DeviceQuery class Null safety

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

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

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

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

See also:

Inheritance

Constructors

DeviceQuery({Key? key, DeviceQueryData? data, BuildContext? context, MediaQueryData? mediaQueryData, required Widget child})
Creates a widget that provides DeviceQueryData to its descendants. [...]

Properties

child Widget
The widget below this widget in the tree. [...]
final, inherited
data DeviceQueryData
Contains information about the current device. [...]
final
hashCode int
The hash code for this object. [...]
@nonVirtual, 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

createElement() InheritedElement
Inflates this configuration to a concrete instance. [...]
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. [...]
override
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.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 DeviceQuery oldWidget) bool
Whether the framework should notify widgets that inherit from this widget. [...]
override

Operators

operator ==(Object other) bool
The equality operator. [...]
@nonVirtual, inherited

Static Methods

deviceType(BuildContext context) DeviceType
Returns isDesktop for the nearest DeviceQuery ancestor or DeviceType.unknown, if no such ancestor exists.
isDesktop(BuildContext context) bool
Returns isDesktop for the nearest DeviceQuery ancestor or false, if no such ancestor exists.
isPhone(BuildContext context) bool
Returns isPhone for the nearest DeviceQuery ancestor or false, if no such ancestor exists.
isTablet(BuildContext context) bool
Returns isTablet for the nearest DeviceQuery ancestor or false, if no such ancestor exists.
isTv(BuildContext context) bool
Returns isTv for the nearest DeviceQuery ancestor or false, if no such ancestor exists.
isWatch(BuildContext context) bool
Returns isWatch for the nearest DeviceQuery ancestor or false, if no such ancestor exists.
isWeb(BuildContext context) bool
Returns isWeb for the nearest DeviceQuery ancestor or false, if no such ancestor exists.
maybeOf(BuildContext context) DeviceQueryData?
The data from the closest instance of this class that encloses the given context, if any. [...]
of(BuildContext context) DeviceQueryData
The data from the closest instance of this class that encloses the given context. [...]