ChildLayoutDryDelegate class

A delegate that performs dry layout operations on behalf of a child.

ChildLayoutDryDelegate wraps an existing ChildLayout and provides the same interface, but performs operations without side effects. It's used for measuring layouts without actually positioning elements.

This class is particularly useful for:

• Calculating intrinsic sizes
• Measuring layouts for scrolling calculations
• Performing "what-if" layout scenarios

Mixed-in types

• ChildLayout

Constructors

ChildLayoutDryDelegate(ChildLayout child, ChildLayoutCache layoutCache)

Creates a dry layout delegate for the given child.

Properties

child → ChildLayout

The actual child layout being delegated to.

final

debugKey → Object?

Debug key for identifying this child in debug output.

no setter, inherited

hashCode → int

The hash code for this object.

no setter, inherited

layoutCache → ChildLayoutCache

The cache to use for this dry layout operation.

final

layoutData → LayoutData

Returns the child's layout data.

no setter, override

nextSibling ↔ ChildLayout?

The next sibling in the dry layout chain.

getter/setter pair, override-getter

offset → LayoutOffset

Throws an exception - offset is not supported in dry layout.

no setter, override

previousSibling ↔ ChildLayout?

The previous sibling in the dry layout chain.

getter/setter pair, override-getter

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

size → LayoutSize

Throws an exception - size is not available in dry layout.

no setter, override

Methods

clearCache() → void

Clears the cache (no-op for dry delegates).

override

dryLayout(LayoutConstraints constraints) → LayoutSize

Performs a dry layout on the child.

override

getDistanceToBaseline(LayoutTextBaseline baseline) → double

Gets the distance to baseline from the child.

override

getMaxIntrinsicHeight(double width) → double

Gets the maximum intrinsic height from the child.

override

getMaxIntrinsicWidth(double height) → double

Gets the maximum intrinsic width from the child.

override

getMinIntrinsicHeight(double width) → double

Gets the minimum intrinsic height from the child.

override

getMinIntrinsicWidth(double height) → double

Gets the minimum intrinsic width from the child.

override

layout(LayoutRect parentOffset, LayoutOffset offset, LayoutSize size, OverflowBounds overflowBounds, {LayoutOffset? revealOffset}) → void

Throws an exception - actual layout is not supported in dry operations.

override

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Methods

backwardCopy(ChildLayout? lastChild, LayoutHandle<Layout> layoutHandle) → ChildLayoutDryDelegate?

Creates a backward-linked chain of dry layout delegates.

forwardCopy(ChildLayout? firstChild, LayoutHandle<Layout> layoutHandle) → ChildLayoutDryDelegate?

Creates a forward-linked chain of dry layout delegates.