Selection class Null safety

The specification of a selection.

A selection is a data query driven by Gestures. When a selection is triggered, data tuples become either selected or unselected states(At least one tuple is selected), thus may causing their aesthetic attributes change if Attr.onSelection is defined.

See also:

  • SelectionUpdater, updates an aesthetic attribute value when the selection state changes.
  • Attr.onSelection, where selection updates are defined.


Selection({Dim? dim, String? variable, Set<GestureType>? on, Set<GestureType>? clear, Set<PointerDeviceKind>? devices, int? layer})
Creates a selection.


clear Set<GestureType>?
Gesture types that will clear selections.
read / write
devices Set<PointerDeviceKind>?
The device kinds on which this selection is tiggered.
read / write
dim Dim?
Which diemsion of data values will be tested.
read / write
hashCode int
The hash code for this object.
layer int?
The layer of the selector mark.
read / write
on Set<GestureType>?
Gesture types that trigger this selection.
read / write
runtimeType Type
A representation of the runtime type of the object.
variable String?
If set, all tuples sharing the same this variable value with the selected tuple, will also be selected.
read / write


noSuchMethod(Invocation invocation) → dynamic
Invoked when a non-existent method or property is accessed.
toString() String
A string representation of this object.


operator ==(Object other) bool
The equality operator.