add PickDelegate

thermion_flutter/thermion_flutter/lib/thermion/widgets/camera/gestures/v2/default_pick_delegate.dart

@@ -0,0 +1,15 @@
+import 'dart:ui';
+
+import 'package:thermion_dart/thermion_dart/thermion_viewer.dart';
+import 'package:thermion_flutter/thermion/widgets/camera/gestures/v2/delegates.dart';
+
+class DefaultPickDelegate extends PickDelegate {
+  final ThermionViewer _viewer;
+
+  const DefaultPickDelegate(this._viewer);
+
+  @override
+  void pick(Offset location) {
+    _viewer.pick(location.dx.toInt(), location.dy.toInt());
+  }
+}

thermion_flutter/thermion_flutter/lib/thermion/widgets/camera/gestures/v2/delegates.dart

@@ -23,3 +23,8 @@ abstract class VelocityDelegate {
     stopDeceleration();
   }
 }
+
+abstract class PickDelegate {
+  const PickDelegate();
+  void pick(Offset location);
+}