Add status callback to detect WiFi disconnections

Author: pennam

libraries/WiFi/src/WiFi.cpp

@@ -17,6 +17,8 @@ int arduino::WiFiClass::begin(const char* ssid, const char* passphrase) {
     return 0;
   }
 
+  wifi_if->attach(&arduino::WiFiClass::statusCallback);
+
   scanNetworks();
   // use scan result to populate security field
   if (!isVisible(ssid)) {
@@ -210,6 +212,15 @@ unsigned long arduino::WiFiClass::getTime() {
   return 0;
 }
 
+void arduino::WiFiClass::statusCallback(nsapi_event_t status, intptr_t param)
+{
+  if (((param == NSAPI_STATUS_DISCONNECTED) ||
+       (param == NSAPI_STATUS_CONNECTING)) &&
+       (WiFi.status() == WL_CONNECTED)) {
+    WiFi._currentNetworkStatus = WL_CONNECTION_LOST;
+  }
+}
+
 #if defined(COMPONENT_4343W_FS)
 
 #define WIFI_FIRMWARE_PATH "/wlan/4343WA1.BIN"

libraries/WiFi/src/WiFi.h

@@ -209,6 +209,7 @@ class WiFiClass : public MbedSocketClass {
   void ensureDefaultAPNetworkConfiguration();
   static void* handleAPEvents(whd_interface_t ifp, const whd_event_header_t* event_header, const uint8_t* event_data, void* handler_user_data);
   bool isVisible(const char* ssid);
+  static void statusCallback(nsapi_event_t status, intptr_t param);
 };
 
 }