Add yaw angle trait with compass

app/src/main/java/com/fieldbook/tracker/traits/AngleTraitLayout.kt

@@ -0,0 +1,86 @@
+package com.fieldbook.tracker.traits
+
+import android.app.Activity
+import android.content.Context
+import android.os.Handler
+import android.os.Looper
+import android.util.AttributeSet
+import com.fieldbook.tracker.R
+import com.fieldbook.tracker.activities.CollectActivity
+import com.fieldbook.tracker.views.CompassView
+import com.google.android.material.floatingactionbutton.FloatingActionButton
+
+/**
+ * A trait for measuring Yaw angle using device orientation.
+ */
+class AngleTraitLayout : BaseTraitLayout {
+
+    companion object {
+        private const val UPDATE_INTERVAL: Long = 100
+    }
+
+    private lateinit var compassView: CompassView
+    private lateinit var captureButton: FloatingActionButton
+    private var currentYaw: Float? = null
+
+    private val updateHandler: Handler = Handler(Looper.getMainLooper())
+    private var isUpdating: Boolean = false
+    private val updateRunnable = object : Runnable {
+        override fun run() {
+            updateFromSensor()
+            if (isUpdating) {
+                updateHandler.postDelayed(this, UPDATE_INTERVAL)
+            }
+        }
+    }
+
+    constructor(context: Context) : super(context)
+    constructor(context: Context, attrs: AttributeSet?) : super(context, attrs)
+    constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int) : super(context, attrs, defStyleAttr)
+
+    override fun deleteTraitListener() {
+        (context as CollectActivity).removeTrait()
+        super.deleteTraitListener()
+    }
+
+    override fun setNaTraitsText() {}
+
+    override fun type(): String = "angle"
+
+    override fun layoutId(): Int = R.layout.trait_angle
+
+    override fun init(act: Activity) {
+        compassView = act.findViewById(R.id.compassView)
+        captureButton = act.findViewById(R.id.captureButton)
+
+        captureButton.setOnClickListener {
+            controller.getRotationRelativeToDevice()?.let { rotation ->
+                val angleValue = "%.2f".format(rotation.yaw)
+                updateObservation(currentTrait, angleValue)
+                collectInputView.text = angleValue
+            }
+        }
+
+        startUpdates()
+    }
+
+    private fun startUpdates() {
+        if (!isUpdating) {
+            isUpdating = true
+            updateHandler.post(updateRunnable)
+        }
+    }
+
+    private fun updateCompass() {
+        currentYaw?.apply {
+            compassView.setYawAngle(this)
+        }
+    }
+
+    private fun updateFromSensor() {
+        controller.getRotationRelativeToDevice()?.let { rotation ->
+            currentYaw = rotation.yaw
+            updateCompass()
+        }
+    }
+}

app/src/main/java/com/fieldbook/tracker/traits/formats/AngleFormat.kt

@@ -0,0 +1,19 @@
+package com.fieldbook.tracker.offbeat.traits.formats.contracts
+
+import com.fieldbook.tracker.R
+import com.fieldbook.tracker.traits.formats.Formats
+import com.fieldbook.tracker.traits.formats.TraitFormat
+import com.fieldbook.tracker.traits.formats.parameters.DetailsParameter
+import com.fieldbook.tracker.traits.formats.parameters.NameParameter
+
+class AngleFormat : TraitFormat(
+    format = Formats.ANGLE,
+    defaultLayoutId = R.layout.trait_angle,
+    layoutView = null,
+    databaseName = "angle",
+    nameStringResourceId = R.string.traits_format_angle,
+    iconDrawableResourceId = R.drawable.ic_trait_angle,
+    stringNameAux = null,
+    NameParameter(),
+    DetailsParameter()
+)

app/src/main/java/com/fieldbook/tracker/traits/formats/Formats.kt

@@ -1,11 +1,12 @@
 package com.fieldbook.tracker.traits.formats
 
 import android.content.Context
+import com.fieldbook.tracker.offbeat.traits.formats.contracts.AngleFormat
 
 enum class Formats(val type: Types = Types.SYSTEM, val isCamera: Boolean = false) {
 
     //SYSTEM formats
-    AUDIO, BOOLEAN, CAMERA(isCamera = true), CATEGORICAL, MULTI_CATEGORICAL, COUNTER, DATE, LOCATION, NUMERIC, PERCENT, TEXT,
+    AUDIO, BOOLEAN, CAMERA(isCamera = true), CATEGORICAL, MULTI_CATEGORICAL, COUNTER, DATE, LOCATION, NUMERIC, PERCENT, TEXT, ANGLE,
 
     //CUSTOM formats
     DISEASE_RATING(Types.CUSTOM), GNSS(Types.CUSTOM),
@@ -38,6 +39,7 @@ enum class Formats(val type: Types = Types.SYSTEM, val isCamera: Boolean = false
         COUNTER -> CounterFormat()
         DATE -> DateFormat()
         LOCATION -> LocationFormat()
+        ANGLE -> AngleFormat()
         GNSS -> GnssFormat()
         NUMERIC -> NumericFormat()
         PERCENT -> PercentFormat()

app/src/main/java/com/fieldbook/tracker/views/CompassView.kt

@@ -0,0 +1,141 @@
+package com.fieldbook.tracker.views
+
+import android.content.Context
+import android.graphics.Canvas
+import android.graphics.Color
+import android.graphics.Paint
+import android.graphics.Path
+import android.util.AttributeSet
+import android.view.View
+import kotlin.math.cos
+import kotlin.math.sin
+
+class CompassView @JvmOverloads constructor(
+    context: Context,
+    attrs: AttributeSet? = null,
+    defStyleAttr: Int = 0
+) : View(context, attrs, defStyleAttr) {
+
+    companion object {
+        private const val CIRCLE_THICKNESS = 4f
+        private const val ANGLE_MARKER_THICKNESS = 2f
+        private const val ANGLE_INTERVAL = 45
+        private var prevAngle = 0f
+    }
+
+    // use prevAngle to avoid resetting to 0f everytime
+    private var currentYawAngle = prevAngle
+    private var size = 0
+
+    private val needleHeadPath = Path()
+    private val needleTailPath = Path()
+
+    private val circle = Paint(Paint.ANTI_ALIAS_FLAG).apply {
+        style = Paint.Style.STROKE
+        strokeWidth = CIRCLE_THICKNESS
+        color = Color.BLACK
+    }
+
+    private val needleHead = Paint(Paint.ANTI_ALIAS_FLAG).apply {
+        style = Paint.Style.FILL
+        color = Color.RED
+    }
+
+    private val needleTail = Paint(Paint.ANTI_ALIAS_FLAG).apply {
+        style = Paint.Style.FILL
+        color = Color.BLACK
+    }
+
+    private val angleText = Paint(Paint.ANTI_ALIAS_FLAG).apply {
+        color = Color.BLACK
+        textAlign = Paint.Align.CENTER
+    }
+
+    private val angleMarker = Paint(Paint.ANTI_ALIAS_FLAG).apply {
+        style = Paint.Style.STROKE
+        strokeWidth = ANGLE_MARKER_THICKNESS
+        color = Color.BLACK
+    }
+
+    // calculates the size of the compass
+    override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
+        size = minOf(
+            MeasureSpec.getSize(widthMeasureSpec),
+            MeasureSpec.getSize(heightMeasureSpec)
+        )
+        setMeasuredDimension(size, size)
+    }
+
+    fun setYawAngle(angle: Float) {
+        currentYawAngle = angle
+        prevAngle = angle
+        invalidate()
+    }
+
+    override fun onDraw(canvas: Canvas) {
+        super.onDraw(canvas)
+
+        needleHeadPath.reset()
+        needleTailPath.reset()
+
+        val centerX = size / 2f
+        val centerY = size / 2f
+        val radius = (size / 2f) - 10f // 10f is for margin
+
+        // compass circle
+        canvas.drawCircle(centerX, centerY, radius, circle)
+
+        angleText.textSize = radius / 8f
+
+        for (angle in 0 until 360 step ANGLE_INTERVAL) {
+            val radian = Math.toRadians((angle + 180).toDouble()).toFloat()
+
+            /*
+                x = centerX + cos(theta) * r
+                y = centerY = sin(theta) * r
+             */
+
+            // angle markers
+            val startX = centerX + cos(radian) * (radius - 20)
+            val startY = centerY + sin(radian) * (radius - 20)
+            val endX = centerX + cos(radian) * radius
+            val endY = centerY + sin(radian) * radius
+
+            canvas.drawLine(startX, startY, endX, endY, angleMarker)
+
+            // angle texts
+            val textX = centerX + cos(radian) * (radius - 40)
+            val heightOfText = (angleText.descent() - angleText.ascent())
+            val textY = centerY + sin(radian) * (radius - 40) +  heightOfText/ 2
+            canvas.drawText(angle.toString(), textX, textY, angleText)
+        }
+
+        canvas.save()
+        canvas.rotate(currentYawAngle-90, centerX, centerY)
+
+        // needle
+        val headLength = radius * 0.8f
+        val tailLength = radius * 0.3f
+        val arrowWidth = radius * 0.15f
+
+        // needleHead
+        needleHeadPath.apply {
+            moveTo(centerX, centerY - headLength)
+            lineTo(centerX - arrowWidth, centerY)
+            lineTo(centerX + arrowWidth, centerY)
+            close()
+            canvas.drawPath(this, needleHead)
+        }
+
+        // needleTail
+        needleTailPath.apply {
+            moveTo(centerX, centerY + tailLength)
+            lineTo(centerX - arrowWidth, centerY)
+            lineTo(centerX + arrowWidth, centerY)
+            close()
+            canvas.drawPath(this, needleTail)
+        }
+
+        canvas.restore()
+    }
+}

app/src/main/res/drawable/ic_trait_angle.xml

@@ -0,0 +1 @@
+<!-- drawable/angle_acute.xml --><vector xmlns:android="http://schemas.android.com/apk/res/android" android:height="24dp" android:width="24dp" android:viewportWidth="24" android:viewportHeight="24"><path android:fillColor="#000000" android:pathData="M20,19H4.09L14.18,4.43L15.82,5.57L11.28,12.13C12.89,12.96 14,14.62 14,16.54C14,16.7 14,16.85 13.97,17H20V19M7.91,17H11.96C12,16.85 12,16.7 12,16.54C12,15.28 11.24,14.22 10.14,13.78L7.91,17Z" /></vector>