packages/flutter/test/rendering/platform_view_test.dart

// Copyright 2019 The Flutter 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 'package:flutter/foundation.dart';
import 'package:flutter/gestures.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter_test/flutter_test.dart';
import 'package:flutter/material.dart';
import '../services/fake_platform_views.dart';
import 'rendering_tester.dart';

void main() {

  group('PlatformViewRenderBox', () {
    FakePlatformViewController fakePlatformViewController;
    PlatformViewRenderBox platformViewRenderBox;
    setUp((){
      fakePlatformViewController = FakePlatformViewController(0);
      platformViewRenderBox = PlatformViewRenderBox(
        controller: fakePlatformViewController,
        hitTestBehavior: PlatformViewHitTestBehavior.opaque,
        gestureRecognizers: <Factory<OneSequenceGestureRecognizer>>{
                  Factory<VerticalDragGestureRecognizer>(
                    () {
                      return VerticalDragGestureRecognizer();
                    },
                  ),
                },);
    });

    test('layout should size to max constraint', () {
      layout(platformViewRenderBox);
      platformViewRenderBox.layout(const BoxConstraints(minWidth: 50, minHeight: 50, maxWidth: 100, maxHeight: 100));
      expect(platformViewRenderBox.size, const Size(100, 100));
    });

    test('send semantics update if id is changed', (){
      final RenderObject tree = RenderConstrainedBox(
        additionalConstraints: const BoxConstraints.tightFor(height: 20.0, width: 20.0),
        child: platformViewRenderBox,
      );
      int semanticsUpdateCount = 0;
      final SemanticsHandle semanticsHandle = renderer.pipelineOwner.ensureSemantics(
          listener: () {
            ++semanticsUpdateCount;
          }
      );
      layout(tree, phase: EnginePhase.flushSemantics);
      // Initial semantics update
      expect(semanticsUpdateCount, 1);

      semanticsUpdateCount = 0;

      // Request semantics update even though nothing changed.
      platformViewRenderBox.markNeedsSemanticsUpdate();
      pumpFrame(phase: EnginePhase.flushSemantics);
      expect(semanticsUpdateCount, 0);

      semanticsUpdateCount = 0;

      final FakePlatformViewController updatedFakePlatformViewController = FakePlatformViewController(10);
      platformViewRenderBox.controller = updatedFakePlatformViewController;
      pumpFrame(phase: EnginePhase.flushSemantics);
      // Update id should update the semantics.
      expect(semanticsUpdateCount, 1);

      semanticsHandle.dispose();
    });
  });
}