feat: Port “Compass view” bottom sheet from Meshtastic-Apple PR #1504

core/strings/src/commonMain/composeResources/values/strings.xml

@@ -1016,4 +1016,17 @@
     <string name="firmware_update_method_detail">Update via %1$s</string>
     <string name="firmware_update_usb_instruction_title">Select DFU USB Drive</string>
     <string name="firmware_update_usb_instruction_text">Your device has rebooted into DFU mode and should appear as a USB drive (e.g., RAK4631).\n\nWhen the file picker opens, please select the root of that drive to save the firmware file.</string>
-</resources>
+
+  <!-- Compass -->
+    <string name="compass_title">Compass</string>
+    <string name="open_compass">Open Compass</string>
+    <string name="compass_distance">Distance: %1$s</string>
+    <string name="compass_bearing">Bearing: %1$s</string>
+    <string name="compass_bearing_na">Bearing: N/A</string>
+    <string name="compass_no_magnetometer">This device does not have a compass sensor. Heading is unavailable.</string>
+    <string name="compass_no_location_permission">Location permission is required to show distance and bearing.</string>
+    <string name="compass_location_disabled">Location provider is disabled. Turn on location services.</string>
+    <string name="compass_no_location_fix">Waiting for a GPS fix to calculate distance and bearing.</string>
+    <string name="compass_uncertainty">Estimated area: \u00b1%1$s (\u00b1%2$s)</string>
+    <string name="compass_uncertainty_unknown">Estimated area: unknown accuracy</string>
+</resources>

feature/node/src/main/kotlin/org/meshtastic/feature/node/compass/CompassHeadingProvider.kt

@@ -0,0 +1,135 @@
+/*
+ * Copyright (c) 2025 Meshtastic LLC
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package org.meshtastic.feature.node.compass
+
+import android.content.Context
+import android.hardware.Sensor
+import android.hardware.SensorEvent
+import android.hardware.SensorEventListener
+import android.hardware.SensorManager
+import android.hardware.GeomagneticField
+import android.location.Location
+import dagger.hilt.android.qualifiers.ApplicationContext
+import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.callbackFlow
+import javax.inject.Inject
+
+private const val ROTATION_MATRIX_SIZE = 9
+private const val ORIENTATION_SIZE = 3
+private const val DEGREES_IN_CIRCLE = 360f
+
+data class HeadingState(
+    val heading: Float? = null, // 0..360 degrees
+    val hasSensor: Boolean = true,
+    val accuracy: Int = SensorManager.SENSOR_STATUS_ACCURACY_MEDIUM,
+)
+
+class CompassHeadingProvider @Inject constructor(@ApplicationContext private val context: Context) {
+
+    /**
+     * Emits compass heading in degrees. If a location is provided, applies true north correction.
+     *
+     * @param location Optional Location from the phone's location provider.
+     */
+    fun headingUpdates(location: Location? = null): Flow<HeadingState> = callbackFlow {
+        val sensorManager = context.getSystemService(Context.SENSOR_SERVICE) as? SensorManager
+        if (sensorManager == null) {
+            trySend(HeadingState(hasSensor = false))
+            close()
+            return@callbackFlow
+        }
+
+        val rotationSensor = sensorManager.getDefaultSensor(Sensor.TYPE_ROTATION_VECTOR)
+        val accelerometer = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER)
+        val magnetometer = sensorManager.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD)
+
+        if (rotationSensor == null && (accelerometer == null || magnetometer == null)) {
+            trySend(HeadingState(hasSensor = false))
+            awaitClose {}
+            return@callbackFlow
+        }
+
+        val rotationMatrix = FloatArray(ROTATION_MATRIX_SIZE)
+        val orientation = FloatArray(ORIENTATION_SIZE)
+        val accelValues = FloatArray(ORIENTATION_SIZE)
+        val magnetValues = FloatArray(ORIENTATION_SIZE)
+        var hasAccel = false
+        var hasMagnet = false
+
+        val listener = object : SensorEventListener {
+            override fun onSensorChanged(event: SensorEvent) {
+                when (event.sensor.type) {
+                    Sensor.TYPE_ROTATION_VECTOR -> {
+                        SensorManager.getRotationMatrixFromVector(rotationMatrix, event.values)
+                    }
+                    Sensor.TYPE_ACCELEROMETER -> {
+                        System.arraycopy(event.values, 0, accelValues, 0, accelValues.size)
+                        hasAccel = true
+                    }
+                    Sensor.TYPE_MAGNETIC_FIELD -> {
+                        System.arraycopy(event.values, 0, magnetValues, 0, magnetValues.size)
+                        hasMagnet = true
+                    }
+                }
+
+                val ready = rotationSensor != null || (hasAccel && hasMagnet)
+                if (ready) {
+                    if (rotationSensor == null) {
+                        SensorManager.getRotationMatrix(rotationMatrix, null, accelValues, magnetValues)
+                    }
+
+                    SensorManager.getOrientation(rotationMatrix, orientation)
+                    var azimuth = Math.toDegrees(orientation[0].toDouble()).toFloat()
+                    var heading = (azimuth + 360) % 360
+
+                    // True north correction using phone location if available
+                    location?.let { loc ->
+                        val geomagnetic = GeomagneticField(
+                            loc.latitude.toFloat(),
+                            loc.longitude.toFloat(),
+                            loc.altitude.toFloat(),
+                            System.currentTimeMillis()
+                        )
+                        heading = (heading + geomagnetic.declination + 360) % 360
+                    }
+
+                    trySend(
+                        HeadingState(
+                            heading = heading,
+                            hasSensor = true,
+                            accuracy = event.accuracy
+                        )
+                    )
+                }
+            }
+
+            override fun onAccuracyChanged(sensor: Sensor, accuracy: Int) {
+                // No-op
+            }
+        }
+
+        rotationSensor?.let { sensorManager.registerListener(listener, it, SensorManager.SENSOR_DELAY_UI) }
+        if (rotationSensor == null) {
+            accelerometer?.let { sensorManager.registerListener(listener, it, SensorManager.SENSOR_DELAY_UI) }
+            magnetometer?.let { sensorManager.registerListener(listener, it, SensorManager.SENSOR_DELAY_UI) }
+        }
+
+        awaitClose { sensorManager.unregisterListener(listener) }
+    }
+}

feature/node/src/main/kotlin/org/meshtastic/feature/node/compass/CompassUiState.kt

@@ -0,0 +1,48 @@
+/*
+ * Copyright (c) 2025 Meshtastic LLC
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package org.meshtastic.feature.node.compass
+
+import androidx.compose.ui.graphics.Color
+import org.meshtastic.proto.ConfigProtos.Config.DisplayConfig.DisplayUnits
+
+private const val DEFAULT_TARGET_COLOR_HEX = 0xFFFF9800
+
+enum class CompassWarning {
+    NO_MAGNETOMETER,
+    NO_LOCATION_PERMISSION,
+    LOCATION_DISABLED,
+    NO_LOCATION_FIX,
+}
+
+/** Render-ready state for the compass sheet (heading, bearing, distances, and warnings). */
+data class CompassUiState(
+    val targetName: String = "",
+    val targetColor: Color = Color(DEFAULT_TARGET_COLOR_HEX),
+    val heading: Float? = null,
+    val bearing: Float? = null,
+    val distanceText: String? = null,
+    val bearingText: String? = null,
+    val lastUpdateText: String? = null,
+    val positionTimeSec: Long? = null, // Epoch seconds for the target position (used for elapsed display)
+    val warnings: List<CompassWarning> = emptyList(),
+    val errorRadiusText: String? = null,
+    val angularErrorDeg: Float? = null,
+    val isAligned: Boolean = false,
+    val hasTargetPosition: Boolean = true,
+    val displayUnits: DisplayUnits = DisplayUnits.METRIC,
+)