BuildableComponentInstance class Components Core

The runtime instance of a BuildableComponent.

A BuildableComponentInstance is created when a stateless BuildableComponent is inserted into the layout. It holds the concrete ComponentInstances for all children built by the BuildableComponent's build method.

The instance:

• Measures and reports its total size based on its children.
• Stacks children vertically, separated by childGap spaces.
• Renders each child in its assigned bounds.

Example:

final menuInstance = Menu(['Home', 'About', 'Exit']).createInstance();
final size = menuInstance.measure(Size(width: 80, height: 24));
menuInstance.render(buffer, someBounds);

See also:

• BuildableComponent for the configuration object.
• ParentComponentInstance for shared child-management behavior.

Inheritance

• Object
• ComponentInstance
• ParentComponentInstance
• BuildableComponentInstance

Constructors

BuildableComponentInstance(BuildableComponent component)

Creates an instance from the given component, immediately building and instantiating its children.

Properties

bounds ↔ Rect

The current layout bounds for this component instance.

getter/setter pair, inherited

childGap → int

Vertical spacing between stacked children.

final

childrenInstance → List<ComponentInstance>

The direct child component instances managed by this parent.

no setter, override

component → BuildableComponent

The stateless BuildableComponent configuration for this instance.

final

direction → Axis

The primary axis along which children are laid out. Defaults to vertical stacking.

no setter, inherited

hashCode → int

The hash code for this object.

no setter, inherited

padding → EdgeInsets

The padding inside the component’s allocated space.

final, inherited

position → Position

The position of this component relative to its parent or container.

final, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

fitHeight() → int

Returns the height this component should occupy based on its content or layout rules.

override

fitWidth() → int

Returns the width this component should occupy based on its content or layout rules.

override

measure(Size maxSize) → Size

Measures the size this component would like to occupy, given a maximum available size.

override

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

render(CanvasBuffer buffer, Rect bounds) → void

Renders the component into the provided CanvasBuffer using the given bounds as the drawing area.

override

shouldRenderChild(ComponentInstance child) → bool

Determines whether a given child should be rendered. Defaults to false, meaning the decision is left to layout/rendering code.

inherited

toString() → String

A string representation of this object.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited