ListWheelViewport class Null safety
A viewport showing a subset of children on a wheel.
Typically used with ListWheelScrollView, this viewport is similar to Viewport in that it shows a subset of children in a scrollable based on the scrolling offset and the children's dimensions. But uses RenderListWheelViewport to display the children on a wheel.
See also:
- ListWheelScrollView, widget that combines this viewport with a scrollable.
- RenderListWheelViewport, the render object that renders the children on a wheel.
- Inheritance
-
- Object
- DiagnosticableTree
- Widget
- RenderObjectWidget
- ListWheelViewport
Constructors
- ListWheelViewport({Key? key, double diameterRatio = RenderListWheelViewport.defaultDiameterRatio, double perspective = RenderListWheelViewport.defaultPerspective, double offAxisFraction = 0.0, bool useMagnifier = false, double magnification = 1.0, double overAndUnderCenterOpacity = 1.0, required double itemExtent, double squeeze = 1.0, bool renderChildrenOutsideViewport = false, required ViewportOffset offset, required ListWheelChildDelegate childDelegate, Clip clipBehavior = Clip.hardEdge})
-
Creates a viewport where children are rendered onto a wheel.
const
Properties
- childDelegate → ListWheelChildDelegate
-
A delegate that lazily instantiates children.
final
- clipBehavior → Clip
-
The content will be clipped (or not) according to this option.
final
- diameterRatio → double
-
A ratio between the diameter of the cylinder and the viewport's size
in the main axis.
final
- hashCode → int
- The hash code for this object.
- itemExtent → double
-
The size of the children along the main axis. Children RenderBoxes will
be given the BoxConstraints of this exact size.
final
- key → Key?
-
Controls how one widget replaces another widget in the tree.
finalinherited
- magnification → double
-
The zoomed-in rate of the magnifier, if it is used.
final
- offAxisFraction → double
-
How much the wheel is horizontally off-center, as a fraction of its width.
This property creates the visual effect of looking at a vertical wheel from
its side where its vanishing points at the edge curves to one side instead
of looking at the wheel head-on.
final
- offset → ViewportOffset
-
ViewportOffset object describing the content that should be visible
in the viewport.
final
- overAndUnderCenterOpacity → double
-
The opacity value that will be applied to the wheel that appears below and
above the magnifier.
final
- perspective → double
-
Perspective of the cylindrical projection.
final
- renderChildrenOutsideViewport → bool
-
Whether to paint children inside the viewport only.
final
- runtimeType → Type
-
A representation of the runtime type of the object.
read-onlyinherited
- squeeze → double
-
The angular compactness of the children on the wheel.
final
- useMagnifier → bool
-
Whether to use the magnifier for the center item of the wheel.
final
Methods
-
createElement(
) → ListWheelElement -
RenderObjectWidgets always inflate to a RenderObjectElement subclass.
override
-
createRenderObject(
BuildContext context) → RenderListWheelViewport -
Creates an instance of the RenderObject class that this
RenderObjectWidget represents, using the configuration described by this
RenderObjectWidget.
override
-
debugDescribeChildren(
) → List< DiagnosticsNode> -
Returns a list of
DiagnosticsNode
objects describing this node's children.protected">@protectedinherited -
debugFillProperties(
DiagnosticPropertiesBuilder properties) → void -
Add additional properties associated with the node.
inherited
-
didUnmountRenderObject(
covariant RenderObject renderObject) → void -
A render object previously associated with this widget has been removed
from the tree. The given RenderObject will be of the same type as
returned by this object's createRenderObject.
protected">@protectedinherited
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a non-existent method or property is accessed.
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 short, textual description of this widget.
inherited
-
updateRenderObject(
BuildContext context, covariant RenderListWheelViewport renderObject) → void -
Copies the configuration described by this RenderObjectWidget to the
given RenderObject, which will be of the same type as returned by this
object's createRenderObject.
override
Operators
-
operator ==(
Object other) → bool -
The equality operator.
nonVirtual">@nonVirtualinherited