PlatformQuery class

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.

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.
finalinherited
data → PlatformQueryData: Contains information about the current device.
final
hashCode → int: The hash code for this object.
no setterinherited
key → Key?: Controls how one widget replaces another widget in the tree.
finalinherited
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited

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 PlatformQuery 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

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.