Fix a lack of backward-compatibility with .tileset.json files created…

… before v0.2

main.py

@@ -36,14 +36,8 @@
 
 # Changes in the next release
 # ----------------------------------
-# Features:
-#   * The maximum width and height of the displayed image are now configurable. These options can be accessed through
-#   File > Preferences. The default dimensions have also been lowered to 400x300 pixels to resolve issues on smaller
-#   screens.
-#   * The .exe should now work on Windows 7
-# Bugfixes:
-#   * Fixed a crash that was occurring when Pixel Scale was changed after creating tiles.
-#   * Made the Grid Size entry a bit wider to accommodate differing grid width and height.
+
+# TODO: Encode text-based files in UTF-8.
 
 import os
 import pathlib

tile.py

@@ -80,7 +80,7 @@ def draw_passthrough(c, x1, y1, x2, y2):
     'tile_id': '',
     'tile_name': '',
     'tile_description': '',
-    'grid_size': 32,    # The grid size as the tile was created (only used if grid_padding is nonzero)
+    'grid_size': (32, 32),    # The grid size as the tile was created (only used if grid_padding is nonzero)
     'grid_padding': 0,  # The grid padding as the tile was created (used w/grid_size in _slice_n_splice)
 
     # Animation
@@ -498,6 +498,10 @@ def __init__(self, canvas, x1, y1, x2, y2, *, outline=None, width=None, scale=1,
         """
         self.error_image = PhotoImage(file=resource_path('data/tile_error.png'))
 
+        # For backward compatibility with .tileset.json files created before v0.2.
+        if 'grid_size' in kwargs and type(old_val := kwargs['grid_size']) == int:
+            kwargs['grid_size'] = (old_val, old_val)
+
         data = {}
         for k in defaults.keys():
             if k in kwargs: