DeviceQuery 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 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:
- DeviceQueryData, the data structure that represents the metrics.
- Inheritance
-
- Object
- DiagnosticableTree
- Widget
- ProxyWidget
- InheritedWidget
- DeviceQuery
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.
finalinherited
- data → DeviceQueryData
-
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 DeviceQuery 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
-
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.