SliverWaterfallFlow class

A sliver that places multiple box children in a two dimensional arrangement and masonry layout.

SliverWaterfallFlow places its children in arbitrary positions determined by gridDelegate. Each child is forced to have the size specified by the gridDelegate.

The main axis direction of a grid is the direction in which it scrolls; the cross axis direction is the orthogonal direction.

This example, which would be inserted into a CustomScrollView.slivers list, shows twenty boxes in a pretty teal grid with masonry layout:

SliverWaterfallFlow(
  gridDelegate: SliverWaterfallFlowDelegate(
    crossAxisCount: 2,
    mainAxisSpacing: 10.0,
    crossAxisSpacing: 10.0,
  ),
  delegate: SliverChildBuilderDelegate(
    (BuildContext context, int index) {
      return Container(
        alignment: Alignment.center,
        color: Colors.teal[100 * (index % 9)],
        child: Text('grid item $index'),
        height: 50.0 + 100.0 * (index % 9)
      );
    },
    childCount: 20,
  ),
)

{@end-tool}

See also:

• SliverList, which places its children in a linear array.
• SliverFixedExtentList, which places its children in a linear array with a fixed extent in the main axis.
• SliverPrototypeExtentList, which is similar to SliverFixedExtentList except that it uses a prototype list item instead of a pixel value to define the main axis extent of each item.
• SliverGrid, which places its children in arbitrary positions.

Inheritance

• Object
• DiagnosticableTree
• Widget
• RenderObjectWidget
• SliverWithKeepAliveWidget
• SliverMultiBoxAdaptorWidget
• SliverWaterfallFlow

Constructors

SliverWaterfallFlow({Key? key, required SliverChildDelegate delegate, required SliverWaterfallFlowDelegate gridDelegate})

Creates a sliver that places multiple box children in a two dimensional arrangement and masonry layout.

const

SliverWaterfallFlow.count({Key? key, required int crossAxisCount, double mainAxisSpacing = 0.0, double crossAxisSpacing = 0.0, List<Widget> children = const <Widget>[], LastChildLayoutTypeBuilder? lastChildLayoutTypeBuilder, CollectGarbage? collectGarbage, ViewportBuilder? viewportBuilder, bool closeToTrailing = false})

Creates a sliver that places multiple box children in a two dimensional arrangement and masonry layout with a fixed number of tiles in the cross axis.

SliverWaterfallFlow.extent({Key? key, required double maxCrossAxisExtent, double mainAxisSpacing = 0.0, double crossAxisSpacing = 0.0, List<Widget> children = const <Widget>[], LastChildLayoutTypeBuilder? lastChildLayoutTypeBuilder, CollectGarbage? collectGarbage, ViewportBuilder? viewportBuilder, bool closeToTrailing = false})

Creates a sliver that places multiple box children in masonry layout with tiles that each have a maximum cross-axis extent.

Properties

delegate → SliverChildDelegate

The delegate that provides the children for this widget.

final, inherited

gridDelegate → SliverWaterfallFlowDelegate

The delegate that controls the size and position of the children.

final

hashCode → int

The hash code for this object.

no setter, inherited

key → Key?

Controls how one widget replaces another widget in the tree.

final, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

createElement() → SliverMultiBoxAdaptorElement

RenderObjectWidgets always inflate to a RenderObjectElement subclass.

inherited

createRenderObject(BuildContext context) → RenderSliverWaterfallFlow

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.

inherited

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.

inherited

estimateMaxScrollOffset(SliverConstraints? constraints, int firstIndex, int lastIndex, double leadingScrollOffset, double trailingScrollOffset) → double?

Returns an estimate of the max scroll extent for all the children.

inherited

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent 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 RenderSliverWaterfallFlow 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.

inherited