I would like to write a custom on-screen keyboard that is supposed to replace the default Windows 7 Touch Keyboard that is part of the Tablet Input Panel (TIP), which appears on Tablet PCs when you tab on the little keyboard icon that appears when you select a text field or press a designated keyboard key on the Tablet PC. I've not been able to find any kind of documentation on how to register an application as a touch keyboard, on-screen keyboard or input method or any other documentation to develop an on-screen keyboard that integrates with Windows 7.
Do you know a tutorial or reference that explains how to replace the default Touch Keyboard with a custom keyboard? Note that the "Touch Keyboard" that is part of the TIP is different from the On-Screen Keyboard (osk.exe) that ships since Windows 2000.
Update: The reason I am looking for an official way to integrate with Windows 7 is because the custom keyboard should also replace the default touch keyboard that appears on the login screen of Windows 7 on Tablet PCs.