Add HRS service

feature_hrs/build.gradle

@@ -0,0 +1,28 @@
+apply from: rootProject.file("library.gradle")
+apply plugin: 'kotlin-parcelize'
+
+dependencies {
+    implementation project(":lib_service")
+    implementation project(":lib_theme")
+    implementation project(":lib_utils")
+
+    implementation libs.chart
+
+    implementation libs.nordic.ble.common
+
+    implementation libs.nordic.log
+
+    implementation libs.bundles.compose
+    implementation libs.androidx.core
+    implementation libs.material
+    implementation libs.lifecycle.activity
+    implementation libs.lifecycle.service
+    implementation libs.compose.lifecycle
+    implementation libs.compose.activity
+
+    testImplementation libs.test.junit
+    androidTestImplementation libs.android.test.junit
+    androidTestImplementation libs.android.test.espresso
+    androidTestImplementation libs.android.test.compose.ui
+    debugImplementation libs.android.test.compose.tooling
+}

feature_hrs/src/androidTest/java/no/nordicsemi/android/hrs/ExampleInstrumentedTest.kt

@@ -0,0 +1,24 @@
+package no.nordicsemi.android.hrs
+
+import androidx.test.platform.app.InstrumentationRegistry
+import androidx.test.ext.junit.runners.AndroidJUnit4
+
+import org.junit.Test
+import org.junit.runner.RunWith
+
+import org.junit.Assert.*
+
+/**
+ * Instrumented test, which will execute on an Android device.
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+@RunWith(AndroidJUnit4::class)
+class ExampleInstrumentedTest {
+    @Test
+    fun useAppContext() {
+        // Context of the app under test.
+        val appContext = InstrumentationRegistry.getInstrumentation().targetContext
+        assertEquals("no.nordicsemi.android.hrs.test", appContext.packageName)
+    }
+}

feature_hrs/src/main/AndroidManifest.xml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="no.nordicsemi.android.hrs">
+
+    <application>
+        <service android:name=".service.HRSService" />
+    </application>
+
+</manifest>

feature_hrs/src/main/java/no/nordicsemi/android/hrs/events/HRSAggregatedData.kt

@@ -0,0 +1,7 @@
+package no.nordicsemi.android.hrs.events
+
+internal data class HRSAggregatedData(
+    val heartRates: List<Int> = emptyList(),
+    val batteryLevel: Int = 0,
+    val sensorLocation: Int = 0
+)

feature_hrs/src/main/java/no/nordicsemi/android/hrs/service/BodySensorLocationParser.kt

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2015, Nordic Semiconductor
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this
+ * software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+ * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package no.nordicsemi.android.hrs.service
+
+import no.nordicsemi.android.ble.data.Data
+
+object BodySensorLocationParser {
+    fun parse(data: Data): String {
+        val value = data.getIntValue(Data.FORMAT_UINT8, 0)!!
+        return when (value) {
+            6 -> "Foot"
+            5 -> "Ear Lobe"
+            4 -> "Hand"
+            3 -> "Finger"
+            2 -> "Wrist"
+            1 -> "Chest"
+            0 -> "Other"
+            else -> "Other"
+        }
+    }
+}

feature_hrs/src/main/java/no/nordicsemi/android/hrs/service/HRSDataBroadcast.kt

@@ -0,0 +1,9 @@
+package no.nordicsemi.android.hrs.service
+
+import no.nordicsemi.android.hrs.events.HRSAggregatedData
+import no.nordicsemi.android.service.BluetoothDataReadBroadcast
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+internal class HRSDataBroadcast @Inject constructor() : BluetoothDataReadBroadcast<HRSAggregatedData>()

feature_hrs/src/main/java/no/nordicsemi/android/hrs/service/HRSManager.kt

@@ -0,0 +1,162 @@
+/*
+ * Copyright (c) 2015, Nordic Semiconductor
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this
+ * software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+ * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package no.nordicsemi.android.hrs.service
+
+import android.bluetooth.BluetoothDevice
+import android.bluetooth.BluetoothGatt
+import android.bluetooth.BluetoothGattCharacteristic
+import android.content.Context
+import android.util.Log
+import androidx.annotation.IntRange
+import no.nordicsemi.android.ble.common.callback.hr.BodySensorLocationDataCallback
+import no.nordicsemi.android.ble.common.callback.hr.HeartRateMeasurementDataCallback
+import no.nordicsemi.android.ble.common.profile.hr.BodySensorLocation
+import no.nordicsemi.android.ble.data.Data
+import no.nordicsemi.android.log.LogContract
+import no.nordicsemi.android.service.BatteryManager
+import java.util.*
+
+/**
+ * HRSManager class performs BluetoothGatt operations for connection, service discovery,
+ * enabling notification and reading characteristics.
+ * All operations required to connect to device with BLE Heart Rate Service and reading
+ * heart rate values are performed here.
+ */
+class HRSManager(context: Context) : BatteryManager<HRSManagerCallbacks>(context) {
+
+    private var heartRateCharacteristic: BluetoothGattCharacteristic? = null
+    private var bodySensorLocationCharacteristic: BluetoothGattCharacteristic? = null
+
+    override fun getGattCallback(): BatteryManagerGattCallback {
+        return HeartRateManagerCallback()
+    }
+
+    /**
+     * BluetoothGatt callbacks for connection/disconnection, service discovery,
+     * receiving notification, etc.
+     */
+    private inner class HeartRateManagerCallback : BatteryManagerGattCallback() {
+        override fun initialize() {
+            super.initialize()
+            readCharacteristic(bodySensorLocationCharacteristic)
+                .with(object : BodySensorLocationDataCallback() {
+
+                    override fun onDataReceived(device: BluetoothDevice, data: Data) {
+                        log(
+                            LogContract.Log.Level.APPLICATION,
+                            "\"" + BodySensorLocationParser.parse(data) + "\" received"
+                        )
+                        super.onDataReceived(device, data)
+                    }
+
+                    override fun onBodySensorLocationReceived(
+                        device: BluetoothDevice,
+                        @BodySensorLocation sensorLocation: Int
+                    ) {
+                        mCallbacks?.onBodySensorLocationReceived(device, sensorLocation)
+                    }
+
+                })
+                .fail { device: BluetoothDevice?, status: Int ->
+                    log(Log.WARN, "Body Sensor Location characteristic not found")
+                }
+                .enqueue()
+
+            setNotificationCallback(heartRateCharacteristic)
+                .with(object : HeartRateMeasurementDataCallback() {
+
+                    override fun onDataReceived(device: BluetoothDevice, data: Data) {
+                        log(
+                            LogContract.Log.Level.APPLICATION,
+                            "\"" + HeartRateMeasurementParser.parse(data) + "\" received"
+                        )
+                        super.onDataReceived(device, data)
+                    }
+
+                    override fun onHeartRateMeasurementReceived(
+                        device: BluetoothDevice,
+                        @IntRange(from = 0) heartRate: Int,
+                        contactDetected: Boolean?,
+                        @IntRange(from = 0) energyExpanded: Int?,
+                        rrIntervals: List<Int>?
+                    ) {
+                        mCallbacks?.onHeartRateMeasurementReceived(
+                            device,
+                            heartRate,
+                            contactDetected,
+                            energyExpanded,
+                            rrIntervals
+                        )
+                    }
+                })
+            enableNotifications(heartRateCharacteristic).enqueue()
+        }
+
+        override fun isRequiredServiceSupported(gatt: BluetoothGatt): Boolean {
+            val service = gatt.getService(HR_SERVICE_UUID)
+            if (service != null) {
+                heartRateCharacteristic = service.getCharacteristic(
+                    HEART_RATE_MEASUREMENT_CHARACTERISTIC_UUID
+                )
+            }
+            return heartRateCharacteristic != null
+        }
+
+        override fun isOptionalServiceSupported(gatt: BluetoothGatt): Boolean {
+            super.isOptionalServiceSupported(gatt)
+            val service = gatt.getService(HR_SERVICE_UUID)
+            if (service != null) {
+                bodySensorLocationCharacteristic = service.getCharacteristic(
+                    BODY_SENSOR_LOCATION_CHARACTERISTIC_UUID
+                )
+            }
+            return bodySensorLocationCharacteristic != null
+        }
+
+        override fun onDeviceDisconnected() {
+            super.onDeviceDisconnected()
+            bodySensorLocationCharacteristic = null
+            heartRateCharacteristic = null
+        }
+
+        override fun onServicesInvalidated() {}
+    }
+
+    companion object {
+
+        val HR_SERVICE_UUID = UUID.fromString("0000180D-0000-1000-8000-00805f9b34fb")
+        private val BODY_SENSOR_LOCATION_CHARACTERISTIC_UUID = UUID.fromString("00002A38-0000-1000-8000-00805f9b34fb")
+        private val HEART_RATE_MEASUREMENT_CHARACTERISTIC_UUID = UUID.fromString("00002A37-0000-1000-8000-00805f9b34fb")
+        private var managerInstance: HRSManager? = null
+
+        /**
+         * Singleton implementation of HRSManager class.
+         */
+        @Synchronized
+        fun getInstance(context: Context): HRSManager? {
+            if (managerInstance == null) {
+                managerInstance = HRSManager(context)
+            }
+            return managerInstance
+        }
+    }
+}

feature_hrs/src/main/java/no/nordicsemi/android/hrs/service/HRSManagerCallbacks.kt

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2015, Nordic Semiconductor
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this
+ * software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+ * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package no.nordicsemi.android.hrs.service
+
+import no.nordicsemi.android.ble.common.profile.hr.BodySensorLocationCallback
+import no.nordicsemi.android.ble.common.profile.hr.HeartRateMeasurementCallback
+import no.nordicsemi.android.service.BatteryManagerCallbacks
+
+interface HRSManagerCallbacks
+    : BatteryManagerCallbacks, BodySensorLocationCallback, HeartRateMeasurementCallback

feature_hrs/src/main/java/no/nordicsemi/android/hrs/service/HRSService.kt

@@ -0,0 +1,53 @@
+package no.nordicsemi.android.hrs.service
+
+import android.bluetooth.BluetoothDevice
+import dagger.hilt.android.AndroidEntryPoint
+import no.nordicsemi.android.ble.BleManagerCallbacks
+import no.nordicsemi.android.hrs.events.HRSAggregatedData
+import no.nordicsemi.android.service.ForegroundBleService
+import no.nordicsemi.android.service.LoggableBleManager
+import javax.inject.Inject
+
+@AndroidEntryPoint
+internal class HRSService : ForegroundBleService<HRSManager>(), HRSManagerCallbacks {
+
+    private var data = HRSAggregatedData()
+    private val points = mutableListOf<Int>()
+
+    @Inject
+    lateinit var localBroadcast: HRSDataBroadcast
+
+    override val manager: HRSManager by lazy {
+        HRSManager(this).apply {
+            setGattCallbacks(this@HRSService)
+        }
+    }
+
+    override fun initializeManager(): LoggableBleManager<out BleManagerCallbacks> {
+        return manager
+    }
+
+    override fun onBatteryLevelChanged(device: BluetoothDevice, batteryLevel: Int) {
+        sendNewData(data.copy(batteryLevel = batteryLevel))
+    }
+
+    override fun onBodySensorLocationReceived(device: BluetoothDevice, sensorLocation: Int) {
+        sendNewData(data.copy(sensorLocation = sensorLocation))
+    }
+
+    override fun onHeartRateMeasurementReceived(
+        device: BluetoothDevice,
+        heartRate: Int,
+        contactDetected: Boolean?,
+        energyExpanded: Int?,
+        rrIntervals: MutableList<Int>?
+    ) {
+        points.add(heartRate)
+        sendNewData(data.copy(heartRates = points))
+    }
+
+    private fun sendNewData(newData: HRSAggregatedData) {
+        data = newData
+        localBroadcast.offer(newData)
+    }
+}

feature_hrs/src/main/java/no/nordicsemi/android/hrs/service/HeartRateMeasurementParser.kt

@@ -0,0 +1,115 @@
+/*
+ * Copyright (c) 2015, Nordic Semiconductor
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this
+ * software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
+ * USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package no.nordicsemi.android.hrs.service
+
+import no.nordicsemi.android.ble.data.Data
+import java.util.*
+
+object HeartRateMeasurementParser {
+
+    private const val HEART_RATE_VALUE_FORMAT: Byte = 0x01 // 1 bit
+    private const val SENSOR_CONTACT_STATUS: Byte = 0x06 // 2 bits
+    private const val ENERGY_EXPANDED_STATUS: Byte = 0x08 // 1 bit
+    private const val RR_INTERVAL: Byte = 0x10 // 1 bit
+
+    fun parse(data: Data): String {
+        var offset = 0
+        val flags = data.getIntValue(Data.FORMAT_UINT8, offset++)!!
+
+        /*
+		 * false 	Heart Rate Value Format is set to UINT8. Units: beats per minute (bpm) 
+		 * true 	Heart Rate Value Format is set to UINT16. Units: beats per minute (bpm)
+		 */
+        val value16bit = flags and HEART_RATE_VALUE_FORMAT.toInt() > 0
+
+        /*
+		 * 0 	Sensor Contact feature is not supported in the current connection
+		 * 1 	Sensor Contact feature is not supported in the current connection
+		 * 2 	Sensor Contact feature is supported, but contact is not detected
+		 * 3 	Sensor Contact feature is supported and contact is detected
+		 */
+        val sensorContactStatus = flags and SENSOR_CONTACT_STATUS.toInt() shr 1
+
+        /*
+		 * false 	Energy Expended field is not present
+		 * true 	Energy Expended field is present. Units: kilo Joules
+		 */
+        val energyExpandedStatus = flags and ENERGY_EXPANDED_STATUS.toInt() > 0
+
+        /*
+		 * false 	RR-Interval values are not present.
+		 * true 	One or more RR-Interval values are present. Units: 1/1024 seconds
+		 */
+        val rrIntervalStatus = flags and RR_INTERVAL.toInt() > 0
+
+        // heart rate value is 8 or 16 bit long
+        val heartRateValue = data.getIntValue(
+            if (value16bit) {
+                Data.FORMAT_UINT16
+            } else {
+                Data.FORMAT_UINT8
+            },
+            offset++
+        ) // bits per minute
+        if (value16bit) offset++
+
+        // energy expanded value is present if a flag was set
+        var energyExpanded = -1
+        if (energyExpandedStatus) energyExpanded = data.getIntValue(Data.FORMAT_UINT16, offset)!!
+        offset += 2
+
+        // RR-interval is set when a flag is set
+        val rrIntervals: MutableList<Float> = ArrayList()
+        if (rrIntervalStatus) {
+            var o = offset
+            while (o < data.value!!.size) {
+                val units = data.getIntValue(Data.FORMAT_UINT16, o)!!
+                rrIntervals.add(units * 1000.0f / 1024.0f) // RR interval is in [1/1024s]
+                o += 2
+            }
+        }
+        val builder = StringBuilder()
+        builder.append("Heart Rate Measurement: ").append(heartRateValue).append(" bpm")
+        when (sensorContactStatus) {
+            0, 1 -> builder.append(",\nSensor Contact Not Supported")
+            2 -> builder.append(",\nContact is NOT Detected")
+            3 -> builder.append(",\nContact is Detected")
+        }
+        if (energyExpandedStatus) {
+            builder.append(",\nEnergy Expanded: ")
+                .append(energyExpanded)
+                .append(" kJ")
+        }
+        if (rrIntervalStatus) {
+            builder.append(",\nRR Interval: ")
+            for (interval in rrIntervals) builder.append(
+                String.format(
+                    Locale.US,
+                    "%.02f ms, ",
+                    interval
+                )
+            )
+            builder.setLength(builder.length - 2) // remove the ", " at the end
+        }
+        return builder.toString()
+    }
+}

feature_hrs/src/main/java/no/nordicsemi/android/hrs/view/ContentView.kt

@@ -0,0 +1,224 @@
+package no.nordicsemi.android.hrs.view
+
+import android.content.Context
+import android.graphics.Color
+import android.graphics.DashPathEffect
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.shape.RoundedCornerShape
+import androidx.compose.material.Button
+import androidx.compose.material.ButtonDefaults
+import androidx.compose.material.Card
+import androidx.compose.material.MaterialTheme
+import androidx.compose.material.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.tooling.preview.Preview
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.viewinterop.AndroidView
+import androidx.core.content.ContextCompat
+import com.github.mikephil.charting.charts.LineChart
+import com.github.mikephil.charting.data.Entry
+import com.github.mikephil.charting.data.LineData
+import com.github.mikephil.charting.data.LineDataSet
+import com.github.mikephil.charting.formatter.IFillFormatter
+import com.github.mikephil.charting.interfaces.datasets.ILineDataSet
+import com.github.mikephil.charting.utils.Utils
+import no.nordicsemi.android.hrs.R
+import no.nordicsemi.android.hrs.viewmodel.HRSViewState
+import no.nordicsemi.android.theme.NordicColors
+import no.nordicsemi.android.theme.view.BatteryLevelView
+import java.util.*
+
+@Composable
+internal fun ContentView(state: HRSViewState, onEvent: (HRSScreenViewEvent) -> Unit) {
+    Column(
+        modifier = Modifier
+            .fillMaxSize()
+            .padding(16.dp),
+        horizontalAlignment = Alignment.CenterHorizontally
+    ) {
+        Card(
+            backgroundColor = NordicColors.NordicGray4.value(),
+            shape = RoundedCornerShape(10.dp),
+            elevation = 0.dp
+        ) {
+            Box(modifier = Modifier.padding(16.dp)) {
+                LineChartView(state)
+            }
+        }
+
+        Spacer(modifier = Modifier.height(16.dp))
+
+        BatteryLevelView(state.batteryLevel)
+
+        Spacer(modifier = Modifier.height(16.dp))
+
+        Button(
+            colors = ButtonDefaults.buttonColors(backgroundColor = MaterialTheme.colors.secondary),
+            onClick = { onEvent(DisconnectEvent) }
+        ) {
+            Text(text = stringResource(id = R.string.disconnect))
+        }
+    }
+}
+
+@Composable
+fun LineChartView(state: HRSViewState) {
+    AndroidView(
+        modifier = Modifier
+            .fillMaxWidth()
+            .height(300.dp),
+        factory = { createLineChartView(it, state) },
+        update = { updateData(state.points, it)  }
+    )
+}
+
+fun createLineChartView(context: Context, state: HRSViewState): LineChart {
+    return LineChart(context).apply {
+        setBackgroundColor(Color.WHITE)
+
+        description.isEnabled = false
+
+        setTouchEnabled(true)
+
+//        setOnChartValueSelectedListener(this)
+        setDrawGridBackground(false)
+
+        isDragEnabled = true
+        setScaleEnabled(true)
+        setPinchZoom(true)
+
+        xAxis.apply {
+            xAxis.enableGridDashedLine(10f, 10f, 0f)
+        }
+        axisLeft.apply {
+            enableGridDashedLine(10f, 10f, 0f)
+
+            axisMaximum = 300f
+            axisMinimum = 100f
+        }
+        axisRight.isEnabled = false
+
+        //---
+
+        val entries = state.points.mapIndexed { i, v ->
+            Entry(i.toFloat(), v.toFloat())
+        }
+        // create a dataset and give it a type
+
+        if (data != null && data.dataSetCount > 0) {
+            val set1 = data!!.getDataSetByIndex(0) as LineDataSet
+            set1.values = entries
+            set1.notifyDataSetChanged()
+            data!!.notifyDataChanged()
+            notifyDataSetChanged()
+        } else {
+            val set1 = LineDataSet(entries, "DataSet 1")
+
+            set1.setDrawIcons(false)
+
+            // draw dashed line
+
+            // draw dashed line
+            set1.enableDashedLine(10f, 5f, 0f)
+
+            // black lines and points
+
+            // black lines and points
+            set1.color = Color.BLACK
+            set1.setCircleColor(Color.BLACK)
+
+            // line thickness and point size
+
+            // line thickness and point size
+            set1.lineWidth = 1f
+            set1.circleRadius = 3f
+
+            // draw points as solid circles
+
+            // draw points as solid circles
+            set1.setDrawCircleHole(false)
+
+            // customize legend entry
+
+            // customize legend entry
+            set1.formLineWidth = 1f
+            set1.formLineDashEffect = DashPathEffect(floatArrayOf(10f, 5f), 0f)
+            set1.formSize = 15f
+
+            // text size of values
+
+            // text size of values
+            set1.valueTextSize = 9f
+
+            // draw selection line as dashed
+
+            // draw selection line as dashed
+            set1.enableDashedHighlightLine(10f, 5f, 0f)
+
+            // set the filled area
+
+            // set the filled area
+            set1.setDrawFilled(true)
+            set1.fillFormatter = IFillFormatter { _, _ ->
+                axisLeft.axisMinimum
+            }
+
+            // set color of filled area
+
+            // set color of filled area
+            if (Utils.getSDKInt() >= 18) {
+                // drawables only supported on api level 18 and above
+                val drawable = ContextCompat.getDrawable(context, R.drawable.fade_red)
+                set1.fillDrawable = drawable
+            } else {
+                set1.fillColor = Color.BLACK
+            }
+
+            val dataSets = ArrayList<ILineDataSet>()
+            dataSets.add(set1) // add the data sets
+
+
+            // create a data object with the data sets
+
+            // create a data object with the data sets
+            val data = LineData(dataSets)
+
+            // set data
+
+            // set data
+            setData(data)
+        }
+    }
+}
+
+private fun updateData(points: List<Int>, chart: LineChart) {
+    val entries = points.mapIndexed { i, v ->
+        Entry(i.toFloat(), v.toFloat())
+    }
+
+    with(chart) {
+        if (data != null && data.dataSetCount > 0) {
+            val set1 = data!!.getDataSetByIndex(0) as LineDataSet
+            set1.values = entries
+            set1.notifyDataSetChanged()
+            data!!.notifyDataChanged()
+            notifyDataSetChanged()
+            invalidate()
+        }
+    }
+}
+
+@Preview
+@Composable
+private fun Preview() {
+    ContentView(state = HRSViewState()) { }
+}

feature_hrs/src/main/java/no/nordicsemi/android/hrs/view/HRSScreen.kt

@@ -0,0 +1,52 @@
+package no.nordicsemi.android.hrs.view
+
+import android.content.Intent
+import androidx.compose.foundation.layout.Column
+import androidx.compose.material.Text
+import androidx.compose.material.TopAppBar
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.collectAsState
+import androidx.compose.ui.platform.LocalContext
+import androidx.compose.ui.res.stringResource
+import androidx.hilt.navigation.compose.hiltViewModel
+import no.nordicsemi.android.hrs.R
+import no.nordicsemi.android.hrs.service.HRSService
+import no.nordicsemi.android.hrs.viewmodel.HRSViewModel
+import no.nordicsemi.android.hrs.viewmodel.HRSViewState
+import no.nordicsemi.android.utils.isServiceRunning
+
+@Composable
+fun HRSScreen(finishAction: () -> Unit) {
+    val viewModel: HRSViewModel = hiltViewModel()
+    val state = viewModel.state.collectAsState().value
+
+    val context = LocalContext.current
+    LaunchedEffect(state.isScreenActive) {
+        if (!state.isScreenActive) {
+            finishAction()
+        }
+        if (context.isServiceRunning(HRSService::class.java.name)) {
+            val intent = Intent(context, HRSService::class.java)
+            context.stopService(intent)
+        }
+    }
+
+    LaunchedEffect("start-service") {
+        if (!context.isServiceRunning(HRSService::class.java.name)) {
+            val intent = Intent(context, HRSService::class.java)
+            context.startService(intent)
+        }
+    }
+
+    HRSView(state) { viewModel.onEvent(it) }
+}
+
+@Composable
+private fun HRSView(state: HRSViewState, onEvent: (HRSScreenViewEvent) -> Unit) {
+    Column {
+        TopAppBar(title = { Text(text = stringResource(id = R.string.hrs_title)) })
+
+        ContentView(state) { onEvent(it) }
+    }
+}

feature_hrs/src/main/java/no/nordicsemi/android/hrs/view/HRSScreenViewEvent.kt

@@ -0,0 +1,5 @@
+package no.nordicsemi.android.hrs.view
+
+sealed class HRSScreenViewEvent
+
+object DisconnectEvent : HRSScreenViewEvent()

feature_hrs/src/main/java/no/nordicsemi/android/hrs/viewmodel/HRSViewModel.kt

@@ -0,0 +1,47 @@
+package no.nordicsemi.android.hrs.viewmodel
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import dagger.hilt.android.lifecycle.HiltViewModel
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.launchIn
+import kotlinx.coroutines.flow.onEach
+import kotlinx.coroutines.withContext
+import no.nordicsemi.android.hrs.events.HRSAggregatedData
+import no.nordicsemi.android.hrs.service.HRSDataBroadcast
+import no.nordicsemi.android.hrs.view.DisconnectEvent
+import no.nordicsemi.android.hrs.view.HRSScreenViewEvent
+import javax.inject.Inject
+
+@HiltViewModel
+internal class HRSViewModel @Inject constructor(
+    private val localBroadcast: HRSDataBroadcast
+) : ViewModel() {
+
+    val state = MutableStateFlow(HRSViewState())
+
+    init {
+        localBroadcast.events.onEach {
+            withContext(Dispatchers.Main) { consumeEvent(it) }
+        }.launchIn(viewModelScope)
+    }
+
+    private fun consumeEvent(event: HRSAggregatedData) {
+        state.value = state.value.copy(
+            points = event.heartRates,
+            batteryLevel = event.batteryLevel,
+            sensorLocation = event.sensorLocation
+        )
+    }
+
+    fun onEvent(event: HRSScreenViewEvent) {
+        (event as? DisconnectEvent)?.let {
+            onDisconnectButtonClick()
+        }
+    }
+
+    private fun onDisconnectButtonClick() {
+        state.tryEmit(state.value.copy(isScreenActive = false))
+    }
+}

feature_hrs/src/main/java/no/nordicsemi/android/hrs/viewmodel/HRSViewState.kt

@@ -0,0 +1,8 @@
+package no.nordicsemi.android.hrs.viewmodel
+
+data class HRSViewState(
+    val points: List<Int> = listOf(1, 2, 3),
+    val batteryLevel: Int = 0,
+    val sensorLocation: Int = 0,
+    val isScreenActive: Boolean = true
+)

feature_hrs/src/main/res/drawable/fade_red.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<shape xmlns:android="http://schemas.android.com/apk/res/android">
+    <gradient
+        android:angle="90"
+        android:startColor="#00ff0000"
+        android:endColor="#ffff0000" />
+</shape>

feature_hrs/src/main/res/values/strings.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+    <string name="hrs_title">HRS</string>
+</resources>

feature_hrs/src/test/java/no/nordicsemi/android/hrs/ExampleUnitTest.kt

@@ -0,0 +1,17 @@
+package no.nordicsemi.android.hrs
+
+import org.junit.Test
+
+import org.junit.Assert.*
+
+/**
+ * Example local unit test, which will execute on the development machine (host).
+ *
+ * See [testing documentation](http://d.android.com/tools/testing).
+ */
+class ExampleUnitTest {
+    @Test
+    fun addition_isCorrect() {
+        assertEquals(4, 2 + 2)
+    }
+}