Refactor API connection code

lib/api.dart

@@ -109,13 +109,11 @@ class InvenTreeAPI {
 
   String makeUrl(String endpoint) => _makeUrl(endpoint);
 
-  UserProfile _profile;
+  UserProfile profile;
 
   // Authentication token (initially empty, must be requested)
   String _token = "";
 
-  bool isConnected() => _token.isNotEmpty;
-
   /*
    * Check server connection and display messages if not connected.
    * Useful as a precursor check before performing operations.
@@ -154,8 +152,14 @@ class InvenTreeAPI {
   // Connection status flag - set once connection has been validated
   bool _connected = false;
 
-  bool get connected {
+  bool _connecting = true;
-    return _connected && baseUrl.isNotEmpty && _token.isNotEmpty;
+
+  bool isConnected() {
+    return profile != null && _connected && baseUrl.isNotEmpty && _token.isNotEmpty;
+  }
+
+  bool isConnecting() {
+    return !isConnected() && _connecting;
   }
 
   // Ensure we only ever create a single instance of the API class
@@ -167,35 +171,15 @@ class InvenTreeAPI {
 
   InvenTreeAPI._internal();
 
-  Future<bool> connect(BuildContext context) async {
+  Future<bool> _connect(BuildContext context) async {
-
-    _profile = await UserProfileDBManager().getSelectedProfile();
-
-    if (_profile == null) {
-      await showErrorDialog(
-          context,
-          "Select Profile",
-          "User profile not selected"
-      );
-      return false;
-    }
-
-    return connectToServer(context);
-  }
-
-  Future<bool> connectToServer(BuildContext context) async {
 
     /* Address is the base address for the InvenTree server,
      * e.g. http://127.0.0.1:8000
      */
 
-    if (_profile == null) return false;
+    String address = profile.server.trim();
-
+    String username = profile.username.trim();
-    String errorMessage = "";
+    String password = profile.password.trim();
-
-    String address = _profile.server.trim();
-    String username = _profile.username.trim();
-    String password = _profile.password.trim();
 
     if (address.isEmpty || username.isEmpty || password.isEmpty) {
       await showErrorDialog(
@@ -220,19 +204,18 @@ class InvenTreeAPI {
      */
 
     _BASE_URL = address;
-    _connected = false;
 
-    print("Connecting to " + apiUrl + " -> " + username + ":" + password);
+    print("Connecting to ${apiUrl} -> ${username}:${password}");
 
     var response = await get("").timeout(Duration(seconds: 5)).catchError((error) {
 
       print("Error connecting to server: ${error.toString()}");
 
       if (error is SocketException) {
-        errorMessage = "Could not connect to server";
+        showServerError(context, "Connection Refused");
         return null;
       } else if (error is TimeoutException) {
-        errorMessage = "Server timeout";
+        showTimeoutDialog(context);
         return null;
       } else {
         // Unknown error type - re-throw the error and Sentry will catch it
@@ -242,8 +225,6 @@ class InvenTreeAPI {
 
     if (response == null) {
       // Null (or error) response: Show dialog and exit
-
-      await showServerError(context, errorMessage);
       return false;
     }
 
@@ -322,6 +303,38 @@ class InvenTreeAPI {
     };
   }
 
+  Future<bool> connectToServer(BuildContext context) async {
+    print("InvenTreeAPI().connectToServer()");
+
+    // Clear connection flag
+    _connected = false;
+
+    // Clear token
+    _token = '';
+
+    // Load selected profile
+    profile = await UserProfileDBManager().getSelectedProfile();
+
+    if (profile == null) {
+      await showErrorDialog(
+          context,
+          "Select Profile",
+          "User profile not selected"
+      );
+      return false;
+    }
+
+    _connecting = true;
+
+    _connect(context).then((result) {
+
+      print("_connect() returned result: ${result}");
+      _connecting = false;
+
+      return result;
+    });
+  }
+
   // Perform a PATCH request
   Future<http.Response> patch(String url, {Map<String, String> body}) async {
     var _url = makeApiUrl(url);
@@ -405,7 +418,9 @@ class InvenTreeAPI {
   Map<String, String> defaultHeaders() {
     var headers = Map<String, String>();
 
-    headers[HttpHeaders.authorizationHeader] = _authorizationHeader(_profile.username, _profile.password);
+    if (profile != null) {
+      headers[HttpHeaders.authorizationHeader] = _authorizationHeader(profile.username, profile.password);
+    }
 
     return headers;
   }

lib/settings/login.dart

@@ -180,7 +180,7 @@ class _InvenTreeLoginSettingsState extends State<InvenTreeLoginSettingsWidget> {
     _reload();
 
     // Attempt server login (this will load the newly selected profile
-    InvenTreeAPI().connect(context);
+    InvenTreeAPI().connectToServer(context);
   }
 
   void _deleteProfile(UserProfile profile) async {
@@ -220,7 +220,7 @@ class _InvenTreeLoginSettingsState extends State<InvenTreeLoginSettingsWidget> {
 
     List<Widget> children = [];
 
-    if (profiles.length > 0) {
+    if (profiles != null && profiles.length > 0) {
       for (int idx = 0; idx < profiles.length; idx++) {
         UserProfile profile = profiles[idx];
 

lib/widget/home.dart

@@ -44,109 +44,7 @@ class _InvenTreeHomePageState extends State<InvenTreeHomePage> {
   // Selected user profile
   UserProfile _profile;
 
-  void _loadProfile() async {
+  BuildContext _context;
-
-    final profile = await UserProfileDBManager().getSelectedProfile();
-
-    print("Loaded selected profile");
-
-    // If a different profile is selected, re-connect
-    if (_profile == null || (_profile.key != profile.key)) {
-      // TODO
-    }
-
-    _profile = profile;
-
-    setState(() {
-
-    });
-  }
-
-  ListTile _serverTile() {
-
-    // No profile selected
-    // Tap to select / create a profile
-    if (_profile == null) {
-      return ListTile(
-        title: Text("No Profile Selected"),
-        subtitle: Text("Tap to create or select a profile"),
-        leading: FaIcon(FontAwesomeIcons.user),
-        onTap: () {
-          _selectProfile();
-        },
-      );
-    }
-
-    // Profile is selected ...
-    if (InvenTreeAPI().isConnected()) {
-      return ListTile(
-        title: Text("Connected to ${_profile.server}"),
-      );
-    } else {
-      return ListTile(
-        title: Text("Could not connect to server"),
-        subtitle: Text("Error connecting to ${_profile.server}"),
-        leading: FaIcon(FontAwesomeIcons.times),
-        onTap: () {
-          _selectProfile();
-        },
-      );
-    }
-  }
-
-  void onConnectSuccess(String msg) async {
-
-    final profile = await UserProfileDBManager().getSelectedProfile();
-
-    String address = profile?.server ?? 'unknown server address';
-
-    _serverConnection = true;
-    _serverMessage = msg;
-    _serverStatus = "Connected to ${address}";
-    _serverStatusColor = Color.fromARGB(255, 50, 250, 50);
-    _serverIcon = new FaIcon(FontAwesomeIcons.checkCircle, color: _serverStatusColor);
-
-    setState(() {});
-  }
-
-  void onConnectFailure(String msg) async {
-
-    final profile = await UserProfileDBManager().getSelectedProfile();
-
-    _serverConnection = false;
-    _serverMessage = msg;
-    _serverStatus = "Could not connect to ${profile?.server}";
-    _serverStatusColor = Color.fromARGB(255, 250, 50, 50);
-    _serverIcon = new FaIcon(FontAwesomeIcons.timesCircle, color: _serverStatusColor);
-
-    setState(() {});
-  }
-
-  /*
-   * Test the server connection
-   */
-  void _checkServerConnection(BuildContext context) async {
-
-    // Reset the connection status variables
-    _serverStatus = "Connecting to server";
-    _serverMessage = "";
-    _serverConnection = false;
-    _serverIcon = new FaIcon(FontAwesomeIcons.spinner);
-    _serverStatusColor = Color.fromARGB(255, 50, 50, 250);
-
-    InvenTreeAPI().connect(context).then((bool result) {
-
-      if (result) {
-        onConnectSuccess("");
-      } else {
-        onConnectFailure("Could not connect to server");
-      }
-
-    });
-
-    // Update widget state
-    setState(() {});
-  }
 
   void _search() {
     if (!InvenTreeAPI().checkConnection(context)) return;
@@ -210,8 +108,130 @@ class _InvenTreeHomePageState extends State<InvenTreeHomePage> {
     );
   }
 
+
+  void _loadProfile() async {
+
+    final profile = await UserProfileDBManager().getSelectedProfile();
+
+    // If a different profile is selected, re-connect
+    if (_profile == null || (_profile.key != profile.key)) {
+
+      if (_context != null) {
+        print("Connecting Profile: ${profile.name} - ${profile.server}");
+
+        InvenTreeAPI().connectToServer(_context).then((result) {
+          setState(() {
+
+          });
+        });
+
+        setState(() {
+        });
+      }
+    }
+
+    _profile = profile;
+
+    setState(() {
+
+    });
+  }
+
+  ListTile _serverTile() {
+
+    // No profile selected
+    // Tap to select / create a profile
+    if (_profile == null) {
+      return ListTile(
+        title: Text("No Profile Selected"),
+        subtitle: Text("Tap to create or select a profile"),
+        leading: FaIcon(FontAwesomeIcons.server),
+        trailing: FaIcon(
+          FontAwesomeIcons.user,
+          color: Color.fromRGBO(250, 50, 50, 1),
+        ),
+        onTap: () {
+          _selectProfile();
+        },
+      );
+    }
+
+    // Profile is selected ...
+    if (InvenTreeAPI().isConnecting()) {
+      return ListTile(
+        title: Text("Connecting to server..."),
+        subtitle: Text("${InvenTreeAPI().baseUrl}"),
+        leading: FaIcon(FontAwesomeIcons.server),
+        trailing: FaIcon(
+          FontAwesomeIcons.spinner,
+          color: Color.fromRGBO(50, 50, 250, 1),
+        )
+      );
+    } else if (InvenTreeAPI().isConnected()) {
+      return ListTile(
+        title: Text("Connected to server"),
+        subtitle: Text("${InvenTreeAPI().baseUrl}"),
+        leading: FaIcon(FontAwesomeIcons.server),
+        trailing: FaIcon(
+          FontAwesomeIcons.checkCircle,
+          color: Color.fromRGBO(50, 250, 50, 1)
+        ),
+        onTap: () {
+          _selectProfile();
+        },
+      );
+    } else {
+      return ListTile(
+        title: Text("Could not connect to server"),
+        subtitle: Text("${_profile.server}"),
+        leading: FaIcon(FontAwesomeIcons.server),
+        trailing: FaIcon(
+          FontAwesomeIcons.timesCircle,
+          color: Color.fromRGBO(250, 50, 50, 1),
+        ),
+        onTap: () {
+          _selectProfile();
+        },
+      );
+    }
+  }
+
+  void onConnectSuccess(String msg) async {
+
+    final profile = await UserProfileDBManager().getSelectedProfile();
+
+    String address = profile?.server ?? 'unknown server address';
+
+    _serverConnection = true;
+    _serverMessage = msg;
+    _serverStatus = "Connected to ${address}";
+    _serverStatusColor = Color.fromARGB(255, 50, 250, 50);
+    _serverIcon = new FaIcon(FontAwesomeIcons.checkCircle, color: _serverStatusColor);
+
+    setState(() {});
+  }
+
+  void onConnectFailure(String msg) async {
+
+    final profile = await UserProfileDBManager().getSelectedProfile();
+
+    _serverConnection = false;
+    _serverMessage = msg;
+    _serverStatus = "Could not connect to ${profile?.server}";
+    _serverStatusColor = Color.fromARGB(255, 250, 50, 50);
+    _serverIcon = new FaIcon(FontAwesomeIcons.timesCircle, color: _serverStatusColor);
+
+    setState(() {});
+  }
+
+
   @override
   Widget build(BuildContext context) {
+
+    _context = context;
+
+    _loadProfile();
+
     // This method is rerun every time setState is called, for instance as done
     // by the _incrementCounter method above.
     //
@@ -369,6 +389,7 @@ class _InvenTreeHomePageState extends State<InvenTreeHomePage> {
             ),
             Spacer(),
             */
+            Spacer(),
             Row(
               mainAxisAlignment: MainAxisAlignment.center,
               crossAxisAlignment: CrossAxisAlignment.center,