Adjust distance traveled graph.

app/build.gradle

@@ -4,6 +4,17 @@ apply plugin: 'kotlin-android'
 
 apply plugin: 'kotlin-android-extensions'
 
+buildscript {
+    repositories {
+        jcenter()
+    }
+    dependencies {
+        classpath "org.jetbrains.dokka:dokka-gradle-plugin:0.10.1"
+    }
+}
+
+apply plugin: 'org.jetbrains.dokka'
+
 android {
     compileSdkVersion 29
     buildToolsVersion "29.0.2"
@@ -23,6 +34,15 @@ android {
     }
 }
 
+dokka {
+    outputFormat = 'html'
+    outputDirectory = "$buildDir/dokka"
+
+    configuration {
+        includeNonPublic = true
+    }
+}
+
 repositories {
     mavenCentral()
     google()

app/src/main/java/com/danilafe/fencelessgrazing/CollarClickListener.kt

@@ -2,6 +2,16 @@ package com.danilafe.fencelessgrazing
 
 import com.danilafe.fencelessgrazing.model.CollarSummary
 
+/**
+ * Simple interface used for the [CollarSummaryAdapter] to
+ * allow items in the collar list to respond to click events.
+ */
 interface CollarClickListener {
+
+    /**
+     * Method called when a collar is clicked in the [CollarSummaryAdapter].
+     *
+     * @param collar the collar that was clicked.
+     */
     fun onCollarClick(collar: CollarSummary?)
 }

app/src/main/java/com/danilafe/fencelessgrazing/CollarDetailActivity.kt

@@ -8,7 +8,6 @@ import android.widget.Toast
 import com.android.volley.RequestQueue
 import com.android.volley.Response
 import com.android.volley.toolbox.Volley
-import com.danilafe.fencelessgrazing.model.CollarPos
 import com.danilafe.fencelessgrazing.model.Polygon
 import com.danilafe.fencelessgrazing.requests.CollarDetailRequest
 import com.danilafe.fencelessgrazing.requests.CollarHistoryRequest
@@ -19,22 +18,76 @@ import org.osmdroid.views.overlay.Polyline
 import java.util.*
 import kotlin.concurrent.timerTask
 
+/**
+ * The activity that handles the display of a single collar, including
+ * the map with the collar's location, the collar's name, and how many
+ * times the collar left the prescribed grazing area in the last day. This
+ * information is gathered from repeated [history][CollarHistoryRequest] and
+ * [details][CollarDetailRequest] requests.
+ */
 class CollarDetailActivity : AppCompatActivity() {
 
+    /**
+     * The [TextView] holding the collar's current name.
+     */
     private lateinit var collarName: TextView
+
+    /**
+     * The [TextView] holding the collar's current position.
+     */
     private lateinit var collarPos: TextView
+
+    /**
+     * The [TextView] holding the number of times the collar left the grazing area.
+     */
     private lateinit var collarStimulus: TextView
 
+    /** Cached value of the API token retrieved from shared preferences.
+     */
     private lateinit var token: String
+
+    /**
+     * Volley queue used for sending requests to the API.
+     */
     private lateinit var queue: RequestQueue
+
+    /**
+     * The identifier of the collar whose details are being viewed. This is
+     * provided by the activity's [Intent][android.content.Intent].
+     */
     private var collarId: Int = -1
 
+    /**
+     * Whether or not the map has been centered on the location of the collar.
+     * Rather than have the map constantly jump around following the collar as it moves, we only
+     * move the map's center when this variable is `false`.
+     */
     private var centerSet: Boolean = false
+
+    /**
+     * The map view that actually handles the display of the OpenStreetMaps tiles and markers.
+     */
     private lateinit var map: MapView
 
+    /**
+     * The timer used for scheduling repeated API calls. The timer is started
+     * in [onResume], and stopped in [onPause].
+     */
     private var refreshTimer = Timer()
 
+    /**
+     * The OpenStreetMaps polygon to be drawn on the map. This polygon is used
+     * to display the valid grazing area for the collar; its vertices
+     * are updated whenever the [boundingBox] property is changed.
+     */
     private lateinit var mapPolygon: org.osmdroid.views.overlay.Polygon
+
+    /**
+     * The [Polygon] that represents the collar's valid grazing area.
+     * Setting this property will also update the [mapPolygon], which
+     * is the visual representation of the grazing area on the map.
+     * Additionally, setting this property will also update the [map].
+     */
     private var boundingBox: Polygon? = null
         set(newValue) {
             if(newValue != null) updateBoundingBox(field, newValue)
@@ -42,8 +95,24 @@ class CollarDetailActivity : AppCompatActivity() {
             field = newValue
         }
 
+    /**
+     * The OpenStreetMaps marker used to display the collar's current location
+     * on the map. This marker is updated whenever the [dataPoints] property is set.
+     */
     private lateinit var mapMarker: Marker
+
+    /**
+     * The OpenStreetMaps line used to display the path the collar has taken thus fur.
+     * This line is updated whenever the [dataPoints] property is set.
+     */
     private lateinit var mapPolyline: Polyline
+
+    /**
+     * The full history of the collar's location. Setting this property
+     * updates the [mapMarker] and [mapPolyline] properties, which
+     * are used to display the collar and its location history, respectively, on the map.
+     * Additionally, setting this property will also update the [map].
+     */
     private var dataPoints: List<GeoPoint> = listOf()
         set(newValue) {
             if(newValue.isNotEmpty()) updateAnimalHistory(newValue)
@@ -55,9 +124,7 @@ class CollarDetailActivity : AppCompatActivity() {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_collar_detail)
 
-        collarName = findViewById(R.id.collarName)
-        collarPos = findViewById(R.id.collarPos)
-        collarStimulus = findViewById(R.id.collarStimulus)
+        findViews()
 
         token = getSharedPreferences("FencelessGrazing", 0).getString("token", null)!!
         collarId = intent.getIntExtra("identifier", -1)
@@ -69,15 +136,6 @@ class CollarDetailActivity : AppCompatActivity() {
         mapMarker = Marker(map)
         mapPolyline = Polyline(map)
         configureMapPolygon()
-
-        boundingBox = Polygon(
-            listOf(
-                CollarPos("20", "20"),
-                CollarPos("20", "21"),
-                CollarPos("21", "21"),
-                CollarPos("21", "20")
-            )
-        )
     }
 
     override fun onPause() {
@@ -94,6 +152,19 @@ class CollarDetailActivity : AppCompatActivity() {
         refreshTimer.schedule(timerTask { triggerRefresh() }, 0L, 5000L)
     }
 
+    /**
+     * Locates all the views in the activity, setting the respective
+     * `lateinit` properties.
+     */
+    private fun findViews() {
+        collarName = findViewById(R.id.collarName)
+        collarPos = findViewById(R.id.collarPos)
+        collarStimulus = findViewById(R.id.collarStimulus)
+    }
+
+    /**
+     * Sends API requests that retrieve updated information about the collar.
+     */
     private fun triggerRefresh() {
         val historyRequest = CollarHistoryRequest(getString(R.string.apiUrl), collarId, token,
             Response.Listener {
@@ -116,6 +187,9 @@ class CollarDetailActivity : AppCompatActivity() {
         queue.add(detailRequest)
     }
 
+    /**
+     * Sets [mapPolygon]'s color, borders, and other relevant settings.
+     */
     private fun configureMapPolygon() {
         mapPolygon.fillPaint.color = Color.parseColor("#32a852")
         mapPolygon.fillPaint.alpha = 127
@@ -124,6 +198,12 @@ class CollarDetailActivity : AppCompatActivity() {
         mapPolygon.title = "Valid Grazing Area"
     }
 
+    /**
+     * Given a new location history of the animal, configures
+     * updates the [map] to include the relevant elements (such as the animal's
+     * [marker][mapMarker]). Additionally, if the map is not centered,
+     * this sets its center to the animal's most recent location.
+     */
     private fun updateAnimalHistory(points : List<GeoPoint>) {
         val currentPoint = points.first()
         collarPos.text = getString(R.string.collarSummaryLocation, currentPoint.longitude, currentPoint.latitude)
@@ -138,12 +218,20 @@ class CollarDetailActivity : AppCompatActivity() {
         map.invalidate()
     }
 
+    /**
+     * If an animal's history is empty, hides all the elements
+     * that depend on said history from the [map].
+     */
     private fun clearAnimalHistory() {
-        map.overlays.remove(mapMarker)
-        map.overlays.remove(mapPolyline)
+        if(map.overlays.contains(mapMarker)) map.overlays.remove(mapMarker)
+        if(map.overlays.contains(mapPolyline)) map.overlays.remove(mapPolyline)
         map.invalidate()
     }
 
+    /**
+     * Updates the [mapPolygon] with the new valid grazing area.
+     * The polygon is added to the [map] if necessary.
+     */
     private fun updateBoundingBox(oldValue: Polygon?, polygon: Polygon) {
         if(oldValue == null) map.overlays.add(mapPolygon)
         val points = polygon.dataPoints.map { GeoPoint(it.longitude.toDouble(), it.latitude.toDouble()) }
@@ -153,6 +241,10 @@ class CollarDetailActivity : AppCompatActivity() {
         map.invalidate()
     }
 
+    /**
+     * If an animal's bounding box is not set, hides
+     * the [mapPolygon] from the [map].
+     */
     private fun clearBoundingBox() {
         map.overlays.remove(mapPolygon)
         map.invalidate()

app/src/main/java/com/danilafe/fencelessgrazing/CollarListActivity.kt

@@ -4,7 +4,6 @@ import android.content.Intent
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
 import android.view.View
-import android.widget.Button
 import android.widget.Toast
 import androidx.preference.PreferenceManager
 import androidx.recyclerview.widget.DividerItemDecoration
@@ -24,21 +23,54 @@ import java.util.*
 import kotlin.concurrent.timerTask
 
 class CollarListActivity : AppCompatActivity() {
-    // The list of collar summaries and its list adapter.
+
+    /**
+     * The list of collar summaries retrieved from the API.
+     */
     private val summaries : MutableList<CollarSummary> = mutableListOf()
+
+    /**
+     * The adapter used to display the [summaries] on the screen.
+     */
     private lateinit var summaryAdapter: CollarSummaryAdapter
+
+    /**
+     * The view of the summaries backed by the [summaryAdapter].
+     */
     private lateinit var collarList: RecyclerView
 
-    // The API token and request queue.
+    /**
+     * The API token and request queue.
+     */
     private lateinit var token: String
+
+    /**
+     * The Volley queue used for sending API requests.
+     */
     private lateinit var queue: RequestQueue
 
-    // The OpenStreetMap map.
+    /**
+     * Whether or not the map has been centered on the location of the collars.
+     * Rather than have the map constantly jump around following the collars as they move, we only
+     * move the map's center when this variable is `false`.
+     */
     private var centerSet: Boolean = false
+
+    /**
+     * The actual view used to display the OpenStreetMaps tiles and the locations of the collars.
+     */
     private lateinit var map: MapView
+
+    /**
+     * Mapping of collar identifiers to the marker that represents them, used
+     * to update markers without clearing the user's selection.
+     */
     private val collarOverlays: MutableMap<Int, Marker> = mutableMapOf()
 
-    // Timer used to schedule refresh
+    /**
+     * The timer used for scheduling repeated API calls. The timer is started
+     * in [onResume], and stopped in [onPause].
+     */
     private var refreshTimer = Timer()
 
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -72,10 +104,17 @@ class CollarListActivity : AppCompatActivity() {
         refreshTimer.purge()
     }
 
+    /**
+     * Method called by the "open statistics" button. Opens the statistics
+     * activity.
+     */
     fun openStatistics(view: View) {
         startActivity(Intent(this, StatisticsActivity::class.java))
     }
 
+    /**
+     * Sends the request to the API to retrieve an updated list of active collars.
+     */
     private fun triggerRefresh() {
         val request = CollarRequest(getString(R.string.apiUrl), token,
             Response.Listener {
@@ -91,11 +130,21 @@ class CollarListActivity : AppCompatActivity() {
         queue.add(request)
     }
 
+    /**
+     * Locates all the views in the activity, setting the respective
+     * `lateinit` properties.
+     */
     private fun findViews() {
         collarList = findViewById(R.id.collarSummaryList)
         map = findViewById(R.id.map)
     }
 
+    /**
+     * Opens the activity [CollarDetailActivity] to give the user more information
+     * on a particular collar.
+     *
+     * @param collar the collar being viewed.
+     */
     private fun startCollarDetailActivity(collar: CollarSummary) {
         val newIntent = Intent(this, CollarDetailActivity::class.java).apply {
             putExtra("identifier", collar.id)
@@ -103,6 +152,10 @@ class CollarListActivity : AppCompatActivity() {
         startActivity(newIntent)
     }
 
+    /**
+     * Configures the [collarList] with the [summaryAdapter], allowing it to
+     * properly display and handle clicks on the items.
+     */
     private fun setupCollarList() {
         val layoutManager = LinearLayoutManager(collarList.context)
         summaryAdapter = CollarSummaryAdapter(summaries, object : CollarClickListener {
@@ -116,11 +169,17 @@ class CollarListActivity : AppCompatActivity() {
         collarList.addItemDecoration(DividerItemDecoration(collarList.context, layoutManager.orientation))
     }
 
+    /**
+     * Updates the map with new collar information.
+     */
     private fun updateMap() {
         updateMapCenter()
         updateMapOverlay()
     }
 
+    /**
+     * Sets the map's center to the average location of the animals.
+     */
     private fun updateMapCenter() {
         if(centerSet) return
 
@@ -130,6 +189,9 @@ class CollarListActivity : AppCompatActivity() {
         map.controller.setCenter(GeoPoint(averageLongitude, averageLatitude))
     }
 
+    /**
+     * Updates the markers on the map with the animals' new locations.
+     */
     private fun updateMapOverlay() {
         val currentSet = mutableSetOf<Int>()
         summaries.forEach {

app/src/main/java/com/danilafe/fencelessgrazing/CollarSummaryAdapter.kt

@@ -11,12 +11,23 @@ import com.android.volley.toolbox.Volley
 import com.danilafe.fencelessgrazing.model.CollarSummary
 import com.danilafe.fencelessgrazing.requests.CollarRequest
 
+/**
+ * A [ListAdapter] subclass to display and manage a list of [CollarSummary] items
+ * collected from a [CollarRequest].
+ *
+ * @param items the list of items that are contained in this adapter.
+ * @param collarClickListener the action to be executed when an item in the list is clicked.
+ */
 class CollarSummaryAdapter(
     private val items: List<CollarSummary>,
     private val collarClickListener: CollarClickListener
 ) : ListAdapter<CollarSummary, CollarViewHolder>(DiffCallback()) {
 
-    class DiffCallback : DiffUtil.ItemCallback<CollarSummary>() {
+    /**
+     * [DiffUtil.ItemCallback] used for the [ListAdapter]. Compares items using
+     * the standard equality method generated for data classes.
+     */
+    internal class DiffCallback : DiffUtil.ItemCallback<CollarSummary>() {
         override fun areItemsTheSame(oldItem: CollarSummary, newItem: CollarSummary): Boolean
             = oldItem.id == newItem.id
 

app/src/main/java/com/danilafe/fencelessgrazing/CollarViewHolder.kt

@@ -5,13 +5,30 @@ import android.widget.TextView
 import androidx.recyclerview.widget.RecyclerView
 import com.danilafe.fencelessgrazing.model.CollarSummary
 
+/**
+ * A [RecyclerView.ViewHolder] used to render [CollarSummary] item entries.
+ */
 class CollarViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
+    /**
+     * The [TextView] that holds the name of a collar.
+     */
     private val nameView: TextView = itemView.findViewById(R.id.collarSummaryName)
+
+    /**
+     * The [TextView] that holds the position of the collar.
+     */
     private val positionView: TextView = itemView.findViewById(R.id.collarSummaryPos)
 
+    /**
+     * Called by the [CollarSummaryAdapter] to update the contents of the view this
+     * class holds.
+     *
+     * @param summary the collar summary whose data should be extracted and placed into the views.
+     * @param collarClickListener the action that should be called when a summary is clicked.
+     */
     fun bindData(summary: CollarSummary, collarClickListener: CollarClickListener) {
         nameView.text = summary.name
-        positionView.text = nameView.resources.getString(R.string.collarSummaryLocation,
+        positionView.text = itemView.resources.getString(R.string.collarSummaryLocation,
             summary.pos.longitude.toDouble(), summary.pos.latitude.toDouble())
         itemView.setOnClickListener {
             collarClickListener.onCollarClick(summary)

app/src/main/java/com/danilafe/fencelessgrazing/DistanceTraveledGraph.kt

@@ -9,18 +9,31 @@ import androidx.fragment.app.Fragment
 import com.android.volley.RequestQueue
 import com.android.volley.Response
 import com.android.volley.toolbox.Volley
+import com.danilafe.fencelessgrazing.model.CollarDistance
 import com.danilafe.fencelessgrazing.requests.DistanceTraveledRequest
 import com.github.mikephil.charting.charts.BarChart
+import com.github.mikephil.charting.components.XAxis
 import com.github.mikephil.charting.data.BarData
 import com.github.mikephil.charting.data.BarDataSet
 import com.github.mikephil.charting.data.BarEntry
 import com.github.mikephil.charting.formatter.IndexAxisValueFormatter
 import com.github.mikephil.charting.utils.ColorTemplate
 
+/**
+ * One of the tabs from the [StatisticsActivity]. Contains the graph
+ * of the distance traveled by each animal, retrieved via the [DistanceTraveledRequest]
+ * from the API.
+ */
 class DistanceTraveledGraph() : Fragment() {
 
+    /**
+     * The BarChart used to display the distance data.
+     */
     private lateinit var distanceTraveledChart: BarChart
 
+    /**
+     * The Volley queue used for making API requests.
+     */
     private lateinit var queue : RequestQueue
 
     override fun onCreateView(
@@ -30,6 +43,7 @@ class DistanceTraveledGraph() : Fragment() {
     ): View? {
         val view = inflater.inflate(R.layout.distance_traveled_layoyt, container, false)
         distanceTraveledChart = view.findViewById(R.id.distanceTraveledChart)
+        setupChart()
         return view
     }
 
@@ -40,28 +54,16 @@ class DistanceTraveledGraph() : Fragment() {
         triggerRefresh()
     }
 
+    /**
+     * Send the API request to retrieve updated distance data.
+     */
     private fun triggerRefresh() {
         val activity = requireActivity()
         val sharedPrefs = activity.getSharedPreferences("FencelessGrazing", 0)
         val token = sharedPrefs.getString("token", null)!!
         val request = DistanceTraveledRequest(activity.getString(R.string.apiUrl), token,
             Response.Listener {
-                val entries = mutableListOf<BarEntry>()
-                val labels = it.map { c -> c.name }
-                it.forEachIndexed { i, v ->
-                    entries.add(BarEntry(i.toFloat(), v.distance))
-                }
-                val dataSet = BarDataSet(entries, "Distance Traveled")
-                dataSet.colors = ColorTemplate.VORDIPLOM_COLORS.toList()
-                val data = BarData(dataSet)
-                data.barWidth = 0.9f
-                distanceTraveledChart.legend.textSize = 20.0f
-                distanceTraveledChart.data = data
-                distanceTraveledChart.setFitBars(true)
-                distanceTraveledChart.xAxis.valueFormatter = IndexAxisValueFormatter(labels)
-                distanceTraveledChart.xAxis.granularity = 1.0f
-                distanceTraveledChart.xAxis.isGranularityEnabled = true
-                distanceTraveledChart.invalidate()
+                updateChartData(it)
             },
             Response.ErrorListener {
                 Toast.makeText(activity, "Failed to retrieve distance traveled!", Toast.LENGTH_SHORT).show()
@@ -69,4 +71,33 @@ class DistanceTraveledGraph() : Fragment() {
         )
         queue.add(request)
     }
+
+    /**
+     * Updates the [distanceTraveledChart] with newly retrieved distance data.
+     */
+    private fun updateChartData(distances: List<CollarDistance>) {
+        val entries = mutableListOf<BarEntry>()
+        val labels = distances.map { c -> c.name }
+        distances.forEachIndexed { i, v ->
+            entries.add(BarEntry(i.toFloat(), v.distance))
+        }
+        val dataSet = BarDataSet(entries, "Distance Traveled")
+        dataSet.colors = ColorTemplate.PASTEL_COLORS.toList()
+        val data = BarData(dataSet)
+        data.barWidth = 0.8f
+        distanceTraveledChart.data = data
+        distanceTraveledChart.xAxis.valueFormatter = IndexAxisValueFormatter(labels)
+        distanceTraveledChart.invalidate()
+    }
+
+    /**
+     * Configure the [distanceTraveledChart] with the proper visual settings.
+     */
+    private fun setupChart() {
+        distanceTraveledChart.setFitBars(true)
+        distanceTraveledChart.xAxis.granularity = 1.0f
+        distanceTraveledChart.xAxis.isGranularityEnabled = true
+        distanceTraveledChart.xAxis.position = XAxis.XAxisPosition.BOTTOM
+        distanceTraveledChart.invalidate()
+    }
 }

app/src/main/java/com/danilafe/fencelessgrazing/MainActivity.kt

@@ -10,13 +10,24 @@ import com.android.volley.Response
 import com.android.volley.toolbox.Volley
 import com.danilafe.fencelessgrazing.requests.LoginRequest
 
+/**
+ * First activity in the app. Prompts the user for their
+ * login information, and attempts authentication to the API.
+ */
 class MainActivity : AppCompatActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
+
+        // If we've already logged in, no need to do it again.
+        val prefs = getSharedPreferences("FencelessGrazing", 0)
+        if(prefs.contains("token")) startCollarActivity()
     }
 
+    /**
+     * Send the authentication request to the API.
+     */
     fun attemptLogin(view: View) {
         val usernameField: TextView = findViewById(R.id.username)
         val passwordField: TextView = findViewById(R.id.password)
@@ -30,12 +41,19 @@ class MainActivity : AppCompatActivity() {
                     editor.putString("token", it.token)
                     editor.apply()
 
-                    val newIntent = Intent(this, CollarListActivity::class.java)
-                    startActivity(newIntent)
+                    startCollarActivity()
                 },
                 Response.ErrorListener {
                     Toast.makeText(this, "Failed to log in! $it", Toast.LENGTH_LONG).show()
                 })
         requestQueue.add(loginRequest)
     }
+
+    /**
+     * Once authentication is complete, moves on to the list of collars.
+     */
+    private fun startCollarActivity() {
+        val newIntent = Intent(this, CollarListActivity::class.java)
+        startActivity(newIntent)
+    }
 }

app/src/main/java/com/danilafe/fencelessgrazing/StatisticsActivity.kt

@@ -8,12 +8,25 @@ import androidx.viewpager2.widget.ViewPager2
 import com.google.android.material.tabs.TabLayout
 import com.google.android.material.tabs.TabLayoutMediator
 
+/**
+ * Activity containing various graphs created from collar data on the server.
+ */
 class StatisticsActivity : AppCompatActivity() {
 
+    /**
+     * The tab layout allowing users to switch between graphs.
+     */
     private lateinit var tabLayout: TabLayout
+
+    /**
+     * The view pager providing swiping functionality between views.
+     */
     private lateinit var viewPager: ViewPager2
 
     companion object {
+        /**
+         * The list of tab names, in the order they appear in the [viewPager].
+         */
         val tabNames = arrayOf("Distance Traveled")
     }
 

app/src/main/java/com/danilafe/fencelessgrazing/StatisticsGraphAdapter.kt

@@ -4,6 +4,9 @@ import androidx.fragment.app.Fragment
 import androidx.fragment.app.FragmentActivity
 import androidx.viewpager2.adapter.FragmentStateAdapter
 
+/**
+ * Adapter for the [ViewPager2][androidx.viewpager2.widget.ViewPager2] class.
+ */
 class StatisticsGraphAdapter(activity : FragmentActivity) : FragmentStateAdapter(activity) {
     override fun getItemCount(): Int = 1
     override fun createFragment(position: Int): Fragment = DistanceTraveledGraph()

app/src/main/java/com/danilafe/fencelessgrazing/model/CollarDetails.kt

@@ -1,3 +1,10 @@
 package com.danilafe.fencelessgrazing.model
 
+/**
+ * Information returned from the `/collar/<id>/details` API endpoint.
+ *
+ * @param id the collar's internal unique identifier.
+ * @param name the collar's current designation in the system.
+ * @param stimulus the number of stimulus activation reports in the last 24 hours.
+ */
 data class CollarDetails(val id: Int, val name: String, val stimulus: Int)

app/src/main/java/com/danilafe/fencelessgrazing/model/CollarDistance.kt

@@ -1,3 +1,10 @@
 package com.danilafe.fencelessgrazing.model
 
+/**
+ * Component of the information returned from the `/collars/stats/distance` AP endpoint.
+ *
+ * @param name the current designation of the collar to which this data point belongs.
+ * @param id the unique identifier of the collar in the system.
+ * @param distance the distance, in kilometers, traveled by this collar.
+ */
 data class CollarDistance(val name: String, val id: Int, val distance: Float)

app/src/main/java/com/danilafe/fencelessgrazing/model/CollarPos.kt

@@ -0,0 +1,9 @@
+package com.danilafe.fencelessgrazing.model
+
+/**
+ * GPS coordinate returned by many of the project's API endpoints.
+ *
+ * @param longitude the longitude of the GPS point.
+ * @param latitude the latitude of the GPS point.
+ */
+data class CollarPos(val longitude: String, val latitude: String)

app/src/main/java/com/danilafe/fencelessgrazing/model/CollarSummary.kt

@@ -1,4 +1,10 @@
 package com.danilafe.fencelessgrazing.model
 
-data class CollarPos(val longitude: String, val latitude: String)
+/**
+ * Minimal information about one of the collars returned by the `/collars` API endpoints.
+ *
+ * @param id the internal identifier of the collar in the system.
+ * @param name the collar's current designation.
+ * @param pos the collar's most recent location.
+ */
 data class CollarSummary(val id: Int, val name: String, val pos: CollarPos)

app/src/main/java/com/danilafe/fencelessgrazing/model/LoginResult.kt

@@ -1,3 +1,8 @@
 package com.danilafe.fencelessgrazing.model
 
+/**
+ * The result of a successful authentication via the `/login` endpoint.
+ *
+ * @param token the JWT authorization token to be used for future API requests.
+ */
 data class LoginResult(val token: String)

app/src/main/java/com/danilafe/fencelessgrazing/model/Polygon.kt

@@ -1,3 +1,8 @@
 package com.danilafe.fencelessgrazing.model
 
+/**
+ * A general polygon returned by many of the system's API endpoints.
+ *
+ * @param dataPoints the vertices of the polygon, in order.
+ */
 data class Polygon(val dataPoints : List<CollarPos>)

app/src/main/java/com/danilafe/fencelessgrazing/requests/AuthenticatedRequest.kt

@@ -0,0 +1,36 @@
+package com.danilafe.fencelessgrazing.requests
+
+import com.android.volley.Response
+import com.android.volley.toolbox.StringRequest
+
+/**
+ * General request aimed at a protected endpoint of the API. The token can be retrieved
+ * via a [LoginRequest], or, if you've made it past the login screen, via Shared Preferences.
+ *
+ * The [AuthenticatedRequest] expects to receive a string from the API endpoint; how this string
+ * is handled is determined by the [Response.Listener] object. One may use
+ * [Response.Listener.toGsonListener] to create a JSON deserializer that expects a [String].
+ *
+ * @param baseUrl the API URL base (for example, `https://dev.danilafe.com`)
+ * @param apiEndpoint the API endpoint to which the request is being made.
+ * @param token the API token used for authentication.
+ * @param listener the listener object called if a valid response is received.
+ * @param error the error listener for the request.
+ */
+open class AuthenticatedRequest(
+    baseUrl: String,
+    apiEndpoint: String,
+    private val token: String,
+    listener: Response.Listener<String>,
+    error: Response.ErrorListener
+) : StringRequest(
+    Method.GET, "${baseUrl}${apiEndpoint}",
+    listener, error
+) {
+
+    override fun getHeaders(): MutableMap<String, String> {
+        val newMap = HashMap(super.getHeaders())
+        newMap["Authorization"] = "Bearer $token"
+        return newMap
+    }
+}

app/src/main/java/com/danilafe/fencelessgrazing/requests/CollarDetailRequest.kt

@@ -7,22 +7,23 @@ import com.danilafe.fencelessgrazing.model.CollarPos
 import com.danilafe.fencelessgrazing.model.CollarSummary
 import com.google.gson.reflect.TypeToken
 
+/**
+ * Request to the `/collars/<id>/details` API endpoint. Retrieves detailed information
+ * about a single collar, stored in a [CollarDetails] object.
+ *
+ * @param baseUrl the base URL of the API.
+ * @param collarId the identifier of the collar whose details are being retrieved.
+ * @param token the API token for authentication.
+ * @param listener the listener that will be called if a valid list of collar details is received.
+ * @param error the error listener for the request.
+ */
 class CollarDetailRequest(
     baseUrl: String,
     collarId: Int,
-    private val token : String,
+    token : String,
     listener: Response.Listener<CollarDetails>,
     error: Response.ErrorListener
-) : StringRequest(
-    Method.GET, "${baseUrl}/collars/$collarId/details",
-    GsonListener(
-        object : TypeToken<CollarDetails>() {}.type,
-        listener
-    ), error
-) {
-
-    override fun getHeaders(): MutableMap<String, String> {
-        return mutableMapOf("Authorization" to "Bearer $token")
-    }
-
-}
+) : AuthenticatedRequest(
+    baseUrl, "/collars/$collarId/details", token,
+    listener.toGsonListener(), error
+)

app/src/main/java/com/danilafe/fencelessgrazing/requests/CollarHistoryRequest.kt

@@ -6,22 +6,24 @@ import com.danilafe.fencelessgrazing.model.CollarPos
 import com.danilafe.fencelessgrazing.model.CollarSummary
 import com.google.gson.reflect.TypeToken
 
+/**
+ * A request to the `/collars/<id>/history` API endpoint. Retrieves the entire list
+ * of coordinates, represented as [CollarPos] objects, that the collar has transmitted.
+ * The coordinates are sorted by date.
+ *
+ * @param baseUrl the base URL of the API.
+ * @param collarId the identifier of the collar whose history is being retrieved.
+ * @param token the API token for authentication.
+ * @param listener the listener that will be called if a valid list of coordinates is received.
+ * @param error the error listener for the request.
+ */
 class CollarHistoryRequest(
     baseUrl: String,
     collarId: Int,
-    private val token : String,
+    token : String,
     listener: Response.Listener<List<CollarPos>>,
     error: Response.ErrorListener
-) : StringRequest(
-    Method.GET, "${baseUrl}/collars/$collarId/history",
-    GsonListener(
-        object : TypeToken<List<CollarPos>>() {}.type,
-        listener
-    ), error
-) {
-
-    override fun getHeaders(): MutableMap<String, String> {
-        return mutableMapOf("Authorization" to "Bearer $token")
-    }
-
-}
+) : AuthenticatedRequest(
+    baseUrl, "/collars/$collarId/history", token,
+    listener.toGsonListener(), error
+)

app/src/main/java/com/danilafe/fencelessgrazing/requests/CollarRequest.kt

@@ -5,21 +5,21 @@ import com.android.volley.toolbox.StringRequest
 import com.danilafe.fencelessgrazing.model.CollarSummary
 import com.google.gson.reflect.TypeToken
 
+/**
+ * A request to the `/collars` API endpoint. Retrieves a list of collar summaries, represented
+ * as [CollarSummary] objects.
+ *
+ * @param baseUrl the base URL of the API.
+ * @param token the API token for authentication.
+ * @param listener the listener that will be called if a valid list of coordinates is received.
+ * @param error the error listener for the request.
+ */
 class CollarRequest(
     baseUrl: String,
-    private val token : String,
+    token : String,
     listener: Response.Listener<List<CollarSummary>>,
     error: Response.ErrorListener
-) : StringRequest(
-    Method.GET, "${baseUrl}/collars",
-    GsonListener(
-        object : TypeToken<List<CollarSummary>>() {}.type,
-        listener
-    ), error
-) {
-
-    override fun getHeaders(): MutableMap<String, String> {
-        return mutableMapOf("Authorization" to "Bearer $token")
-    }
-
-}
+) : AuthenticatedRequest(
+    baseUrl, "/collars", token,
+    listener.toGsonListener(), error
+)

app/src/main/java/com/danilafe/fencelessgrazing/requests/DistanceTraveledRequest.kt

@@ -5,21 +5,22 @@ import com.android.volley.Response
 import com.android.volley.toolbox.StringRequest
 import com.google.gson.reflect.TypeToken
 
+/**
+ * A request to the `/collars/stats/distance` API endpoint. Retrieves
+ * a list of [CollarDistance] objects, containing, among other things, the total
+ * distance traveled by each animal.
+ *
+ * @param baseUrl the base URL of the API.
+ * @param token the API token for authentication.
+ * @param listener the listener that will be called if a valid list of distances is received.
+ * @param error the error listener for the request.
+ */
 class DistanceTraveledRequest(
     baseUrl: String,
-    private val token : String,
+    token : String,
     listener: Response.Listener<List<CollarDistance>>,
     error: Response.ErrorListener
-) : StringRequest(
-    Method.GET, "${baseUrl}/collars/stats/distance",
-    GsonListener(
-        object : TypeToken<List<CollarDistance>>() {}.type,
-        listener
-    ), error
-) {
-
-    override fun getHeaders(): MutableMap<String, String> {
-        return mutableMapOf("Authorization" to "Bearer $token")
-    }
-
-}
+) : AuthenticatedRequest(
+    baseUrl, "/collars/stats/distance", token,
+    listener.toGsonListener(), error
+)

app/src/main/java/com/danilafe/fencelessgrazing/requests/GsonListener.kt

@@ -3,15 +3,36 @@ package com.danilafe.fencelessgrazing.requests
 import android.util.Log
 import com.android.volley.Response
 import com.google.gson.Gson
+import com.google.gson.reflect.TypeToken
 import java.lang.reflect.Type
 
-class GsonListener<T : Any>(private val targetType : Type, private val stringListener : Response.Listener<T>) : Response.Listener<String> {
-
-    private val gson = Gson()
-
+/**
+ * It appears as though a type parameter, even on that's `reified`, is erased when an anonymous
+ * object is declared inside an `inline` function. This means that [Gson] serialization with
+ * a [TypeToken] created inside this anonymous object wil _still_ fail, even though the
+ * surrounding function is `inline` and with a `reified` type. To work around this,
+ * we create the type in the function itself, and pass it as an argument to this
+ * [GsonListener].
+ *
+ * @param listener the underlying listener expecting a value of type [T].
+ * @param type the type to which [Gson] should deserialize the expected string.
+ */
+class GsonListener<T>(val listener: Response.Listener<T>, private val type: Type) : Response.Listener<String> {
     override fun onResponse(response: String?) {
-        if(response == null) { return stringListener.onResponse(null) }
-        stringListener.onResponse(gson.fromJson<T>(response, targetType))
+        val transformed = response?.let { Gson().fromJson<T>(it, type) }
+        listener.onResponse(transformed)
     }
+}
+
+/**
+ * Converts a [Response.Listener] of an arbitrary type [T] to a listener of type [String].
+ * This is done by converting the input [String] into [T] via [Gson].
+ * This function must be reified to prevent type erasure.
+ *
+ * @receiver the listener that will be called when the [String] is converted into [T].
+ * @return the resulting [String]-based listener.
+ */
+inline fun <reified T> Response.Listener<T>.toGsonListener(): Response.Listener<String> {
+    return GsonListener(this, object : TypeToken<T>(){}.type)
+}
 
-}

app/src/main/java/com/danilafe/fencelessgrazing/requests/LoginRequest.kt

@@ -4,6 +4,16 @@ import com.android.volley.Response
 import com.android.volley.toolbox.StringRequest
 import com.danilafe.fencelessgrazing.model.LoginResult
 
+/**
+ * A request to the `/login` endpoint of the API, intended to retrieve the JWT authentication
+ * token to be used for the remainder of the interaction with the API.
+ *
+ * @param baseUrl the base URL of the API.
+ * @param username the username with which to attempt to authenticate.
+ * @param password the password with which to attempt to authenticate.
+ * @param listener the listener that will be called if authentication succeeds.
+ * @param error the error listener for the request.
+ */
 class LoginRequest(
     baseUrl: String,
     private val username: String,
@@ -12,7 +22,7 @@ class LoginRequest(
     error: Response.ErrorListener
 ) : StringRequest (
     Method.POST, "${baseUrl}/login",
-    GsonListener(LoginResult::class.java, listener), error
+    listener.toGsonListener(), error
 ) {
 
     override fun getParams(): MutableMap<String, String> {