbsolutePath() are equal strings.

I think that somehow the fileprovider with its meta-data xml file are somehow hiding the file path from BitmapFactory.decodefile().

The picture is taken when I test the app and is also stored inside my phone picture gallery.

Please provide any advice or suggestions since I need to proceed with the tess-two library and perform OCR with the pictures from the camera.

Thanks for your suggestions

Answer 1

I have faced exactly the same problem and this is how I dealed with it: first of all set i.setFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION); as suggested above, before launching the camera. Then, DO NOT use the BitmapFactory.decodeFile() method as it only works with the file:/// type of Uris retrieved using Uri.fromFile(), but not with the content:// type of Uris retrieved using FileProvider.getUriForFile() which is the required way for APIs >= 24.

Instead, use a ContentResolver to open an InputStream and decode the image as follows:

BitmapFactory.Options bmOptions = new BitmapFactory.Options();
bmOptions.inJustDecodeBounds = true;
ContentResolver cr = getActivity().getContentResolver();
InputStream input = null;
InputStream input1 = null;
try {
    input = cr.openInputStream(photoUri);
    BitmapFactory.decodeStream(input, null, bmOptions);
    if (input != null) {
        input.close();
    }
} catch (Exception e) {
    e.printStackTrace();
}

int photoW = bmOptions.outWidth;
int photoH = bmOptions.outHeight;
try {
    input1 = cr.openInputStream(photoUri);
    Bitmap takenImage = BitmapFactory.decodeStream(input1);                
    if (input1 != null) {
        input1.close();
    }
} catch (Exception e) {
    e.printStackTrace();
}

Note, that in order to obtain the Bitmap, you have to open a 2nd input stream, since the first one cannot be reused.