PO Contact (#305)

* Bug fix in API forms

- Allow form fields to specify custom filters at runtime

* Add "contact" model to purchase order edit form

* Add action to create new purchase order from list widget

* widget updates for purchase order

lib/widget/purchase_order_detail.dart

@@ -83,11 +83,19 @@ class _PurchaseOrderDetailState extends RefreshableState<PurchaseOrderDetailWidg
     );
   }
 
+  // Edit the currently displayed PurchaseOrder
   Future <void> editOrder(BuildContext context) async {
+    var fields = order.formFields();
+    fields.remove("supplier");
+
+    if (!api.supportsContactModel) {
+      fields.remove("contact");
+    }
 
     order.editForm(
       context,
       L10().purchaseOrderEdit,
+      fields: fields,
       onSuccess: (data) async {
         refresh(context);
         showSnackIcon(L10().purchaseOrderUpdated, success: true);
@@ -143,8 +151,8 @@ class _PurchaseOrderDetailState extends RefreshableState<PurchaseOrderDetailWidg
 
     tiles.add(ListTile(
       title: Text(L10().lineItems),
-      leading: FaIcon(FontAwesomeIcons.clipboardList, color: COLOR_CLICK),
-      trailing: Text("${order.lineItemCount}"),
+      leading: FaIcon(FontAwesomeIcons.clipboardCheck),
+      trailing: Text("${completedLines} /  ${order.lineItemCount}"),
     ));
 
     tiles.add(ListTile(
@@ -155,12 +163,6 @@ class _PurchaseOrderDetailState extends RefreshableState<PurchaseOrderDetailWidg
       ),
     ));
 
-    tiles.add(ListTile(
-      title: Text(L10().received),
-      leading: FaIcon(FontAwesomeIcons.clipboardCheck, color: COLOR_CLICK),
-      trailing: Text("${completedLines}"),
-    ));
-
     if (order.issueDate.isNotEmpty) {
       tiles.add(ListTile(
         title: Text(L10().issueDate),
@@ -312,8 +314,6 @@ class _PurchaseOrderDetailState extends RefreshableState<PurchaseOrderDetailWidg
 
     List<Widget> tiles = [];
 
-    tiles.add(headerTile(context));
-
     for (var line in lines) {
 
       InvenTreeSupplierPart? supplierPart = line.supplierPart;
@@ -347,9 +347,6 @@ class _PurchaseOrderDetailState extends RefreshableState<PurchaseOrderDetailWidg
               ),
             ),
             onTap: () {
-              // TODO: ?
-            },
-            onLongPress: () {
               lineItemMenu(context, line);
             },
           )