CupertinoTabScaffold class

Implements a tabbed iOS application's root layout and behavior structure.

The scaffold lays out the tab bar at the bottom and the content between or behind the tab bar.

A tabBar and a tabBuilder are required. The CupertinoTabScaffold will automatically listen to the provided CupertinoTabBar's tap callbacks to change the active tab.

Tabs' contents are built with the provided tabBuilder at the active tab index. The tabBuilder must be able to build the same number of pages as there are tabBar.items. Inactive tabs will be moved Offstage and their animations disabled.

Use CupertinoTabView as the root widget of each tab to support tabs with parallel navigation state and history. Since each CupertinoTabView contains a Navigator, rebuilding the CupertinoTabView with a different WidgetBuilder instance in CupertinoTabView.builder will not recreate the CupertinoTabView's navigation stack or update its UI. To update the contents of the CupertinoTabView after it's built, trigger a rebuild (via State.setState, for instance) from its descendant rather than from its ancestor.

A sample code implementing a typical iOS information architecture with tabs.
CupertinoTabScaffold(
  tabBar: CupertinoTabBar(
    items: <BottomNavigationBarItem> [
      // ...
    ],
  ),
  tabBuilder: (BuildContext context, int index) {
    return CupertinoTabView(
      builder: (BuildContext context) {
        return CupertinoPageScaffold(
          navigationBar: CupertinoNavigationBar(
            middle: Text('Page 1 of tab $index'),
          ),
          child: Center(
            child: CupertinoButton(
              child: const Text('Next page'),
              onPressed: () {
                Navigator.of(context).push(
                  CupertinoPageRoute<void>(
                    builder: (BuildContext context) {
                      return CupertinoPageScaffold(
                        navigationBar: CupertinoNavigationBar(
                          middle: Text('Page 2 of tab $index'),
                        ),
                        child: Center(
                          child: CupertinoButton(
                            child: const Text('Back'),
                            onPressed: () { Navigator.of(context).pop(); },
                          ),
                        ),
                      );
                    },
                  ),
                );
              },
            ),
          ),
        );
      },
    );
  },
)

To push a route above all tabs instead of inside the currently selected one (such as when showing a dialog on top of this scaffold), use Navigator.of(rootNavigator: true) from inside the BuildContext of a CupertinoTabView.

See also:

Inheritance

Constructors

CupertinoTabScaffold({Key key, @required CupertinoTabBar tabBar, @required IndexedWidgetBuilder tabBuilder, Color backgroundColor, bool resizeToAvoidBottomInset: true })
Creates a layout for applications with a tab bar at the bottom. [...]
const

Properties

backgroundColor Color
The color of the widget that underlies the entire scaffold. [...]
final
resizeToAvoidBottomInset bool
Whether the child should size itself to avoid the window's bottom inset. [...]
final
tabBar CupertinoTabBar
The tabBar is a CupertinoTabBar drawn at the bottom of the screen that lets the user switch between different tabs in the main content area when present. [...]
final
tabBuilder IndexedWidgetBuilder
An IndexedWidgetBuilder that's called when tabs become active. [...]
final
hashCode int
The hash code for this object. [...]
read-only, inherited
key Key
Controls how one widget replaces another widget in the tree. [...]
final, inherited
runtimeType Type
A representation of the runtime type of the object.
read-only, inherited

Methods

createState() → _CupertinoTabScaffoldState
Creates the mutable state for this widget at a given location in the tree. [...]
override
createElement() StatefulElement
Creates a StatefulElement to manage this widget's location in the tree. [...]
inherited
debugDescribeChildren() List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children. [...]
@protected, inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
Add additional properties associated with the node. [...]
inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed. [...]
inherited
toDiagnosticsNode({String name, DiagnosticsTreeStyle style }) DiagnosticsNode
Returns a debug representation of the object that is used by debugging tools and by DiagnosticsNode.toStringDeep. [...]
inherited
toString({DiagnosticLevel minLevel: DiagnosticLevel.debug }) String
Returns a string representation of this object.
inherited
toStringDeep({String prefixLineOne: '', String prefixOtherLines, DiagnosticLevel minLevel: DiagnosticLevel.debug }) String
Returns a string representation of this node and its descendants. [...]
inherited
toStringShallow({String joiner: ', ', DiagnosticLevel minLevel: DiagnosticLevel.debug }) String
Returns a one-line detailed description of the object. [...]
inherited
toStringShort() String
A short, textual description of this widget.
inherited

Operators

operator ==(dynamic other) bool
The equality operator. [...]
inherited