ScaleGestureRecognizer class

Recognizes a scale gesture.

ScaleGestureRecognizer tracks the pointers in contact with the screen and calculates their focal point and indicated scale. When a focal pointer is established, the recognizer calls onStart. As the focal point and scale change, the recognizer calls onUpdate. When the pointers are no longer in contact with the screen, the recognizer calls onEnd.

Inheritance

Constructors

ScaleGestureRecognizer({Object debugOwner })
Create a gesture recognizer for interactions intended for scaling content.

Properties

debugDescription String
Returns a very short pretty description of the gesture that the recognizer looks for, like 'tap' or 'horizontal drag'.
read-only
onEnd GestureScaleEndCallback
The pointers are no longer in contact with the screen.
read / write
onStart GestureScaleStartCallback
The pointers in contact with the screen have established a focal point and initial scale of 1.0.
read / write
onUpdate GestureScaleUpdateCallback
The pointers in contact with the screen have indicated a new focal point and/or scale.
read / write
debugOwner Object
The recognizer's owner. [...]
final, inherited
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
team GestureArenaTeam
The team that this recognizer belongs to, if any. [...]
read / write, inherited

Methods

acceptGesture(int pointer) → void
addPointer(PointerEvent event) → void
Registers a new pointer that might be relevant to this gesture detector. [...]
didStopTrackingLastPointer(int pointer) → void
Called when the number of pointers this recognizer is tracking changes from one to zero. [...]
dispose() → void
handleEvent(PointerEvent event) → void
Called when a pointer event is routed to this recognizer.
rejectGesture(int pointer) → void
debugDescribeChildren() List<DiagnosticsNode>
Returns a list of DiagnosticsNode objects describing this node's children. [...]
inherited
debugFillProperties(DiagnosticPropertiesBuilder properties) → void
inherited
invokeCallback<T>(String name, RecognizerCallback<T> callback, { String debugReport() }) → T
Invoke a callback provided by the application, catching and logging any exceptions. [...]
@protected, inherited
noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed. [...]
inherited
resolve(GestureDisposition disposition) → void
Resolves this recognizer's participation in each gesture arena with the given disposition.
@mustCallSuper, @protected, inherited
startTrackingPointer(int pointer) → void
Causes events related to the given pointer ID to be routed to this recognizer. [...]
@protected, inherited
stopTrackingIfPointerNoLongerDown(PointerEvent event) → void
Stops tracking the pointer associated with the given event if the event is a PointerUpEvent or a PointerCancelEvent event.
@protected, inherited
stopTrackingPointer(int pointer) → void
Stops events related to the given pointer ID from being routed to this recognizer. [...]
@protected, inherited
toDiagnosticsNode({String name, DiagnosticsTreeStyle style }) DiagnosticsNode
inherited
toString({DiagnosticLevel minLevel: DiagnosticLevel.debug }) String
Returns 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
inherited

Operators

operator ==(dynamic other) bool
The equality operator. [...]
inherited