Add counter on comment form

lib/ui/screens/conversation_screen.dart

@@ -325,15 +325,8 @@ class _ConversationScreenState extends State<ConversationScreen> {
               maxLengthEnforced: true,
 
               // Show max length only when there is some text already typed
-              buildCounter: (
-                BuildContext context, {
-                @required int currentLength,
-                @required int maxLength,
-                @required bool isFocused,
-              }) =>
-                  currentLength > 0
-                      ? Text("$currentLength/$maxLength")
-                      : Container(),
+              buildCounter: smartInputCounterWidgetBuilder,
+
               enabled: !_isSendingMessage,
               controller: _textEditingController,
               onChanged: _updatedText,

lib/ui/tiles/post_tile.dart

@@ -250,6 +250,11 @@ class _PostTileState extends State<PostTile> {
           // Comment input
           Expanded(
             child: TextField(
+              // Comment max size
+              maxLength: 255,
+              maxLines: null,
+              buildCounter: smartInputCounterWidgetBuilder,
+
               controller: _commentController,
               onChanged: (s) => setState(() {}),
               onSubmitted: _canSubmitComment ? (s) => _submitComment() : null,
@@ -270,7 +275,8 @@ class _PostTileState extends State<PostTile> {
                   right: 10,
                   bottom: 5,
                   top: 5,
-                  )),
+                ),
+              ),
             ),
           ),
 

lib/utils/ui_utils.dart

@@ -153,3 +153,13 @@ Future<bool> showConfirmDialog({
 
   return result != null && result;
 }
+
+/// Smart [InputCounterWidgetBuilder] that show text limit only when some
+/// text has already been entered by the user
+Widget smartInputCounterWidgetBuilder(
+  BuildContext context, {
+  @required int currentLength,
+  @required int maxLength,
+  @required bool isFocused,
+}) =>
+    currentLength > 0 ? Text("$currentLength/$maxLength") : Container();