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// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
// @dart = 2.12
part of dart.ui;
/// How the pointer has changed since the last report.
enum PointerChange {
/// The input from the pointer is no longer directed towards this receiver.
cancel,
/// The device has started tracking the pointer.
///
/// For example, the pointer might be hovering above the device, having not yet
/// made contact with the surface of the device.
add,
/// The device is no longer tracking the pointer.
///
/// For example, the pointer might have drifted out of the device's hover
/// detection range or might have been disconnected from the system entirely.
remove,
/// The pointer has moved with respect to the device while not in contact with
/// the device.
hover,
/// The pointer has made contact with the device.
down,
/// The pointer has moved with respect to the device while in contact with the
/// device.
move,
/// The pointer has stopped making contact with the device.
up,
}
/// The kind of pointer device.
enum PointerDeviceKind {
/// A touch-based pointer device.
touch,
/// A mouse-based pointer device.
mouse,
/// A pointer device with a stylus.
stylus,
/// A pointer device with a stylus that has been inverted.
invertedStylus,
/// An unknown pointer device.
unknown
}
/// The kind of pointer signal event.
enum PointerSignalKind {
/// The event is not associated with a pointer signal.
none,
/// A pointer-generated scroll (e.g., mouse wheel or trackpad scroll).
scroll,
/// An unknown pointer signal kind.
unknown
}
/// Information about the state of a pointer.
class PointerData {
/// Creates an object that represents the state of a pointer.
const PointerData({
this.embedderId = 0,
this.timeStamp = Duration.zero,
this.change = PointerChange.cancel,
this.kind = PointerDeviceKind.touch,
this.signalKind,
this.device = 0,
this.pointerIdentifier = 0,
this.physicalX = 0.0,
this.physicalY = 0.0,
this.physicalDeltaX = 0.0,
this.physicalDeltaY = 0.0,
this.buttons = 0,
this.obscured = false,
this.synthesized = false,
this.pressure = 0.0,
this.pressureMin = 0.0,
this.pressureMax = 0.0,
this.distance = 0.0,
this.distanceMax = 0.0,
this.size = 0.0,
this.radiusMajor = 0.0,
this.radiusMinor = 0.0,
this.radiusMin = 0.0,
this.radiusMax = 0.0,
this.orientation = 0.0,
this.tilt = 0.0,
this.platformData = 0,
this.scrollDeltaX = 0.0,
this.scrollDeltaY = 0.0,
});
/// Unique identifier that ties the [PointerEvent] to embedder event created it.
///
/// No two pointer events can have the same [embedderId]. This is different from
/// [pointerIdentifier] - used for hit-testing, whereas [embedderId] is used to
/// identify the platform event.
final int embedderId;
/// Time of event dispatch, relative to an arbitrary timeline.
final Duration timeStamp;
/// How the pointer has changed since the last report.
final PointerChange change;
/// The kind of input device for which the event was generated.
final PointerDeviceKind kind;
/// The kind of signal for a pointer signal event.
final PointerSignalKind? signalKind;
/// Unique identifier for the pointing device, reused across interactions.
final int device;
/// Unique identifier for the pointer.
///
/// This field changes for each new pointer down event. Framework uses this
/// identifier to determine hit test result.
final int pointerIdentifier;
/// X coordinate of the position of the pointer, in physical pixels in the
/// global coordinate space.
final double physicalX;
/// Y coordinate of the position of the pointer, in physical pixels in the
/// global coordinate space.
final double physicalY;
/// The distance of pointer movement on X coordinate in physical pixels.
final double physicalDeltaX;
/// The distance of pointer movement on Y coordinate in physical pixels.
final double physicalDeltaY;
/// Bit field using the *Button constants (primaryMouseButton,
/// secondaryStylusButton, etc). For example, if this has the value 6 and the
/// [kind] is [PointerDeviceKind.invertedStylus], then this indicates an
/// upside-down stylus with both its primary and secondary buttons pressed.
final int buttons;
/// Set if an application from a different security domain is in any way
/// obscuring this application's window. (Aspirational; not currently
/// implemented.)
final bool obscured;
/// Set if this pointer data was synthesized by pointer data packet converter.
/// pointer data packet converter will synthesize additional pointer datas if
/// the input sequence of pointer data is illegal.
///
/// For example, a down pointer data will be synthesized if the converter receives
/// a move pointer data while the pointer is not previously down.
final bool synthesized;
/// The pressure of the touch as a number ranging from 0.0, indicating a touch
/// with no discernible pressure, to 1.0, indicating a touch with "normal"
/// pressure, and possibly beyond, indicating a stronger touch. For devices
/// that do not detect pressure (e.g. mice), returns 1.0.
final double pressure;
/// The minimum value that [pressure] can return for this pointer. For devices
/// that do not detect pressure (e.g. mice), returns 1.0. This will always be
/// a number less than or equal to 1.0.
final double pressureMin;
/// The maximum value that [pressure] can return for this pointer. For devices
/// that do not detect pressure (e.g. mice), returns 1.0. This will always be
/// a greater than or equal to 1.0.
final double pressureMax;
/// The distance of the detected object from the input surface (e.g. the
/// distance of a stylus or finger from a touch screen), in arbitrary units on
/// an arbitrary (not necessarily linear) scale. If the pointer is down, this
/// is 0.0 by definition.
final double distance;
/// The maximum value that a distance can return for this pointer. If this
/// input device cannot detect "hover touch" input events, then this will be
/// 0.0.
final double distanceMax;
/// The area of the screen being pressed, scaled to a value between 0 and 1.
/// The value of size can be used to determine fat touch events. This value
/// is only set on Android, and is a device specific approximation within
/// the range of detectable values. So, for example, the value of 0.1 could
/// mean a touch with the tip of the finger, 0.2 a touch with full finger,
/// and 0.3 the full palm.
final double size;
/// The radius of the contact ellipse along the major axis, in logical pixels.
final double radiusMajor;
/// The radius of the contact ellipse along the minor axis, in logical pixels.
final double radiusMinor;
/// The minimum value that could be reported for radiusMajor and radiusMinor
/// for this pointer, in logical pixels.
final double radiusMin;
/// The minimum value that could be reported for radiusMajor and radiusMinor
/// for this pointer, in logical pixels.
final double radiusMax;
/// For PointerDeviceKind.touch events:
///
/// The angle of the contact ellipse, in radius in the range:
///
/// -pi/2 < orientation <= pi/2
///
/// ...giving the angle of the major axis of the ellipse with the y-axis
/// (negative angles indicating an orientation along the top-left /
/// bottom-right diagonal, positive angles indicating an orientation along the
/// top-right / bottom-left diagonal, and zero indicating an orientation
/// parallel with the y-axis).
///
/// For PointerDeviceKind.stylus and PointerDeviceKind.invertedStylus events:
///
/// The angle of the stylus, in radians in the range:
///
/// -pi < orientation <= pi
///
/// ...giving the angle of the axis of the stylus projected onto the input
/// surface, relative to the positive y-axis of that surface (thus 0.0
/// indicates the stylus, if projected onto that surface, would go from the
/// contact point vertically up in the positive y-axis direction, pi would
/// indicate that the stylus would go down in the negative y-axis direction;
/// pi/4 would indicate that the stylus goes up and to the right, -pi/2 would
/// indicate that the stylus goes to the left, etc).
final double orientation;
/// For PointerDeviceKind.stylus and PointerDeviceKind.invertedStylus events:
///
/// The angle of the stylus, in radians in the range:
///
/// 0 <= tilt <= pi/2
///
/// ...giving the angle of the axis of the stylus, relative to the axis
/// perpendicular to the input surface (thus 0.0 indicates the stylus is
/// orthogonal to the plane of the input surface, while pi/2 indicates that
/// the stylus is flat on that surface).
final double tilt;
/// Opaque platform-specific data associated with the event.
final int platformData;
/// For events with signalKind of PointerSignalKind.scroll:
///
/// The amount to scroll in the x direction, in physical pixels.
final double scrollDeltaX;
/// For events with signalKind of PointerSignalKind.scroll:
///
/// The amount to scroll in the y direction, in physical pixels.
final double scrollDeltaY;
@override
String toString() => 'PointerData(x: $physicalX, y: $physicalY)';
/// Returns a complete textual description of the information in this object.
String toStringFull() {
return '$runtimeType('
'embedderId: $embedderId, '
'timeStamp: $timeStamp, '
'change: $change, '
'kind: $kind, '
'signalKind: $signalKind, '
'device: $device, '
'pointerIdentifier: $pointerIdentifier, '
'physicalX: $physicalX, '
'physicalY: $physicalY, '
'physicalDeltaX: $physicalDeltaX, '
'physicalDeltaY: $physicalDeltaY, '
'buttons: $buttons, '
'synthesized: $synthesized, '
'pressure: $pressure, '
'pressureMin: $pressureMin, '
'pressureMax: $pressureMax, '
'distance: $distance, '
'distanceMax: $distanceMax, '
'size: $size, '
'radiusMajor: $radiusMajor, '
'radiusMinor: $radiusMinor, '
'radiusMin: $radiusMin, '
'radiusMax: $radiusMax, '
'orientation: $orientation, '
'tilt: $tilt, '
'platformData: $platformData, '
'scrollDeltaX: $scrollDeltaX, '
'scrollDeltaY: $scrollDeltaY'
')';
}
}
/// A sequence of reports about the state of pointers.
class PointerDataPacket {
/// Creates a packet of pointer data reports.
const PointerDataPacket({ this.data = const <PointerData>[] }) : assert(data != null); // ignore: unnecessary_null_comparison
/// Data about the individual pointers in this packet.
///
/// This list might contain multiple pieces of data about the same pointer.
final List<PointerData> data;
}