Question

I have an application in which I can use the device’s camera to take a picture. What I would like to do is to start the ACTION_IMAGE_CAPTURE intent without assigning an EXTRA_OUTPUT, and then move the file that is created in the default location to my own custom location using file.renameTo. My code is something like this:

/* Start camera activity without EXTRA_OUTPUT */
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, _REQUESTCODE_ATTACH_CAMERA);

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == RESULT_OK) {
        switch(requestCode) {
            case _REQUESTCODE_ATTACH_CAMERA:
                /* Get path to most recently added image */
                final String[] imageColumns = { MediaStore.Images.Media._ID, MediaStore.Images.Media.DATA };
                final String imageOrderBy = MediaStore.Images.Media._ID + " DESC";
                Cursor imageCursor = managedQuery(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, imageColumns, null, null, imageOrderBy);
                String fullPath = "";
                if(imageCursor.moveToFirst()){
                    fullPath = imageCursor.getString(imageCursor.getColumnIndex(MediaStore.Images.Media.DATA));
                    imageCursor.close();
                }

                File f = Environment.getExternalStorageDirectory();
                f = new File(f.getAbsolutePath() + File.separator + "DCIM" + File.separator + MY_APP_NAME;
                if(!f.exists()) {
                    f.mkdirs();
                }

                /* Create new file based on name of most recently created image */
                File oldFile = new File(fullPath);
                String newPath = f.getAbsolutePath() + File.separator + oldFile.getName() ;

                /* Move file with renameTo */
                oldFile.renameTo(new File(newPath));

                break;
            ...
        }
    }
}

All of this works quite well, however there is one strange thing that is occurring. In my app, I have another button that allows selecting an existing image from the phone’s gallery. That code looks like this:

Intent galleryIntent = new Intent(Intent.ACTION_GET_CONTENT);
galleryIntent.setType("image/*");
activity.startActivityForResult(galleryIntent, _REQUESTCODE_ATTACH_GALLERY);

This also works, but if I take a picture with the camera using the code posted above, and then try to select another image from the gallery, there will be blank “broken link” type items in the gallery that contain no content and are unselectable. These seem to correspond with photos taken and moved using renameTo; if I put in code in onActivityResult to post the filename to LogCat, the name that gets logged is the same as the name of the previously moved file that it corresponds to. Trying to create a File object or in any way access that filename, results in null objects and force closes.

The strange part is that there is no evidence of these “broken link” files in Eclipse DDMS, nor in the phone itself if I use Root Browser, and they disappear if I remount the SD Card.

The whole reason I am moving the images after capturing them with the camera is to avoid filling up the phone’s gallery storage with unnecessary images. While these empty “broken link” type files don’t appear to be taking up any storage space, they would still be very annoying to an end-user trying to browse through their gallery. Does anyone have any ideas on what is happening here or how to solve this problem?

EDIT:
Here is a photo showing what the gallery looks like with a “broken link” type image displayed. One of these will appear for every photo that is taken using my app, and they will all disappear if I remount the SD Card.

Answer 1

Thanks in part to this SO thread, I have discovered a solution. It actually makes sense that it would behave this way since there is a table kept for media content and so removing something without telling the table would definitely create a “broken link” type scenario.

The ultimate solution is to use contentResolver.delete to remove the reference to the file within the content resolver, but there are two different ways that I have found that will work.

/* Moving with renameTo */
//Use the same exact code as I had before (shortened for brevity) to move the file
oldFile.renameTo(newFile);
//Get URI from contentResolver using file Id from cursor
Uri oldUri = ContentUris.withAppendedId(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, imageCursor.getString(imageCursor.getColumnIndex(MediaStore.Images.Media._ID)));
//Delete old file
getContentResolver().delete(oldUri, null, null);

Getting the URI in this way is necessary because it requires a reference to the image in the contentResolver rather than the path to its location in storage. This way might feel dirty to some since you are moving a file and then calling a delete function on that file in order to sort of trick the content resolver into removing the link to the file. If you would rather, you can do it without using renameTo so that the call to delete(…) actually does delete the image.

/* Moving with streams */
//Get streams
InputStream in = new FileInputStream(oldFile);
OutputStream out = new FileOutputStream(newFile);
byte[] buffer = new byte[1024];
int bytesRead = 0;
//Read old file into new file
while((bytesRead = in.read(buffer)) > 0) {
    out.write(buffer, 0, bytesRead);
}

//Get URI from contentResolver using file Id from cursor
Uri oldUri = ContentUris.withAppendedId(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, imageCursor.getString(imageCursor.getColumnIndex(MediaStore.Images.Media._ID)));
//Delete old file
getContentResolver().delete(oldUri, null, null);

The call to contentResolver.delete is the same either way, I just wanted to point out that it will still work if the image has already been removed.

During this I discovered a solution to a problem that I didn’t even realize that I had that I will post here as well in case anyone with this same problem comes across this in the future. In order to keep the image as selectable in the device gallery from the new location, you need to let the media scanner know that a change has been made. There are two ways that I found to do this:

/* This is the only way that I know of to handle multiple new files at once. I 
   really would use this sparingly, however, since it will rescan the entire 
   SD Card. Not only could this take a long time if the user has a lot of files 
   on their card, it will also show a notification so it is not exactly a 
   transparent operation. */
sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED, Uri.parse("file://" + Environment.getExternalStorageDirectory())));

/* You *could* do multiple files with this by passing in the path for each one 
   in the array of Strings, however an instance of this will get called for each 
   one rather than it doing them all at once. Likewise, your onScanCompleted 
   (if you choose to include one) will get called once for each file in the list. 
   So really, while this is much better for a small number of files, if you plan 
   on scanning a very large amount then the full rescan above would probably be 
   a better option. */
MediaScannerConnection.scanFile(context, new String[]{ newFilePathAsString }, null, 
    new MediaScannerConnection.OnScanCompletedListener() { 
        public void onScanCompleted(String path, Uri uri) {
            //This executes when scanning is completed
        }
    }
);