IntelliJ IDEA
IntelliJ IDEA – the Leading Java and Kotlin IDE, by JetBrains
Features
Type Hierarchy View for Flex Applications
The Type Hierarchy action (Ctrl+H shortcut or View menu, Type Hierarchy) works in IntelliJ IDEA 9 (Maia) for Flex sources (*.mxml and *.as files) showing class, superclass and subclass hierarchy in the same way as for Java sources.