improvements

src/app/src/main/java/com/xfarrow/locatemydevice/MainActivity.java

@@ -9,6 +9,7 @@ import androidx.core.app.ActivityCompat;
 
 import android.Manifest;
 import android.content.Intent;
+import android.content.pm.PackageManager;
 import android.os.Bundle;
 import android.util.Log;
 import android.view.Menu;
@@ -17,33 +18,47 @@ import android.view.View;
 import android.widget.Button;
 
 public class MainActivity extends AppCompatActivity {
-    private final int MY_PERMISSIONS_REQUEST_SMS_RECEIVE = 10;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
-        requirePermissions();
+        checkPermissions();
     }
 
-    private void requirePermissions(){
+    private void checkPermissions(){
+        if(ActivityCompat.checkSelfPermission(this, Manifest.permission.RECEIVE_SMS) != PackageManager.PERMISSION_GRANTED) {
+
             ActivityCompat.requestPermissions(this,
                     new String[]{Manifest.permission.RECEIVE_SMS},
-                MY_PERMISSIONS_REQUEST_SMS_RECEIVE); // Understand what this is
+                    Utils.PERMISSION_SMS_RECEIVE);
+        }
+
+        if(ActivityCompat.checkSelfPermission(this, Manifest.permission.SEND_SMS) != PackageManager.PERMISSION_GRANTED) {
 
             ActivityCompat.requestPermissions(this,
                     new String[]{Manifest.permission.SEND_SMS},
-                200); // Understand what this is
+                    Utils.PERMISSION_SMS_SEND);
+        }
+        if(ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
 
             ActivityCompat.requestPermissions(this,
                     new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
-                1);
+                    Utils.PERMISSION_ACCESS_FINE_LOCATION);
+        }
     }
 
     @Override
     public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
         super.onRequestPermissionsResult(requestCode, permissions, grantResults);
-        if (requestCode == MY_PERMISSIONS_REQUEST_SMS_RECEIVE) {
+        if (requestCode == Utils.PERMISSION_SMS_RECEIVE) {
+
+        }
+        else if(requestCode == Utils.PERMISSION_SMS_SEND){
+
+        }
+        else if(requestCode == Utils.PERMISSION_ACCESS_FINE_LOCATION){
+
         }
     }
 

src/app/src/main/java/com/xfarrow/locatemydevice/SmsHandler.java

@@ -57,57 +57,57 @@ public class SmsHandler {
         SmsManager smsManager = SmsManager.getDefault();
 
         // locate
-        if (providedOption.equals(Settings.LOCATE_OPTION)) {
+        if (providedOption.equals(Utils.LOCATE_OPTION)) {
 
             LocationManager locationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE);
 
-            // GPS is off
+            if(!locationManager.isLocationEnabled()){
-            if (!locationManager.isLocationEnabled()) {
+                // TODO: get last known location (requies google play services)
-                smsManager.sendTextMessage(sender, null, "GPS is off ", null, null);
-                return;
-            }
-
-            // GPS permission not granted
-            if (ActivityCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
                 smsManager.sendTextMessage(sender, null,
-                        "GPS permission is not granted. " +
+                        "Location is not enabled. " +
                                 "Unable to serve request.",null, null);
                 return;
             }
 
-            // API 30 and above
+            // Location permission not granted
-            if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) {
+            if (ActivityCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED &&
-                locationManager.getCurrentLocation(LocationManager.GPS_PROVIDER, null, context.getMainExecutor(), new Consumer<Location>() {
+                    ActivityCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
+
+                    smsManager.sendTextMessage(sender, null,
+                        "Location permission is not granted. " +
+                        "Unable to serve request.",null, null);
+                return;
+            }
+
+            // API 31 and above
+            if(android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.S){
+                locationManager.getCurrentLocation(LocationManager.FUSED_PROVIDER, null, context.getMainExecutor(), new Consumer<Location>() {
                     @Override
                     public void accept(Location location) {
-                        double latitude = location.getLatitude();
+                        sendGpsCoordinates(smsManager, sender, location.getLatitude(), location.getLongitude());
-                        double longitude = location.getLongitude();
-                        smsManager.sendTextMessage(sender, null,
-                                "GPS coordinates are: " +
-                                "\nLatitude: " + latitude +
-                                "\nLongitude: " + longitude + "\n" +
-                                Utils.buildOSMLink(latitude, longitude), null, null);
                     }
                 });
             }
 
-            // Legacy (API < 29)
+            // Legacy (API < 31)
             else{
                 Criteria locationCriteria = new Criteria();
                 locationCriteria.setAccuracy(Criteria.ACCURACY_FINE);
                 locationManager.requestSingleUpdate(locationCriteria, new LocationListener() {
                     @Override
                     public void onLocationChanged(@NonNull Location location) {
-                        double latitude = location.getLatitude();
+                        sendGpsCoordinates(smsManager, sender, location.getLatitude(), location.getLongitude());
-                        double longitude = location.getLongitude();
-                        smsManager.sendTextMessage(sender, null,
-                                "GPS coordinates are:" +
-                                        "\nLatitude: " + latitude +
-                                        "\nLongitude: " + longitude + "\n" +
-                                        Utils.buildOSMLink(latitude, longitude), null, null);
                     }
                 }, null);
             }
         }
     }
+
+    private void sendGpsCoordinates(SmsManager smsManager, String sendTo, double latitude, double longitude){
+        smsManager.sendTextMessage(sendTo, null,
+                "GPS coordinates are:" +
+                        "\nLatitude: " + latitude +
+                        "\nLongitude: " + longitude + "\n" +
+                        Utils.buildOSMLink(latitude, longitude), null, null);
+    }
 }

src/app/src/main/java/com/xfarrow/locatemydevice/Utils.java

@@ -1,8 +1,16 @@
 package com.xfarrow.locatemydevice;
 
 public class Utils {
+
+    public static final int PERMISSION_SMS_RECEIVE = 100;
+    public static final int PERMISSION_SMS_SEND = 101;
+    public static final int PERMISSION_ACCESS_FINE_LOCATION = 102;
+
+
     public static final String LOCATE_OPTION = "locate";
+
     public static String buildOSMLink(double latitude, double longitude){
         return "https://www.openstreetmap.org/?mlat=" + latitude + "&mlon=" + longitude;
     }
+
 }