ListWheelChildBuilderDelegate class
A delegate that supplies children for ListWheelScrollView using a builder callback.
ListWheelScrollView lazily constructs its children to avoid creating more children than are visible through the Viewport. This delegate provides children using an IndexedWidgetBuilder callback, so that the children do not have to be built until they are displayed.
- Inheritance
- Object
- ListWheelChildDelegate
- ListWheelChildBuilderDelegate
Constructors
- ListWheelChildBuilderDelegate({@required IndexedWidgetBuilder builder, int childCount })
- Constructs the delegate from a builder callback.
Properties
- builder → IndexedWidgetBuilder
-
Called lazily to build children.
final
- childCount → int
-
If non-null, childCount is the maximum number of children that can be
provided, and children are available from 0 to childCount - 1. [...]
final
- estimatedChildCount → int
-
Returns an estimate of the number of children this delegate will build.
read-only, override
- 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
Methods
-
build(
BuildContext context, int index) → Widget -
Return the child at the given index. If the child at the given
index does not exist, return null.
override
-
shouldRebuild(
covariant ListWheelChildBuilderDelegate oldDelegate) → bool -
Called to check whether this and the old delegate are actually 'different',
so that the caller can decide to rebuild or not.
override
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a non-existent method or property is accessed. [...]
inherited
-
toString(
) → String -
Returns a string representation of this object.
inherited
-
trueIndexOf(
int index) → int -
Returns the true index for a child built at a given index. Defaults to
the given index, however if the delegate is ListWheelChildLoopingListDelegate,
this value is the index of the true element that the delegate is looping to. [...]
inherited
Operators
-
operator ==(
dynamic other) → bool -
The equality operator. [...]
inherited