handle sms permissions

app/src/main/AndroidManifest.xml

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.vernu.sms">
-
+    <uses-permission android:name="android.permission.SEND_SMS" />
     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"

app/src/main/java/com/vernu/sms/MainActivity.java

@@ -1,12 +1,18 @@
 package com.vernu.sms;
 
 import androidx.appcompat.app.AppCompatActivity;
+import androidx.core.app.ActivityCompat;
+import androidx.core.content.ContextCompat;
 
+import android.Manifest;
+import android.content.Context;
+import android.content.pm.PackageManager;
 import android.os.Bundle;
 import android.view.View;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.Switch;
+import android.widget.Toast;
 
 import com.google.android.material.snackbar.Snackbar;
 
@@ -16,6 +22,8 @@ public class MainActivity extends AppCompatActivity {
     private EditText gatewayKeyEditText;
     private Button updateKeyButton, grantSMSPermissionBtn;
 
+    private static final int SEND_SMS_PERMISSION_REQUEST_CODE = 0;
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
@@ -25,14 +33,57 @@ public class MainActivity extends AppCompatActivity {
         updateKeyButton = findViewById(R.id.updateKeyButton);
         grantSMSPermissionBtn = findViewById(R.id.grantSMSPermissionBtn);
 
+        if (isSMSPermissionGranted(getApplicationContext())) {
+            grantSMSPermissionBtn.setEnabled(false);
+            grantSMSPermissionBtn.setText("SMS Permission Granted");
+        } else {
+            grantSMSPermissionBtn.setOnClickListener(new View.OnClickListener() {
+                @Override
+                public void onClick(View view) {
+                    handleSMSRequestPermission(view);
+                }
+            });
+
+        }
+
+
+    }
 
-        grantSMSPermissionBtn.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View view) {
-                Snackbar.make(view, "Pls give permissions", Snackbar.LENGTH_SHORT).show();
+    @Override
+    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
+        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
+        switch (requestCode) {
+            case SEND_SMS_PERMISSION_REQUEST_CODE: {
+                if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
+                    Toast.makeText(getApplicationContext(), "Yay!   .",
+                            Toast.LENGTH_LONG).show();
+                } else {
+                    Toast.makeText(getApplicationContext(),
+                            "Permission Denied :(", Toast.LENGTH_LONG).show();
+                    return;
+                }
             }
-        });
+        }
+
+    }
 
+    private void handleSMSRequestPermission(View view) {
+        if (isSMSPermissionGranted(view.getContext())) {
+            Snackbar.make(view, "Already got permissions", Snackbar.LENGTH_SHORT).show();
+        } else {
+            if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,
+                    Manifest.permission.SEND_SMS)) {
+                Snackbar.make(view, "PERMISSION DENIED, Pls grant SMS Permission in app settings", Snackbar.LENGTH_SHORT).show();
+            } else {
+                Snackbar.make(view, "Grant SMS Permissions to continue", Snackbar.LENGTH_SHORT).show();
+                ActivityCompat.requestPermissions(MainActivity.this,
+                        new String[]{Manifest.permission.SEND_SMS},
+                        SEND_SMS_PERMISSION_REQUEST_CODE);
+            }
+        }
+    }
 
+    private boolean isSMSPermissionGranted(Context context) {
+        return ContextCompat.checkSelfPermission(context, Manifest.permission.SEND_SMS) == PackageManager.PERMISSION_GRANTED;
     }
 }