TSF Application interfaces

The first stop on the TSF tour is the application interfaces.  These are implemented by applications or text controls.

An application (or text control) must implement ITextStoreACP to be considered ‘TSF-aware'.  It may choose to implement any of the other interfaces described in the table below.  I also describe how TSF obtains an instance of each interface.

Interface	Optional?	How Obtained?
ITextStoreACP	No	Passed to ITfDocumentMgr::CreateContext
ITfInputScope	Yes	Returned from ITextStoreACP::RequestSupportedAttrs with GUID_PROP_INPUTSCOPE.
ITfInputScope2	Yes	QI from ITfInputScope
ITfPersistentPropertyLoaderACP	Yes	Passed to ITextStoreACPServices::Unserialize
ITfMouseTrackerACP	Yes	QI from ITextStoreACP
ITfContextOwnerCompositionSink	Yes	Passed to ITfDocumentMgr::CreateContext
ITfUIElementSink	Yes	Passed to ITfSource::AdviseSink (see below)

Note: I put ITfUIElementSink here because text services never implement this interface, even though it's an event sink (described in a future post).   Full-screen applications (or games) would implement this interface if they wish to control the UI drawn by text services.  (See the discussion of UILess mode in MSDN.)

Interface	When to implement
ITextStoreACP	Always implement this.
ITfInputScope	Consider implementing this.  It's not hard, and some text services use it to improve recognition (e.g., Windows Speech Recognition knows about the URL input scope, and has special code for that).
ITfInputScope2	Implement this if you implemented ITfInputScope, and you need the extra functionality (string enumeration).
ITfPersistentPropertyLoaderACP	Implement this if you support asynchronous property loading.  If you don't know what that means, you don't need to implement this.
ITfMouseTrackerACP	Implement this to help handwriting recognition (I believe that you must implement this to get gestures).
ITfContextOwnerCompositionSink	Implement this if you need control over compositions.
ITfUIElementSink	Only implement this if your application takes over the screen, and you still want IMEs to work inside your application.  It's a fair amount of work to implement this.

Comments

• Anonymous
  April 27, 2007
  Great start Eric. This was useful to me too :).