Update the mouse over units by listening to the unit-conversion plugin

CHANGES.rst

@@ -105,6 +105,8 @@ Cubeviz
 - Flux units are now correct for collapsed spectra when using the sum function
   when units are in per steradian. [#2873]
 
+- Mouse over coordinates now responds to the selected surface brightness unit. [#2931]
+
 Imviz
 ^^^^^
 

jdaviz/configs/imviz/plugins/coords_info/coords_info.py

@@ -12,12 +12,12 @@
 from jdaviz.configs.mosviz.plugins.viewers import (MosvizImageView, MosvizProfileView,
                                                    MosvizProfile2DView)
 from jdaviz.configs.specviz.plugins.viewers import SpecvizProfileView
-from jdaviz.core.events import ViewerAddedMessage
+from jdaviz.core.events import ViewerAddedMessage, GlobalDisplayUnitChanged
 from jdaviz.core.helpers import data_has_valid_wcs
 from jdaviz.core.marks import PluginScatter, PluginLine
 from jdaviz.core.registries import tool_registry
 from jdaviz.core.template_mixin import TemplateMixin, DatasetSelectMixin
-from jdaviz.utils import _eqv_pixar_sr
+from jdaviz.utils import _eqv_pixar_sr, _convert_surface_brightness_units
 
 __all__ = ['CoordsInfo']
 
@@ -34,7 +34,9 @@ class CoordsInfo(TemplateMixin, DatasetSelectMixin):
 
     _viewer_classes_with_marker = (SpecvizProfileView, MosvizProfile2DView)
 
-    dataset_icon = Unicode("").tag(sync=True)  # option for layer (auto, none, or specific layer)
+    dataset_icon = Unicode("").tag(
+        sync=True
+    )  # option for layer (auto, none, or specific layer)
     icon = Unicode("").tag(sync=True)  # currently exposed layer
 
     row1a_title = Unicode("").tag(sync=True)
@@ -56,6 +58,7 @@ def __init__(self, *args, **kwargs):
         self._marks = {}
         self._dict = {}  # dictionary representation of current mouseover info
         self._x, self._y = None, None  # latest known cursor positions
+        self.current_unit = None
 
         # subscribe/unsubscribe to mouse events across all existing viewers
         viewer_refs = []
@@ -73,6 +76,9 @@ def __init__(self, *args, **kwargs):
 
         # subscribe to mouse events on any new viewers
         self.hub.subscribe(self, ViewerAddedMessage, handler=self._on_viewer_added)
+        self.hub.subscribe(
+            self, GlobalDisplayUnitChanged, handler=self._on_global_display_unit_changed
+        )
 
     def _create_marks_for_viewer(self, viewer, id=None):
         if id is None:
@@ -112,6 +118,12 @@ def _create_viewer_callbacks(self, viewer):
     def _on_viewer_added(self, msg):
         self._create_viewer_callbacks(self.app.get_viewer_by_id(msg.viewer_id))
 
+    def _on_global_display_unit_changed(self, msg):
+        new_unit = u.Unit(msg.unit)
+        uc = self.app._jdaviz_helper.plugins.get("Unit Conversion", None)
+        if self.config == "cubeviz" and new_unit in uc.sb_unit.choices:
+            self.current_unit = new_unit
+
     @property
     def marks(self):
         """
@@ -458,7 +470,14 @@ def _image_viewer_update(self, viewer, x, y):
             elif isinstance(viewer, CubevizImageView):
                 arr = image.get_component(attribute).data
                 unit = image.get_component(attribute).units
-                value = self._get_cube_value(image, arr, x, y, viewer)
+                value = self._get_cube_value(
+                    image, arr, x, y, viewer
+                )
+                if image.ndim != 2 and self.current_unit is not None:
+                    value = _convert_surface_brightness_units(
+                        value, unit, self.current_unit
+                    )
+                    unit = self.current_unit
 
                 if associated_dq_layers is not None:
                     associated_dq_layer = associated_dq_layers[0]

jdaviz/configs/specviz/plugins/unit_conversion/tests/test_unit_conversion.py

@@ -206,17 +206,44 @@ def test_sb_unit_conversion(cubeviz_helper):
     uc_plg.sb_unit = 'Jy / sr'
     y_display_unit = u.Unit(viewer_1d.state.y_display_unit)
     assert y_display_unit == u.Jy / u.sr
+    label_mouseover = cubeviz_helper.app.session.application._tools["g-coords-info"]
+    flux_viewer = cubeviz_helper.app.get_viewer(
+        cubeviz_helper._default_flux_viewer_reference_name
+    )
+    label_mouseover._viewer_mouse_event(
+        flux_viewer, {"event": "mousemove", "domain": {"x": 10, "y": 8}}
+    )
+    assert label_mouseover.as_text() == (
+            "Pixel x=00010.0 y=00008.0 Value +1.00000e+06 Jy / sr",
+            "World 13h39m59.7037s +27d00m03.2400s (ICRS)",
+            "204.9987654313 27.0008999946 (deg)")
 
     # Try a second conversion
     uc_plg.sb_unit = 'W / Hz sr m2'
     y_display_unit = u.Unit(viewer_1d.state.y_display_unit)
     assert y_display_unit == u.Unit("W / (Hz sr m2)")
 
+    y_display_unit = u.Unit(viewer_1d.state.y_display_unit)
+    label_mouseover._viewer_mouse_event(
+        flux_viewer, {"event": "mousemove", "domain": {"x": 10, "y": 8}}
+    )
+    assert label_mouseover.as_text() == (
+            "Pixel x=00010.0 y=00008.0 Value +1.00000e-20 W / (Hz sr m2)",
+            "World 13h39m59.7037s +27d00m03.2400s (ICRS)",
+            "204.9987654313 27.0008999946 (deg)")
+
     # really a translation test, test_unit_translation loads a Flux
     # cube, this test load a Surface Brightness Cube, this ensures
     # two-way translation
     uc_plg.sb_unit = 'MJy / sr'
     y_display_unit = u.Unit(viewer_1d.state.y_display_unit)
+    label_mouseover._viewer_mouse_event(
+        flux_viewer, {"event": "mousemove", "domain": {"x": 10, "y": 8}}
+    )
+    assert label_mouseover.as_text() == (
+            "Pixel x=00010.0 y=00008.0 Value +1.00000e+00 MJy / sr",
+            "World 13h39m59.7037s +27d00m03.2400s (ICRS)",
+            "204.9987654313 27.0008999946 (deg)")
 
     uc_plg._obj.flux_or_sb_selected = 'Flux'
     uc_plg.flux_unit = 'MJy'

jdaviz/utils.py

@@ -355,6 +355,12 @@ def flux_conversion(spec, values, original_units, target_units):
     return (values * orig_units).to_value(targ_units, equivalencies=eqv)
 
 
+def _convert_surface_brightness_units(data, from_unit, to_unit):
+    quantity = data * u.Unit(from_unit)
+    converted_quantity = quantity.to(u.Unit(to_unit))
+    return converted_quantity.value
+
+
 def _eqv_pixar_sr(pixar_sr):
     def converter_flux(x):  # Surface Brightness -> Flux
         return x * pixar_sr