nav_bar_test.dart

// Copyright 2017 The Chromium 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/cupertino.dart';
import 'package:flutter/rendering.dart';
import 'package:flutter_test/flutter_test.dart';

int count = 0;

void main() {
  testWidgets('Middle still in center with asymmetrical actions', (WidgetTester tester) async {
    await tester.pumpWidget(
      new WidgetsApp(
        color: const Color(0xFFFFFFFF),
        onGenerateRoute: (RouteSettings settings) {
          return new PageRouteBuilder<Null>(
            settings: settings,
            pageBuilder: (BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation) {
              return const CupertinoNavigationBar(
                leading: const CupertinoButton(child: const Text('Something'), onPressed: null,),
                middle: const Text('Title'),
              );
            },
          );
        },
      ),
    );

    // Expect the middle of the title to be exactly in the middle of the screen.
    expect(tester.getCenter(find.text('Title')).dx, 400.0);
  });

  testWidgets('Opaque background does not add blur effects', (WidgetTester tester) async {
    await tester.pumpWidget(
      new WidgetsApp(
        color: const Color(0xFFFFFFFF),
        onGenerateRoute: (RouteSettings settings) {
          return new PageRouteBuilder<Null>(
            settings: settings,
            pageBuilder: (BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation) {
              return const CupertinoNavigationBar(
                middle: const Text('Title'),
                backgroundColor: const Color(0xFFE5E5E5),
              );
            },
          );
        },
      ),
    );
    expect(find.byType(BackdropFilter), findsNothing);
  });

  testWidgets('Non-opaque background adds blur effects', (WidgetTester tester) async {
    await tester.pumpWidget(
      new WidgetsApp(
        color: const Color(0xFFFFFFFF),
        onGenerateRoute: (RouteSettings settings) {
          return new PageRouteBuilder<Null>(
            settings: settings,
            pageBuilder: (BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation) {
              return const CupertinoNavigationBar(
                middle: const Text('Title'),
              );
            },
          );
        },
      ),
    );
    expect(find.byType(BackdropFilter), findsOneWidget);
  });

  testWidgets('Verify styles of each slot', (WidgetTester tester) async {
    count = 0x000000;
    await tester.pumpWidget(
      new WidgetsApp(
        color: const Color(0xFFFFFFFF),
        onGenerateRoute: (RouteSettings settings) {
          return new PageRouteBuilder<Null>(
            settings: settings,
            pageBuilder: (BuildContext context, Animation<double> animation, Animation<double> secondaryAnimation) {
              return const CupertinoNavigationBar(
                leading: const _ExpectStyles(color: const Color(0xFF001122), index: 0x000001),
                middle: const _ExpectStyles(color: const Color(0xFF000000), index: 0x000100),
                trailing: const _ExpectStyles(color: const Color(0xFF001122), index: 0x010000),
                actionsForegroundColor: const Color(0xFF001122),
              );
            },
          );
        },
      ),
    );
    expect(count, 0x010101);
  });
}

class _ExpectStyles extends StatelessWidget {
  const _ExpectStyles({ this.color, this.index });

  final Color color;
  final int index;

  @override
  Widget build(BuildContext context) {
    final TextStyle style = DefaultTextStyle.of(context).style;
    expect(style.color, color);
    expect(style.fontSize, 17.0);
    expect(style.letterSpacing, -0.24);
    count += index;
    return new Container();
  }
}