test to reproduce #302 (#303)

* test to reproduce #302

* fix single scale images

---------

Co-authored-by: Grzegorz Bokota <bokota+github@gmail.com>

Author: LucaMarconato

src/napari_spatialdata/_view.py

@@ -307,12 +307,16 @@ def _channel_changed(self, event: Event) -> None:
 
         current_point = list(event.value)
         displayed = self._viewer.dims.displayed
-        for i, (lo_size, hi_size, cord) in enumerate(zip(layer.data[-1].shape, layer.data[0].shape, current_point)):
-            if i in displayed:
-                current_point[i] = slice(None)
-            else:
-                current_point[i] = int(cord * lo_size / hi_size)
-
+        if layer.multiscale:
+            for i, (lo_size, hi_size, cord) in enumerate(zip(layer.data[-1].shape, layer.data[0].shape, current_point)):
+                if i in displayed:
+                    current_point[i] = slice(None)
+                else:
+                    current_point[i] = int(cord * lo_size / hi_size)
+        else:
+            for i in range(len(current_point)):
+                if i in displayed:
+                    current_point[i] = slice(None)
         # TODO remove once contrast limits in napari are fixed
         if isinstance(layer.data, MultiScaleData):
             # just compute lowest resolution

tests/test_view.py

@@ -1,16 +1,19 @@
 from typing import Any
 
+import numpy as np
 import pytest
 from napari.utils.events import EventedList
 from napari_spatialdata._sdata_widgets import SdataWidget
 from napari_spatialdata._view import QtAdataViewWidget
 from napari_spatialdata.utils._test_utils import click_list_widget_item, get_center_pos_listitem
 from spatialdata.datasets import blobs
+from spatialdata.transformations import Affine, set_transformation
 
 
 @pytest.mark.parametrize("widget", [QtAdataViewWidget])
 @pytest.mark.parametrize("n_channels", [3, 5])
-def test_channel_slider_images(qtbot, make_napari_viewer: any, widget: Any, n_channels: int):
+def test_channel_slider_images_bug_282(qtbot, make_napari_viewer: any, widget: Any, n_channels: int):
+    # https://github.com/scverse/napari-spatialdata/issues/282
     channels = [f"channel_{i}" for i in range(n_channels)]
     sdata_blobs = blobs(c_coords=channels)
     viewer = make_napari_viewer()
@@ -63,3 +66,38 @@ def test_plot_dataframe_annotation_on_points(qtbot, make_napari_viewer: any, wid
     )
     widget.dataframe_columns_widget._onAction([column])
     viewer.close()
+
+
+@pytest.mark.parametrize("multiscale", [True, False])
+@pytest.mark.parametrize("widget", [QtAdataViewWidget])
+def test_channel_slider_images_bug_302(qtbot, make_napari_viewer: any, widget: Any, multiscale: bool):
+    # https://github.com/scverse/napari-spatialdata/issues/302
+    channels = [f"channel_{i}" for i in range(3)]
+    sdata_blobs = blobs(c_coords=channels)
+
+    # set a transformation to the single-scale and multi-scale images
+    element_name = "blobs_image" if not multiscale else "blobs_multiscale_image"
+    affine = Affine(np.array([[10, 20, 30], [40, 50, 60], [0, 0, 1]]), input_axes=("x", "y"), output_axes=("x", "y"))
+    set_transformation(sdata_blobs[element_name], transformation=affine, to_coordinate_system="global")
+
+    viewer = make_napari_viewer()
+    sdata_widget = SdataWidget(viewer, EventedList([sdata_blobs]))
+
+    viewer.window.add_dock_widget(sdata_widget, name="SpatialData")
+    sdata_widget.viewer_model.add_sdata_image(sdata_blobs, element_name, "global", False)
+
+    # this connects the slider to the viewer (done in __init__)
+    _ = widget(viewer)
+
+    # check if the slider is present
+    start, stop, step = viewer.dims.range[0]
+    assert start == 0
+    assert step == 1
+
+    # simulate position change of the slider
+    viewer.dims.set_current_step(0, 0)
+    qtbot.wait(50)  # wait for a short time to simulate user interaction
+    viewer.dims.set_current_step(0, 1)
+    qtbot.wait(50)  # wait for a short time to simulate user interaction
+
+    viewer.close()