Create post container

lib/ui/widgets/post_container_widget.dart

@@ -0,0 +1,24 @@
+import 'package:flutter/material.dart';
+
+/// Here is a widget used to contain a post
+///
+/// @author Pierre Hubert
+
+class PostContainer extends StatelessWidget {
+  final Widget child;
+
+  const PostContainer({Key key, @required this.child})
+      : assert(child != null),
+        super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return Align(
+      alignment: Alignment.center,
+      child: ConstrainedBox(
+        constraints: BoxConstraints.loose(Size.fromWidth(500)),
+        child: child,
+      ),
+    );
+  }
+}