From 95df68d76c5c583e66c9c3f451a1731867a13e44 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20R=C3=BCth?= <jan@djiehmail.com>
Date: Mon, 13 May 2024 20:50:12 +0200
Subject: [PATCH] Card scanning check is optional

As reported in #8, it seems that card scanning is not available on all scanners.
This change makes it optional and simply returns no card scanning when the feature seems to not be available.
---
 es2button/src/listener.rs | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/es2button/src/listener.rs b/es2button/src/listener.rs
index 0e2b50f..7a9b466 100644
--- a/es2button/src/listener.rs
+++ b/es2button/src/listener.rs
@@ -74,9 +74,20 @@ impl<'a> Listener<'a> {
         self.scanner
             .get_bool_value_for_key(es2command::ESKEY_DOCUMENT_LOADED)
     }
+
     fn is_card_scanning(&self) -> Result<bool, ESError> {
-        self.scanner
+        match self
+            .scanner
             .get_bool_value_for_key(es2command::ESKEY_CARD_SCANNING)
+        {
+            // Not all scanners support card scanning, in this case,
+            // we get a InvalidParameter, we just report this as no card scanning
+            Err(ESError::InvalidParameter) => {
+                trace!("Got InvalidParameter for \"cardScanning\" lookup, assuming no card scanning available");
+                Ok(false)
+            }
+            x => x,
+        }
     }
 
     fn handle_button_press(&self, button: u8) -> Result<(), anyhow::Error> {