Add haptic feedback (Kr0oked#38)

app/src/main/java/com/bobek/compass/CompassFragment.kt

@@ -91,6 +91,7 @@ class CompassFragment : Fragment() {
     private fun initPreferenceStore() {
         preferenceStore = PreferenceStore(requireContext(), lifecycle)
         preferenceStore.trueNorth.observe(viewLifecycleOwner) { compassViewModel.trueNorth.value = it }
+        preferenceStore.hapticFeedback.observe(viewLifecycleOwner) { compassViewModel.hapticFeedback.value = it }
     }
 
     private fun setupSystemServices() {

app/src/main/java/com/bobek/compass/model/Azimuth.kt

@@ -1,6 +1,6 @@
 /*
  * This file is part of Compass.
- * Copyright (C) 2022 Philipp Bobek <philipp.bobek@mailbox.org>
+ * Copyright (C) 2023 Philipp Bobek <philipp.bobek@mailbox.org>
  *
  * 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
@@ -20,8 +20,6 @@ package com.bobek.compass.model
 
 class Azimuth(_degrees: Float) {
 
-    operator fun plus(degrees: Float) = Azimuth(this.degrees + degrees)
-
     val degrees = normalizeAngle(_degrees)
 
     val cardinalDirection: CardinalDirection = when (degrees) {
@@ -57,6 +55,12 @@ class Azimuth(_degrees: Float) {
     override fun toString(): String {
         return "Azimuth(degrees=$degrees)"
     }
+
+    operator fun plus(degrees: Float) = Azimuth(this.degrees + degrees)
+
+    operator fun minus(degrees: Float) = Azimuth(this.degrees - degrees)
+
+    operator fun compareTo(azimuth: Azimuth) = this.degrees.compareTo(azimuth.degrees)
 }
 
 private data class SemiClosedFloatRange(val fromInclusive: Float, val toExclusive: Float)

app/src/main/java/com/bobek/compass/preference/PreferenceConstants.kt

@@ -22,6 +22,8 @@ object PreferenceConstants {
 
     const val TRUE_NORTH = "true_north"
 
+    const val HAPTIC_FEEDBACK = "haptic_feedback"
+
     const val SCREEN_ORIENTATION_LOCKED = "screen_orientation_locked"
 
     const val NIGHT_MODE = "night_mode"

app/src/main/java/com/bobek/compass/preference/PreferenceStore.kt

@@ -33,6 +33,7 @@ private const val TAG = "PreferenceStore"
 class PreferenceStore(context: Context, lifecycle: Lifecycle) {
 
     val trueNorth = MutableLiveData<Boolean>()
+    val hapticFeedback = MutableLiveData<Boolean>()
     val screenOrientationLocked = MutableLiveData<Boolean>()
     val nightMode = MutableLiveData<AppNightMode>()
     val accessCoarseLocationPermissionRequested = MutableLiveData<Boolean>()
@@ -42,6 +43,7 @@ class PreferenceStore(context: Context, lifecycle: Lifecycle) {
     private val sharedPreferenceChangeListener = SharedPreferenceChangeListener()
 
     private val trueNorthObserver = getTrueNorthObserver()
+    private val hapticFeedbackObserver = getHapticFeedbackObserver()
     private val screenOrientationLockedObserver = getScreenOrientationLockedObserver()
     private val nightModeObserver = getNightModeObserver()
     private val accessCoarseLocationPermissionRequestedObserver = getAccessCoarseLocationPermissionRequestedObserver()
@@ -52,6 +54,7 @@ class PreferenceStore(context: Context, lifecycle: Lifecycle) {
         sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context)
 
         updateTrueNorth()
+        updateHapticFeedback()
         updateScreenOrientationLocked()
         updateNightMode()
         updateAccessCoarseLocationPermissionRequested()
@@ -63,6 +66,7 @@ class PreferenceStore(context: Context, lifecycle: Lifecycle) {
 
         override fun onCreate(owner: LifecycleOwner) {
             trueNorth.observeForever(trueNorthObserver)
+            hapticFeedback.observeForever(hapticFeedbackObserver)
             screenOrientationLocked.observeForever(screenOrientationLockedObserver)
             nightMode.observeForever(nightModeObserver)
             accessCoarseLocationPermissionRequested.observeForever(accessCoarseLocationPermissionRequestedObserver)
@@ -74,6 +78,7 @@ class PreferenceStore(context: Context, lifecycle: Lifecycle) {
             sharedPreferences.unregisterOnSharedPreferenceChangeListener(sharedPreferenceChangeListener)
 
             trueNorth.removeObserver(trueNorthObserver)
+            hapticFeedback.removeObserver(hapticFeedbackObserver)
             screenOrientationLocked.removeObserver(screenOrientationLockedObserver)
             nightMode.removeObserver(nightModeObserver)
             accessCoarseLocationPermissionRequested.removeObserver(accessCoarseLocationPermissionRequestedObserver)
@@ -84,6 +89,7 @@ class PreferenceStore(context: Context, lifecycle: Lifecycle) {
         override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String?) {
             when (key) {
                 PreferenceConstants.TRUE_NORTH -> updateTrueNorth()
+                PreferenceConstants.HAPTIC_FEEDBACK -> updateHapticFeedback()
                 PreferenceConstants.SCREEN_ORIENTATION_LOCKED -> updateScreenOrientationLocked()
                 PreferenceConstants.NIGHT_MODE -> updateNightMode()
                 PreferenceConstants.ACCESS_COARSE_LOCATION_PERMISSION_REQUESTED -> {
@@ -100,6 +106,13 @@ class PreferenceStore(context: Context, lifecycle: Lifecycle) {
         }
     }
 
+    private fun updateHapticFeedback() {
+        val storedValue = sharedPreferences.getBoolean(PreferenceConstants.HAPTIC_FEEDBACK, true)
+        if (hapticFeedback.value != storedValue) {
+            hapticFeedback.value = storedValue
+        }
+    }
+
     private fun updateScreenOrientationLocked() {
         val storedValue = sharedPreferences.getBoolean(PreferenceConstants.SCREEN_ORIENTATION_LOCKED, false)
         if (screenOrientationLocked.value != storedValue) {
@@ -133,6 +146,13 @@ class PreferenceStore(context: Context, lifecycle: Lifecycle) {
         Log.d(TAG, "Persisted trueNorth: $it")
     }
 
+    private fun getHapticFeedbackObserver(): (t: Boolean) -> Unit = {
+        val edit = sharedPreferences.edit()
+        edit.putBoolean(PreferenceConstants.HAPTIC_FEEDBACK, it)
+        edit.apply()
+        Log.d(TAG, "Persisted hapticFeedback: $it")
+    }
+
     private fun getScreenOrientationLockedObserver(): (t: Boolean) -> Unit = {
         val edit = sharedPreferences.edit()
         edit.putBoolean(PreferenceConstants.SCREEN_ORIENTATION_LOCKED, it)

app/src/main/java/com/bobek/compass/util/MathUtils.kt

@@ -25,6 +25,7 @@ import com.bobek.compass.model.Azimuth
 import com.bobek.compass.model.DisplayRotation
 import com.bobek.compass.model.DisplayRotation.*
 import com.bobek.compass.model.RotationVector
+import kotlin.math.roundToInt
 
 private const val AZIMUTH = 0
 private const val AXIS_SIZE = 3
@@ -72,4 +73,7 @@ object MathUtils {
         val geomagneticField = GeomagneticField(latitude, longitude, altitude, time)
         return geomagneticField.declination
     }
+
+    fun getClosestNumberFromInterval(number: Float, interval: Float): Float =
+        (number / interval).roundToInt() * interval
 }

app/src/main/java/com/bobek/compass/view/CompassView.kt

@@ -22,6 +22,7 @@ import android.content.Context
 import android.util.AttributeSet
 import android.util.TypedValue
 import android.util.TypedValue.COMPLEX_UNIT_PX
+import android.view.HapticFeedbackConstants
 import android.view.LayoutInflater
 import androidx.annotation.AnyRes
 import androidx.annotation.IdRes
@@ -30,13 +31,18 @@ import androidx.constraintlayout.widget.ConstraintSet
 import com.bobek.compass.R
 import com.bobek.compass.databinding.CompassViewBinding
 import com.bobek.compass.model.Azimuth
+import com.bobek.compass.util.MathUtils
 import kotlin.math.roundToInt
 
+private const val HAPTIC_FEEDBACK_INTERVAL = 2.0f
+
 class CompassView(context: Context, attributes: AttributeSet) : ConstraintLayout(context, attributes) {
 
     @IdRes
     private val center = R.id.compass_rose_image
 
+    private var lastHapticFeedbackPoint: Azimuth? = null
+
     private var binding: CompassViewBinding
 
     init {
@@ -90,6 +96,7 @@ class CompassView(context: Context, attributes: AttributeSet) : ConstraintLayout
         val rotation = azimuth.degrees.unaryMinus()
         rotateCompassRoseImage(rotation)
         rotateCompassRoseTexts(rotation)
+        handleHapticFeedback(azimuth)
 
         visibility = VISIBLE
     }
@@ -151,4 +158,32 @@ class CompassView(context: Context, attributes: AttributeSet) : ConstraintLayout
     private fun calculateTextRadius(ratio: Float): Int {
         return width / 2 - (width * ratio).toInt()
     }
+
+    private fun handleHapticFeedback(azimuth: Azimuth) {
+        lastHapticFeedbackPoint
+            ?.also { checkHapticFeedback(azimuth, it) }
+            ?: run { initializeLastHapticFeedbackPoint(azimuth) }
+    }
+
+    private fun checkHapticFeedback(azimuth: Azimuth, lastHapticFeedbackkPoint: Azimuth) {
+        val boundaryStart = lastHapticFeedbackkPoint - HAPTIC_FEEDBACK_INTERVAL
+        val boundaryEnd = lastHapticFeedbackkPoint + HAPTIC_FEEDBACK_INTERVAL
+
+        if (azimuth < boundaryStart) {
+            this.lastHapticFeedbackPoint = boundaryStart
+            performHapticFeedback()
+        } else if (azimuth > boundaryEnd) {
+            this.lastHapticFeedbackPoint = boundaryEnd
+            performHapticFeedback()
+        }
+    }
+
+    private fun performHapticFeedback() {
+        performHapticFeedback(HapticFeedbackConstants.VIRTUAL_KEY)
+    }
+
+    private fun initializeLastHapticFeedbackPoint(azimuth: Azimuth) {
+        val closestIntervalPoint = MathUtils.getClosestNumberFromInterval(azimuth.degrees, HAPTIC_FEEDBACK_INTERVAL)
+        lastHapticFeedbackPoint = Azimuth(closestIntervalPoint)
+    }
 }

app/src/main/java/com/bobek/compass/view/CompassViewModel.kt

@@ -27,6 +27,7 @@ class CompassViewModel : ViewModel() {
 
     val sensorAccuracy = MutableLiveData(SensorAccuracy.NO_CONTACT)
     val trueNorth = MutableLiveData(false)
+    val hapticFeedback = MutableLiveData(true)
     val accessCoarseLocationPermissionGranted = MutableLiveData(false)
     val location = MutableLiveData<Location>()
 }

app/src/main/res/layout-land/fragment_compass.xml

@@ -32,6 +32,7 @@
                 android:id="@+id/compass"
                 android:layout_width="wrap_content"
                 android:layout_height="match_parent"
+                android:hapticFeedbackEnabled="@{model.hapticFeedback}"
                 android:keepScreenOn="true"
                 app:layout_constraintBottom_toBottomOf="parent"
                 app:layout_constraintEnd_toEndOf="parent"

app/src/main/res/layout/fragment_compass.xml

@@ -32,6 +32,7 @@
                 android:id="@+id/compass"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
+                android:hapticFeedbackEnabled="@{model.hapticFeedback}"
                 android:keepScreenOn="true"
                 app:layout_constraintBottom_toTopOf="@id/location_container"
                 app:layout_constraintEnd_toEndOf="parent"

app/src/main/res/values-bs/strings.xml

@@ -61,6 +61,9 @@
     <!--TODO<string name="true_north">True North</string>-->
     <!--TODO<string name="true_north_summary">Correct the magnetic declination and show to true north. Requires access to your coarse location.</string>-->
 
+    <!--TODO<string name="haptic_feedback">Haptic feedback</string>-->
+    <!--TODO<string name="haptic_feedback_summary">The compass vibrates when the direction changes.</string>-->
+
     <!--TODO<string name="display">Display</string>-->
     <!--TODO<string name="night_mode">Night mode</string>-->
     <!--TODO<string name="night_mode_follow_system">System</string>-->

app/src/main/res/values-cs/strings.xml

@@ -61,6 +61,9 @@
     <!--TODO<string name="true_north">True North</string>-->
     <!--TODO<string name="true_north_summary">Correct the magnetic declination and show to true north. Requires access to your coarse location.</string>-->
 
+    <!--TODO<string name="haptic_feedback">Haptic feedback</string>-->
+    <!--TODO<string name="haptic_feedback_summary">The compass vibrates when the direction changes.</string>-->
+
     <string name="display">Ukázat</string>
     <string name="night_mode">Noční režim</string>
     <string name="night_mode_follow_system">Systém</string>

app/src/main/res/values-de/strings.xml

@@ -61,6 +61,9 @@
     <string name="true_north">Geografischer Norden</string>
     <string name="true_north_summary">Die magnetische Deklination wird korrigiert um zum geografischen Norden zu zeigen. Dafür muss auf ihren groben Standort zugegriffen werden.</string>
 
+    <string name="haptic_feedback">Haptisches Feedback</string>
+    <string name="haptic_feedback_summary">Der Kompass vibriert wenn sich die Richtung ändert.</string>
+
     <string name="display">Anzeige</string>
     <string name="night_mode">Nachtmodus</string>
     <string name="night_mode_follow_system">System</string>

app/src/main/res/values-el/strings.xml

@@ -61,6 +61,9 @@
     <!--TODO<string name="true_north">True North</string>-->
     <!--TODO<string name="true_north_summary">Correct the magnetic declination and show to true north. Requires access to your coarse location.</string>-->
 
+    <!--TODO<string name="haptic_feedback">Haptic feedback</string>-->
+    <!--TODO<string name="haptic_feedback_summary">The compass vibrates when the direction changes.</string>-->
+
     <!--TODO<string name="display">Display</string>-->
     <!--TODO<string name="night_mode">Night mode</string>-->
     <!--TODO<string name="night_mode_follow_system">System</string>-->

app/src/main/res/values-fi/strings.xml

@@ -61,6 +61,9 @@
     <!--TODO<string name="true_north">True North</string>-->
     <!--TODO<string name="true_north_summary">Correct the magnetic declination and show to true north. Requires access to your coarse location.</string>-->
 
+    <!--TODO<string name="haptic_feedback">Haptic feedback</string>-->
+    <!--TODO<string name="haptic_feedback_summary">The compass vibrates when the direction changes.</string>-->
+
     <!--TODO<string name="display">Display</string>-->
     <!--TODO<string name="night_mode">Night mode</string>-->
     <!--TODO<string name="night_mode_follow_system">System</string>-->

app/src/main/res/values-fr/strings.xml

@@ -61,6 +61,9 @@
     <!--TODO<string name="true_north">True North</string>-->
     <!--TODO<string name="true_north_summary">Correct the magnetic declination and show to true north. Requires access to your coarse location.</string>-->
 
+    <!--TODO<string name="haptic_feedback">Haptic feedback</string>-->
+    <!--TODO<string name="haptic_feedback_summary">The compass vibrates when the direction changes.</string>-->
+
     <!--TODO<string name="display">Display</string>-->
     <!--TODO<string name="night_mode">Night mode</string>-->
     <!--TODO<string name="night_mode_follow_system">System</string>-->

app/src/main/res/values-hr/strings.xml

@@ -61,6 +61,9 @@
     <!--TODO<string name="true_north">True North</string>-->
     <!--TODO<string name="true_north_summary">Correct the magnetic declination and show to true north. Requires access to your coarse location.</string>-->
 
+    <!--TODO<string name="haptic_feedback">Haptic feedback</string>-->
+    <!--TODO<string name="haptic_feedback_summary">The compass vibrates when the direction changes.</string>-->
+
     <!--TODO<string name="display">Display</string>-->
     <!--TODO<string name="night_mode">Night mode</string>-->
     <!--TODO<string name="night_mode_follow_system">System</string>-->

app/src/main/res/values-mk/strings.xml

@@ -61,6 +61,9 @@
     <!--TODO<string name="true_north">True North</string>-->
     <!--TODO<string name="true_north_summary">Correct the magnetic declination and show to true north. Requires access to your coarse location.</string>-->
 
+    <!--TODO<string name="haptic_feedback">Haptic feedback</string>-->
+    <!--TODO<string name="haptic_feedback_summary">The compass vibrates when the direction changes.</string>-->
+
     <!--TODO<string name="display">Display</string>-->
     <!--TODO<string name="night_mode">Night mode</string>-->
     <!--TODO<string name="night_mode_follow_system">System</string>-->

app/src/main/res/values-nl/strings.xml

@@ -61,6 +61,9 @@
     <!--TODO<string name="true_north">True North</string>-->
     <!--TODO<string name="true_north_summary">Correct the magnetic declination and show to true north. Requires access to your coarse location.</string>-->
 
+    <!--TODO<string name="haptic_feedback">Haptic feedback</string>-->
+    <!--TODO<string name="haptic_feedback_summary">The compass vibrates when the direction changes.</string>-->
+
     <!--TODO<string name="display">Display</string>-->
     <!--TODO<string name="night_mode">Night mode</string>-->
     <!--TODO<string name="night_mode_follow_system">System</string>-->

app/src/main/res/values-ru/strings.xml

@@ -61,6 +61,9 @@
     <!--TODO<string name="true_north">True North</string>-->
     <!--TODO<string name="true_north_summary">Correct the magnetic declination and show to true north. Requires access to your coarse location.</string>-->
 
+    <!--TODO<string name="haptic_feedback">Haptic feedback</string>-->
+    <!--TODO<string name="haptic_feedback_summary">The compass vibrates when the direction changes.</string>-->
+
     <!--TODO<string name="display">Display</string>-->
     <!--TODO<string name="night_mode">Night mode</string>-->
     <!--TODO<string name="night_mode_follow_system">System</string>-->

app/src/main/res/values-sr/strings.xml

@@ -61,6 +61,9 @@
     <!--TODO<string name="true_north">True North</string>-->
     <!--TODO<string name="true_north_summary">Correct the magnetic declination and show to true north. Requires access to your coarse location.</string>-->
 
+    <!--TODO<string name="haptic_feedback">Haptic feedback</string>-->
+    <!--TODO<string name="haptic_feedback_summary">The compass vibrates when the direction changes.</string>-->
+
     <!--TODO<string name="display">Display</string>-->
     <!--TODO<string name="night_mode">Night mode</string>-->
     <!--TODO<string name="night_mode_follow_system">System</string>-->

app/src/main/res/values-tr/strings.xml

@@ -61,6 +61,9 @@
     <!--TODO<string name="true_north">True North</string>-->
     <!--TODO<string name="true_north_summary">Correct the magnetic declination and show to true north. Requires access to your coarse location.</string>-->
 
+    <!--TODO<string name="haptic_feedback">Haptic feedback</string>-->
+    <!--TODO<string name="haptic_feedback_summary">The compass vibrates when the direction changes.</string>-->
+
     <!--TODO<string name="display">Display</string>-->
     <!--TODO<string name="night_mode">Night mode</string>-->
     <!--TODO<string name="night_mode_follow_system">System</string>-->

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

@@ -61,6 +61,9 @@
     <string name="true_north">True North</string>
     <string name="true_north_summary">Correct the magnetic declination and show to true north. Requires access to your coarse location.</string>
 
+    <string name="haptic_feedback">Haptic feedback</string>
+    <string name="haptic_feedback_summary">The compass vibrates when the direction changes.</string>
+
     <string name="display">Display</string>
     <string name="night_mode">Night mode</string>
     <string name="night_mode_follow_system">System</string>

app/src/main/res/xml/preferences.xml

@@ -32,6 +32,12 @@
                 app:summary="@string/true_north_summary"
                 app:defaultValue="false" />
 
+        <SwitchPreferenceCompat
+                app:key="haptic_feedback"
+                app:title="@string/haptic_feedback"
+                app:summary="@string/haptic_feedback_summary"
+                app:defaultValue="true" />
+
     </PreferenceCategory>
 
     <PreferenceCategory