Add some comments.

app/src/main/java/com/danilafe/fencelessgrazing/requests/authenticated/AuthenticatedPostRequest.kt

@@ -7,6 +7,17 @@ import com.google.gson.Gson
 import com.google.gson.JsonObject
 import org.json.JSONObject
 
+/**
+ * General POST 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.
+ *
+ * @param value the value to send as JSON to the API.
+ * @param baseUrl the base URL of the API.
+ * @param apiEndpoint the API endpoint to send the request to.
+ * @param token the token to use to authenticate with the API.
+ * @param listener the listener to be called when a response is received.
+ * @param error the error handler to be called if a request fails.
+ */
 open class AuthenticatedPostRequest<T>(
     private val value: T,
     baseUrl: String,

app/src/main/java/com/danilafe/fencelessgrazing/requests/authenticated/SetBoundaryRequest.kt

@@ -3,6 +3,18 @@ package com.danilafe.fencelessgrazing.requests.authenticated
 import com.android.volley.Response
 import com.danilafe.fencelessgrazing.model.CollarPos
 
+/**
+ * Request to the API's `/collar/<id>/boundary/set` endpoint, used to update a collar's
+ * valid grazing area. Note that although this request takes an arbitrary number of points,
+ * the collar itself only supports at most 10 vertices.
+ *
+ * @param baseUrl the base URl of the API.
+ * @param token the API token used for authentication.
+ * @param identifier the collar whose boundary is being set.
+ * @param coordinates the list of coordinates representing, in order, the new grazing boundary's vertices.
+ * @param listener the listener to be called when an OK response is received.
+ * @param error the error listener.
+ */
 class SetBoundaryRequest(
     baseUrl: String,
     token: String,

app/src/main/java/com/danilafe/fencelessgrazing/ui/activities/BoundaryEditorActivity.kt

@@ -18,15 +18,42 @@ import org.osmdroid.views.MapView
 import org.osmdroid.views.overlay.Marker
 import org.osmdroid.views.overlay.Polygon
 
+/**
+ * Activity used to update a grazing boundary for a particular collar.
+ */
 class BoundaryEditorActivity : AppCompatActivity(),
     Marker.OnMarkerDragListener,
     Marker.OnMarkerClickListener {
 
+    /**
+     * The map displaying the boundary vertices and polygon.
+     */
     private lateinit var map: MapView
+
+    /**
+     * The list of markers representing the new grazing boundary's edges.
+     */
     private val markers: MutableList<Marker> = mutableListOf()
+
+    /**
+     * The polygon used to display the grazing area on the [map].
+     */
     private lateinit var polygon: GrazingPolygon
+
+    /**
+     * The center around which the [map] was originally centered,
+     * used also for creating new vertices.
+     */
     private lateinit var center: GeoPoint
+
+    /**
+     * The identifier of the collar whose boundary is being changed.
+     */
     private var identifier: Int = -1
+
+    /**
+     * The Volley queue used for sending API requests.
+     */
     private lateinit var queue: RequestQueue
 
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -45,6 +72,9 @@ class BoundaryEditorActivity : AppCompatActivity(),
         map.controller.setCenter(center)
     }
 
+    /**
+     * Removes a marker from the [map].
+     */
     private fun removeMarker(m: Marker) {
         markers.remove(m)
         map.overlays.remove(m)
@@ -52,6 +82,10 @@ class BoundaryEditorActivity : AppCompatActivity(),
         map.invalidate()
     }
 
+    /**
+     * Sends the current list of points to the API endpoint, closing
+     * the activity if successful.
+     */
     fun sendBoundary(v: View) {
         val request = SetBoundaryRequest(
             getString(R.string.apiUrl),
@@ -72,6 +106,10 @@ class BoundaryEditorActivity : AppCompatActivity(),
         queue.add(request)
     }
 
+    /**
+     * Adds a new marker to the [map], starting it at the previously-configured
+     * [center].
+     */
     fun addMarker(v : View) {
         if(markers.size >= 10) {
             Toast.makeText(
@@ -92,6 +130,11 @@ class BoundaryEditorActivity : AppCompatActivity(),
         map.invalidate()
     }
 
+    /**
+     * Ensures that the polygon's vertices are synchronized
+     * with the user-placed markers, making it so that the
+     * grazing area is visible to the user.
+     */
     private fun updatePolygon() {
         polygon.points.clear()
         if(markers.isEmpty()) return

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

@@ -202,6 +202,9 @@ class CollarDetailActivity : AppCompatActivity() {
         queue.add(detailRequest)
     }
 
+    /**
+     * Open the [BoundaryEditorActivity] to edit the current collar's grazing boundary.
+     */
     fun changeGrazingBoundary(v : View) {
         startActivity(Intent(this, BoundaryEditorActivity::class.java).apply {
             val center = dataPoints.lastOrNull()?.let {

app/src/main/java/com/danilafe/fencelessgrazing/ui/components/GrazingPolygon.kt

@@ -4,6 +4,9 @@ import android.graphics.Color
 import org.osmdroid.views.MapView
 import org.osmdroid.views.overlay.Polygon
 
+/**
+ * OpenStreetMaps polygon with some default visual settings for the Fenceless Grazing System.
+ */
 class GrazingPolygon(map: MapView) : Polygon(map) {
     init {
         fillPaint.color = Color.parseColor("#32a852")