Backport PR #2541: Don't try to update viewer state if it was deleted

CHANGES.rst

@@ -12,6 +12,9 @@ Cubeviz
 Imviz
 ^^^^^
 
+- Plot options layer selection no longer gets stuck in some cases when deleting
+  the currently selected viewer. [#2541]
+
 Mosviz
 ^^^^^^
 

jdaviz/configs/default/plugins/plot_options/plot_options.py

@@ -564,7 +564,8 @@ def _update_stretch_histogram(self, msg={}):
             viewer_label_old = msg.get('old')
             if isinstance(viewer_label_old, list):
                 viewer_label_old = viewer_label_old[0]
-            if len(viewer_label_old):
+            # If the previously selected viewer was deleted, we don't need to do this.
+            if viewer_label_old in self.app._viewer_store:
                 vs_old = self.app.get_viewer(viewer_label_old).state
                 for attr in ('x_min', 'x_max', 'y_min', 'y_max'):
                     vs_old.remove_callback(attr, self._update_stretch_histogram)

jdaviz/configs/imviz/tests/test_viewers.py

@@ -6,6 +6,7 @@
 from jdaviz.core.config import get_configuration
 from jdaviz.configs.imviz.helper import Imviz
 from jdaviz.configs.imviz.plugins.viewers import ImvizImageView
+from jdaviz.configs.imviz.tests.utils import BaseImviz_WCS_NoWCS
 
 
 @pytest.mark.parametrize(
@@ -94,3 +95,17 @@ def test_mastviz_config():
 
     assert im.app.get_viewer_ids() == ['mastviz-0']
     assert im.app.data_collection[0].shape == (2, 2)
+
+
+class TestDeleteData(BaseImviz_WCS_NoWCS):
+
+    def test_plot_options_after_destroy(self):
+        self.imviz.create_image_viewer(viewer_name="imviz-1")
+        self.imviz.app.add_data_to_viewer('imviz-1', 'no_wcs[SCI,1]')
+
+        po = self.imviz.plugins['Plot Options']
+        po.open_in_tray()
+        po.viewer = "imviz-1"
+        po.stretch_function = "Square Root"
+        self.imviz.destroy_viewer("imviz-1")
+        assert len(po.layer.choices) == 2