LayoutItem class abstract
An interface for widgets that participate in custom layout algorithms.
LayoutItem defines the common properties that layout widgets use to control their positioning, sizing, and behavior within a layout container. It provides a standardized way for layout algorithms to access and manipulate widget properties during the layout process.
This interface is implemented by widgets like FlexItem and AbsoluteItem that need to communicate layout constraints and positioning information to their parent layout containers.
- Implemented types
- Implementers
- Available extensions
Constructors
Properties
- asAbsoluteItem → Widget
-
Available on Widget, provided by the WidgetExtension extension
Explicitly wraps this widget as an AbsoluteItem.no setter - asFlexItem → Widget
-
Available on Widget, provided by the WidgetExtension extension
Explicitly wraps this widget as a FlexItem.no setter - aspectRatio → double?
-
The aspect ratio constraint (width/height) for this item.
no setter
- bottom → PositionUnit?
-
The offset from the bottom edge of the parent container.
no setter
- hashCode → int
-
The hash code for this object.
no setterinherited
- height → SizeUnit?
-
The preferred height of this item.
no setter
- key → Key?
-
Controls how one widget replaces another widget in the tree.
finalinherited
- left → PositionUnit?
-
The offset from the left edge of the parent container.
no setter
- maxHeight → SizeUnit?
-
The maximum height constraint for this item.
no setter
- maxWidth → SizeUnit?
-
The maximum width constraint for this item.
no setter
- minHeight → SizeUnit?
-
The minimum height constraint for this item.
no setter
- minWidth → SizeUnit?
-
The minimum width constraint for this item.
no setter
- paintOrder → int?
-
The paint order for this item, controlling drawing order when overlapping.
Lower values are painted first (behind), higher values are painted last (on top).
no setter
- right → PositionUnit?
-
The offset from the right edge of the parent container.
no setter
- runtimeType → Type
-
A representation of the runtime type of the object.
no setterinherited
- top → PositionUnit?
-
The offset from the top edge of the parent container.
no setter
- width → SizeUnit?
-
The preferred width of this item.
no setter
Methods
-
aspectRatio(
double aspectRatio, [Key? key]) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets the aspect ratio constraint for this widget. -
bottom(
PositionUnit bottom, [Key? key]) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets the distance from the bottom edge of the parent container. -
constrained(
{SizeUnit? minWidth, SizeUnit? maxWidth, SizeUnit? minHeight, SizeUnit? maxHeight, Key? key}) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets comprehensive size constraints including both minimum and maximum bounds. -
createElement(
) → Element -
Inflates this configuration to a concrete instance.
inherited
-
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
-
flexGrow(
double flexGrow, [Key? key]) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets the flex grow factor for this widget within a flex container. -
flexShrink(
double flexShrink, [Key? key]) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets the flex shrink factor for this widget within a flex container. -
height(
SizeUnit height, [Key? key]) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets the height of this widget using a SizeUnit. -
id(
Object valueKey) → Widget -
Available on Widget, provided by the WidgetExtension extension
Assigns a ValueKey to this widget using the provided value. -
key(
Key key) → Widget -
Available on Widget, provided by the WidgetExtension extension
Assigns a Key to this widget. -
left(
PositionUnit left, [Key? key]) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets the distance from the left edge of the parent container. -
maxHeight(
SizeUnit maxHeight, [Key? key]) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets the maximum height constraint for this widget using a SizeUnit. -
maxSized(
{SizeUnit? maxWidth, SizeUnit? maxHeight, Key? key}) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets maximum width and height constraints simultaneously. -
maxWidth(
SizeUnit maxWidth, [Key? key]) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets the maximum width constraint for this widget using a SizeUnit. -
minHeight(
SizeUnit minHeight, [Key? key]) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets the minimum height constraint for this widget using a SizeUnit. -
minSized(
{SizeUnit? minWidth, SizeUnit? minHeight, Key? key}) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets minimum width and height constraints simultaneously. -
minWidth(
SizeUnit minWidth, [Key? key]) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets the minimum width constraint for this widget using a SizeUnit. -
noSuchMethod(
Invocation invocation) → dynamic -
Invoked when a nonexistent method or property is accessed.
inherited
-
paintOrder(
int paintOrder, [Key? key]) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets the paint order for this widget within its parent container. -
position(
PositionType position, [Key? key]) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets the position type for this widget to control positioning context. -
positioned(
{PositionUnit? top, PositionUnit? left, PositionUnit? bottom, PositionUnit? right, Key? key}) → Widget -
Available on Widget, provided by the WidgetExtension extension
Positions the widget using multiple edge offsets simultaneously. -
right(
PositionUnit right, [Key? key]) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets the distance from the right edge of the parent container. -
selfAligned(
BoxAlignmentGeometry alignSelf, [Key? key]) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets the alignment of this widget within its parent flex container. -
sized(
{SizeUnit? width, SizeUnit? height, Key? key}) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets both width and height dimensions simultaneously. -
toDiagnosticsNode(
{String? name, DiagnosticsTreeStyle? style}) → DiagnosticsNode -
Returns a debug representation of the object that is used by debugging
tools and by DiagnosticsNode.toStringDeep.
inherited
-
top(
PositionUnit top, [Key? key]) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets the distance from the top edge of the parent container. -
toString(
{DiagnosticLevel minLevel = DiagnosticLevel.info}) → String -
A string representation of this object.
inherited
-
toStringDeep(
{String prefixLineOne = '', String? prefixOtherLines, DiagnosticLevel minLevel = DiagnosticLevel.debug, int wrapWidth = 65}) → 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
-
width(
SizeUnit width, [Key? key]) → Widget -
Available on Widget, provided by the WidgetExtension extension
Sets the width of this widget using a SizeUnit.
Operators
-
operator ==(
Object other) → bool -
The equality operator.
inherited