Image display data refuses to update when an image is opened with segmentation. The image must be reselected in the 'Files' tab in order to allow display data to be updated.

Image file is deselected after loading segmentation

Steps to reproduce

1. Open image
2. Open segmentation
3. Move sliders for display size or display center position

This line in mainwindow.py partially contributes to this issue

Description

The image is not updated when different MRI file is selected after specifying more than one set of segmentation

Reproduce

1. Open image folder
2. Open segmentation folder
3. Select one of the case with segmentation available
4. Play with the sliders for zoom/pan
5. Open another segmentation folder
6. Select another case --> nothing happens (but the window is not crashed)

Error messages

Original exception was:
Traceback (most recent call last):
  File "C:\Users\king ra\PycharmProjects\NIfTI-gridview\nifti_gridview\ngv_gui\mainwindow.py", line 319, in _update_image_data
    config['segment'].append(seg_temp[display_lrange:display_urange + 1])
TypeError: 'NoneType' object is not subscriptable

Image display shifts by itself when switching image files

Replication steps

1. Load image
2. Change display size or display center position
3. Load another image

First image

Second image

When shifting the setting display size and x y position, there could be a mismatch between the contour and the image.