Fix several warnings

android/src/main/java/com/baseflow/permissionhandler/PermissionHandlerPlugin.java

@@ -19,6 +19,7 @@ import android.telephony.TelephonyManager;
 import android.text.TextUtils;
 import android.text.TextUtils;
 import android.util.Log;
 import android.util.Log;
 
 
+import androidx.annotation.NonNull;
 import androidx.annotation.RequiresApi;
 import androidx.annotation.RequiresApi;
 import androidx.core.app.NotificationManagerCompat;
 import androidx.core.app.NotificationManagerCompat;
 import io.flutter.plugin.common.PluginRegistry.ActivityResultListener;
 import io.flutter.plugin.common.PluginRegistry.ActivityResultListener;
@@ -213,7 +214,7 @@ public class PermissionHandlerPlugin implements MethodCallHandler {
   private Map<Integer, Integer> mRequestResults = new HashMap<>();
   private Map<Integer, Integer> mRequestResults = new HashMap<>();
 
 
   @Override
   @Override
-  public void onMethodCall(MethodCall call, Result result) {
+  public void onMethodCall(MethodCall call, @NonNull Result result) {
     switch (call.method) {
     switch (call.method) {
       case "checkPermissionStatus": {
       case "checkPermissionStatus": {
         @PermissionGroup final int permission = (int) call.arguments;
         @PermissionGroup final int permission = (int) call.arguments;
@@ -293,7 +294,7 @@ public class PermissionHandlerPlugin implements MethodCallHandler {
           PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
           PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
           // PowerManager.isIgnoringBatteryOptimizations has been included in Android M first.
           // PowerManager.isIgnoringBatteryOptimizations has been included in Android M first.
           if (VERSION.SDK_INT >= VERSION_CODES.M) {
           if (VERSION.SDK_INT >= VERSION_CODES.M) {
-            if (pm.isIgnoringBatteryOptimizations(packageName)) {
+            if (pm != null && pm.isIgnoringBatteryOptimizations(packageName)) {
               return PERMISSION_STATUS_GRANTED;
               return PERMISSION_STATUS_GRANTED;
             } else {
             } else {
               return PERMISSION_STATUS_DENIED;
               return PERMISSION_STATUS_DENIED;
@@ -344,7 +345,7 @@ public class PermissionHandlerPlugin implements MethodCallHandler {
       TelephonyManager telephonyManager = (TelephonyManager) context
       TelephonyManager telephonyManager = (TelephonyManager) context
           .getSystemService(Context.TELEPHONY_SERVICE);
           .getSystemService(Context.TELEPHONY_SERVICE);
 
 
-      if (telephonyManager.getPhoneType() == TelephonyManager.PHONE_TYPE_NONE) {
+      if (telephonyManager == null || telephonyManager.getPhoneType() == TelephonyManager.PHONE_TYPE_NONE) {
         return SERVICE_STATUS_NOT_APPLICABLE;
         return SERVICE_STATUS_NOT_APPLICABLE;
       }
       }
 
 
@@ -426,7 +427,7 @@ public class PermissionHandlerPlugin implements MethodCallHandler {
           continue;
           continue;
         }
         }
 
 
-        if (permission == PERMISSION_GROUP_IGNORE_BATTERY_OPTIMIZATIONS) {
+        if (VERSION.SDK_INT >= VERSION_CODES.M && permission == PERMISSION_GROUP_IGNORE_BATTERY_OPTIMIZATIONS) {
           String packageName = mRegistrar.context().getPackageName();
           String packageName = mRegistrar.context().getPackageName();
           Intent intent = new Intent();
           Intent intent = new Intent();
           intent.setAction(Settings.ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS);
           intent.setAction(Settings.ACTION_REQUEST_IGNORE_BATTERY_OPTIMIZATIONS);
@@ -637,7 +638,7 @@ public class PermissionHandlerPlugin implements MethodCallHandler {
         if (hasPermissionInManifest(Manifest.permission.USE_SIP))
         if (hasPermissionInManifest(Manifest.permission.USE_SIP))
           permissionNames.add(Manifest.permission.USE_SIP);
           permissionNames.add(Manifest.permission.USE_SIP);
 
 
-        if (hasPermissionInManifest(Manifest.permission.BIND_CALL_REDIRECTION_SERVICE))
+        if (VERSION.SDK_INT >= VERSION_CODES.Q && hasPermissionInManifest(Manifest.permission.BIND_CALL_REDIRECTION_SERVICE))
           permissionNames.add(Manifest.permission.BIND_CALL_REDIRECTION_SERVICE);
           permissionNames.add(Manifest.permission.BIND_CALL_REDIRECTION_SERVICE);
 
 
         if (VERSION.SDK_INT >= VERSION_CODES.O && hasPermissionInManifest(Manifest.permission.ANSWER_PHONE_CALLS))
         if (VERSION.SDK_INT >= VERSION_CODES.O && hasPermissionInManifest(Manifest.permission.ANSWER_PHONE_CALLS))
@@ -775,7 +776,6 @@ public class PermissionHandlerPlugin implements MethodCallHandler {
     return isNeverAskAgainSelected;
     return isNeverAskAgainSelected;
   }
   }
 
 
-  @SuppressWarnings("deprecation")
   private boolean isLocationServiceEnabled(Context context) {
   private boolean isLocationServiceEnabled(Context context) {
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
       final LocationManager locationManager = context.getSystemService(LocationManager.class);
       final LocationManager locationManager = context.getSystemService(LocationManager.class);