Clarion Projects – Touch support in the RTL

Touch input affects all Windows (all objects with HWND handles), and all controls. A generalized processing of touch gestures and mouse input requires changes in the hierarchy of classes within the RTL that deal with user interactions. By generalized I mean the ACCEPT loop must recognize and handle all possible “gestures”, and then it needs to decode sequences of WM_POINTER* messages to matching gestures and send them back to the your program in a way that makes it easy to respond to. And further, indirectly Touch support affects some areas that are not related to input at all, for example setting and getting properties.

The RTL also needs to expect that touch/pointer messages can be sent to different windows depending upon where the touch is done, and to windows running in different threads as well.  Clarion programs are typically very thread-intensive, unlike the typical MS VC/VB/C# programs which in terms of use of threads, are diametrically the opposite (the UI is almost always single-threaded).

In other words the implementation isn’t a project for a rainy weekend, instead its a complex melding of current code to recognize
user input, with a brand new set of requirements for touch gestures.

A brief description of some of the functionality being worked on:
– scrolling of LIST control
– Zoom in/out
– touch to press button, toggle checkbox, select radio option
– touch to give focus to other controls
– and others that we are still imagining