move gesture detector

lib/src/message_input.dart

@@ -657,17 +657,6 @@ class MessageInputState extends State<MessageInput> {
               ),
             ],
           ),
-          Container(
-            decoration: BoxDecoration(
-              color: Colors.white,
-              borderRadius: BorderRadius.only(
-                topLeft: Radius.circular(16.0),
-                topRight: Radius.circular(16.0),
-              ),
-            ),
-            child: Row(
-              mainAxisAlignment: MainAxisAlignment.center,
-              children: [
           GestureDetector(
             onVerticalDragUpdate: (update) {
               setState(() {
@@ -679,6 +668,17 @@ class MessageInputState extends State<MessageInput> {
                 }
               });
             },
+            child: Container(
+              decoration: BoxDecoration(
+                color: Colors.white,
+                borderRadius: BorderRadius.only(
+                  topLeft: Radius.circular(16.0),
+                  topRight: Radius.circular(16.0),
+                ),
+              ),
+              child: Container(
+                width: double.infinity,
+                child: Center(
                   child: Padding(
                     padding: const EdgeInsets.all(8.0),
                     child: Container(
@@ -691,7 +691,7 @@ class MessageInputState extends State<MessageInput> {
                     ),
                   ),
                 ),
-              ],
+              ),
             ),
           ),
           Expanded(