Add snackbar with icon

- stock adjust
- part edit
- location edit

lib/widget/snacks.dart

@@ -0,0 +1,33 @@
+
+/*
+ * Display a snackbar with:
+ *
+ * a) Text on the left
+ * b) Icon on the right
+ *
+ * | Text          <icon> |
+ */
+
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:font_awesome_flutter/font_awesome_flutter.dart';
+
+void showSnackIcon(GlobalKey<ScaffoldState> key, String text, {IconData icon, bool success}) {
+
+  // If icon not specified, use the success status
+  if (icon == null) {
+    icon = (success == true) ? FontAwesomeIcons.checkCircle : FontAwesomeIcons.timesCircle;
+  }
+
+  key.currentState.showSnackBar(
+    SnackBar(
+      content: Row(
+        children: [
+          Text(text),
+          Spacer(),
+          FaIcon(icon)
+        ]
+      ),
+    )
+  );
+}