IInvalidating  - AS3 Flex

Calling this method results in a call to the component's validateDisplayList() method before the display list is rendered.

For components that extend UIComponent, this implies that updateDisplayList() is called.

Calling this method results in a call to the component's validateProperties() method before the display list is rendered.

For components that extend UIComponent, this implies that commitProperties() is called.

Calling this method results in a call to the component's validateSize() method before the display list is rendered.

For components that extend UIComponent, this implies that measure() is called, unless the component has both explicitWidth and explicitHeight set.

Validates and updates the properties and layout of this object by immediately calling validateProperties(), validateSize(), and validateDisplayList(), if necessary.

When properties are changed, the new values do not usually have an immediate effect on the component. Usually, all of the application code that needs to be run at that time is executed. Then the LayoutManager starts calling the validateProperties(), validateSize(), and validateDisplayList() methods on components, based on their need to be validated and their depth in the hierarchy of display list objects.

For example, setting the width property is delayed, because it may require recalculating the widths of the object's children or its parent. Delaying the processing also prevents it from being repeated multiple times if the application code sets the width property more than once. This method lets you manually override this behavior.