How to enable Location access programmatically in android?

Here is a simple way of programmatically enabling location like Maps app:

protected void enableLocationSettings() {
       LocationRequest locationRequest = LocationRequest.create()
             .setInterval(LOCATION_UPDATE_INTERVAL)
             .setFastestInterval(LOCATION_UPDATE_FASTEST_INTERVAL)
             .setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);

        LocationSettingsRequest.Builder builder = new LocationSettingsRequest.Builder()
                .addLocationRequest(locationRequest);

        LocationServices
                .getSettingsClient(this)
                .checkLocationSettings(builder.build())
                .addOnSuccessListener(this, (LocationSettingsResponse response) -> {
                    // startUpdatingLocation(...);
                })
                .addOnFailureListener(this, ex -> {
                    if (ex instanceof ResolvableApiException) {
                        // Location settings are NOT satisfied,  but this can be fixed  by showing the user a dialog.
                        try {
                            // Show the dialog by calling startResolutionForResult(),  and check the result in onActivityResult().
                            ResolvableApiException resolvable = (ResolvableApiException) ex;
                            resolvable.startResolutionForResult(TrackingListActivity.this, REQUEST_CODE_CHECK_SETTINGS);
                        } catch (IntentSender.SendIntentException sendEx) {
                            // Ignore the error.
                        }
                    }
                });
 }

And onActivityResult:

@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
    if (REQUEST_CODE_CHECK_SETTINGS == requestCode) {
        if(Activity.RESULT_OK == resultCode){
            //user clicked OK, you can startUpdatingLocation(...);

        }else{
            //user clicked cancel: informUserImportanceOfLocationAndPresentRequestAgain();
        }
    }
}

You can see the documentation here: https://developer.android.com/training/location/change-location-settings

Use below code to check. If it is disabled, dialog box will be generated

public void statusCheck() {
    final LocationManager manager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

    if (!manager.isProviderEnabled(LocationManager.GPS_PROVIDER)) {
        buildAlertMessageNoGps();

    }
}

private void buildAlertMessageNoGps() {
    final AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setMessage("Your GPS seems to be disabled, do you want to enable it?")
            .setCancelable(false)
            .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                public void onClick(final DialogInterface dialog, final int id) {
                    startActivity(new Intent(android.provider.Settings.ACTION_LOCATION_SOURCE_SETTINGS));
                }
            })
            .setNegativeButton("No", new DialogInterface.OnClickListener() {
                public void onClick(final DialogInterface dialog, final int id) {
                    dialog.cancel();
                }
            });
    final AlertDialog alert = builder.create();
    alert.show();
}