SliverWaterfallFlowDelegate class abstract

create by zmtzawqlp on 2019/11/9

Controls the masonry layout of tiles.

Given the current constraints on the grid, a SliverGridDelegate computes the masonry layout for the tiles in the grid. The tiles can be placed as masonry layout with equally cross-axis sized and spaced. A contiguous sequence of children are laid out after the shortest one of the previous row/column。

See also:

• SliverWaterfallFlowDelegateWithFixedCrossAxisCount, which creates a masonry layout with a fixed number of tiles in the cross axis.
• SliverWaterfallFlowDelegateWithMaxCrossAxisExtent, which creates a masonry layout that have a maximum cross-axis extent.
• GridMasonryView, which uses this delegate to control the layout of its tiles.
• SliverWaterfallFlow, which uses this delegate to control the layout of its tiles.
• RenderSliverWaterfallFlow, which uses this delegate to control the layout of its tiles.

Inheritance

• Object
• ExtendedListDelegate
• SliverWaterfallFlowDelegate

Constructors

SliverWaterfallFlowDelegate({double mainAxisSpacing = 0.0, double crossAxisSpacing = 0.0, LastChildLayoutTypeBuilder? lastChildLayoutTypeBuilder, CollectGarbage? collectGarbage, ViewportBuilder? viewportBuilder, bool closeToTrailing = false})

Creates a delegate that makes masonry layout with tiles in the cross axis.

const

Properties

closeToTrailing → bool

when reverse property of List is true, layout is as following. it likes chat list, and new session will insert to zero index but it's not right when items are not full of viewport.

final, inherited

collectGarbage → CollectGarbage?

Call when collect garbage, return indexes of children which are disposed to collect

final, inherited

crossAxisSpacing → double

The number of logical pixels between each child along the cross axis.

final

hashCode → int

The hash code for this object.

no setter, inherited

lastChildLayoutTypeBuilder → LastChildLayoutTypeBuilder?

The builder to get layout type of last child Notice: it should only for last child

final, inherited

mainAxisSpacing → double

The number of logical pixels between each child along the main axis.

final

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

viewportBuilder → ViewportBuilder?

The builder to get indexes in viewport

final, inherited

Methods

getChildUsableCrossAxisExtent(SliverConstraints constraints) → double

Return usable cross-axis extent of each child.

getCrossAxisCount(SliverConstraints constraints) → int

Return crossAxisCount by SliverWaterfallFlowDelegateWithFixedCrossAxisCount and SliverWaterfallFlowDelegateWithMaxCrossAxisExtent.

getCrossAxisOffset(SliverConstraints constraints, int? crossAxisIndex) → double

Return the offset of the child in the non-scrolling axis.

getLastChildLayoutType(int index) → LastChildLayoutType

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

shouldRelayout(SliverWaterfallFlowDelegate oldDelegate) → bool

Return true when the children need to be laid out.

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited