PointerEvent class Null safety
Base class for touch, stylus, or mouse events.
Pointer events operate in the coordinate space of the screen, scaled to logical pixels. Logical pixels approximate a grid with about 38 pixels per centimeter, or 96 pixels per inch.
This allows gestures to be recognized independent of the precise hardware characteristics of the device. In particular, features such as touch slop (see kTouchSlop) can be defined in terms of roughly physical lengths so that the user can shift their finger by the same distance on a high-density display as on a low-resolution device.
For similar reasons, pointer events are not affected by any transforms in the rendering layer. This means that deltas may need to be scaled before being applied to movement within the rendering. For example, if a scrolling list is shown scaled by 2x, the pointer deltas will have to be scaled by the inverse amount if the list is to appear to scroll with the user's finger.
See also:
- dart:ui.FlutterView.devicePixelRatio, which defines the device's current resolution.
- Listener, a widget that calls callbacks in response to common pointer events.
- Mixed in types
- Implementers
- Annotations
Constructors
- PointerEvent({int embedderId = 0, Duration timeStamp = Duration.zero, int pointer = 0, PointerDeviceKind kind = PointerDeviceKind.touch, int device = 0, Offset position = Offset.zero, Offset delta = Offset.zero, int buttons = 0, bool down = false, bool obscured = false, double pressure = 1.0, double pressureMin = 1.0, double pressureMax = 1.0, double distance = 0.0, double distanceMax = 0.0, double size = 0.0, double radiusMajor = 0.0, double radiusMinor = 0.0, double radiusMin = 0.0, double radiusMax = 0.0, double orientation = 0.0, double tilt = 0.0, int platformData = 0, bool synthesized = false, Matrix4? transform, PointerEvent? original})
-
Abstract const constructor. This constructor enables subclasses to provide
const constructors so that they can be used in const expressions.
const
Properties
-
Bit field using the *Button constants such as kPrimaryMouseButton,
kSecondaryStylusButton, etc.
final
- delta → Offset
-
Distance in logical pixels that the pointer moved since the last
PointerMoveEvent or PointerHoverEvent.
final
- device → int
-
Unique identifier for the pointing device, reused across interactions.
final
- distance → double
-
The distance of the detected object from the input surface.
final
- distanceMax → double
-
The maximum value that distance can return for this pointer.
final
- distanceMin → double
-
The minimum value that distance can return for this pointer.
read-only
- down → bool
-
Set if the pointer is currently down.
final
- embedderId → int
-
Unique identifier that ties the PointerEvent to the embedder event that created it.
final
- hashCode → int
-
The hash code for this object.
read-onlyinherited
- kind → PointerDeviceKind
-
The kind of input device for which the event was generated.
final
- localDelta → Offset
-
The delta transformed into the event receiver's local coordinate
system according to transform.
read-only
- localPosition → Offset
-
The position transformed into the event receiver's local coordinate
system according to transform.
read-only
- obscured → bool
-
Set if an application from a different security domain is in any way
obscuring this application's window.
final
- orientation → double
-
The orientation angle of the detected object, in radians.
final
- original → PointerEvent?
-
The original un-transformed PointerEvent before any transforms were
applied.
final
- platformData → int
-
Opaque platform-specific data associated with the event.
final
- pointer → int
-
Unique identifier for the pointer, not reused. Changes for each new
pointer down event.
final
- position → Offset
-
Coordinate of the position of the pointer, in logical pixels in the global
coordinate space.
final
- pressure → double
-
The pressure of the touch.
final
- pressureMax → double
-
The maximum value that pressure can return for this pointer.
final
- pressureMin → double
-
The minimum value that pressure can return for this pointer.
final
- radiusMajor → double
-
The radius of the contact ellipse along the major axis, in logical pixels.
final
- radiusMax → double
-
The maximum value that could be reported for radiusMajor and radiusMinor
for this pointer, in logical pixels.
final
- radiusMin → double
-
The minimum value that could be reported for radiusMajor and radiusMinor
for this pointer, in logical pixels.
final
- radiusMinor → double
-
The radius of the contact ellipse along the minor axis, in logical pixels.
final
- runtimeType → Type
-
A representation of the runtime type of the object.
read-onlyinherited
- size → double
-
The area of the screen being pressed.
final
- synthesized → bool
-
Set if the event was synthesized by Flutter.
final
- tilt → double
-
The tilt angle of the detected object, in radians.
final
- timeStamp → Duration
-
Time of event dispatch, relative to an arbitrary timeline.
final
- transform → Matrix4?
-
The transformation used to transform this event from the global coordinate
space into the coordinate space of the event receiver.
final
Methods
-
copyWith(
{Duration? timeStamp, int? pointer, PointerDeviceKind? kind, int? device, Offset? position, Offset? delta, int? buttons, bool? obscured, double? pressure, double? pressureMin, double? pressureMax, double? distance, double? distanceMax, double? size, double? radiusMajor, double? radiusMinor, double? radiusMin, double? radiusMax, double? orientation, double? tilt, bool? synthesized, int? embedderId}) → PointerEvent - Creates a copy of event with the specified properties replaced.
-
debugFillProperties(
DiagnosticPropertiesBuilder properties) → void - Add additional properties associated with the node.
-
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
-
toStringShort(
) → String -
A brief description of this object, usually just the runtimeType and the
hashCode.
inherited
-
transformed(
Matrix4? transform) → PointerEvent - Transforms the event from the global coordinate space into the coordinate space of an event receiver.
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited
Static Methods
-
removePerspectiveTransform(
Matrix4 transform) → Matrix4 -
Removes the "perspective" component from
transform
. -
transformDeltaViaPositions(
{required Offset untransformedEndPosition, Offset? transformedEndPosition, required Offset untransformedDelta, required Matrix4? transform}) → Offset -
Transforms
untransformedDelta
into the coordinate system described bytransform
. -
transformPosition(
Matrix4? transform, Offset position) → Offset -
Returns the transformation of
position
into the coordinate system described bytransform
.