Create pick user dialog

lib/ui/widgets/dialogs/cancel_dialog_button.dart

@@ -0,0 +1,17 @@
+import 'package:comunic/utils/intl_utils.dart';
+import 'package:flutter/material.dart';
+
+/// Render a cancel button for an alert dialog
+///
+/// @author Pierre HUBERT
+
+class CancelDialogButton extends StatelessWidget {
+  @override
+  Widget build(BuildContext context) {
+    return MaterialButton(
+      onPressed: () => Navigator.of(context).pop(),
+      child: Text(tr("Cancel").toUpperCase()),
+      textColor: Colors.red,
+    );
+  }
+}

lib/ui/widgets/dialogs/confirm_dialog_button.dart

@@ -0,0 +1,27 @@
+import 'package:comunic/utils/intl_utils.dart';
+import 'package:flutter/material.dart';
+
+/// Confirm dialog button
+///
+/// @author Pierre HUBERT
+
+class ConfirmDialogButton<T> extends StatelessWidget {
+  final bool enabled;
+  final T value;
+
+  const ConfirmDialogButton({
+    Key key,
+    this.enabled = true,
+    @required this.value,
+  })  : assert(enabled != null),
+        super(key: key);
+
+  @override
+  Widget build(BuildContext context) {
+    return MaterialButton(
+      onPressed: enabled ? () => Navigator.of(context).pop(value) : null,
+      child: Text(tr("Confirm").toUpperCase()),
+      textColor: Colors.green,
+    );
+  }
+}