commit a5c07d237c8492ae7e634d604b0bc53ab2032604
author Victor Sanni <victorsanniay@gmail.com> Tue Feb 04 17:49:25 2025 -0800
committer dart-internal-monorepo <dart-internal-monorepo@dart-ci-internal.iam.gserviceaccount.com> Tue Feb 04 18:35:06 2025 -0800
tree c8283011ac4b6185cbfc34938294df377d5e5df5
parent ddc0b9396aed722e395f57e16e06596ee82c1217

Make CupertinoSheetRoute usable with Cupertino(Sliver)NavigationBar (#162181)

Working on the cupertino nav bars recently gave me some context on those
widgets, so when I saw this
[comment](https://github.com/flutter/flutter/pull/157568#issuecomment-2590955571)
I was inspired to add a fix :)

Thanks @MaherSafadii for [starting the
exploration](https://github.com/flutter/flutter/pull/157568#issuecomment-2592535332)
and also for the very helpful
[screenshots](https://github.com/flutter/flutter/issues/162021#issuecomment-2608430023).

Removes the following when
CupertinoNavigationBar/CupertinoSliverNavigationBar is used in a
CupertinoSheetRoute:
- Unneeded back button
- Superfluous top padding in CupertinoNavigationBar
- Full page route transitions

## Before:

https://github.com/user-attachments/assets/a6da3957-0cff-4491-9380-bbc676ac799d

## After:

https://github.com/user-attachments/assets/37cd1628-a47e-44aa-85c7-abceda6e7944

<details>
<summary>Sample code</summary>

```dart
// Copyright 2014 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/cupertino.dart';

/// Flutter code sample for [CupertinoSheetRoute].

class CupertinoSheetApp extends StatelessWidget {
  const CupertinoSheetApp({super.key});

  @override
  Widget build(BuildContext context) {
    return const CupertinoApp(title: 'Cupertino Sheet', home: HomePage());
  }
}

class HomePage extends StatelessWidget {
  const HomePage({super.key});

  @override
  Widget build(BuildContext context) {
    return CupertinoPageScaffold(
      navigationBar: const CupertinoNavigationBar(
        middle: Text('Sheet Example'),
        automaticBackgroundVisibility: false,
      ),
      child: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            CupertinoButton.filled(
              onPressed: () {
                Navigator.of(context).push(
                  CupertinoSheetRoute<void>(
                    builder: (BuildContext context) => const _SheetScaffold(),
                  ),
                );
              },
              child: const Text('Open Bottom Sheet'),
            ),
          ],
        ),
      ),
    );
  }
}

class _SheetScaffold extends StatelessWidget {
  const _SheetScaffold();

  @override
  Widget build(BuildContext context) {
    return CupertinoPageScaffold(
      navigationBar: CupertinoNavigationBar(
        backgroundColor: CupertinoColors.systemGrey.withOpacity(0.5),
        middle: const Text('CupertinoNavigationBar Sample'),
        automaticBackgroundVisibility: false,
      ),
      child: Column(
        children: <Widget>[
          Container(height: 50, color: CupertinoColors.systemRed),
          Container(height: 50, color: CupertinoColors.systemGreen),
          Container(height: 50, color: CupertinoColors.systemBlue),
          Container(height: 50, color: CupertinoColors.systemYellow),
          Center(
            child: CupertinoButton.filled(
              onPressed: () {
                Navigator.of(context).push(
                  CupertinoSheetRoute<void>(
                    builder: (BuildContext context) =>
                        const SliverNavBarExample(),
                  ),
                );
              },
              child: const Text('Open Bottom Sheet'),
            ),
          )
        ],
      ),
    );
  }
}

class SliverNavBarExample extends StatelessWidget {
  const SliverNavBarExample({super.key});

  @override
  Widget build(BuildContext context) {
    return CupertinoPageScaffold(
      child: CustomScrollView(
        slivers: <Widget>[
          const CupertinoSliverNavigationBar(
            leading: Icon(CupertinoIcons.person_2),
            largeTitle: Text('Contacts'),
            trailing: Icon(CupertinoIcons.add_circled),
          ),
          SliverFillRemaining(
            child: Padding(
              padding: const EdgeInsets.symmetric(horizontal: 10.0),
              child: Column(
                mainAxisAlignment: MainAxisAlignment.spaceEvenly,
                children: <Widget>[
                  const Text('Drag me up', textAlign: TextAlign.center),
                  CupertinoButton.filled(
                    onPressed: () {},
                    child: const Text('Bottom Automatic mode'),
                  ),
                  CupertinoButton.filled(
                    onPressed: () {},
                    child: const Text('Bottom Always mode'),
                  ),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }
}

```
</details>

Fixes [Cupertino navbars apply too much top padding within a
sheet](https://github.com/flutter/flutter/issues/162021).

## Pre-launch Checklist

- [x] I read the [Contributor Guide] and followed the process outlined
there for submitting PRs.
- [x] I read the [Tree Hygiene] wiki page, which explains my
responsibilities.
- [x] I read and followed the [Flutter Style Guide], including [Features
we expect every widget to implement].
- [x] I signed the [CLA].
- [x] I listed at least one issue that this PR fixes in the description
above.
- [ ] I updated/added relevant documentation (doc comments with `///`).
- [x] I added new tests to check the change I am making, or this PR is
[test-exempt].
- [x] I followed the [breaking change policy] and added [Data Driven
Fixes] where supported.
- [x] All existing and new tests are passing.
https://dart.googlesource.com/external/github.com/flutter/flutter/+/dfb36f032e6d3c2a0102f469c32ddce45c8a74ce