Add location accuracy

android/src/toga_android/hardware/location.py

@@ -14,8 +14,6 @@
 
 def toga_location(location):
     """Convert an Android location into a Toga LatLng and altitude."""
-    latlng = LatLng(location.getLatitude(), location.getLongitude())
-
     # MSL altitude was added in API 34. We can't test this at runtime
     if Build.VERSION.SDK_INT >= 34 and location.hasMslAltitude():  # pragma: no cover
         altitude = location.getMslAltitudeMeters()
@@ -24,6 +22,20 @@ def toga_location(location):
     else:
         altitude = None
 
+    latlng = LatLng(
+        location.getLatitude(),
+        location.getLongitude(),
+        altitude=altitude,
+        horizontal_accuracy=(
+            location.getAccuracy() if location.hasAccuracy() else None
+        ),
+        vertical_accuracy=(
+            location.getVerticalAccuracyMeters()
+            if location.hasVerticalAccuracy()
+            else None
+        ),
+    )
+
     return {
         "location": latlng,
         "altitude": altitude,

changes/3112.feature.md

@@ -0,0 +1 @@
+Add altitude, horizontal accuracy and vertical accuracy to LatLng.

cocoa/src/toga_cocoa/hardware/location.py

@@ -11,17 +11,20 @@
 
 def toga_location(location):
     """Convert a Cocoa location into a Toga LatLng and altitude."""
+    # A non-positive vertical accuracy indicates altitude is invalid.
+    altitude_valid = location.verticalAccuracy > 0.0
+    altitude = location.altitude if altitude_valid else None
+
     latlng = LatLng(
         location.coordinate.latitude,
         location.coordinate.longitude,
+        altitude=altitude,
+        horizontal_accuracy=(
+            location.horizontalAccuracy if location.horizontalAccuracy > 0.0 else None
+        ),
+        vertical_accuracy=location.verticalAccuracy if altitude_valid else None,
     )
 
-    # A vertical accuracy that non-positive indicates altitude is invalid.
-    if location.verticalAccuracy > 0.0:
-        altitude = location.altitude
-    else:
-        altitude = None
-
     return {
         "location": latlng,
         "altitude": altitude,

core/src/toga/types.py

@@ -23,14 +23,47 @@
     """
 
 
-class LatLng(NamedTuple):
-    """A geographic coordinate."""
+class LatLng(tuple):
+    """A geographic coordinate, with optional altitude and accuracy attributes.
 
-    lat: float
-    """Latitude"""
+    A LatLng compares equal to a 2-tuple (lat, lng). The optional
+    altitude, horizontal_accuracy, and vertical_accuracy attributes
+    are not considered for equality or hashing.
+    """
 
-    lng: float
-    """Longitude"""
+    altitude: float | None = None
+    """Altitude in meters, or None if not available."""
+
+    horizontal_accuracy: float | None = None
+    """Horizontal accuracy in meters, or None if not available."""
+
+    vertical_accuracy: float | None = None
+    """Vertical accuracy in meters, or None if not available."""
+
+    def __new__(
+        cls,
+        lat: float,
+        lng: float,
+        *,
+        altitude: float | None = None,
+        horizontal_accuracy: float | None = None,
+        vertical_accuracy: float | None = None,
+    ) -> LatLng:
+        self = super().__new__(cls, (lat, lng))
+        self.altitude = altitude
+        self.horizontal_accuracy = horizontal_accuracy
+        self.vertical_accuracy = vertical_accuracy
+        return self
+
+    @property
+    def lat(self) -> float:
+        """Latitude"""
+        return self[0]
+
+    @property
+    def lng(self) -> float:
+        """Longitude"""
+        return self[1]
 
     def __str__(self) -> str:
         return f"({self.lat:6f}, {self.lng:6f})"

core/tests/test_types.py

@@ -1,4 +1,53 @@
-from toga.types import Position, Size
+import pytest
+
+from toga.types import LatLng, Position, Size
+
+
+def test_latlng_required_properties():
+    """A LatLng class has latitude and longitude values."""
+    LAT = -31.95
+    LNG = 115.86
+    ll = LatLng(LAT, LNG)
+    assert ll.lat == pytest.approx(LAT)
+    assert ll.lng == pytest.approx(LNG)
+    assert str(ll) == f"({LAT:6f}, {LNG:6f})"
+
+    assert ll == LatLng(LAT, LNG)
+    assert ll != LatLng(LAT, LNG + 1)
+
+    assert ll == (LAT, LNG)  # Tuple equivalence for backwards-compatibility
+    assert ll != (LAT + 1, LNG)
+    assert hash(ll) == hash((LAT, LNG))
+
+    # Optional values were not filled in
+    assert ll.altitude is None
+    assert ll.horizontal_accuracy is None
+    assert ll.vertical_accuracy is None
+
+
+def test_latlng_optional_properties():
+    """A LatLng class has optional values for altitude and accuracies."""
+    LAT = -31.95
+    LNG = 115.86
+    ALT = 20.1
+    HORIZONTAL_ACC = 10.2
+    VERTICAL_ACC = 11.3
+    bare_ll = LatLng(LAT, LNG)
+    ll = LatLng(
+        LAT,
+        LNG,
+        altitude=ALT,
+        horizontal_accuracy=HORIZONTAL_ACC,
+        vertical_accuracy=VERTICAL_ACC,
+    )
+    assert ll.altitude == pytest.approx(ALT)
+    assert ll.horizontal_accuracy == pytest.approx(HORIZONTAL_ACC)
+    assert ll.vertical_accuracy == pytest.approx(VERTICAL_ACC)
+
+    assert bare_ll == ll  # optional values are not used for comparison
+    assert bare_ll.altitude != ll.altitude
+    assert bare_ll.horizontal_accuracy != ll.horizontal_accuracy
+    assert bare_ll.vertical_accuracy != ll.vertical_accuracy
 
 
 def test_position_properties():

gtk/src/toga_gtk/hardware/location.py

@@ -34,8 +34,15 @@
 
 def toga_location(location):
     """Convert a ``Geoclue.Location`` into ``OnLocationChangeHandler`` kwargs."""
-    latlng = LatLng(location.props.latitude, location.props.longitude)
-    altitude = location.get_property("altitude")
+    altitude = location.props.altitude
+    latlng = LatLng(
+        location.props.latitude,
+        location.props.longitude,
+        altitude=altitude,
+        horizontal_accuracy=(
+            location.props.accuracy if location.props.accuracy > 0.0 else None
+        ),
+    )
 
     return {
         "location": latlng,

iOS/src/toga_iOS/hardware/location.py

@@ -14,17 +14,20 @@
 
 def toga_location(location):
     """Convert a Cocoa location into a Toga LatLng and altitude."""
+    # A non-positive vertical accuracy indicates altitude is invalid.
+    altitude_valid = location.verticalAccuracy > 0.0
+    altitude = location.altitude if altitude_valid else None
+
     latlng = LatLng(
         location.coordinate.latitude,
         location.coordinate.longitude,
+        altitude=altitude,
+        horizontal_accuracy=(
+            location.horizontalAccuracy if location.horizontalAccuracy > 0.0 else None
+        ),
+        vertical_accuracy=location.verticalAccuracy if altitude_valid else None,
     )
 
-    # A vertical accuracy that non-positive indicates altitude is invalid.
-    if location.verticalAccuracy > 0.0:
-        altitude = location.altitude
-    else:
-        altitude = None
-
     return {
         "location": latlng,
         "altitude": altitude,