Part detail view is now refreshabel

- lso add a progress dialog when reloading a model object

lib/inventree/model.dart

@@ -89,9 +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");

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 app_bar_title = "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
    */
@@ -154,22 +163,11 @@ class _PartDisplayState extends State<PartDetailWidget> {
   }
 
   @override
-  Widget build(BuildContext context) {
-    return Scaffold(
-      appBar: AppBar(
-        title: Text("Part Details"),
-      ),
-      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(
+  Widget getBody(BuildContext context) {
+    return Center(
       child: ListView(
         children: partTiles(),
       ),
-      )
     );
   }
 }

lib/widget/stock_detail.dart

@@ -50,7 +50,7 @@ class _StockItemDisplayState extends RefreshableState<StockDetailWidget> {
 
   @override
   Future<void> request(BuildContext context) async {
-    await item.reload();
+    await item.reload(context);
   }
 
   void _editStockItem() {