dont init wifi widget if there is no adapter

selfdrive/ui/qt/offroad/wifi.cc

@@ -21,7 +21,12 @@ void clearLayout(QLayout* layout) {
 }
 
 WifiUI::WifiUI(QWidget *parent, int page_length) : QWidget(parent), networks_per_page(page_length) {
+  try {
     wifi = new WifiManager;
+  } catch (std::exception &e) {
+    return;
+  }
+
   QObject::connect(wifi, SIGNAL(wrongPassword(QString)), this, SLOT(wrongPassword(QString)));
 
   QVBoxLayout * top_layout = new QVBoxLayout;

selfdrive/ui/qt/offroad/wifi.hpp

@@ -18,7 +18,7 @@ public:
   explicit WifiUI(QWidget *parent = 0, int page_length = 5);
 
 private:
-  WifiManager* wifi;
+  WifiManager* wifi = nullptr;
   const int networks_per_page;
 
   QStackedWidget *swidget;

selfdrive/ui/qt/offroad/wifiManager.cc

@@ -61,8 +61,12 @@ WifiManager::WifiManager() {
   qDBusRegisterMetaType<IpConfig>();
   connecting_to_network = "";
   adapter = get_adapter();
-  has_adapter = adapter != "";
-  if (has_adapter) {
+
+  bool has_adapter = adapter != "";
+  if (!has_adapter){
+    throw std::runtime_error("Error connecting to panda");
+  }
+
   QDBusInterface nm(nm_service, adapter, device_iface, bus);
   bus.connect(nm_service, adapter, device_iface, "StateChanged", this, SLOT(change(unsigned int, unsigned int, unsigned int)));
 
@@ -70,7 +74,6 @@ WifiManager::WifiManager() {
   QDBusMessage response = device_props.call("Get", device_iface, "State");
   raw_adapter_state = get_response<uint>(response);
   change(raw_adapter_state, 0, 0);
-  }
 
   // Compute tethering ssid as "Weedle" + first 4 characters of a dongle id
   tethering_ssid = "weedle";
@@ -81,8 +84,6 @@ WifiManager::WifiManager() {
 }
 
 void WifiManager::refreshNetworks() {
-  if (!has_adapter) return;
-
   bus = QDBusConnection::systemBus();
   seen_networks.clear();
   seen_ssids.clear();
@@ -249,8 +250,6 @@ void WifiManager::clear_connections(QString ssid) {
 }
 
 void WifiManager::request_scan() {
-  if (!has_adapter) return;
-
   QDBusInterface nm(nm_service, adapter, wireless_device_iface, bus);
   nm.call("RequestScan",  QVariantMap());
 }

selfdrive/ui/qt/offroad/wifiManager.hpp

@@ -30,7 +30,6 @@ class WifiManager : public QWidget {
 public:
   explicit WifiManager();
 
-  bool has_adapter;
   void request_scan();
   QVector<Network> seen_networks;