An interface is basically a contract between two classes. In the example below, the class containing the mentioned line doesn't care which class is passed to it from the _textFlow.interactionManager property, it just makes sure that it implements the interface (i.e. the contract). So, _textFlow.interactionManager probably returns an untyped Object and the command IEditManager() casts it so the compiler doesn't throw an error when the method applyParagraphFormat() is called. In other word, if the IEditManager() command was to be removed, the compiler would have choked out since _textFlow.interactionManager returns an Object and that applyParagraphFormat() is not a method belonging to a standard Object. Interface allows for polymorphism and is a very powerful tool in any OOP programmer tool belt. You definitely need to read up on it and understand it. You can find good tutorials on-line or just read the Programming AS3 section in the help.
________________________________ From: [email protected] [mailto:[email protected]] On Behalf Of foodyi Sent: Monday, May 25, 2009 2:12 AM To: [email protected] Subject: [flexcoders] as3 interface syntax ? hi,all i read adobe textlayout framwork's sample code , i don't understand the code below: IEditManager(_textFlow.interactionManager).applyParagraphFormat(pf); thanks for your reply. foodyi
