feat: calculate distance to find most logical closest feature

pickLayer/core/set_active_layer_tool.py

@@ -141,20 +141,24 @@ def _get_default_search_radius(self) -> float:
             * context.mapToPixel().mapUnitsPerPixel()
         )
 
-    def _get_distance_to_feature_on_layer(
+    def _get_distances_to_feature_on_layer(
         self,
         layer: QgsVectorLayer,
         feature: QgsFeature,
         origin_map_point: QgsPointXY,
-    ) -> float:
+    ) -> tuple[float, float]:
         # for unknown reasons saving all geoms to variables avoids fatal exs
         origin_layer_point = self.toLayerCoordinates(layer, origin_map_point)
         origin_geom = QgsGeometry.fromPointXY(origin_layer_point)
         feature_geom = feature.geometry()
         closest_geom = feature_geom.nearestPoint(origin_geom)
         closest_layer_point = closest_geom.asPoint()
         closest_map_point = self.toMapCoordinates(layer, closest_layer_point)
-        return origin_map_point.distance(closest_map_point)
+        distance_to_feature = origin_map_point.distance(closest_map_point)
+        centroid_geom = feature_geom.centroid().asPoint()
+        centroid_map_point = self.toMapCoordinates(layer, centroid_geom)
+        distance_to_centroid = centroid_map_point.distance(closest_map_point)
+        return distance_to_feature, distance_to_centroid
 
     def _choose_layer_from_identify_results(
         self,
@@ -170,32 +174,39 @@ def _choose_layer_from_identify_results(
         best_match: Optional[QgsVectorLayer] = None
         best_match_geom_type_preference = 0
         best_match_distance = 0.0
+        best_match_distance_to_centroid = 0.0
 
         for result in results:
             if not isinstance(result.mLayer, QgsVectorLayer):
                 continue
 
+            (
+                distance_to_feature,
+                distance_to_centroid,
+            ) = self._get_distances_to_feature_on_layer(
+                result.mLayer, result.mFeature, origin_map_coordinates
+            )
             if (
                 best_match is None
                 or geom_type_preference.get(result.mLayer.geometryType(), 99)
                 < best_match_geom_type_preference
                 or (
                     geom_type_preference.get(result.mLayer.geometryType(), 99)
                     == best_match_geom_type_preference
-                    and self._get_distance_to_feature_on_layer(
-                        result.mLayer, result.mFeature, origin_map_coordinates
+                    and (
+                        (distance_to_feature < best_match_distance)
+                        or (
+                            distance_to_feature <= best_match_distance
+                            and distance_to_centroid < best_match_distance_to_centroid
+                        )
                     )
-                    < best_match_distance
                 )
             ):
                 best_match = result.mLayer
                 best_match_geom_type_preference = geom_type_preference.get(
                     result.mLayer.geometryType(), 99
                 )
-                best_match_distance = self._get_distance_to_feature_on_layer(
-                    result.mLayer,
-                    result.mFeature,
-                    origin_map_coordinates,
-                )
+                best_match_distance = distance_to_feature
+                best_match_distance_to_centroid = distance_to_centroid
 
         return best_match

test/unit/test_set_active_layer_tool.py

@@ -435,6 +435,38 @@ def test_top_polygon_chosen_from_multiple_nested_even_if_top_not_closest(
     assert call_layer.name() == "polygon-0-10"
 
 
+def test_bottom_polygon_chosen_from_multiple_nested_when_bottom_closest(
+    map_tool: SetActiveLayerTool,
+    mocker: MockerFixture,
+    qgis_iface: QgisInterface,
+    qgis_new_project,
+):
+    results = create_identify_result(
+        [
+            ("POLYGON((0 0, 0 10, 10 10, 10 0, 0 0))", "EPSG:3067", "polygon-0-10"),
+            ("POLYGON((3 3, 3 5, 5 5, 5 3, 3 3))", "EPSG:3067", "polygon-3-5"),
+        ]
+    )
+
+    QgsProject.instance().setCrs(QgsCoordinateReferenceSystem("EPSG:3067"))
+    map_tool.canvas().setDestinationCrs(QgsCoordinateReferenceSystem("EPSG:3067"))
+
+    mocker.patch.object(map_tool, "identify", return_value=results)
+
+    m_set_active_layer = mocker.patch.object(
+        qgis_iface, "setActiveLayer", return_value=None
+    )
+
+    # emulate click near the center of 3-5
+    map_tool.set_active_layer_using_closest_feature(QgsPointXY(4.2, 4.2))
+
+    m_set_active_layer.assert_called_once()
+
+    args, _ = m_set_active_layer.call_args_list[0]
+    call_layer = args[0]
+    assert call_layer.name() == "polygon-3-5"
+
+
 def test_only_raster_present_no_change_active_layer(
     map_tool: SetActiveLayerTool,
     mocker: MockerFixture,