<itemvalue="Schedule a callback for the end of this frame. Does not request a new frame. This callback is run during a frame, just after the persistent frame callbacks (which is when the main rendering pipeline has been flushed). If a frame is in progress and post-frame callbacks haven't been executed yet, then the registered callback is still executed during the frame. Otherwise, the registered callback is executed during the next frame. The callbacks are executed in the order in which they have been added. Post-frame callbacks cannot be unregistered. They are called exactly once. See also: [scheduleFrameCallback], which registers a callback for the start of the next frame."/>
<itemvalue="Fullscreen display with status and navigation elements rendered over the application. Available starting at SDK 29 or Android 10. Earlier versions of Android will not be affected by this setting. For applications running on iOS, the status bar and home indicator will be visible. The system overlays will not disappear or reappear in this mode as they are permanently displayed on top of the application. See also: [SystemUiOverlayStyle], can be used to configure transparent status and navigation bars with or without a contrast scrim."/>
<itemvalue="Specifies the [SystemUiMode] to have visible when the application is running. The `overlays` argument is a list of [SystemUiOverlay] enum values denoting the overlays to show when configured with [SystemUiMode.manual]. If a particular mode is unsupported on the platform, enabling or disabling that mode will be ignored. The settings here can be overridden by the platform when System UI becomes necessary for functionality. For example, on Android, when the keyboard becomes visible, it will enable the navigation bar and status bar system UI overlays. When the keyboard is closed, Android will not restore the previous UI visibility settings, and the UI visibility cannot be changed until 1 second after the keyboard is closed to prevent malware locking users from navigation buttons. To regain "fullscreen" after text entry, the UI overlays can be set again after a delay of at least 1 second through [restoreSystemUIOverlays] or calling this again. Otherwise, the original UI overlay settings will be automatically restored only when the application loses and regains focus. Alternatively, a [SystemUiChangeCallback] can be provided to respond to changes in the System UI. This will be called, for example, when in [SystemUiMode.leanBack] and the user taps the screen to bring up the system overlays. The callback provides a boolean to represent if the application is currently in a fullscreen mode or not, so that the application can respond to these changes. When `systemOverlaysAreVisible` is true, the application is not fullscreen. See [SystemChrome.setSystemUIChangeCallback] to respond to these changes in a fullscreen application."/>
@ -54,13 +56,11 @@
<itemvalue="A material design app bar that integrates with a [CustomScrollView]. An app bar consists of a toolbar and potentially other widgets, such as a [TabBar] and a [FlexibleSpaceBar]. App bars typically expose one or more common actions with [IconButton]s which are optionally followed by a [PopupMenuButton] for less common operations. {@youtube 560 315 https:www.youtube.comwatch?v=R9C5KMJKluE} Sliver app bars are typically used as the first child of a [CustomScrollView], which lets the app bar integrate with the scroll view so that it can vary in height according to the scroll offset or float above the other content in the scroll view. For a fixed-height app bar at the top of the screen see [AppBar], which is used in the [Scaffold.appBar] slot. The AppBar displays the toolbar widgets, [leading], [title], and [actions], above the [bottom] (if any). If a [flexibleSpace] widget is specified then it is stacked behind the toolbar and the bottom widget."/>
<itemvalue="A sliver that places multiple box children in a two dimensional arrangement. [SliverGrid] places its children in arbitrary positions determined by [gridDelegate]. Each child is forced to have the size specified by the [gridDelegate]. The main axis direction of a grid is the direction in which it scrolls; the cross axis direction is the orthogonal direction. {@youtube 560 315 https:www.youtube.comwatch?v=ORiTTaVY6mM} {@tool snippet} This example, which would be inserted into a [CustomScrollView.slivers] list, shows twenty boxes in a pretty teal grid:"/>
<itemvalue="A sliver that places multiple box children in a linear array along the main axis. Each child is forced to have the [SliverConstraints.crossAxisExtent] in the cross axis but determines its own main axis extent. [SliverList] determines its scroll offset by "dead reckoning" because children outside the visible part of the sliver are not materialized, which means [SliverList] cannot learn their main axis extent. Instead, newly materialized children are placed adjacent to existing children. {@youtube 560 315 https:www.youtube.comwatch?v=ORiTTaVY6mM} If the children have a fixed extent in the main axis, consider using [SliverFixedExtentList] rather than [SliverList] because [SliverFixedExtentList] does not need to perform layout on its children to obtain their extent in the main axis and is therefore more efficient. {@macro flutter.widgets.SliverChildDelegate.lifecycle} See also: <https:flutter.devdocsdevelopmentuiadvancedslivers>, a description of what slivers are and how to use them. [SliverFixedExtentList], which is more efficient for children with the same extent in the main axis. [SliverPrototypeExtentList], which is similar to [SliverFixedExtentList] except that it uses a prototype list item instead of a pixel value to define the main axis extent of each item. [SliverGrid], which places its children in arbitrary positions."/>
<itemvalue="A [ScrollView] that creates custom scroll effects using slivers. A [CustomScrollView] lets you supply [slivers] directly to create various scrolling effects, such as lists, grids, and expanding headers. For example, to create a scroll view that contains an expanding app bar followed by a list and a grid, use a list of three slivers: [SliverAppBar], [SliverList], and [SliverGrid]. [Widget]s in these [slivers] must produce [RenderSliver] objects. To control the initial scroll offset of the scroll view, provide a [controller] with its [ScrollController.initialScrollOffset] property set. {@animation 400 376 https:flutter.github.ioassets-for-api-docsassetswidgetscustom_scroll_view.mp4} {@tool snippet} This sample code shows a scroll view that contains a flexible pinned app bar, a grid, and an infinite list."/>
<itemvalue="A base class for the `State` of widgets with implicit animations. [ImplicitlyAnimatedWidgetState] requires that subclasses respond to the animation themselves. If you would like `setState()` to be called automatically as the animation changes, use [AnimatedWidgetBaseState]. Properties that subclasses choose to animate are represented by [Tween] instances. Subclasses must implement the [forEachTween] method to allow [ImplicitlyAnimatedWidgetState] to iterate through the widget's fields and animate them."/>
