Selector fixes (#304)

kushalkolar · web-flow · commit a363713abfa4 · 2023-09-18T05:48:54.000-04:00
* bugfix for axis=y, use round() instead of int() in get_selected_index(), more accurate

* add _pygfx_event = None to BaseSelector init

* fix type annotation for Synchronizer
diff --git a/fastplotlib/graphics/selectors/_base_selector.py b/fastplotlib/graphics/selectors/_base_selector.py
@@ -87,6 +87,8 @@ def __init__(
         # otherwise annoying and requires too much accuracy to move just an edge
         self._edge_hovered: bool = False
 
+        self._pygfx_event = None
+
     def get_selected_index(self):
         """Not implemented for this selector"""
         raise NotImplementedError
diff --git a/fastplotlib/graphics/selectors/_linear.py b/fastplotlib/graphics/selectors/_linear.py
@@ -107,8 +107,8 @@ def __init__(
 
             line_data = np.column_stack([xs, ys, zs])
         elif axis == "y":
-            xs = np.zeros(end_points)
-            ys = np.array(2)
+            xs = np.array(end_points)
+            ys = np.zeros(2)
             zs = np.zeros(2)
 
             line_data = np.column_stack([xs, ys, zs])
@@ -158,7 +158,6 @@ def __init__(
         )
 
         self._move_info: dict = None
-        self._pygfx_event = None
 
         self.parent = parent
 
@@ -349,17 +348,17 @@ def _get_selected_index(self, graphic):
                 or math.fabs(find_value - geo_positions[idx - 1])
                 < math.fabs(find_value - geo_positions[idx])
             ):
-                return int(idx - 1)
+                return round(idx - 1)
             else:
-                return int(idx)
+                return round(idx)
 
         if (
             "Heatmap" in graphic.__class__.__name__
             or "Image" in graphic.__class__.__name__
         ):
             # indices map directly to grid geometry for image data buffer
             index = self.selection() - offset
-            return int(index)
+            return round(index)
 
     def _move_graphic(self, delta: np.ndarray):
         """
diff --git a/fastplotlib/graphics/selectors/_sync.py b/fastplotlib/graphics/selectors/_sync.py
@@ -1,8 +1,9 @@
 from . import LinearSelector
+from typing import *
 
 
 class Synchronizer:
-    def __init__(self, *selectors: LinearSelector, key_bind: str = "Shift"):
+    def __init__(self, *selectors: LinearSelector, key_bind: Union[str, None] = "Shift"):
         """
         Synchronize the movement of `Selectors`. Selectors will move in sync only when the selected `"key_bind"` is
         used during the mouse movement event. Valid key binds are: ``"Control"``, ``"Shift"`` and ``"Alt"``.
