add: remove overlay

js/models/event_handler.js

@@ -310,6 +310,8 @@ export default class EventHandler {
       add_MOC_from_URL: this.messageHandler.handleAddMOCFromURL,
       add_MOC_from_dict: this.messageHandler.handleAddMOCFromDict,
       add_overlay: this.messageHandler.handleAddOverlay,
+      remove_overlay: this.messageHandler.handleRemoveOverlay,
+      get_overlays: this.messageHandler.handleGetOverlays,
       change_colormap: this.messageHandler.handleChangeColormap,
       get_JPG_thumbnail: this.messageHandler.handleGetJPGThumbnail,
       trigger_selection: this.messageHandler.handleTriggerSelection,

js/models/message_handler.js

@@ -144,6 +144,31 @@ export default class MessageHandler {
     }
   }
 
+  handleRemoveOverlay = (msg) => {
+    const overlay_names = msg["overlay_names"];
+    for (const overlay_name of overlay_names) {
+      console.info(`Sending removeOverlay for ${overlay_name}`);
+      this.aladin.removeOverlay(overlay_name);
+    }
+    this.handleGetOverlays();
+  };
+
+  handleGetOverlays = () => {
+    const overlay_names = [];
+    const overlays = this.aladin.getOverlays();
+    for (const overlay of overlays) {
+      const overlay_name = overlay["name"];
+      overlay_names.push(overlay_name);
+    }
+    console.info(`Current overlays are ${overlay_names}`);
+    this.model.send({
+      event_type: "current_overlays",
+      content: {
+        overlays: overlay_names,
+      },
+    });
+  };
+
   handleChangeColormap(msg) {
     this.aladin.getBaseImageLayer().setColormap(msg["colormap"]);
   }

src/ipyaladin/widget.py

@@ -178,6 +178,11 @@ class Aladin(anywidget.AnyWidget):
     ).tag(sync=True)
     _wcs = traitlets.Dict().tag(sync=True)
     _fov_xy = traitlets.Dict().tag(sync=True)
+    # Overlays
+    _overlays = traitlets.List(
+        [],
+        help="A list of overlays on the widget.",
+    ).tag(sync=True)
 
     # content of the last click
     clicked_object = traitlets.Dict().tag(sync=True)
@@ -259,6 +264,9 @@ def _handle_custom_message(self, _: any, message: dict, buffers: any) -> None:
             self.listener_callback["select"](message["content"])
         elif event_type == "save_view_as_image":
             self._save_file(message["path"], buffers[0])
+        elif event_type == "current_overlays":
+            self._overlays = message["content"]["overlays"]
+            self.listener_callback["current_overlays"](message["content"])
 
     @property
     def selected_objects(self) -> List[Table]:
@@ -276,6 +284,17 @@ def selected_objects(self) -> List[Table]:
             catalogs.append(Table(objects_data))
         return catalogs
 
+    @property
+    def overlays(self) -> List:
+        """The list of overlays on the widget.
+
+        Returns
+        -------
+        list
+            A list of strings representing the widget overlays.
+        """
+        return self._overlays
+
     @property
     def height(self) -> int:
         """The height of the widget.
@@ -992,6 +1011,35 @@ def add_graphic_overlay_from_stcs(
             }
         )
 
+    @widget_should_be_loaded
+    def remove_overlay(self, overlay_name: Union[Iterable[str], str]) -> None:
+        """Remove an overlay layer defined by a string.
+
+        Parameters
+        ----------
+        overlay_name : str, Iterable[str]
+            The string or an iterable of strings.
+        """
+        overlay_names = (
+            [overlay_name] if isinstance(overlay_name, str) else overlay_name
+        )
+
+        self.send(
+            {
+                "event_name": "remove_overlay",
+                "overlay_names": overlay_names,
+            }
+        )
+
+    @widget_should_be_loaded
+    def get_overlays(self) -> List:
+        """Update the current overlays defined by their names."""
+        self.send(
+            {
+                "event_name": "get_overlays",
+            }
+        )
+
     @widget_should_be_loaded
     def set_color_map(self, color_map_name: str) -> None:
         """Change the color map of the Aladin Lite widget.
@@ -1043,7 +1091,8 @@ def set_listener(self, listener_type: str, callback: Callable) -> None:
         Parameters
         ----------
         listener_type : str
-            Can either be 'object_hovered', 'object_clicked', 'click' or 'select'
+            Can either be 'object_hovered', 'object_clicked', 'click', 'select',
+            or 'current_overlays'
         callback : Callable
             A python function to be called when the event corresponding to the
             listener_type is detected
@@ -1057,10 +1106,13 @@ def set_listener(self, listener_type: str, callback: Callable) -> None:
             self.listener_callback["click"] = callback
         elif listener_type == "select":
             self.listener_callback["select"] = callback
+        elif listener_type == "current_overlays":
+            self.listener_callback["current_overlays"] = callback
         else:
             raise ValueError(
                 "listener_type must be 'object_hovered', "
-                "'object_clicked', 'click' or 'select'"
+                "'object_clicked', 'click', 'select', "
+                "or 'current_overlays'"
             )
 
     @widget_should_be_loaded

src/tests/test_aladin.py

@@ -322,3 +322,51 @@ def test_add_table(monkeypatch: Callable) -> None:
         "conversion_maj_axis": 1,
     }
     assert table_sent_message["options"]["ellipse_error"] == ellipse_options
+
+
+test_overlay_names = [
+    "overlay",
+    ["overlay", "overlay_1", "2MASS"],
+    "catalog",
+    ["overlay_1", "2MASS"],
+]
+
+
+@pytest.mark.parametrize("overlay_names", test_overlay_names)
+def test_remove_overlay(
+    monkeypatch: Callable,
+    overlay_names: Union[Iterable[str], str],
+) -> None:
+    """Test proper messages sent for removing overlays using their name string(s).
+
+    Parameters
+    ----------
+    overlay_names : Union[Iterable[str], str]
+        The name strings of overlays.
+    """
+    mock_send = Mock()
+    monkeypatch.setattr(Aladin, "send", mock_send)
+    aladin.remove_overlay(overlay_names)
+
+    event_name = mock_send.call_args[0][0]["event_name"]
+    assert isinstance(event_name, str)
+    assert event_name == "remove_overlay"
+
+    name_info = mock_send.call_args[0][0]["overlay_names"]
+    assert isinstance(name_info, list)
+    assert name_info[0] in overlay_names
+
+    if isinstance(overlay_names, list):
+        assert name_info == overlay_names
+
+
+def test_get_overlays(
+    monkeypatch: Callable,
+) -> None:
+    """Test proper message sent for getting current overlays."""
+    mock_send = Mock()
+    monkeypatch.setattr(Aladin, "send", mock_send)
+    aladin.get_overlays()
+    event_name = mock_send.call_args[0][0]["event_name"]
+    assert isinstance(event_name, str)
+    assert event_name == "get_overlays"