fix linear and linear region selectors offset when parent is None (#945)

kushalkolar · web-flow · commit 7b4c68746ddb · 2025-11-16T12:33:45.000-05:00
diff --git a/fastplotlib/graphics/selectors/_linear.py b/fastplotlib/graphics/selectors/_linear.py
@@ -183,10 +183,13 @@ def __init__(
         world_object.add(line_outer)
         world_object.add(line_inner)
 
-        if axis == "x":
-            offset = (parent.offset[0], 0, 0)
-        elif axis == "y":
-            offset = (0, parent.offset[1], 0)
+        if parent is None:
+            offset = (0, 0, 0)
+        else:
+            if axis == "x":
+                offset = (parent.offset[0], 0, 0)
+            elif axis == "y":
+                offset = (0, parent.offset[1], 0)
 
         # init base selector
         BaseSelector.__init__(
diff --git a/fastplotlib/graphics/selectors/_linear_region.py b/fastplotlib/graphics/selectors/_linear_region.py
@@ -277,12 +277,15 @@ def __init__(
         outer_edges = (line0_outer, line1_outer)
         group.add(*edges, *outer_edges)
 
-        # TODO: if parent offset changes, we should set the selector offset too, use offset evented property
-        # TODO: add check if parent is `None`, will throw error otherwise
-        if axis == "x":
-            offset = (parent.offset[0], center + parent.offset[1], 0)
-        elif axis == "y":
-            offset = (center + parent.offset[1], parent.offset[1], 0)
+        if parent is None:
+            offset = (0, 0, 0)
+        else:
+            # TODO: if parent offset changes, we should set the selector offset too, use offset evented property
+            # TODO: add check if parent is `None`, will throw error otherwise
+            if axis == "x":
+                offset = (parent.offset[0], center + parent.offset[1], 0)
+            elif axis == "y":
+                offset = (center + parent.offset[1], parent.offset[1], 0)
 
         # set the initial bounds of the selector
         # compensate for any offset from the parent graphic
