Merge pull request spacetelescope#2895 from kecnry/viewer-slices-gene…

…ralize

Generalize viewer slices logic

jdaviz/configs/cubeviz/plugins/slice/slice.py

@@ -125,6 +125,9 @@ def _initialize_location(self, *args):
             if str(viewer.state.x_att) not in self.valid_slice_att_names:
                 # avoid setting value to degs, before x_att is changed to wavelength, for example
                 continue
+            # ensure the cache is reset (if previous attempts to initialize failed resulting in an
+            # empty list as the cache)
+            viewer._clear_cache('slice_values')
             slice_values = viewer.slice_values
             if len(slice_values):
                 self.value = slice_values[int(len(slice_values)/2)]

jdaviz/configs/cubeviz/plugins/viewers.py

@@ -47,20 +47,20 @@ def _get_component(layer):
                 # or slice_component_label is not a component in this layer
                 # either way, return an empty array and skip this layer
                 return np.array([])
-            data_obj = data_comp.data
-            data_units = data_comp.units
-            data_spec_axis = np.asarray(data_obj.data, dtype=float) * u.Unit(data_units)
 
             # Convert axis if display units are set and are different
-            if slice_display_units and slice_display_units != data_units:
-                return data_spec_axis.to_value(slice_display_units,
-                                               equivalencies=u.spectral())
+            data_units = getattr(data_comp, 'units', None)
+            if slice_display_units and data_units and slice_display_units != data_units:
+                data = np.asarray(data_comp.data, dtype=float) * u.Unit(data_units)
+                return data.to_value(slice_display_units,
+                                     equivalencies=u.spectral())
             else:
-                return data_spec_axis
+                return data_comp.data
         try:
             return np.asarray(np.unique(np.concatenate([_get_component(layer) for layer in self.layers])),  # noqa
                               dtype=float)
         except ValueError:
+            # NOTE: this will result in caching an empty list
             return np.array([])
 
     def _set_slice_indicator_value(self, value):
@@ -109,23 +109,22 @@ def slice_values(self):
 
             try:
                 # Retrieve layer data and units using the slice index of the world components ids
-                data_obj = layer.layer.data.get_component(world_comp_ids[self.slice_index]).data
-                data_units = layer.layer.data.get_component(world_comp_ids[self.slice_index]).units
+                data_comp = layer.layer.data.get_component(world_comp_ids[self.slice_index])
             except (AttributeError, KeyError):
                 continue
 
-            # Find the spectral axis
-            data_spec_axis = np.asarray(data_obj.take(0, take_inds[0]).take(0, take_inds[1]),  # noqa
-                                        dtype=float)
+            data = np.asarray(data_comp.data.take(0, take_inds[0]).take(0, take_inds[1]),  # noqa
+                              dtype=float)
 
             # Convert to display units if applicable
-            if slice_display_units and slice_display_units != data_units:
-                converted_axis = (data_spec_axis * u.Unit(data_units)).to_value(
+            data_units = getattr(data_comp, 'units', None)
+            if slice_display_units and data_units and slice_display_units != data_units:
+                converted_axis = (data * u.Unit(data_units)).to_value(
                     slice_display_units,
                     equivalencies=u.spectral() + u.pixel_scale(1*u.pix)
                 )
             else:
-                converted_axis = data_spec_axis
+                converted_axis = data
 
         return converted_axis
 

jdaviz/configs/default/plugins/viewers.py

@@ -10,6 +10,7 @@
 from jdaviz.components.toolbar_nested import NestedJupyterToolbar
 from jdaviz.core.astrowidgets_api import AstrowidgetsImageViewerMixin
 from jdaviz.core.registries import viewer_registry
+from jdaviz.core.template_mixin import WithCache
 from jdaviz.core.user_api import ViewerUserApi
 from jdaviz.utils import ColorCycler, get_subset_type, _wcs_only_label, layer_is_not_dq
 
@@ -20,7 +21,7 @@
 viewer_registry.add("g-table-viewer", label="Table", cls=TableViewer)
 
 
-class JdavizViewerMixin:
+class JdavizViewerMixin(WithCache):
     toolbar = None
     tools_nested = []
     _prev_limits = None

jdaviz/core/template_mixin.py

@@ -69,7 +69,7 @@
 __all__ = ['show_widget', 'TemplateMixin', 'PluginTemplateMixin',
            'skip_if_no_updates_since_last_active', 'skip_if_not_tray_instance',
            'with_spinner', 'with_temp_disable',
-           'ViewerPropertiesMixin',
+           'WithCache', 'ViewerPropertiesMixin',
            'BasePluginComponent',
            'MultiselectMixin',
            'SelectPluginComponent', 'UnitSelectPluginComponent', 'EditableSelectPluginComponent',
@@ -186,7 +186,19 @@ def flux_viewer(self):
         return self.app.get_viewer(viewer_reference)
 
 
-class TemplateMixin(VuetifyTemplate, HubListener, ViewerPropertiesMixin):
+class WithCache:
+    def _clear_cache(self, *attrs):
+        """
+        provide convenience function to clearing the cache for cached_properties
+        """
+        if not len(attrs):
+            attrs = getattr(self, '_cached_properties', [])
+        for attr in attrs:
+            if attr in self.__dict__:
+                del self.__dict__[attr]
+
+
+class TemplateMixin(VuetifyTemplate, HubListener, ViewerPropertiesMixin, WithCache):
     config = Unicode("").tag(sync=True)
     vdocs = Unicode("").tag(sync=True)
     popout_button = Any().tag(sync=True, **widget_serialization)
@@ -612,7 +624,7 @@ def show(self, loc="inline", title=None):  # pragma: no cover
         show_widget(self, loc=loc, title=title)
 
 
-class BasePluginComponent(HubListener, ViewerPropertiesMixin):
+class BasePluginComponent(HubListener, ViewerPropertiesMixin, WithCache):
     """
     This base class handles attaching traitlets from the plugin itself to logic
     handled within the component, support for caching and clearing caches on properties,
@@ -637,16 +649,6 @@ def __setattr__(self, attr, value, force_super=False):
 
         return setattr(self._plugin, self._plugin_traitlets.get(attr), value)
 
-    def _clear_cache(self, *attrs):
-        """
-        provide convenience function to clearing the cache for cached_properties
-        """
-        if not len(attrs):
-            attrs = self._cached_properties
-        for attr in attrs:
-            if attr in self.__dict__:
-                del self.__dict__[attr]
-
     def add_traitlets(self, **traitlets):
         for k, v in traitlets.items():
             if v is None: