Ans:

IChildList: Indicates the number of children in a container.

IStyleClient: Indicates that the component can inherit styles from another object, and supports the setStyle() and getStyle() methods.

ILayoutManager: The LayoutManager is the engine behind Flex's measurement and layout strategy. Layout is performed in three phases; commit, measurement, and layout.

IToolTipManagerClient: Indicates that a component or object can participate in the LayoutManager's commit, measure, and update sequence.

IInvalidating: Indicates that a component or object can use the invalidation mechanism to perform delayed, rather than immediate, property commitment, measurement, and drawing or layout.

IValidatorListener: Indicates that a component can listen for validation events, and therefore show a validation state, such as a red border and error tooltips.

IFlexModule: The IFlexModule interface is used as an optional contract with IFlexModuleFactory. When an IFlexModule instance is created with the IFlexModuleFactory, the factory stores a reference to itself after creation.

IAutomationObject: The IAutomationObject interface defines the interface for a delegate object that implements automation for a component.

IPropertyChangeNotifier: The IPropertyChangeNotifier interface defines a marker interface. Classes that support this interface declare support for event propagation in a specialized manner.

IRepeaterClient: Indicates that a component or object can be used with the Repeater class.

ISimpleStyleClient: This interface describes the properties and methods that an object must implement so that it can participate in the style subsystem. This interface is intended to be used by classes that obtain their style values from other objects rather than through locally set values and type selectors. This interface is implemented by ProgrammaticSkin.

IStateClient: The IStateClient interface defines the interface that components must implement to support view states.

IConstraintClient: The IConstraintClient interface defines the interface for components that support layout constraints. This interface is only used by implementations of constraint-based layout.