Added FINE_LOCATION permission checks. Added location update and save logic.

app/src/main/java/com/rtbishop/lookingsat/MainActivity.kt

@@ -1,6 +1,10 @@
 package com.rtbishop.lookingsat
 
+import android.Manifest
+import android.content.SharedPreferences
 import android.content.pm.ActivityInfo
+import android.content.pm.PackageManager
+import android.location.Location
 import android.os.Bundle
 import android.os.CountDownTimer
 import android.view.Menu
@@ -11,6 +15,9 @@ import android.widget.Toast
 import androidx.appcompat.app.AppCompatActivity
 import androidx.appcompat.widget.Toolbar
 import androidx.constraintlayout.widget.ConstraintLayout
+import androidx.core.app.ActivityCompat
+import androidx.core.content.ContextCompat
+import androidx.core.content.edit
 import androidx.drawerlayout.widget.DrawerLayout
 import androidx.lifecycle.ViewModelProviders
 import androidx.navigation.findNavController
@@ -18,27 +25,38 @@ import androidx.navigation.ui.AppBarConfiguration
 import androidx.navigation.ui.navigateUp
 import androidx.navigation.ui.setupActionBarWithNavController
 import androidx.navigation.ui.setupWithNavController
+import androidx.preference.PreferenceManager
+import com.google.android.gms.location.FusedLocationProviderClient
+import com.google.android.gms.location.LocationServices
 import com.google.android.material.navigation.NavigationView
 import java.util.*
 import java.util.concurrent.TimeUnit
 
+const val LOCATION_REQ = 101
+const val LOCATION_PERM = Manifest.permission.ACCESS_FINE_LOCATION
+const val GRANTED = PackageManager.PERMISSION_GRANTED
+
 class MainActivity : AppCompatActivity() {
 
     private lateinit var appBarConfig: AppBarConfiguration
-    private lateinit var mainViewModel: MainViewModel
+    private lateinit var viewModel: MainViewModel
     private lateinit var timerLayout: ConstraintLayout
     private lateinit var timeToAos: TextView
+    private lateinit var fusedLocationClient: FusedLocationProviderClient
+    private lateinit var preferences: SharedPreferences
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
-        setupViews()
+        setupComponents()
         setupNavigation()
         setupTimer()
     }
 
-    private fun setupViews() {
-        mainViewModel = ViewModelProviders.of(this).get(MainViewModel::class.java)
+    private fun setupComponents() {
+        viewModel = ViewModelProviders.of(this).get(MainViewModel::class.java)
+        fusedLocationClient = LocationServices.getFusedLocationProviderClient(this)
+        preferences = PreferenceManager.getDefaultSharedPreferences(this)
         timerLayout = findViewById(R.id.timer_layout)
         timeToAos = findViewById(R.id.time_to_aos)
     }
@@ -99,6 +117,47 @@ class MainActivity : AppCompatActivity() {
         timer.start()
     }
 
+    private fun updateLocation() {
+        fusedLocationClient.lastLocation.addOnSuccessListener { location: Location? ->
+            val currentLat = location?.latitude
+            val currentLon = location?.longitude
+            val currentHeight = location?.altitude
+
+            preferences.edit {
+                putString("LATITUDE", currentLat.toString())
+                putString("LONGITUDE", currentLon.toString())
+                putString("HEIGHT", currentHeight.toString())
+                apply()
+            }
+        }
+    }
+
+    private fun checkPermissions() {
+        if (ContextCompat.checkSelfPermission(this, LOCATION_PERM) != GRANTED) {
+            if (ActivityCompat.shouldShowRequestPermissionRationale(this, LOCATION_PERM)) {
+                Toast.makeText(this, "Missing permissions", Toast.LENGTH_LONG).show()
+            } else {
+                ActivityCompat.requestPermissions(this, arrayOf(LOCATION_PERM), LOCATION_REQ)
+            }
+        } else {
+            updateLocation()
+        }
+    }
+
+    override fun onRequestPermissionsResult(
+        requestCode: Int,
+        permissions: Array<out String>,
+        grantResults: IntArray
+    ) {
+        when (requestCode) {
+            LOCATION_REQ -> {
+                if (grantResults.isNotEmpty() && grantResults[0] == GRANTED) {
+                    updateLocation()
+                }
+            }
+        }
+    }
+
     override fun onSupportNavigateUp(): Boolean {
         val navController = findNavController(R.id.nav_host)
         return navController.navigateUp(appBarConfig) || super.onSupportNavigateUp()
@@ -111,11 +170,8 @@ class MainActivity : AppCompatActivity() {
 
     override fun onOptionsItemSelected(item: MenuItem): Boolean {
         when (item.itemId) {
-            R.id.fetch_trans -> Toast.makeText(
-                this,
-                "Fetching transmitters",
-                Toast.LENGTH_SHORT
-            ).show()
+            R.id.update_location -> checkPermissions()
+            R.id.fetch_trans -> Toast.makeText(this, "Fetch transmit", Toast.LENGTH_SHORT).show()
             R.id.save_to_db -> Toast.makeText(this, "Saving to DB", Toast.LENGTH_SHORT).show()
             R.id.load_from_db -> Toast.makeText(this, "Loading from DB", Toast.LENGTH_SHORT).show()
             R.id.fetch_tle -> Toast.makeText(this, "Fetching TLE", Toast.LENGTH_SHORT).show()