ThemeQuery<T extends ThemeQueryData> class

Establishes a subtree in which Theme queries resolve to the given data.

For example, to learn the size of the current Theme (e.g., the window containing your app), you can read the ThemeQueryData.size property from the ThemeQueryData returned by ThemeQuery.of: ThemeQuery.of(context).size.

Querying the current Theme using ThemeQuery.of will cause your widget to rebuild automatically whenever the ThemeQueryData changes (e.g., if the user rotates their Theme).

If no ThemeQuery is in scope then the ThemeQuery.of method will throw an exception. Alternatively, ThemeQuery.maybeOf may be used, which returns null instead of throwing if no ThemeQuery is in scope.

See also:

• ThemeQueryData, the data structure that represents the metrics.

Inheritance

• Object
• DiagnosticableTree
• Widget
• ProxyWidget
• InheritedWidget
• ThemeQuery

Constructors

ThemeQuery({Key? key, required T data, BuildContext? context, MediaQueryData? mediaQueryData, required Widget child})

Creates a widget that provides ThemeQueryData to its descendants.

const

Properties

child → Widget

The widget below this widget in the tree.

final, inherited

data → T

Contains information about the current Theme.

final

hashCode → int

The hash code for this object.

no setter, 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.

no setter, inherited

Methods

createElement() → InheritedElement

Inflates this configuration to a concrete instance.

inherited

debugDescribeChildren() → List<DiagnosticsNode>

Returns a list of DiagnosticsNode objects describing this node's children.

inherited

debugFillProperties(DiagnosticPropertiesBuilder properties) → void

Add additional properties associated with the node.

override

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent 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.info}) → String

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

updateShouldNotify(covariant ThemeQuery<ThemeQueryData> oldWidget) → bool

Whether the framework should notify widgets that inherit from this widget.

override

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Methods

dark<T extends ThemeQueryData>(BuildContext context) → ThemeData?

Returns isDesktop for the nearest ThemeQuery ancestor or ThemeType.unknown, if no such ancestor exists.

light<T extends ThemeQueryData>(BuildContext context) → ThemeData?

Returns isDesktop for the nearest ThemeQuery ancestor or ThemeType.unknown, if no such ancestor exists.

maybeOf<T extends ThemeQueryData>(BuildContext context) → T?

The data from the closest instance of this class that encloses the given context, if any.

of<T extends ThemeQueryData>(BuildContext context) → T

The data from the closest instance of this class that encloses the given context.