Can update a conversation message

lib/utils/ui_utils.dart

@@ -1,7 +1,10 @@
 import 'package:cached_network_image/cached_network_image.dart';
+import 'package:comunic/utils/intl_utils.dart';
 import 'package:flutter/material.dart';
 
 /// User interface utilities
+///
+/// @author Pierre HUBERT
 
 /// Build centered progress bar
 Widget buildCenteredProgressBar() {
@@ -52,17 +55,66 @@ Widget buildErrorCard(String message, {List<Widget> actions}) {
 /// Show an image with a given [url] in full screen
 void showImageFullScreen(BuildContext context, String url) {
   Navigator.of(context).push(MaterialPageRoute(builder: (c) {
-
     // TODO : add better support later
     return CachedNetworkImage(
       imageUrl: url,
     );
-
   }));
 }
 
-
 /// Show simple snack
 void showSimpleSnack(BuildContext context, String message) {
   Scaffold.of(context).showSnackBar(SnackBar(content: Text(message)));
-}
+}
+
+/// Show an alert dialog to ask the user to enter a string
+Future<String> askUserString({
+  @required BuildContext context,
+  @required String title,
+  @required String message,
+  @required String defaultValue,
+  @required String hint,
+}) async {
+  assert(context != null);
+  assert(title != null);
+  assert(message != null);
+  assert(defaultValue != null);
+  assert(hint != null);
+
+  TextEditingController controller = TextEditingController(text: defaultValue);
+
+  final confirm = await showDialog<bool>(
+      context: context,
+      builder: (c) => AlertDialog(
+            title: Text(title),
+            content: Column(
+              children: <Widget>[
+                Text(message),
+                TextField(
+                  controller: controller,
+                  maxLines: null,
+                  maxLength: 200,
+                  keyboardType: TextInputType.text,
+                  decoration: InputDecoration(
+                    labelText: hint,
+                    alignLabelWithHint: true,
+                  ),
+                )
+              ],
+            ),
+            actions: <Widget>[
+              FlatButton(
+                child: Text(tr("Cancel").toUpperCase()),
+                onPressed: () => Navigator.pop(c, false),
+              ),
+              FlatButton(
+                child: Text(tr("OK")),
+                onPressed: () => Navigator.pop(c, true),
+              ),
+            ],
+          ));
+
+  if (confirm == null || !confirm) return null;
+
+  return controller.text;
+}