From 251c89951d80e1d217c1ed09658830c54d73e2e9 Mon Sep 17 00:00:00 2001
From: Matthew Brett <matthew.brett@gmail.com>
Date: Fri, 29 Mar 2024 17:23:44 +0000
Subject: [PATCH] WIP: generalize class for opening image

Allow FileHolder subclasses to change the ImageOpener class.
---
 nibabel/fileholders.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/nibabel/fileholders.py b/nibabel/fileholders.py
index a27715350..00c329d5d 100644
--- a/nibabel/fileholders.py
+++ b/nibabel/fileholders.py
@@ -23,6 +23,9 @@ class FileHolderError(Exception):
 class FileHolder:
     """class to contain filename, fileobj and file position"""
 
+    # Default image opener class / callable
+    make_image_opener = ImageOpener
+
     def __init__(
         self,
         filename: str | None = None,
@@ -68,10 +71,11 @@ def get_prepare_fileobj(self, *args, **kwargs) -> ImageOpener:
            ``self.pos``
         """
         if self.fileobj is not None:
-            obj = ImageOpener(self.fileobj)  # for context manager
+            # for context manager
+            obj = self.make_image_opener(self.fileobj)
             obj.seek(self.pos)
         elif self.filename is not None:
-            obj = ImageOpener(self.filename, *args, **kwargs)
+            obj = self.make_image_opener(self.filename, *args, **kwargs)
             if self.pos != 0:
                 obj.seek(self.pos)
         else: