PointerEvent class
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:
- Window.devicePixelRatio, which defines the device's current resolution.
- Implementers
- Annotations
- @immutable
Constructors
- PointerEvent({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 })
-
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. [...]
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
- kind → PointerDeviceKind
-
The kind of input device for which the event was generated.
final
- 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
- platformData → int
-
Opaque platform-specific data associated with the event.
final
- pointer → int
-
Unique identifier for the pointer, not reused.
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 minimum 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
- 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
- hashCode → int
-
The hash code for this object. [...]
read-only, inherited
- runtimeType → Type
-
A representation of the runtime type of the object.
read-only, inherited
Methods
-
toString(
) → String -
Returns a string representation of this object.
override
-
toStringFull(
) → String - Returns a complete textual description of this event.
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a non-existent method or property is accessed. [...]
inherited
Operators
-
operator ==(
dynamic other) → bool -
The equality operator. [...]
inherited