session_shells/ermine/utils/lib/src/view_handle.dart

// Copyright 2021 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import 'dart:async';

import 'package:fidl_fuchsia_ui_views/fidl_async.dart';
import 'package:fuchsia_logger/logger.dart';
import 'package:fuchsia_scenic_flutter/fuchsia_view.dart' as fuchsia_view;

/// A helper class that wraps [ViewRef] and provides convenient accessors.
class ViewHandle {
  final ViewRef viewRef;
  ViewHandle(this.viewRef);

  /// Two [ViewHandle] objects are equal if their [koid]s match.
  @override
  bool operator ==(Object other) {
    return other is ViewHandle && koid == other.koid ||
        other is ViewRef && koid == other.reference.handle?.koid;
  }

  @override
  int get hashCode => koid.hashCode;

  @override
  String toString() => 'ViewRef[koid: $koid]';

  int get koid => viewRef.reference.handle?.koid ?? -1;

  int get handle => viewRef.reference.handle?.handle ?? -1;

  /// Request focus to be transfered to the view with [handle].
  Future<void> focus() async {
    try {
      await fuchsia_view.FocusState.instance.requestFocus(handle);
      // ignore: avoid_catches_without_on_clauses
    } catch (e) {
      log.warning('Exception on requestFocus: $e ${StackTrace.current}');
    }
  }
}