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

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

@@ -12,7 +12,7 @@
 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
@@ -22,6 +22,15 @@
 __all__ = ['CoordsInfo']
 
 
+def _convert_surface_brightness_units(data, from_unit, to_unit):
+    try:
+        quantity = data * u.Unit(from_unit)
+        converted_quantity = quantity.to(u.Unit(to_unit))
+        return converted_quantity.value
+    except u.UnitConversionError:
+        raise ValueError(f"Conversion from {from_unit} to {to_unit} is not possible.")
+
+
 @tool_registry('g-coords-info')
 class CoordsInfo(TemplateMixin, DatasetSelectMixin):
     template_file = __file__, "coords_info.vue"
@@ -34,7 +43,9 @@ 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)
@@ -56,7 +67,9 @@ 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 = "MJy/sr"
+        self.previous_unit = "MJy/sr"
+        self.unit_changed = False
         # subscribe/unsubscribe to mouse events across all existing viewers
         viewer_refs = []
         for viewer in self.app._viewer_store.values():
@@ -73,6 +86,9 @@ 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 +128,14 @@ 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 new_unit != self.current_unit and new_unit in uc.sb_unit.choices:
+            self.previous_unit = self.current_unit
+            self.current_unit = new_unit
+            self.unit_changed = True
+
     @property
     def marks(self):
         """
@@ -457,8 +481,11 @@ def _image_viewer_update(self, viewer, x, y):
                 unit = image.get_component(attribute).units
             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)
+                unit = self.current_unit
+                value = self._get_cube_value(
+                    image, arr, x, y, viewer
+                )._convert_surface_brightness_units(value, self.previous_unit, unit)
+                self.unit_changed = False
 
                 if associated_dq_layers is not None:
                     associated_dq_layer = associated_dq_layers[0]
@@ -475,7 +502,7 @@ def _image_viewer_update(self, viewer, x, y):
                     dq_text = f' (DQ: {int(dq_value):d})'
             else:
                 dq_text = ''
-            self.row1b_text = f'{value:+10.5e} {unit}{dq_text}'
+            self.row1b_text = f'{value:+10.5e} {self.current_unit}{dq_text}'
             self._dict['value'] = float(value)
             self._dict['value:unit'] = unit
             self._dict['value:unreliable'] = unreliable_pixel