Do not show too many comments at the same time

lib/ui/tiles/post_tile.dart

@@ -1,4 +1,5 @@
 import 'dart:io';
+import 'dart:math';
 
 import 'package:comunic/enums/post_kind.dart';
 import 'package:comunic/enums/post_visibility_level.dart';
@@ -76,6 +77,7 @@ class _PostTileState extends State<PostTile> {
   TextEditingController _commentController = TextEditingController();
   File _commentImage;
   bool _submitting = false;
+  int _maxNumberOfCommentToShow = 10;
 
   User get _user => widget.usersInfo.getUser(widget.post.userID);
 
@@ -344,13 +346,18 @@ class _PostTileState extends State<PostTile> {
     assert(widget.post.hasComments);
 
     final comments = List<Widget>.generate(
-      widget.post.comments.length,
-      (num) => CommentTile(
-        comment: widget.post.comments[num],
-        user: widget.usersInfo.getUser(widget.post.comments[num].userID),
-        onUpdateComment: _updateCommentContent,
-        onDeleteComment: _deleteComment,
-      ),
+      min(widget.post.comments.length, _maxNumberOfCommentToShow),
+      (num) {
+        final index = num +
+            max(0, widget.post.comments.length - _maxNumberOfCommentToShow);
+        final comment = widget.post.comments[index];
+        return CommentTile(
+          comment: comment,
+          user: widget.usersInfo.getUser(comment.userID),
+          onUpdateComment: _updateCommentContent,
+          onDeleteComment: _deleteComment,
+        );
+      },
     );
 
     // Add comments form
@@ -361,12 +368,23 @@ class _PostTileState extends State<PostTile> {
       child: Padding(
         padding: const EdgeInsets.only(top: 8.0, bottom: 8.0),
         child: Column(
-          children: comments,
+          children: (widget.post.comments.length > _maxNumberOfCommentToShow
+              ? [_buildShowMoreCommentsButton()]
+              : [])
+            ..addAll(comments),
         ),
       ),
     );
   }
 
+  Widget _buildShowMoreCommentsButton() => InkWell(
+        onTap: () => setState(() => _maxNumberOfCommentToShow += 10),
+        child: Padding(
+          padding: const EdgeInsets.all(8.0),
+          child: Text(tr("Show more comments")),
+        ),
+      );
+
   /// Build comments form
   Widget _buildCommentsForm() {
     return Padding(