Merge branch 'barcodez'

lib/api.dart

@@ -182,15 +182,22 @@ class InvenTreeAPI {
     var response = await get("").timeout(Duration(seconds: 10)).catchError((error) {
 
       if (error is SocketException) {
-        errorMessage = "Could not connect to server.";
+        print("Could not connect to server");
-        print(errorMessage);
+        return null;
-        throw errorMessage;
+      } else if (error is TimeoutException) {
+        print("Server timeout");
+        return null;
       } else {
         // Unknown error type, re-throw error
+        print("Unknown error: ${error.toString()}");
         throw error;
       }
     });
 
+    if (response == null) {
+      return false;
+    }
+
     if (response.statusCode != 200) {
       print("Invalid status code: " + response.statusCode.toString());
       return false;

lib/barcode.dart

@@ -1,3 +1,4 @@
+import 'package:InvenTree/widget/dialogs.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:qr_utils/qr_utils.dart';
@@ -5,6 +6,8 @@ import 'package:qr_utils/qr_utils.dart';
 import 'package:InvenTree/inventree/stock.dart';
 import 'package:InvenTree/inventree/part.dart';
 
+import 'package:InvenTree/api.dart';
+
 import 'package:InvenTree/widget/location_display.dart';
 import 'package:InvenTree/widget/part_detail.dart';
 import 'package:InvenTree/widget/category_display.dart';
@@ -12,59 +15,139 @@ import 'package:InvenTree/widget/stock_detail.dart';
 
 import 'dart:convert';
 
-void scanQrCode(BuildContext context) async {
+Future<void> scanQrCode(BuildContext context) async {
 
-  QrUtils.scanQR.then((String result) {
+  QrUtils.scanQR.then((String barcode) {
 
-    print("Scanned: $result");
+    print("Scanned: $barcode");
 
-    // Look for JSON data in the result...
+    showProgressDialog(context, "Querying Server", "Sending barcode data to server");
-    final data = json.decode(result);
 
-    // Look for an 'InvenTree' style barcode
+    /*
-    if ((data['tool'] ?? '').toString().toLowerCase() == 'inventree') {
+     * POST the scanned barcode data to the server.
-      _handleInvenTreeBarcode(context, data);
+     * It is the responsibility of the server to validate and sanitize the barcode data,
-    }
+     * and return a "common" response that we know how to deal with.
+     */
+    InvenTreeAPI().post("barcode/", body: {"barcode": barcode}).then((var response) {
 
-    // Unknown barcode style!
+      hideProgressDialog(context);
-    else {
-     showDialog(
-       context: context,
-       child: new SimpleDialog(
-         title: new Text("Unknown barcode"),
-         children: <Widget>[
-           Text("Data: $result"),
-         ]
-       )
-     );
-    }
 
+      if (response.statusCode != 200) {
+        showDialog(
+          context: context,
+          child: new SimpleDialog(
+            title: Text("Server Error"),
+            children: <Widget>[
+              ListTile(
+                title: Text("Error ${response.statusCode}"),
+                subtitle: Text("${response.body.toString().split("\n").first}"),
+              )
+            ],
+          ),
+        );
+
+        return;
+      }
+
+      final Map<String, dynamic> body = json.decode(response.body);
+
+      // TODO - Handle potential error decoding response
+
+      print("Barcode response:");
+      print(body.toString());
+
+      if (body.containsKey('error')) {
+        showDialog(
+          context: context,
+          child: new SimpleDialog(
+            title: Text("Barcode Error"),
+            children: <Widget>[
+              ListTile(
+                title: Text("${body['error']}"),
+                subtitle: Text("Plugin: ${body['plugin'] ?? '<no plugin information>'}"),
+              )
+            ],
+          )
+        );
+      } else if (body.containsKey('success')) {
+        // Decode the barcode!
+        // Ideally, the server has returned unto us something sensible...
+        _handleBarcode(context, body);
+      } else {
+        showDialog(
+          context: context,
+          child: new SimpleDialog(
+            title: Text("Unknown response"),
+            children: <Widget>[
+              ListTile(
+                title: Text("Response data"),
+                subtitle: Text("${body.toString()}"),
+              )
+            ],
+          )
+        );
+      }
+
+      print("body: ${body.toString()}");
+
+    });
   });
 }
 
-void _handleInvenTreeBarcode(BuildContext context, Map<String, dynamic> data) {
+void _handleBarcode(BuildContext context, Map<String, dynamic> data) {
 
-  final String codeType = (data['type'] ?? '').toString().toLowerCase();
+  int pk;
 
-  final int pk = (data['id'] ?? -1) as int;
+  // A stocklocation has been passed?
+  if (data.containsKey('stocklocation')) {
 
-  if (codeType == 'stocklocation') {
+    pk = data['stocklocation']['pk'] as int ?? null;
 
-    // Try to open a stock location...
+    if (pk != null) {
-    InvenTreeStockLocation().get(pk).then((var loc) {
+      InvenTreeStockLocation().get(context, pk).then((var loc) {
-      if (loc is InvenTreeStockLocation) {
+        if (loc is InvenTreeStockLocation) {
-        Navigator.push(context, MaterialPageRoute(builder: (context) => LocationDisplayWidget(loc)));
+          Navigator.push(context, MaterialPageRoute(builder: (context) => LocationDisplayWidget(loc)));
-      }
+        }
-    });
+      });
+    } else {
+      // TODO - Show an error here!
+    }
 
-  } else if (codeType == 'stockitem') {
+  } else if (data.containsKey('stockitem')) {
-    InvenTreeStockItem().get(pk).then((var item) {
+
-      Navigator.push(context, MaterialPageRoute(builder: (context) => StockDetailWidget(item)));
+    pk = data['stockitem']['pk'] as int ?? null;
-    });
+
-  } else if (codeType == 'part') {
+    if (pk != null) {
-    InvenTreePart().get(pk).then((var part) {
+      InvenTreeStockItem().get(context, pk).then((var item) {
-      Navigator.push(context,
+        Navigator.push(context, MaterialPageRoute(builder: (context) => StockDetailWidget(item)));
-          MaterialPageRoute(builder: (context) => PartDetailWidget(part)));
+      });
-    });
+    } else {
+      // TODO - Show an error here!
+    }
+  } else if (data.containsKey('part')) {
+
+    pk = data['part']['pk'] as int ?? null;
+
+    if (pk != null) {
+      InvenTreePart().get(context, pk).then((var part) {
+        Navigator.push(context,
+            MaterialPageRoute(builder: (context) => PartDetailWidget(part)));
+      });
+    } else {
+      // TODO - Show an error here!
+    }
+  } else {
+    showDialog(
+      context: context,
+      child: SimpleDialog(
+        title: Text("Unknown response"),
+        children: <Widget>[
+          ListTile(
+            title: Text("Response data"),
+            subtitle: Text(data.toString()),
+          )
+        ],
+      )
+    );
   }
 }

lib/inventree/company.dart

@@ -5,6 +5,10 @@ import 'model.dart';
  * The InvenTreeCompany class repreents the Company model in the InvenTree database.
  */
 class InvenTreeCompany extends InvenTreeModel {
+
+  @override
+  String NAME = "Company";
+
   @override
   String URL = "company/";
 

lib/inventree/model.dart

@@ -1,4 +1,8 @@
+import 'dart:async';
+
 import 'package:InvenTree/api.dart';
+import 'package:InvenTree/widget/dialogs.dart';
+import 'package:flutter/cupertino.dart';
 
 import 'dart:convert';
 
@@ -15,6 +19,8 @@ class InvenTreeModel {
   // Override the endpoint URL for each subclass
   String URL = "";
 
+  String NAME = "Model";
+
   // JSON data which defines this object
   Map<String, dynamic> jsondata = {};
 
@@ -83,9 +89,30 @@ class InvenTreeModel {
   /*
    * Reload this object, by requesting data from the server
    */
-  Future<bool> reload() async {
+  Future<bool> reload(BuildContext context) async {
 
-    var response = await api.get(url, params: defaultGetFilters());
+    showProgressDialog(context, "Refreshing data", "Refreshing data for ${NAME}");
+
+    var response = await api.get(url, params: defaultGetFilters())
+      .timeout(Duration(seconds: 10))
+      .catchError((e) {
+
+          hideProgressDialog(context);
+
+          if (e is TimeoutException) {
+            showErrorDialog(context, "Timeout", "No response from server");
+          } else {
+            showErrorDialog(context, "Error", e.toString());
+          }
+
+          return null;
+    });
+    
+    if (response == null) {
+      return false;
+    }
+    
+    hideProgressDialog(context);
 
     if (response.statusCode != 200) {
       print("Error retrieving data");
@@ -100,7 +127,7 @@ class InvenTreeModel {
   }
 
   // Return the detail view for the associated pk
-  Future<InvenTreeModel> get(int pk, {Map<String, String> filters}) async {
+  Future<InvenTreeModel> get(BuildContext context, int pk, {Map<String, String> filters}) async {
 
     // TODO - Add "timeout"
     // TODO - Add error catching
@@ -122,7 +149,27 @@ class InvenTreeModel {
 
     print("GET: $addr ${params.toString()}");
 
-    var response = await api.get(addr, params: params);
+    showProgressDialog(context, "Requesting Data", "Requesting ${NAME} data from server");
+
+    var response = await api.get(addr, params: params)
+        .timeout(Duration(seconds: 10))
+        .catchError((e) {
+
+          hideProgressDialog(context);
+
+          if (e is TimeoutException) {
+            showErrorDialog(context, "Timeout", "No response from server");
+          } else {
+            showErrorDialog(context, "Error", e.toString());
+          }
+          return null;
+      });
+
+    if (response == null) {
+      return null;
+    }
+
+    hideProgressDialog(context);
 
     if (response.statusCode != 200) {
       print("Error retrieving data");
@@ -135,7 +182,7 @@ class InvenTreeModel {
   }
 
   // Return list of objects from the database, with optional filters
-  Future<List<InvenTreeModel>> list({Map<String, String> filters}) async {
+  Future<List<InvenTreeModel>> list(BuildContext context, {Map<String, String> filters}) async {
 
     if (filters == null) {
       filters = {};
@@ -154,7 +201,28 @@ class InvenTreeModel {
     // TODO - Add "timeout"
     // TODO - Add error catching
 
-    var response = await api.get(URL, params:params);
+    showProgressDialog(context, "Requesting Data", "Requesting ${NAME} data from server");
+
+    var response = await api.get(URL, params:params)
+      .timeout(Duration(seconds: 10))
+      .catchError((e) {
+
+        hideProgressDialog(context);
+
+        if (e is TimeoutException) {
+          showErrorDialog(context, "Timeout", "No response from server");
+        } else {
+          showErrorDialog(context, "Error", e.toString());
+        }
+
+        return null;
+    });
+
+    if (response == null) {
+      return null;
+    }
+
+    hideProgressDialog(context);
 
     // A list of "InvenTreeModel" items
     List<InvenTreeModel> results = new List<InvenTreeModel>();

lib/inventree/part.dart

@@ -9,6 +9,10 @@ import 'package:path/path.dart' as path;
 import 'package:http/http.dart' as http;
 
 class InvenTreePartCategory extends InvenTreeModel {
+
+  @override
+  String NAME = "PartCategory";
+
   @override
   String URL = "part/category/";
 
@@ -61,6 +65,9 @@ class InvenTreePartCategory extends InvenTreeModel {
 
 class InvenTreePart extends InvenTreeModel {
 
+  @override
+  String NAME = "Part";
+
   @override
   String URL = "part/";
 

lib/inventree/stock.dart

@@ -6,6 +6,10 @@ import 'model.dart';
 import 'package:InvenTree/api.dart';
 
 class InvenTreeStockItem extends InvenTreeModel {
+
+  @override
+  String NAME = "StockItem";
+
   @override
   String URL = "stock/";
 
@@ -208,6 +212,10 @@ class InvenTreeStockItem extends InvenTreeModel {
 
 
 class InvenTreeStockLocation extends InvenTreeModel {
+
+  @override
+  String NAME = "StockLocation";
+
   @override
   String URL = "stock/location/";
 

lib/main.dart

@@ -22,6 +22,8 @@ import 'preferences.dart';
 
 import 'package:InvenTree/inventree/part.dart';
 
+
+
 void main() async {
 
   // await PrefService.init(prefix: "inventree_");
@@ -31,10 +33,10 @@ void main() async {
   // Load login details
   InvenTreePreferences().loadLoginDetails();
 
-  runApp(MyApp());
+  runApp(InvenTreeApp());
 }
 
-class MyApp extends StatelessWidget {
+class InvenTreeApp extends StatelessWidget {
   // This widget is the root of your application.
 
   @override
@@ -42,16 +44,8 @@ class MyApp extends StatelessWidget {
     return MaterialApp(
       title: 'InvenTree',
       theme: ThemeData(
-        // This is the theme of your application.
+        primarySwatch: Colors.lightBlue,
-        //
+        secondaryHeaderColor: Colors.blueGrey,
-        // Try running your application with "flutter run". You'll see the
-        // application has a blue toolbar. Then, without quitting the app, try
-        // changing the primarySwatch below to Colors.green and then invoke
-        // "hot reload" (press "r" in the console where you ran "flutter run",
-        // or simply save your changes to "hot reload" in a Flutter IDE).
-        // Notice that the counter didn't reset back to zero; the application
-        // is not restarted.
-        primarySwatch: Colors.lightGreen,
       ),
       home: MyHomePage(title: 'InvenTree'),
     );
@@ -59,34 +53,6 @@ class MyApp extends StatelessWidget {
 }
 
 
-class ProductList extends StatelessWidget {
-  final List<InvenTreePart> _parts;
-
-  ProductList(this._parts);
-
-  Widget _buildPart(BuildContext context, int index) {
-    InvenTreePart part;
-
-    if (index < _parts.length) {
-      part = _parts[index];
-    }
-
-    return Card(
-        child: Column(
-            children: <Widget>[
-              Text('${part.name} - ${part.description}'),
-            ]
-        )
-    );
-  }
-
-  @override
-  Widget build(BuildContext context) {
-    return ListView.builder(itemBuilder: _buildPart, itemCount: _parts.length);
-  }
-}
-
-
 class MyHomePage extends StatefulWidget {
   MyHomePage({Key key, this.title}) : super(key: key);
 
@@ -168,22 +134,6 @@ class _MyHomePageState extends State<MyHomePage> {
         onConnectFailure("Could not connect to server");
       }
 
-    }).catchError((e) {
-
-      String fault = "Connection error";
-
-      _serverConnection = false;
-      _serverStatusColor = Color.fromARGB(255, 250, 50, 50);
-
-      _serverStatus = "Error connecting to $_serverAddress";
-
-      if (e is TimeoutException) {
-        fault = "Timeout: No response from server";
-      } else {
-        fault = e.toString();
-      }
-
-      onConnectFailure(fault);
     });
 
     // Update widget state

lib/widget/category_display.dart

@@ -5,6 +5,7 @@ import 'package:InvenTree/preferences.dart';
 
 import 'package:InvenTree/widget/part_detail.dart';
 import 'package:InvenTree/widget/drawer.dart';
+import 'package:InvenTree/widget/refreshable_state.dart';
 
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/foundation.dart';
@@ -26,11 +27,12 @@ class CategoryDisplayWidget extends StatefulWidget {
 }
 
 
-class _CategoryDisplayState extends State<CategoryDisplayWidget> {
+class _CategoryDisplayState extends RefreshableState<CategoryDisplayWidget> {
 
-  _CategoryDisplayState(this.category) {
+  @override
-    _requestData();
+  String getAppBarTitle(BuildContext context) { return "Part Category"; }
-  }
+
+  _CategoryDisplayState(this.category) {}
 
   // The local InvenTreePartCategory object
   final InvenTreePartCategory category;
@@ -39,24 +41,18 @@ class _CategoryDisplayState extends State<CategoryDisplayWidget> {
 
   List<InvenTreePart> _parts = List<InvenTreePart>();
 
-  String get _titleString {
+  @override
-
+  Future<void> onBuild(BuildContext context) async {
-    if (category == null) {
+    refresh();
-      return "Part Categories";
-    } else {
-      return "Part Category - ${category.name}";
-    }
   }
 
-  /*
+  @override
-   * Request data from the server
+  Future<void> request(BuildContext context) async {
-   */
-  void _requestData() {
 
     int pk = category?.pk ?? -1;
 
     // Request a list of sub-categories under this one
-    InvenTreePartCategory().list(filters: {"parent": "$pk"}).then((var cats) {
+    InvenTreePartCategory().list(context, filters: {"parent": "$pk"}).then((var cats) {
       _subcategories.clear();
 
       for (var cat in cats) {
@@ -70,7 +66,7 @@ class _CategoryDisplayState extends State<CategoryDisplayWidget> {
     });
 
     // Request a list of parts under this category
-    InvenTreePart().list(filters: {"category": "$pk"}).then((var parts) {
+    InvenTreePart().list(context, filters: {"category": "$pk"}).then((var parts) {
       _parts.clear();
 
       for (var part in parts) {
@@ -112,7 +108,7 @@ class _CategoryDisplayState extends State<CategoryDisplayWidget> {
                   Navigator.push(context, MaterialPageRoute(builder: (context) => CategoryDisplayWidget(null)));
                 } else {
                   // TODO - Refactor this code into the InvenTreePart class
-                  InvenTreePartCategory().get(category.parentId).then((var cat) {
+                  InvenTreePartCategory().get(context, category.parentId).then((var cat) {
                     if (cat is InvenTreePartCategory) {
                       Navigator.push(context, MaterialPageRoute(builder: (context) => CategoryDisplayWidget(cat)));
                     }
@@ -127,74 +123,68 @@ class _CategoryDisplayState extends State<CategoryDisplayWidget> {
   }
 
   @override
-  Widget build(BuildContext context) {
+  Widget getBody(BuildContext context) {
-    return Scaffold(
+    return ListView(
-      appBar: AppBar(
+      children: <Widget>[
-        title: Text(_titleString),
+        getCategoryDescriptionCard(),
-      ),
+        ExpansionPanelList(
-      drawer: new InvenTreeDrawer(context),
+          expansionCallback: (int index, bool isExpanded) {
-      body: ListView(
+            setState(() {
-          children: <Widget>[
-            getCategoryDescriptionCard(),
-            ExpansionPanelList(
-              expansionCallback: (int index, bool isExpanded) {
-                setState(() {
 
-                  switch (index) {
+              switch (index) {
-                    case 0:
+                case 0:
-                      InvenTreePreferences().expandCategoryList = !isExpanded;
+                  InvenTreePreferences().expandCategoryList = !isExpanded;
-                      break;
+                  break;
-                    case 1:
+                case 1:
-                      InvenTreePreferences().expandPartList = !isExpanded;
+                  InvenTreePreferences().expandPartList = !isExpanded;
-                      break;
+                  break;
-                    default:
+                default:
-                      break;
+                  break;
-                  }
+              }
-                });
+            });
+          },
+          children: <ExpansionPanel> [
+            ExpansionPanel(
+              headerBuilder: (BuildContext context, bool isExpanded) {
+                return ListTile(
+                  title: Text("Subcategories"),
+                  leading: FaIcon(FontAwesomeIcons.stream),
+                  trailing: Text("${_subcategories.length}"),
+                  onTap: () {
+                    setState(() {
+                      InvenTreePreferences().expandCategoryList = !InvenTreePreferences().expandCategoryList;
+                    });
+                  },
+                  onLongPress: () {
+                    // TODO - Context menu for e.g. creating a new PartCategory
+                  },
+                );
               },
-              children: <ExpansionPanel> [
+              body: SubcategoryList(_subcategories),
-                ExpansionPanel(
+              isExpanded: InvenTreePreferences().expandCategoryList && _subcategories.length > 0,
-                  headerBuilder: (BuildContext context, bool isExpanded) {
-                    return ListTile(
-                      title: Text("Subcategories"),
-                      leading: FaIcon(FontAwesomeIcons.stream),
-                      trailing: Text("${_subcategories.length}"),
-                      onTap: () {
-                        setState(() {
-                          InvenTreePreferences().expandCategoryList = !InvenTreePreferences().expandCategoryList;
-                        });
-                      },
-                      onLongPress: () {
-                        // TODO - Context menu for e.g. creating a new PartCategory
-                      },
-                    );
-                  },
-                  body: SubcategoryList(_subcategories),
-                  isExpanded: InvenTreePreferences().expandCategoryList && _subcategories.length > 0,
-                ),
-                ExpansionPanel(
-                  headerBuilder: (BuildContext context, bool isExpanded) {
-                    return ListTile(
-                      title: Text("Parts"),
-                      leading: FaIcon(FontAwesomeIcons.shapes),
-                      trailing: Text("${_parts.length}"),
-                      onTap: () {
-                        setState(() {
-                          InvenTreePreferences().expandPartList = !InvenTreePreferences().expandPartList;
-                        });
-                      },
-                      onLongPress: () {
-                        // TODO - Context menu for e.g. creating a new Part
-                      },
-                    );
-                  },
-                  body: PartList(_parts),
-                  isExpanded: InvenTreePreferences().expandPartList && _parts.length > 0,
-                )
-              ],
             ),
-          ]
+            ExpansionPanel(
-        )
+              headerBuilder: (BuildContext context, bool isExpanded) {
+                return ListTile(
+                  title: Text("Parts"),
+                  leading: FaIcon(FontAwesomeIcons.shapes),
+                  trailing: Text("${_parts.length}"),
+                  onTap: () {
+                    setState(() {
+                      InvenTreePreferences().expandPartList = !InvenTreePreferences().expandPartList;
+                    });
+                  },
+                  onLongPress: () {
+                    // TODO - Context menu for e.g. creating a new Part
+                  },
+                );
+              },
+              body: PartList(_parts),
+              isExpanded: InvenTreePreferences().expandPartList && _parts.length > 0,
+            )
+          ],
+        ),
+      ]
     );
   }
 }
@@ -211,7 +201,7 @@ class SubcategoryList extends StatelessWidget {
   void _openCategory(BuildContext context, int pk) {
 
     // Attempt to load the sub-category.
-    InvenTreePartCategory().get(pk).then((var cat) {
+    InvenTreePartCategory().get(context, pk).then((var cat) {
       if (cat is InvenTreePartCategory) {
 
         Navigator.push(context, MaterialPageRoute(builder: (context) => CategoryDisplayWidget(cat)));
@@ -252,7 +242,7 @@ class PartList extends StatelessWidget {
 
   void _openPart(BuildContext context, int pk) {
     // Attempt to load the part information
-    InvenTreePart().get(pk).then((var part) {
+    InvenTreePart().get(context, pk).then((var part) {
       if (part is InvenTreePart) {
 
         Navigator.push(context, MaterialPageRoute(builder: (context) => PartDetailWidget(part)));

lib/widget/company_detail.dart

@@ -2,6 +2,7 @@
 import 'package:InvenTree/api.dart';
 import 'package:InvenTree/inventree/company.dart';
 import 'package:InvenTree/widget/drawer.dart';
+import 'package:InvenTree/widget/refreshable_state.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
@@ -18,10 +19,18 @@ class CompanyDetailWidget extends StatefulWidget {
 }
 
 
-class _CompanyDetailState extends State<CompanyDetailWidget> {
+class _CompanyDetailState extends RefreshableState<CompanyDetailWidget> {
 
   final InvenTreeCompany company;
 
+  @override
+  String getAppBarTitle(BuildContext context) { return "Company"; }
+
+  @override
+  Future<void> request(BuildContext context) async {
+    await company.reload(context);
+  }
+
   _CompanyDetailState(this.company) {
     // TODO
   }
@@ -122,17 +131,11 @@ class _CompanyDetailState extends State<CompanyDetailWidget> {
   }
 
   @override
-  Widget build(BuildContext context) {
+  Widget getBody(BuildContext context) {
 
-    return Scaffold(
+    return Center(
-      appBar: AppBar(
+      child: ListView(
-        title: Text("${company.name}"),
+        children: _companyTiles(),
-      ),
-      drawer: new InvenTreeDrawer(context),
-      body: Center(
-        child: ListView(
-          children: _companyTiles(),
-        )
       )
     );
   }

lib/widget/company_list.dart

@@ -6,6 +6,7 @@ import 'package:flutter/material.dart';
 import 'package:InvenTree/api.dart';
 import 'package:InvenTree/inventree/company.dart';
 import 'package:InvenTree/widget/drawer.dart';
+import 'package:InvenTree/widget/refreshable_state.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 
 abstract class CompanyListWidget extends StatefulWidget {
@@ -30,23 +31,30 @@ class CustomerListWidget extends CompanyListWidget {
 }
 
 
-class _CompanyListState extends State<CompanyListWidget> {
+class _CompanyListState extends RefreshableState<CompanyListWidget> {
 
   var _companies = new List<InvenTreeCompany>();
 
   var _filteredCompanies = new List<InvenTreeCompany>();
 
-  var _title = "Companies";
+  String _title = "Companies";
+
+  @override
+  String getAppBarTitle(BuildContext context) { return _title; }
 
   Map<String, String> _filters = Map<String, String>();
 
-  _CompanyListState(this._title, this._filters) {
+  _CompanyListState(this._title, this._filters) {}
-    _requestData();
+
+  @override
+  Future<void> onBuild(BuildContext context) async {
+    refresh();
   }
 
-  void _requestData() {
+  @override
+  Future<void> request(BuildContext context) async {
 
-    InvenTreeCompany().list(filters: _filters).then((var companies) {
+    InvenTreeCompany().list(context, filters: _filters).then((var companies) {
 
       _companies.clear();
 
@@ -85,7 +93,7 @@ class _CompanyListState extends State<CompanyListWidget> {
         ),
         onTap: () {
           if (company.pk > 0) {
-            InvenTreeCompany().get(company.pk).then((var c) {
+            InvenTreeCompany().get(context, company.pk).then((var c) {
               Navigator.push(context, MaterialPageRoute(builder: (context) => CompanyDetailWidget(c)));
             });
           }
@@ -94,38 +102,24 @@ class _CompanyListState extends State<CompanyListWidget> {
   }
 
   @override
-  Widget build(BuildContext context) {
+  Widget getBody(BuildContext context) {
-    return Scaffold(
+    return ListView(
-        appBar: AppBar(
+      children: <Widget>[
-          title: Text("$_title"),
+        TextField(
-          actions: <Widget>[
+          decoration: InputDecoration(
-            IconButton(
+          hintText: 'Filter results',
-              icon: FaIcon(FontAwesomeIcons.plus),
+          ),
-              tooltip: 'New',
+          onChanged: (String text) {
-              onPressed: null,
+            setState(() {
-            )
+              _filterResults(text);
-          ],
+            });
+          },
         ),
-        drawer: new InvenTreeDrawer(context),
+        ListView.builder(
-        body: ListView(
+          shrinkWrap: true,
-          children: <Widget>[
+            physics: ClampingScrollPhysics(),
-            TextField(
+            itemBuilder: _showCompany, itemCount: _filteredCompanies.length)
-              decoration: InputDecoration(
+      ],
-              hintText: 'Filter results',
-              ),
-              onChanged: (String text) {
-                setState(() {
-                  _filterResults(text);
-                });
-              },
-            ),
-            ListView.builder(
-              shrinkWrap: true,
-                physics: ClampingScrollPhysics(),
-                itemBuilder: _showCompany, itemCount: _filteredCompanies.length)
-          ],
-        )
     );
   }
-
 }

lib/widget/dialogs.dart

@@ -0,0 +1,41 @@
+
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:font_awesome_flutter/font_awesome_flutter.dart';
+
+void showErrorDialog(BuildContext context, String title, String description) {
+  showDialog(
+    context: context,
+    child: SimpleDialog(
+      title: ListTile(
+        title: Text("Error"),
+        leading: FaIcon(FontAwesomeIcons.exclamationCircle),
+      ),
+      children: <Widget>[
+        ListTile(
+          title: Text(title),
+          subtitle: Text(description)
+        )
+      ]
+    )
+  );
+}
+
+void showProgressDialog(BuildContext context, String title, String description) {
+
+  showDialog(
+    context: context,
+    barrierDismissible: false,
+    child: SimpleDialog(
+      title: Text(title),
+      children: <Widget>[
+        CircularProgressIndicator(),
+        Text(description),
+      ],
+    )
+  );
+}
+
+void hideProgressDialog(BuildContext context) {
+  Navigator.pop(context);
+}

lib/widget/location_display.dart

@@ -8,6 +8,8 @@ import 'package:flutter/material.dart';
 import 'package:flutter/foundation.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 
+import 'package:InvenTree/widget/refreshable_state.dart';
+
 class LocationDisplayWidget extends StatefulWidget {
 
   LocationDisplayWidget(this.location, {Key key}) : super(key: key);
@@ -20,15 +22,15 @@ class LocationDisplayWidget extends StatefulWidget {
   _LocationDisplayState createState() => _LocationDisplayState(location);
 }
 
-
+class _LocationDisplayState extends RefreshableState<LocationDisplayWidget> {
-class _LocationDisplayState extends State<LocationDisplayWidget> {
-
-  _LocationDisplayState(this.location) {
-    _requestData();
-  }
 
   final InvenTreeStockLocation location;
 
+  @override
+  String getAppBarTitle(BuildContext context) { return "Stock Location"; }
+
+  _LocationDisplayState(this.location) {}
+
   List<InvenTreeStockLocation> _sublocations = List<InvenTreeStockLocation>();
 
   String _locationFilter = '';
@@ -44,28 +46,18 @@ class _LocationDisplayState extends State<LocationDisplayWidget> {
 
   List<InvenTreeStockItem> _items = List<InvenTreeStockItem>();
 
-  String get _title {
+  @override
-
+  Future<void> onBuild(BuildContext context) async {
-    if (location == null) {
+    refresh();
-      return "Stock Locations";
-    } else {
-      return "Stock Location - ${location.name}";
-    }
   }
 
-  /*
+  @override
-   * Request data from the server.
+  Future<void> request(BuildContext context) async {
-   * It will be displayed once loaded
-   *
-   * - List of sublocations under this one
-   * - List of stock items at this location
-   */
-  void _requestData() {
 
     int pk = location?.pk ?? -1;
 
     // Request a list of sub-locations under this one
-    InvenTreeStockLocation().list(filters: {"parent": "$pk"}).then((var locs) {
+    InvenTreeStockLocation().list(context, filters: {"parent": "$pk"}).then((var locs) {
       _sublocations.clear();
 
       for (var loc in locs) {
@@ -76,18 +68,18 @@ class _LocationDisplayState extends State<LocationDisplayWidget> {
 
       setState(() {});
 
-    // Request a list of stock-items under this one
+      // Request a list of stock-items under this one
-    InvenTreeStockItem().list(filters: {"location": "$pk"}).then((var items) {
+      InvenTreeStockItem().list(context, filters: {"location": "$pk"}).then((var items) {
-      _items.clear();
+        _items.clear();
 
-      for (var item in items) {
+        for (var item in items) {
-        if (item is InvenTreeStockItem) {
+          if (item is InvenTreeStockItem) {
-          _items.add(item);
+            _items.add(item);
+          }
         }
-      }
 
-      setState(() {});
+        setState(() {});
-    });
+      });
 
     });
   }
@@ -119,7 +111,7 @@ class _LocationDisplayState extends State<LocationDisplayWidget> {
                 if (location.parentId < 0) {
                   Navigator.push(context, MaterialPageRoute(builder: (context) => LocationDisplayWidget(null)));
                 } else {
-                  InvenTreeStockLocation().get(location.parentId).then((var loc) {
+                  InvenTreeStockLocation().get(context, location.parentId).then((var loc) {
                     if (loc is InvenTreeStockLocation) {
                       Navigator.push(context, MaterialPageRoute(builder: (context) => LocationDisplayWidget(loc)));
                     }
@@ -134,68 +126,63 @@ class _LocationDisplayState extends State<LocationDisplayWidget> {
   }
 
   @override
-  Widget build(BuildContext context) {
+  Widget getBody(BuildContext context) {
-    return Scaffold(
-      appBar: AppBar(
-        title: Text(_title),
-      ),
-      drawer: new InvenTreeDrawer(context),
-      body: ListView(
-        children: <Widget> [
-          locationDescriptionCard(),
-          ExpansionPanelList(
-            expansionCallback: (int index, bool isExpanded) {
-              setState(() {
-                switch (index) {
-                  case 0:
-                    InvenTreePreferences().expandLocationList = !isExpanded;
-                    break;
-                  case 1:
-                    InvenTreePreferences().expandStockList = !isExpanded;
-                    break;
-                  default:
-                    break;
-                }
-              });
 
-            },
+    return ListView(
-            children: <ExpansionPanel> [
+      children: <Widget> [
-              ExpansionPanel(
+      locationDescriptionCard(),
-                headerBuilder: (BuildContext context, bool isExpanded) {
+      ExpansionPanelList(
-                  return ListTile(
+          expansionCallback: (int index, bool isExpanded) {
-                    title: Text("Sublocations"),
+            setState(() {
-                    leading: FaIcon(FontAwesomeIcons.mapMarkerAlt),
+              switch (index) {
-                    trailing: Text("${_sublocations.length}"),
+                case 0:
-                    onTap: () {
+                  InvenTreePreferences().expandLocationList = !isExpanded;
-                      setState(() {
+                  break;
-                        InvenTreePreferences().expandLocationList = !InvenTreePreferences().expandLocationList;
+                case 1:
-                      });
+                  InvenTreePreferences().expandStockList = !isExpanded;
-                    },
+                  break;
-                  );
+                default:
-                },
+                  break;
-                body: SublocationList(_sublocations),
+              }
-                isExpanded: InvenTreePreferences().expandLocationList && _sublocations.length > 0,
+            });
-              ),
+
-              ExpansionPanel(
+          },
-                headerBuilder: (BuildContext context, bool isExpanded) {
+          children: <ExpansionPanel> [
-                  return ListTile(
+            ExpansionPanel(
-                    title: Text("Stock Items"),
+              headerBuilder: (BuildContext context, bool isExpanded) {
-                    leading: FaIcon(FontAwesomeIcons.boxes),
+                return ListTile(
-                    trailing: Text("${_items.length}"),
+                  title: Text("Sublocations"),
-                    onTap: () {
+                  leading: FaIcon(FontAwesomeIcons.mapMarkerAlt),
-                      setState(() {
+                  trailing: Text("${_sublocations.length}"),
-                        InvenTreePreferences().expandStockList = !InvenTreePreferences().expandStockList;
+                  onTap: () {
-                      });
+                    setState(() {
-                    },
+                      InvenTreePreferences().expandLocationList = !InvenTreePreferences().expandLocationList;
-                  );
+                    });
-                },
+                  },
-                body: StockList(_items),
+                );
-                isExpanded: InvenTreePreferences().expandStockList && _items.length > 0,
+              },
-              )
+              body: SublocationList(_sublocations),
-            ]
+              isExpanded: InvenTreePreferences().expandLocationList && _sublocations.length > 0,
-          ),
+            ),
-        ]
+            ExpansionPanel(
-      )
+              headerBuilder: (BuildContext context, bool isExpanded) {
+                return ListTile(
+                  title: Text("Stock Items"),
+                  leading: FaIcon(FontAwesomeIcons.boxes),
+                  trailing: Text("${_items.length}"),
+                  onTap: () {
+                    setState(() {
+                      InvenTreePreferences().expandStockList = !InvenTreePreferences().expandStockList;
+                    });
+                  },
+                );
+              },
+              body: StockList(_items),
+              isExpanded: InvenTreePreferences().expandStockList && _items.length > 0,
+            )
+          ]
+      ),
+    ]
     );
   }
 }
@@ -208,7 +195,7 @@ class SublocationList extends StatelessWidget {
 
   void _openLocation(BuildContext context, int pk) {
 
-    InvenTreeStockLocation().get(pk).then((var loc) {
+    InvenTreeStockLocation().get(context, pk).then((var loc) {
       if (loc is InvenTreeStockLocation) {
 
         Navigator.push(context, MaterialPageRoute(builder: (context) => LocationDisplayWidget(loc)));
@@ -244,7 +231,7 @@ class StockList extends StatelessWidget {
   StockList(this._items);
 
   void _openItem(BuildContext context, int pk) {
-    InvenTreeStockItem().get(pk).then((var item) {
+    InvenTreeStockItem().get(context, pk).then((var item) {
       if (item is InvenTreeStockItem) {
         Navigator.push(context, MaterialPageRoute(builder: (context) => StockDetailWidget(item)));
       }

lib/widget/part_detail.dart

@@ -6,6 +6,7 @@ import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 
 import 'package:InvenTree/api.dart';
+import 'package:InvenTree/widget/refreshable_state.dart';
 import 'package:InvenTree/widget/drawer.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 
@@ -21,7 +22,10 @@ class PartDetailWidget extends StatefulWidget {
 }
 
 
-class _PartDisplayState extends State<PartDetailWidget> {
+class _PartDisplayState extends RefreshableState<PartDetailWidget> {
+
+  @override
+  String getAppBarTitle(BuildContext context) { return "Part"; }
 
   _PartDisplayState(this.part) {
     // TODO
@@ -29,6 +33,11 @@ class _PartDisplayState extends State<PartDetailWidget> {
 
   InvenTreePart part;
 
+  @override
+  Future<void> request(BuildContext context) async {
+    await part.reload(context);
+  }
+
   /*
    * Build a list of tiles to display under the part description
    */
@@ -62,7 +71,7 @@ class _PartDisplayState extends State<PartDetailWidget> {
             leading: FaIcon(FontAwesomeIcons.stream),
             onTap: () {
               if (part.categoryId > 0) {
-                InvenTreePartCategory().get(part.categoryId).then((var cat) {
+                InvenTreePartCategory().get(context, part.categoryId).then((var cat) {
                   Navigator.push(context, MaterialPageRoute(
                       builder: (context) => CategoryDisplayWidget(cat)));
                 });
@@ -154,22 +163,11 @@ class _PartDisplayState extends State<PartDetailWidget> {
   }
 
   @override
-  Widget build(BuildContext context) {
+  Widget getBody(BuildContext context) {
-    return Scaffold(
+    return Center(
-      appBar: AppBar(
+      child: ListView(
-        title: Text("Part Details"),
+        children: partTiles(),
       ),
-      drawer: new InvenTreeDrawer(context),
-      floatingActionButton: FloatingActionButton(
-        child: FaIcon(FontAwesomeIcons.ellipsisH),
-        // TODO - Add pop-up icons
-        // Ref: https://stackoverflow.com/questions/46480221/flutter-floating-action-button-with-speed-dial#46480722
-      ),
-      body: Center(
-        child: ListView(
-          children: partTiles(),
-        ),
-      )
     );
   }
 }

lib/widget/refreshable_state.dart

@@ -0,0 +1,66 @@
+import 'package:InvenTree/widget/drawer.dart';
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/widgets.dart';
+
+import 'package:InvenTree/widget/drawer.dart';
+
+
+abstract class RefreshableState<T extends StatefulWidget> extends State<T> {
+
+  // Storage for context once "Build" is called
+  BuildContext context;
+
+  String getAppBarTitle(BuildContext context) { return "App Bar Title"; }
+
+  void initState() {
+    super.initState();
+    WidgetsBinding.instance.addPostFrameCallback((_) => onBuild(context));
+  }
+
+  // Function called after the widget is first build
+  Future<void> onBuild(BuildContext context) async {
+    return;
+  }
+
+  // Function to request data for this page
+  Future<void> request(BuildContext context) async {
+    return;
+  }
+
+  Future<void> refresh() async {
+    await request(context);
+    setState(() {});
+  }
+
+  // Function to construct an appbar (override if needed)
+  AppBar getAppBar(BuildContext context) {
+    return AppBar(
+      title: Text(getAppBarTitle(context))
+    );
+  }
+
+  // Function to construct a drawer (override if needed)
+  Widget getDrawer(BuildContext context) {
+    return InvenTreeDrawer(context);
+  }
+
+  // Function to construct a body (MUST BE PROVIDED)
+  Widget getBody(BuildContext context);
+
+  @override
+  Widget build(BuildContext context) {
+
+    // Save the context for future use
+    this.context = context;
+
+    return Scaffold(
+      appBar: getAppBar(context),
+      drawer: getDrawer(context),
+      body: RefreshIndicator(
+        onRefresh: refresh,
+        child: getBody(context)
+      )
+    );
+  }
+}

lib/widget/stock_detail.dart

@@ -4,12 +4,15 @@ import 'package:InvenTree/inventree/stock.dart';
 import 'package:InvenTree/inventree/part.dart';
 import 'package:InvenTree/widget/location_display.dart';
 import 'package:InvenTree/widget/part_detail.dart';
+import 'package:InvenTree/widget/refreshable_state.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 
 import 'package:InvenTree/api.dart';
 
 import 'package:InvenTree/widget/drawer.dart';
+import 'package:InvenTree/widget/refreshable_state.dart';
+
 import 'package:flutter/services.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
 import 'package:flutter_speed_dial/flutter_speed_dial.dart';
@@ -25,7 +28,10 @@ class StockDetailWidget extends StatefulWidget {
 }
 
 
-class _StockItemDisplayState extends State<StockDetailWidget> {
+class _StockItemDisplayState extends RefreshableState<StockDetailWidget> {
+
+  @override
+  String getAppBarTitle(BuildContext context) { return "Stock Item"; }
 
   final TextEditingController _quantityController = TextEditingController();
   final TextEditingController _notesController = TextEditingController();
@@ -42,13 +48,9 @@ class _StockItemDisplayState extends State<StockDetailWidget> {
 
   final InvenTreeStockItem item;
 
-  /**
+  @override
-   * Function to reload the page data
+  Future<void> request(BuildContext context) async {
-   */
+    await item.reload(context);
-  Future<void> _refresh() async {
-
-    await item.reload();
-    setState(() {});
   }
 
   void _editStockItem() {
@@ -92,7 +94,7 @@ class _StockItemDisplayState extends State<StockDetailWidget> {
     _notesController.clear();
 
     // TODO - Handle error cases
-    _refresh();
+    refresh();
   }
 
   void _addStockDialog() async {
@@ -158,7 +160,7 @@ class _StockItemDisplayState extends State<StockDetailWidget> {
 
     // TODO - Handle error cases
 
-    _refresh();
+    refresh();
   }
 
   void _removeStockDialog() {
@@ -227,7 +229,7 @@ class _StockItemDisplayState extends State<StockDetailWidget> {
 
     // TODO - Handle error cases
 
-    _refresh();
+    refresh();
   }
 
   void _countStockDialog() async {
@@ -322,7 +324,7 @@ class _StockItemDisplayState extends State<StockDetailWidget> {
         leading: FaIcon(FontAwesomeIcons.shapes),
         onTap: () {
           if (item.partId > 0) {
-            InvenTreePart().get(item.partId).then((var part) {
+            InvenTreePart().get(context, item.partId).then((var part) {
               if (part is InvenTreePart) {
                 Navigator.push(context, MaterialPageRoute(builder: (context) => PartDetailWidget(part)));
               }
@@ -362,7 +364,7 @@ class _StockItemDisplayState extends State<StockDetailWidget> {
           leading: FaIcon(FontAwesomeIcons.mapMarkerAlt),
           onTap: () {
             if (item.locationId > 0) {
-              InvenTreeStockLocation().get(item.locationId).then((var loc) {
+              InvenTreeStockLocation().get(context, item.locationId).then((var loc) {
                 Navigator.push(context, MaterialPageRoute(
                   builder: (context) => LocationDisplayWidget(loc)));
               });
@@ -464,26 +466,30 @@ class _StockItemDisplayState extends State<StockDetailWidget> {
     return buttons;
   }
 
+  @override
+  Widget getBody(BuildContext context) {
+    return ListView(
+      children: stockTiles()
+    );
+  }
+
   @override
   Widget build(BuildContext context) {
+
+    this.context = context;
+
     return Scaffold(
-      appBar: AppBar(
+      appBar: getAppBar(context),
-        title: Text("Stock Item"),
+      drawer: getDrawer(context),
-      ),
-      drawer: new InvenTreeDrawer(context),
       floatingActionButton: SpeedDial(
         visible: true,
         animatedIcon: AnimatedIcons.menu_close,
         heroTag: 'stock-item-fab',
         children: actionButtons(),
       ),
-      body: Center(
+      body: RefreshIndicator(
-        child: new RefreshIndicator(
+        onRefresh: refresh,
-          onRefresh: _refresh,
+        child: getBody(context)
-          child: ListView(
-            children: stockTiles(),
-          )
-        )
       )
     );
   }