Extensions to resolve file paths from uri on Android

UriPath.kt

fun isExternalStorageDocument(uri: Uri) = "com.android.externalstorage.documents" == uri.authority

fun isDownloadsDocument(uri: Uri) = "com.android.providers.downloads.documents" == uri.authority

fun isMediaDocument(uri: Uri) = "com.android.providers.media.documents" == uri.authority

/**
 * Get a file path from a Uri. This will get the the path for Storage Access
 * Framework Documents, as well as the _data field for the MediaStore and
 * other file-based ContentProviders.
 *
 * @param context The context.
 * @param uri The Uri to query.
 * @author paulburke
 */
fun Uri.getPath(context: Context): String? {

    val uri = this

    // DocumentProvider
    if (DocumentsContract.isDocumentUri(context, this)) {
        // ExternalStorageProvider
        if (isExternalStorageDocument(uri)) {
            val docId = DocumentsContract.getDocumentId(uri)
            val split = docId.split(":").toTypedArray()
            val type = split[0]

            if ("primary".equals(type, ignoreCase = true)) {
                return Environment.getExternalStorageDirectory().absolutePath + "/" + split[1]
            }

            // TODO handle non-primary volumes
        } else if (isDownloadsDocument(uri)) {

            val id = DocumentsContract.getDocumentId(uri)
            val contentUri = ContentUris.withAppendedId(
                Uri.parse("content://downloads/public_downloads"), java.lang.Long.valueOf(id)
            )

            return contentUri?.getDataColumn(null, null)
        } else if (isMediaDocument(uri)) {
            val docId = DocumentsContract.getDocumentId(uri)
            val split = docId.split(":").toTypedArray()
            val type = split[0]

            var contentUri: Uri? = null
             when (type) {
                "image" -> contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI
                "video" -> contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI
                "audio" -> contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI
            }

            val selection = "_id=?"
            val selectionArgs = arrayOf(split[1])

            return contentUri?.getDataColumn(selection, selectionArgs)
        }// MediaProvider
        // DownloadsProvider
    } else if ("content".equals(uri.scheme, ignoreCase = true)) {
        return uri.getDataColumn(null, null)
    } else if ("file".equals(uri.scheme, ignoreCase = true)) {
        return uri.path
    }// File
    // MediaStore (and general)

    return null
}

/**
 * Get the value of the data column for this Uri. This is useful for
 * MediaStore Uris, and other file-based ContentProviders.
 *
 * @param selection (Optional) Filter used in the query.
 * @param selectionArgs (Optional) Selection arguments used in the query.
 * @return The value of the _data column, which is typically a file path.
 */
fun Uri.getDataColumn(
    selection: String?,
    selectionArgs: Array<String>?,
    contentResolver: ContentResolver = appCtx.contentResolver
): String? {

    var cursor: Cursor? = null
    val column = "_data"
    val projection = arrayOf(column)

    try {
        cursor = contentResolver.query(this, projection, selection, selectionArgs, null)
        if (cursor?.moveToFirst() == true) {
            val columnIndex = cursor.getColumnIndexOrThrow(column)
            return cursor.getString(columnIndex)
        }
    } finally {
        cursor?.close()
    }
    return null
}