TimelineTileBuilderDelegate class
The widgets returned from the builder callback are automatically wrapped in AutomaticKeepAlive widgets if addAutomaticKeepAlives is true (the default) and in RepaintBoundary widgets if addRepaintBoundaries is true (also the default).
Accessibility
The CustomScrollView requires that its semantic children are annotated
using IndexedSemantics. This is done by default in the delegate with the
addSemanticIndexes parameter set to true.
If multiple delegates are used in a single scroll view, then the indexes
will not be correct by default. The semanticIndexOffset can be used to
offset the semantic indexes of each delegate so that the indexes are
monotonically increasing. For example, if a scroll view contains two
delegates where the first has 10 children contributing semantics, then the
second delegate should offset its children by 10.
See also:
- IndexedSemantics, for an example of manually annotating child nodes with semantic indexes.
- Inheritance
-
- Object
- SliverChildDelegate
- SliverChildBuilderDelegate
- TimelineTileBuilderDelegate
Constructors
- TimelineTileBuilderDelegate(NullableIndexedWidgetBuilder builder, {ChildIndexGetter? findChildIndexCallback, int? childCount, bool addAutomaticKeepAlives = true, bool addRepaintBoundaries = true, bool addSemanticIndexes = true, SemanticIndexCallback semanticIndexCallback = _kDefaultSemanticIndexCallback, int semanticIndexOffset = 0})
Properties
- addAutomaticKeepAlives → bool
-
Whether to wrap each child in an AutomaticKeepAlive.
finalinherited
- addRepaintBoundaries → bool
-
Whether to wrap each child in a RepaintBoundary.
finalinherited
- addSemanticIndexes → bool
-
Whether to wrap each child in an IndexedSemantics.
finalinherited
- builder → NullableIndexedWidgetBuilder
-
Called to build children for the sliver.
finalinherited
- childCount → int?
-
The total number of children this delegate can provide.
finalinherited
- estimatedChildCount → int?
-
Returns an estimate of the number of children this delegate will build.
no setterinherited
- findChildIndexCallback → ChildIndexGetter?
-
Called to find the new index of a child based on its key in case of reordering.
finalinherited
- hashCode → int
-
The hash code for this object.
no setterinherited
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
- semanticIndexCallback → SemanticIndexCallback
-
A SemanticIndexCallback which is used when addSemanticIndexes is true.
finalinherited
- semanticIndexOffset → int
-
An initial offset to add to the semantic indexes generated by this widget.
finalinherited
Methods
-
build(
BuildContext context, int index) → Widget? -
Returns the child with the given index.
inherited
-
debugFillDescription(
List< String> description) → void -
Add additional information to the given description for use by toString.
inherited
-
didFinishLayout(
int firstIndex, int lastIndex) → void -
Called at the end of layout to indicate that layout is now complete.
inherited
-
estimateMaxScrollOffset(
int firstIndex, int lastIndex, double leadingScrollOffset, double trailingScrollOffset) → double? -
Returns an estimate of the max scroll extent for all the children.
inherited
-
findIndexByKey(
Key key) → int? -
Find index of child element with associated key.
inherited
-
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
shouldRebuild(
covariant SliverChildBuilderDelegate oldDelegate) → bool -
Called whenever a new instance of the child delegate class is
provided to the sliver.
inherited
-
toString(
) → String -
A string representation of this object.
inherited
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited