PlatformQuery 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 PlatformQueryData.size property from the PlatformQueryData returned by PlatformQuery.of: PlatformQuery.of(context).size.

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

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

See also:

Inheritance

Constructors

PlatformQuery({Key? key, PlatformQueryData? data, required Widget child})
Creates a widget that provides PlatformQueryData to its descendants. [...]

Properties

child Widget
The widget below this widget in the tree. [...]
final, inherited
data PlatformQueryData
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 PlatformQuery 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

isAndroid(BuildContext context) bool
Returns isAndroid for the nearest PlatformQuery ancestor or false, if no such ancestor exists.
isIos(BuildContext context) bool
Returns isIos for the nearest PlatformQuery ancestor or false, if no such ancestor exists.
isLinux(BuildContext context) bool
Returns isLinux for the nearest PlatformQuery ancestor or false, if no such ancestor exists.
isMacos(BuildContext context) bool
Returns isMacos for the nearest PlatformQuery ancestor or false, if no such ancestor exists.
isWeb(BuildContext context) bool
Returns isWeb for the nearest PlatformQuery ancestor or false, if no such ancestor exists.
isWindows(BuildContext context) bool
Returns isWindows for the nearest PlatformQuery ancestor or false, if no such ancestor exists.
maybeOf(BuildContext context) PlatformQueryData?
The data from the closest instance of this class that encloses the given context, if any. [...]
of(BuildContext context) PlatformQueryData
The data from the closest instance of this class that encloses the given context. [...]
platformType(BuildContext context) PlatformType
Returns isDesktop for the nearest PlatformQuery ancestor or DeviceType.unknown, if no such ancestor exists.