Inspired by the review on #146182.
This PR adds boundary feature to the drag gestures, including `MultiDragGestureRecognizer` and `DragGestureRecognizer`. The `GestureDetector` widget will also benefit from this.
Fixes#33799
Allows for a route to inform the route below it in the navigation stack how to animate when the topmost route enters are leaves the stack.
It does this by making a `DelegatedTransition` available for the previous route to look up and use. If available, the route lower in the stack will wrap it's transition builders with that delegated transition and use it instead of it's default secondary transition.
This is what the sample code in this PR shows an app that is able to use both a Material zoom transition and a Cupertino slide transition in one app. It also includes a custom vertical transition. Every page animates off the screen in a way to match up with the incoming page's transition. When popped, the correct transitions play in reverse.
https://github.com/user-attachments/assets/1fc910fa-8cde-4e05-898e-daad8ff4a697
The below video shows this logic making a pseudo iOS styled sheet transition.
https://github.com/flutter/flutter/assets/58190796/207163d8-d87f-48b1-aad9-7e770d1d96c5
All existing page transitions in Flutter will be overwritten by the incoming route if a `delegatedTransition` is provided. This can be opted out of through `canTransitionTo` for a new route widget. Of Flutter's existing page transitions, this PR only adds a `DelegatedTransition` for the Zoom and Cupertino transitions. The other transitions possible in Material will get delegated transitions in a later PR.
Fixes https://github.com/flutter/flutter/issues/155551
### Description
- Adds example for `WidgetStateMouseCursor`
- Adds tests for `examples/api/lib/widgets/widget_state/widget_state_mouse_cursor.0.dart`
Fixes https://github.com/flutter/flutter/issues/155557
### Description
- Adds example for `WidgetStateBorderSide`
- Adds tests for `examples/api/lib/widgets/widget_state/widget_state_border_side.0.dart`
This PR contributes to https://github.com/flutter/flutter/issues/155313
### Description
- Adds example for `WidgetStateProperty`
- Adds tests for `examples/api/lib/widgets/widget_state/widget_state_property.0.dart`
CustomScrollViewExampleApp
Part of https://github.com/flutter/flutter/issues/130459
The test is checking:
- if all crucial Widgets are initially visible
- if IconButton click will expand existing SliverList
- if IconButton click and mouse scroll will reveal additional SliverList
I've updated these two examples to support state restoration of the navigation stack and verified that they work with predictive back in the tests. This was motivated by a worry that users are not properly setting up their navigation and that our examples are misleading them in the name of simplicity.
Contributes to https://github.com/flutter/flutter/issues/130459
It adds a test for
- `examples/api/lib/widgets/single_child_scroll_view/single_child_scroll_view.0.dart`
- `examples/api/lib/widgets/single_child_scroll_view/single_child_scroll_view.1.dart`
I also fixed a mistake in the documentation
A relatively elaborate PinnedSliverHeader example which creates an app bar that's similar to the one that appears in the iOS Settings app. In this example the pinned header starts out transparent and the first item in the list serves as the app's "Settings" title. When the title item has been scrolled completely behind the pinned header, the header animates its opacity from 0 to 1 and its (centered) "Settings" title appears. The fact that the header's opacity depends on the height of the title item - which is unknown until the list has been laid out - necessitates monitoring its SliverConstraints.scrollExtent from a scroll NotificationListener.
https://github.com/flutter/flutter/assets/1377460/539e2591-d0d7-4508-8ce8-4b8f587d7648
A sliver that shows its [child] when the user scrolls forward and hides it when the user scrolls backwards. Similar headers can be found in Google Photos and Facebook.
This sliver is preferable to the general purpose SliverPersistentHeader for its relatively narrow use case because there's no need to create a SliverPersistentHeaderDelegate or to predict the header's size.
https://github.com/flutter/flutter/assets/1377460/82b67dfb-5d38-4adf-9415-fc8527d0eb9f
