The document discusses the Flex invalidation mechanism, which is used by the Flex framework to optimize handling of visual changes to components and layout of containers. It introduces the three key methods - commitProperties(), measure(), and updateDisplayList() - that components override to implement invalidation. Components call invalidate() to flag changes, and the layout manager then calls the validation methods in priority order to synchronize updates efficiently across the display list. Examples are provided to illustrate how invalidation works and improves performance over directly calling update().

1. Invalidation Routines, Pounded Into Your Cranium, Once And For All! Sakri Rosenstrom

4. The How? Meet the 3 methods!

5. The How? Meet the 3 methods! commitProperties() commitProperties()

6. The How? Meet the 3 methods! measure() measure()

7. The How? Meet the 3 methods! updateDisplayList() updateDisplayList()

15. The necessary ‘Flow’ Graphic!