RawGestureDetector class Null safety

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.

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)),
)

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

Constructors

RawGestureDetector({Key? key, Widget? child, Map<Type, GestureRecognizerFactory<GestureRecognizer>> gestures = const <Type, GestureRecognizerFactory>{}, HitTestBehavior? behavior, bool excludeFromSemantics = false, SemanticsGestureDelegate? semantics})
Creates a widget that detects gestures.
const

Properties

behavior HitTestBehavior?
How this gesture detector should behave during hit testing.
final
child Widget?
The widget below this widget in the tree.
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.
@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
semantics SemanticsGestureDelegate?
Describes the semantics notations that should be added to the underlying render object RenderSemanticsGestureHandler.
final

Methods

createElement() StatefulElement
Creates a StatefulElement to manage this widget's location in the tree.
inherited
createState() RawGestureDetectorState
Creates the mutable state for this widget at a given location in the tree.
override
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.
inherited
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

Operators

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