Add search delegate for stock items

lib/widget/category_display.dart

@@ -41,20 +41,20 @@ class _CategoryDisplayState extends RefreshableState<CategoryDisplayWidget> {
   @override
   List<Widget> getAppBarActions(BuildContext context) {
     return <Widget>[
+      IconButton(
+          icon: FaIcon(FontAwesomeIcons.search),
+          onPressed: () {
+            showSearch(
+                context: context,
+                delegate: PartSearchDelegate(filters: {"category": "${category.pk}"})
+            );
+          }
+      ),
       IconButton(
         icon: FaIcon(FontAwesomeIcons.edit),
         tooltip: I18N.of(context).edit,
         onPressed: _editCategoryDialog,
       ),
-      IconButton(
-        icon: FaIcon(FontAwesomeIcons.search),
-        onPressed: () {
-          showSearch(
-              context: context,
-              delegate: PartSearchDelegate(filters: {"category": "${category.pk}"})
-          );
-        }
-      )
     ];
   }
 

lib/widget/location_display.dart

@@ -6,6 +6,7 @@ import 'package:InvenTree/widget/progress.dart';
 import 'package:InvenTree/widget/refreshable_state.dart';
 import 'package:InvenTree/widget/fields.dart';
 import 'package:InvenTree/widget/dialogs.dart';
+import 'package:InvenTree/widget/search.dart';
 import 'package:InvenTree/widget/snacks.dart';
 import 'package:InvenTree/widget/stock_detail.dart';
 
@@ -39,6 +40,15 @@ class _LocationDisplayState extends RefreshableState<LocationDisplayWidget> {
   @override
   List<Widget> getAppBarActions(BuildContext context) {
     return <Widget>[
+      IconButton(
+        icon: FaIcon(FontAwesomeIcons.search),
+        onPressed: () {
+          showSearch(
+            context: context,
+            delegate: StockSearchDelegate(filters: {"location": "${location.pk}"})
+          );
+        }
+      ),
       IconButton(
         icon: FaIcon(FontAwesomeIcons.edit),
         tooltip: I18N.of(context).edit,

lib/widget/search.dart

@@ -2,6 +2,7 @@
 import 'package:InvenTree/widget/part_detail.dart';
 import 'package:InvenTree/widget/progress.dart';
 import 'package:InvenTree/widget/snacks.dart';
+import 'package:InvenTree/widget/stock_detail.dart';
 import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:font_awesome_flutter/font_awesome_flutter.dart';
@@ -12,6 +13,7 @@ import 'package:InvenTree/inventree/stock.dart';
 
 import '../api.dart';
 
+// TODO - Refactor duplicate code in this file!
 
 class PartSearchDelegate extends SearchDelegate<InvenTreePart> {
 
@@ -127,12 +129,16 @@ class PartSearchDelegate extends SearchDelegate<InvenTreePart> {
   @override
   Widget buildResults(BuildContext context) {
 
-    print("Build results called...");
-
     if (_searching) {
       return progressIndicator();
     }
 
+    if (query.length == 0) {
+      return ListTile(
+        title: Text("Enter search query")
+      );
+    }
+
     if (query.length < 3) {
       return ListTile(
         title: Text("Query too short"),
@@ -162,6 +168,167 @@ class PartSearchDelegate extends SearchDelegate<InvenTreePart> {
     return Column();
   }
 
+  // Ensure the search theme matches the app theme
+  @override
+  ThemeData appBarTheme(BuildContext context) {
+    assert(context != null);
+    final ThemeData theme = Theme.of(context);
+    assert(theme != null);
+    return theme;
+  }
+}
+
+
+class StockSearchDelegate extends SearchDelegate<InvenTreeStockItem> {
+
+  final key = GlobalKey<ScaffoldState>();
+
+  bool _searching = false;
+
+  // Custom filters for the stock item search
+  Map<String, String> filters;
+
+  StockSearchDelegate({this.filters}) {
+    if (filters == null) {
+      filters = {};
+    }
+  }
+
+  // List of StockItem results
+  List<InvenTreeStockItem> itemResults = [];
+
+  Future<void> search(BuildContext context) async {
+    // Search string too short!
+    if (query.length < 3) {
+      itemResults.clear();
+      showResults(context);
+      return;
+    }
+
+    _searching = true;
+
+    print("Searching...");
+
+    showResults(context);
+
+    // Enable cascading part search by default
+    filters["cascade"] = "true";
+
+    final results = await InvenTreeStockItem().search(
+        context, query, filters: filters);
+
+    itemResults.clear();
+
+    for (int idx = 0; idx < results.length; idx++) {
+      if (results[idx] is InvenTreeStockItem) {
+        itemResults.add(results[idx]);
+      }
+    }
+
+    _searching = false;
+
+    // TODO - Show a snackbar icon with number of results.
+    showSuggestions(context);
+    showResults(context);
+  }
+
+  @override
+  List<Widget> buildActions(BuildContext context) {
+    return [
+      IconButton(
+        icon: FaIcon(FontAwesomeIcons.backspace),
+        onPressed: () {
+          query = '';
+          search(context);
+        },
+      ),
+      IconButton(
+          icon: FaIcon(FontAwesomeIcons.search),
+          onPressed: () {
+            search(context);
+          }
+      ),
+    ];
+  }
+
+  @override
+  Widget buildLeading(BuildContext context) {
+    return IconButton(
+        icon: Icon(Icons.arrow_back),
+        onPressed: () {
+          this.close(context, null);
+        }
+    );
+  }
+
+  Widget _itemResult(BuildContext context, int index) {
+
+    InvenTreeStockItem item = itemResults[index];
+
+    return ListTile(
+      title: Text(item.partName),
+      subtitle: Text(item.partDescription),
+      leading: InvenTreeAPI().getImage(
+        item.partThumbnail,
+        width: 40,
+        height: 40,
+      ),
+      trailing: Text(item.serialOrQuantityDisplay()),
+      onTap: () {
+        InvenTreeStockItem().get(context, item.pk).then((var it) {
+          if (it is InvenTreeStockItem) {
+            Navigator.push(
+              context,
+              MaterialPageRoute(builder: (context) => StockDetailWidget(it))
+            );
+          }
+        });
+      }
+    );
+  }
+
+  @override
+  Widget buildResults(BuildContext context) {
+
+    if (_searching) {
+      return progressIndicator();
+    }
+
+    if (query.length == 0) {
+      return ListTile(
+          title: Text("Enter search query")
+      );
+    }
+
+    if (query.length < 3) {
+      return ListTile(
+          title: Text("Query too short"),
+          subtitle: Text("Enter a query of at least three characters")
+      );
+    }
+
+    if (itemResults.length == 0) {
+      return ListTile(
+          title: Text("No Results"),
+          subtitle: Text("No results matching query")
+      );
+    }
+
+    return ListView.separated(
+      shrinkWrap: true,
+      physics: ClampingScrollPhysics(),
+      separatorBuilder: (_, __) => const Divider(height: 3),
+      itemBuilder: _itemResult,
+      itemCount: itemResults.length,
+    );
+  }
+
+  @override
+  Widget buildSuggestions(BuildContext context) {
+    // TODO - Implement
+    return Column();
+  }
+
   // Ensure the search theme matches the app theme
   @override
   ThemeData appBarTheme(BuildContext context) {