RawGestureDetectorModifier class

A widget that detects gestures described by the given gesture factories.

For common gestures, use a GestureRecognizer. RawGestureDetector is useful primarily when developing your own gesture recognizers.

Configuring the gesture recognizers requires a carefully constructed map, as described in gestures and as shown in the example below.

{@tool snippet}

This example shows how to hook up a TapGestureRecognizer. It assumes that the code is being used inside a State object with a _last field that is then displayed as the child of the gesture detector.

RawGestureDetector(
  gestures: <Type, GestureRecognizerFactory>{
    TapGestureRecognizer: GestureRecognizerFactoryWithHandlers<TapGestureRecognizer>(
      () => TapGestureRecognizer(),
      (TapGestureRecognizer instance) {
        instance
          ..onTapDown = (TapDownDetails details) { setState(() { _last = 'down'; }); }
          ..onTapUp = (TapUpDetails details) { setState(() { _last = 'up'; }); }
          ..onTap = () { setState(() { _last = 'tap'; }); }
          ..onTapCancel = () { setState(() { _last = 'cancel'; }); };
      },
    ),
  },
  child: Container(width: 300.0, height: 300.0, color: Colors.yellow, child: Text(_last)),
)

{@end-tool}

See also:

• GestureDetector, a less flexible but much simpler widget that does the same thing.
• Listener, a widget that reports raw pointer events.
• GestureRecognizer, the class that you extend to create a custom gesture recognizer.

Inheritance

• Object
• DiagnosticableTree
• Widget
• StatelessWidget
• SingleChildStatelessModifier
• RawGestureDetectorModifier

Available extensions

• ModifierTransformer

Constructors

RawGestureDetectorModifier({Key? key, Widget? child, Key? modifierKey, Map<Type, GestureRecognizerFactory<GestureRecognizer>> gestures = const <Type, GestureRecognizerFactory>{}, HitTestBehavior? behavior, SemanticsGestureDelegate? semantics, bool excludeFromSemantics = false})

Creates a widget that detects gestures.

const

Properties

behavior → HitTestBehavior?

How this gesture detector should behave during hit testing.

final

excludeFromSemantics → bool

Whether to exclude these gestures from the semantics tree. For example, the long-press gesture for showing a tooltip is excluded because the tooltip itself is included in the semantics tree directly and so having a gesture to show it would result in duplication of information.

final

gestures → Map<Type, GestureRecognizerFactory<GestureRecognizer>>

The gestures that this widget will attempt to recognize.

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

modifierKey → Key?

The actual key of the widget, which Modifier wrapped

final, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

semantics → SemanticsGestureDelegate?

Describes the semantics notations that should be added to the underlying render object RenderSemanticsGestureHandler.

final

Methods

build(BuildContext context) → Widget

Describes the part of the user interface represented by this widget.

inherited

buildWithChild(BuildContext context, Widget? child) → Widget

A build method that receives an extra child parameter.

override

createElement() → SingleChildStatelessElement

Create a SingleChildStatelessElement

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.

inherited

modified() → Modifier

Available on Widget, provided by the ModifierTransformer extension

Transform normal widget to Modifier

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, int wrapWidth = 65}) → 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

Operators

operator ==(Object other) → bool

The equality operator.

inherited