VerticalDragGestureRecognizer class
Recognizes movement in the vertical direction.
Used for vertical scrolling.
See also:
- HorizontalDragGestureRecognizer, for a similar recognizer but for horizontal movement.
- MultiDragGestureRecognizer, for a family of gesture recognizers that track each touch point independently.
- Inheritance
-
- Object
- GestureArenaMember
- GestureRecognizer
- OneSequenceGestureRecognizer
- DragGestureRecognizer
- VerticalDragGestureRecognizer
Constructors
-
VerticalDragGestureRecognizer({Object? debugOwner, Set<
PointerDeviceKind> ? supportedDevices, AllowedButtonsFilter allowedButtonsFilter = _defaultButtonAcceptBehavior}) - Create a gesture recognizer for interactions in the vertical axis.
Properties
- allowedButtonsFilter → AllowedButtonsFilter
-
Called when interaction starts. This limits the dragging behavior
for custom clicks (such as scroll click). Its parameter comes
from PointerEvent.buttons.
finalinherited
- debugDescription → String
-
Returns a very short pretty description of the gesture that the
recognizer looks for, like 'tap' or 'horizontal drag'.
no setteroverride
- debugLastPendingEventTimestamp → Duration?
-
When asserts are enabled, returns the last tracked pending event timestamp
for this recognizer.
no setterinherited
- debugOwner → Object?
-
The recognizer's owner.
finalinherited
- dragStartBehavior ↔ DragStartBehavior
-
Configure the behavior of offsets passed to onStart.
getter/setter pairinherited
- gestureSettings ↔ DeviceGestureSettings?
-
Optional device specific configuration for device gestures that will
take precedence over framework defaults.
getter/setter pairinherited
- hashCode → int
-
The hash code for this object.
no setterinherited
- maxFlingVelocity ↔ double?
-
Fling velocity magnitudes will be clamped to this value.
getter/setter pairinherited
- minFlingDistance ↔ double?
-
The minimum distance an input pointer drag must have moved
to be considered a fling gesture.
getter/setter pairinherited
- minFlingVelocity ↔ double?
-
The minimum velocity for an input pointer drag to be considered fling.
getter/setter pairinherited
- multitouchDragStrategy ↔ MultitouchDragStrategy
-
Configure the multi-finger drag strategy on multi-touch devices.
getter/setter pairinherited
- onCancel ↔ GestureDragCancelCallback?
-
The pointer that previously triggered onDown did not complete.
getter/setter pairinherited
- onDown ↔ GestureDragDownCallback?
-
A pointer has contacted the screen with a primary button and might begin
to move.
getter/setter pairinherited
- onEnd ↔ GestureDragEndCallback?
-
A pointer that was previously in contact with the screen with a primary
button and moving is no longer in contact with the screen and was moving
at a specific velocity when it stopped contacting the screen.
getter/setter pairinherited
- onlyAcceptDragOnThreshold ↔ bool
-
Whether the drag threshold should be met before dispatching any drag callbacks.
getter/setter pairinherited
- onStart ↔ GestureDragStartCallback?
-
A pointer has contacted the screen with a primary button and has begun to
move.
getter/setter pairinherited
- onUpdate ↔ GestureDragUpdateCallback?
-
A pointer that is in contact with the screen with a primary button and
moving has moved again.
getter/setter pairinherited
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
-
supportedDevices
↔ Set<
PointerDeviceKind> ? -
The kind of devices that are allowed to be recognized as provided by
supportedDevices
in the constructor, or the currently deprecatedkind
. These cannot both be set. If both are null, events from all device kinds will be tracked and recognized.getter/setter pairinherited - team ↔ GestureArenaTeam?
-
The team that this recognizer belongs to, if any.
getter/setter pairinherited
- velocityTrackerBuilder ↔ GestureVelocityTrackerBuilder
-
Determines the type of velocity estimation method to use for a potential
drag gesture, when a new pointer is added.
getter/setter pairinherited
Methods
-
acceptGesture(
int pointer) → void -
Called when this member wins the arena for the given pointer id.
inherited
-
addAllowedPointer(
PointerDownEvent event) → void -
Registers a new pointer that's been checked to be allowed by this gesture
recognizer.
inherited
-
addAllowedPointerPanZoom(
PointerPanZoomStartEvent event) → void -
Registers a new pointer pan/zoom that's been checked to be allowed by this
gesture recognizer.
inherited
-
addPointer(
PointerDownEvent event) → void -
Registers a new pointer that might be relevant to this gesture
detector.
inherited
-
addPointerPanZoom(
PointerPanZoomStartEvent event) → void -
Registers a new pointer pan/zoom that might be relevant to this gesture
detector.
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
-
didStopTrackingLastPointer(
int pointer) → void -
Called when the number of pointers this recognizer is tracking changes from one to zero.
inherited
-
dispose(
) → void -
Releases any resources used by the object.
inherited
-
getKindForPointer(
int pointer) → PointerDeviceKind -
For a given pointer ID, returns the device kind associated with it.
inherited
-
handleEvent(
PointerEvent event) → void -
Called when a pointer event is routed to this recognizer.
inherited
-
handleNonAllowedPointer(
PointerDownEvent event) → void -
Handles a pointer being added that's not allowed by this recognizer.
inherited
-
handleNonAllowedPointerPanZoom(
PointerPanZoomStartEvent event) → void -
Handles a pointer pan/zoom being added that's not allowed by this recognizer.
inherited
-
invokeCallback<
T> (String name, RecognizerCallback< T> callback, {String debugReport()?}) → T? -
Invoke a callback provided by the application, catching and logging any
exceptions.
inherited
-
isFlingGesture(
VelocityEstimate estimate, PointerDeviceKind kind) → bool -
Determines if a gesture is a fling or not based on velocity.
override
-
isPointerAllowed(
PointerEvent event) → bool -
Checks whether or not a pointer is allowed to be tracked by this recognizer.
inherited
-
isPointerPanZoomAllowed(
PointerPanZoomStartEvent event) → bool -
Checks whether or not a pointer pan/zoom is allowed to be tracked by this recognizer.
inherited
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
rejectGesture(
int pointer) → void -
Called when this member loses the arena for the given pointer id.
inherited
-
resolve(
GestureDisposition disposition) → void -
Resolves this recognizer's participation in each gesture arena with the
given disposition.
inherited
-
resolvePointer(
int pointer, GestureDisposition disposition) → void -
Resolves this recognizer's participation in the given gesture arena with
the given disposition.
inherited
-
startTrackingPointer(
int pointer, [Matrix4? transform]) → void -
Causes events related to the given pointer ID to be routed to this recognizer.
inherited
-
stopTrackingIfPointerNoLongerDown(
PointerEvent event) → void -
Stops tracking the pointer associated with the given event if the event is
a PointerUpEvent or a PointerCancelEvent event.
inherited
-
stopTrackingPointer(
int pointer) → void -
Stops events related to the given pointer ID from being routed to this recognizer.
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 brief description of this object, usually just the runtimeType and the
hashCode.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited