Fix 3D point adding by passing in dims as well as layer (#48)

* Fix 3D point adding by passing in dims as well as layer
* Fix tests
* Fix click test

src/zarpaint/_add_3d_points.py

@@ -36,7 +36,7 @@ def get_data_ray(data, start_point, end_point):
     return clipped_coords, ray
 
 
-def find_midpoint_of_first_segment(layer, event):
+def find_midpoint_of_first_segment(layer, dims, event):
     """Return the world coordinate of a Labels layer mouse event in 2D or 3D.
 
     In 2D, this is just the event's position.
@@ -58,14 +58,14 @@ def find_midpoint_of_first_segment(layer, event):
     coordinates : array of int
         The world coordinates for the mouse event.
     """
-    ndim = len(layer._dims_displayed)
+    ndim = len(dims.displayed)
     if ndim == 2:
         coordinates = event.position
     else:  # 3d
         start, end = layer.get_ray_intersections(
                 position=event.position,
                 view_direction=event.view_direction,
-                dims_displayed=layer._dims_displayed,
+                dims_displayed=list(dims.displayed),
                 world=True,
                 )
         coordinates, ray = get_data_ray(layer.data, start, end)
@@ -85,6 +85,7 @@ def find_midpoint_of_first_segment(layer, event):
 
 @magicgui.magic_factory
 def add_points_3d_with_alt_click(
+        viewer: napari.Viewer,
         labels: napari.layers.Labels,
         points: napari.layers.Points,
         ):
@@ -95,7 +96,9 @@ def click_callback(layer, event):
         if not (len(event.modifiers) == 1
                 and event.modifiers[0].name == 'Alt'):
             return
-        world_click_coordinates = find_midpoint_of_first_segment(layer, event)
+        world_click_coordinates = find_midpoint_of_first_segment(
+                layer, viewer.dims, event
+                )
         if world_click_coordinates is not None:
             pts_coordinates = pts_world2data(world_click_coordinates)
             points.add(pts_coordinates)

src/zarpaint/_tests/test_zarpaint.py

@@ -46,6 +46,7 @@ def test_get_ray_coordinates():
 
 def test_midpoint_2d_empty_ray(make_napari_viewer):
     viewer = make_napari_viewer()
+    dims = viewer.dims
 
     mock_data = np.zeros(shape=(5, 5), dtype="uint8")
     layer_data = Labels(mock_data)
@@ -55,12 +56,13 @@ def test_midpoint_2d_empty_ray(make_napari_viewer):
     view_direction = [1, 0]
     mouse_event = MockMouseEvent(position, view_direction)
 
-    result = find_midpoint_of_first_segment(layer_data, mouse_event)
+    result = find_midpoint_of_first_segment(layer_data, dims, mouse_event)
     assert result == (0, 0)
 
 
 def test_midpoint_2d_nonempty_ray(make_napari_viewer):
     viewer = make_napari_viewer()
+    dims = viewer.dims
 
     mock_data = np.ones(shape=(5, 5), dtype="uint8")
     layer_data = Labels(mock_data)
@@ -70,21 +72,22 @@ def test_midpoint_2d_nonempty_ray(make_napari_viewer):
     view_direction = [1, 0]
     mouse_event = MockMouseEvent(position, view_direction)
 
-    result = find_midpoint_of_first_segment(layer_data, mouse_event)
+    result = find_midpoint_of_first_segment(layer_data, dims, mouse_event)
     assert result == (3, 0)
 
 
 def test_midpoint_3d_empty_ray(make_napari_viewer):
     viewer = make_napari_viewer()
     viewer.dims.ndisplay = 3
+    dims = viewer.dims
 
     mock_data = np.zeros(shape=(5, 5, 5), dtype="uint8")
     layer_data = Labels(mock_data)
     mouse_event = MockMouseEvent((2, 2, 0), [1, 0, 0])
 
     viewer.add_layer(layer_data)
 
-    result = find_midpoint_of_first_segment(layer_data, mouse_event)
+    result = find_midpoint_of_first_segment(layer_data, dims, mouse_event)
     assert result is None
 
     mock_data[1:4, 1:4, 1:4] = 1
@@ -93,21 +96,22 @@ def test_midpoint_3d_empty_ray(make_napari_viewer):
 
     viewer.add_layer(layer_data)
 
-    result = find_midpoint_of_first_segment(layer_data, mouse_event)
+    result = find_midpoint_of_first_segment(layer_data, dims, mouse_event)
     assert result is None
 
 
 def test_midpoint_3d_nonempty_ray(make_napari_viewer):
     viewer = make_napari_viewer()
     viewer.dims.ndisplay = 3
+    dims = viewer.dims
 
     mock_data = np.zeros(shape=(5, 5, 5), dtype="uint8")
     mock_data[1:4, 1:4, 1:4] = 1
     layer_data = Labels(mock_data)
     viewer.add_layer(layer_data)
 
     mouse_event = MockMouseEvent((2, 2, 0), [0, 1, 1])
-    result = find_midpoint_of_first_segment(layer_data, mouse_event)
+    result = find_midpoint_of_first_segment(layer_data, dims, mouse_event)
     np.testing.assert_allclose(result, [2., 3.5, 1.5])
 
 
@@ -124,7 +128,7 @@ def test_add_point_3d_alt_click(make_napari_viewer):
     viewer.layers.selection.active = label_layer
 
     point_widget = add_points_3d_with_alt_click()
-    point_widget(label_layer, points_layer)
+    point_widget(viewer, label_layer, points_layer)
 
     view = viewer.window._qt_viewer
     click_coordinates = (view.canvas.size[0] / 2, view.canvas.size[1] / 2, 0)