On Tue, 2010-08-17 at 09:49 +0200, Stéphane Chatty wrote: > Le 16 août 10 à 17:30, Henrik Rydberg a écrit : > > - the single touch emulation is highly device dependent. I was (and > still am) pretty proud of my choice of tracking the 'oldest' finger > on the panel: this turns multitouch panels into single touch panels > that are impervious to parasite touches. But the drawback is that > currently there is no generic method for this tracking: I used > whatever device-specific information I could use (order of fingers in > a message, tracking id, etc). Stéphan, Can you explain in more detail why you chose an 'oldest' finger approach for single touch emulation? I wonder if it's the best mechanism. Take the following example: 1. User touches with one finger and intends to drag an object on screen 2. User touches another finger down, either accidentally or intentionally, while dragging the first finger 3. User releases first finger to end the drag 4. Object suddenly is dragged under the second finger As I'm implementing support for the Magic Trackpad right now, I'm having to figure out the best way to do single-touch emulation. What I'm currently doing is converting the first finger touched for single-touch emulation, and when that finger is released no single-touch emulation can occur until all fingers have left the screen again. This should hopefully become a moot point once everyone understands MT input, but sadly we have to deal with the reality of X not being MT aware quite yet :). Thanks, -- Chase -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
