This PR introduces a new boolean flag, `isMomentary`, to the
`CupertinoSlidingSegmentedControl` widget.
When `isMomentary` is set to `true`, the segmented control behaves like
a momentary switch. Selecting a segment triggers its associated action
(e.g., via `onValueChanged`), but the segment doesn't stay visually
selected after the interaction ends. The control visually returns to its
previous state or a default state (often no segment selected).
When `isMomentary` is `false` (the default behavior), the control
maintains the selection state visually, highlighting the last chosen
segment.
**Motivation**
Currently, `CupertinoSlidingSegmentedControl` always maintains a
selected state. There are use cases where developers might want to use
the segmented control purely for triggering actions without persisting a
visual selection state, similar to how a `UISegmentedControl` can be
configured on iOS with `isMomentary = true`. This provides more
flexibility and aligns the Flutter widget closer to its native
counterpart's capabilities.
For example, this could be useful for triggering sorting actions, view
changes, or other immediate operations where maintaining a persistent
"selected" state isn't desired or meaningful.
**Related Issues**
fixes: #164077
**Videos**
UISegmentedControl behaviour when `isMomentary` flag is set to true.
https://github.com/user-attachments/assets/84d00312-4530-4b7a-9696-142f60ad89c0
CupertinoSlidingSegmentedControl behaviour when `isMomentary` flag is
set to true.
https://github.com/user-attachments/assets/b308b4fa-e641-417a-a518-4e0908876eed
## 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.
- [x] 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.
This auto-formats all *.dart files in the repository outside of the
`engine` subdirectory and enforces that these files stay formatted with
a presubmit check.
**Reviewers:** Please carefully review all the commits except for the
one titled "formatted". The "formatted" commit was auto-generated by
running `dev/tools/format.sh -a -f`. The other commits were hand-crafted
to prepare the repo for the formatting change. I recommend reviewing the
commits one-by-one via the "Commits" tab and avoiding Github's "Files
changed" tab as it will likely slow down your browser because of the
size of this PR.
---------
Co-authored-by: Kate Lovett <katelovett@google.com>
Co-authored-by: LongCatIsLooong <31859944+LongCatIsLooong@users.noreply.github.com>
Fixes https://github.com/flutter/flutter/issues/149625
This adds a new constructor CupertinoNavigationBar.large for the large style navigation bar. CupertinoSliverNavigationBar enables dynamically changing between the smaller and larger layouts for native iOS headers in response to scrolling, this change makes it possible to configure the static navigation bar in one style or the other.
This PR is making the `CupertinoNavigationBar` and `CupertinoSliverNavigationBar` appear transparent as long as the content is not scrolled under them, so they look like standard iOS apps nav bars.
https://github.com/flutter/flutter/assets/423393/eee2700b-2a91-4577-922c-6163d47cb357https://github.com/flutter/flutter/assets/423393/3847f2b5-0dac-4d5e-aa6f-03c1d2893e30
<details>
<summary>Demo app code</summary>
```dart
import 'package:flutter/cupertino.dart';
/// Flutter code sample for [CupertinoTabScaffold].
void main() => runApp(const TabScaffoldApp());
class TabScaffoldApp extends StatefulWidget {
const TabScaffoldApp({super.key});
@override
State<TabScaffoldApp> createState() => _TabScaffoldAppState();
}
class _TabScaffoldAppState extends State<TabScaffoldApp> {
Brightness _brightness = Brightness.light;
@override
Widget build(BuildContext context) {
return CupertinoApp(
theme: CupertinoThemeData(brightness: _brightness),
home: TabScaffoldExample(
brightness: _brightness, onBrightnessToggle: _toggleBrightness),
);
}
void _toggleBrightness() {
setState(() {
_brightness =
_brightness == Brightness.light ? Brightness.dark : Brightness.light;
});
}
}
class TabScaffoldExample extends StatefulWidget {
const TabScaffoldExample(
{required this.brightness, required this.onBrightnessToggle, super.key});
final VoidCallback onBrightnessToggle;
final Brightness brightness;
@override
State<TabScaffoldExample> createState() => _TabScaffoldExampleState();
}
class _TabScaffoldExampleState extends State<TabScaffoldExample> {
@override
Widget build(BuildContext context) {
return CupertinoTabScaffold(
tabBar: CupertinoTabBar(
items: const <BottomNavigationBarItem>[
BottomNavigationBarItem(
icon: Icon(CupertinoIcons.home),
label: 'Home',
),
BottomNavigationBarItem(
icon: Icon(CupertinoIcons.search_circle_fill),
label: 'Explore',
),
BottomNavigationBarItem(
icon: Icon(CupertinoIcons.person_fill),
label: 'Profile',
),
BottomNavigationBarItem(
icon: Icon(CupertinoIcons.settings_solid),
label: 'Settings',
),
],
),
tabBuilder: (BuildContext context, int index) {
return CupertinoTabView(
builder: (BuildContext context) {
return CupertinoPageScaffold(
backgroundColor: index == 3
? CupertinoColors.secondarySystemBackground
.resolveFrom(context)
: null,
child: CustomScrollView(
slivers: [
CupertinoSliverNavigationBar(
largeTitle: Text('Tab $index'),
initiallyTransparent: index != 2,
trailing: CupertinoButton(
padding: EdgeInsets.zero,
onPressed: widget.onBrightnessToggle,
child: Icon(
widget.brightness == Brightness.light
? CupertinoIcons.moon_stars
: CupertinoIcons.sun_max,
),
),
),
SliverSafeArea(
top: false,
sliver: SliverList.list(
children: [
CupertinoButton(
child: const Text('Next page'),
onPressed: () {
Navigator.of(context).push(
CupertinoPageRoute<void>(
builder: (BuildContext context) {
return CupertinoPageScaffold(
navigationBar: CupertinoNavigationBar(
middle: Text('Inner page of tab $index'),
),
child: ListView(
children: [
Center(
child: CupertinoButton(
child: const Text('Back'),
onPressed: () {
Navigator.of(context).pop();
},
),
),
if (index == 0) const _LongList(),
const SizedBox(height: 20),
],
),
);
},
),
);
},
),
if (index == 1) const _LongList(),
const SizedBox(height: 20),
],
),
),
],
),
);
},
);
},
);
}
}
class _LongList extends StatelessWidget {
const _LongList();
@override
Widget build(BuildContext context) {
return Column(
children: [
for (int i = 0; i < 50; i++) ...[
CupertinoListTile(
leading: const Icon(CupertinoIcons.book),
title: Text('Bookstore item $i'),
),
],
],
);
}
}
```
</details>
This is the continuation of https://github.com/flutter/flutter/pull/142439.
I tried to keep the simplest API possible, so it's only introducing a new `automaticBackgroundVisibility` boolean parameter.
In the implementation I had to use the `CupertinoPageScaffold` background color to make it look transparent instead of a 0 opacity, because of issues with route transitions.
I used an `InheritedWidget` so the nav bar is always getting the right background color from the parent scaffold, whether it is overridden or not. It would probably be better to make the inherited widget private but we'd need to move all the nav bar code to the same file as the scaffold, so for now I've just hidden it from the export. Let me know if it is okay to do that.
This PR is not dealing with the bottom tab bar, because the same [straightforward approach](dde8ec6dc7) doesn't work here. The problem is that the scroll notification is sent only when the scroll view is created or updated, so it doesn't work if one pushes a screen and navigates back.
Issues:
- #78607
- #60411
This PR removes the usage of Material widgets from unit tests of `CupertinoAlertDialog`. Other than it being just wrong, it also introduces bad behavior, such as the scroll view can't be overscrolled so that the overscroll behavior can't be tested.
* Since there are no longer M2 or M3 variants of tests, I straight up rewrote the unit tests for "default look" with similar tests as those of `CupertinoActionSheet` ([here](https://github.com/flutter/flutter/blob/master/packages/flutter/test/cupertino/action_sheet_test.dart#L21))
This PR also replaces `showCupertinoModalPopup` with `showCupertinoDialog` in `CupertinoAlertDialog`'s example code. The former should only be used by `CupertinoActionSheet`, which has a different animation from the correct `showCupertinoDialog`.
