BuilderFlexItem class

A builder variant of FlexItem that allows dynamic child construction.

BuilderFlexItem provides the same flex layout capabilities as DirectFlexItem, but instead of taking a pre-built child widget, it accepts a builder function that receives layout information at build time.

This is useful when the flex content needs access to layout bounds, scroll positions, or other dynamic layout state that may change during the widget's lifetime.

Usage

BuilderFlexItem(
  flexGrow: 1.0,
  builder: (context, layoutBox) {
    return Container(
      color: Colors.blue,
      child: Text('Size: ${layoutBox.size}'),
    );
  },
)

Inheritance

Implemented types

FlexItem

Available extensions

WidgetExtension

Constructors

BuilderFlexItem({Key? key, required Widget builder(BuildContext context, LayoutBox box), int? paintOrder, SizeUnit? width, SizeUnit? height, SizeUnit? minWidth, SizeUnit? maxWidth, SizeUnit? minHeight, SizeUnit? maxHeight, double flexGrow = 0.0, double flexShrink = 0.0, double? aspectRatio, PositionUnit? top, PositionUnit? left, PositionUnit? bottom, PositionUnit? right, BoxAlignmentGeometry? alignSelf, PositionType? position}): Creates a flex item with a builder function.
const

Properties

alignSelf → BoxAlignmentGeometry?: The cross-axis alignment for this specific flex item.
final
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.
final
bottom → PositionUnit?: The offset from the bottom edge of the parent container.
final
builder → Widget Function(BuildContext context, LayoutBox box): Builder function that creates the child widget with layout information.
final
flexGrow → double: The flex grow factor for this item.
final
flexShrink → double: The flex shrink factor for this item.
final
hashCode → int: The hash code for this object.
no setterinherited
height → SizeUnit?: The preferred height of this item.
final
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.
final
maxHeight → SizeUnit?: The maximum height constraint for this item.
final
maxWidth → SizeUnit?: The maximum width constraint for this item.
final
minHeight → SizeUnit?: The minimum height constraint for this item.
final
minWidth → SizeUnit?: The minimum width constraint for this item.
final
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).
final
position → PositionType?: The positioning type for this flex item.
final
right → PositionUnit?: The offset from the right edge of the parent container.
final
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.
final
width → SizeUnit?: The preferred width of this item.
final

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.
build(BuildContext context) → Widget: Builds the widget tree for this builder flex item.
override
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() → StatelessElement: Creates a StatelessElement to manage this widget's location in the tree.
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.
override
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