Add pen & tablet support to whiteboard

[Joel Phillips]

Have the whiteboard application directly support pen and tablets (e.g. those from Wacom).

I don't have a detailed understanding of this, but it appears that pen and tablets seem to send similar messages to mice, except that rather than a binary "button1 down" or "button1 up" event / state, they send a pressure. For my tablet, that pressure can be a number from 0 to 511.

Currently, it is possible to use a pen and tablet with the whiteboard (I have tested the Wacom Bamboo on OS X.5). This is because the pentablet driver converts pen pressures into mouse clicks and so the whiteboard just sees mouse clicks. However, I found that I had to edit the (undocumented) tablet configuration to get this conversion to work properly. Without the editing, the whiteboard was always in a "mouse button down" state, i.e. all handwriting appeared very joined up.

http://thecoccinella.org/node/264

The "constant button mouse down" problem is nothing to do with Coccinella - it's a consequence of the tablet driver configuration. However, if the whiteboard were able to interpret pen pressures directly, there would be no need for the configuration hack.

Tablets also send additional information. For example, my pen has a stylus at one end and an "eraser" at the other. Using the eraser sends a different message to the application. Photoshop, for example, takes "eraser" messages and applies the eraser tool, rather than the current drawing tool. The Coccinella whiteboard could have similar functionality.

Maybe there's a Tcl library that can help with all this?

[sander (s-devrieze)]

http://groups.google.com/group/comp.lang.tcl/browse_thread/thread/97c18e6d6ff79df9/cd905389dc92b8d8?lnk=gst&q=Tablet+support+in+Tk%3F#