I am utterly befuddled by this. I was under the impression that ALL BRS components have their methods implemented by way of BRS interfaces. I seem to recollect somewhere it was saying components are just a collection of interfaces and nothing else.
But here is example of it not being the case. By documentation,
roParagraphScreen has
ifSetMessagePort - but not in practice:
BrightScript Debugger> para = CreateObject("roParagraphScreen")
BrightScript Debugger> ? para
<Component: roParagraphScreen>
BrightScript Debugger> ? getInterface(para, "ifSetMessagePort")
invalid
BrightScript Debugger> para.SetMessagePort(invalid)
BrightScript Debugger> para.ifSetMessagePort.SetMessagePort(invalid)
Interface not a member of BrightScript Component (runtime error &hf3) in $LIVECOMPILE(152)
Same is the case with
roListScreen,
roCaptionRenderer and probably more.
You can set the port with
SetMessagePort() but the interface
ifSetMessagePort is not there, how is that possible?
On the other hand,
roUrlTransfer delivers on the promise of
ifSetMessagePort - and so do many (most?) others:
BrightScript Debugger> url = CreateObject("roUrlTransfer")
BrightScript Debugger> ? getInterface(url, "ifSetMessagePort")
<Interface: ifSetMessagePort>
BrightScript Debugger> url.ifSetMessagePort.setMessagePort(invalid)
BrightScript Debugger> url.setMessagePort(invalid)
BrightScript Debugger>
