On Thu, Nov 11, 2010 at 11:41 AM, Henrik Rydberg <rydberg@xxxxxxxxxxx> wrote: > > Right. Perhaps this is a good time to discuss some additional helper functions > Chris and myself are playing with right now. > > /** > * input_mt_report_state() - report contact state > * @dev: input device with allocated MT slots > * @active: true if contact is active, false otherwise > * > * Reports an active touch via ABS_MT_TRACKING_ID. If active is > * true and the slot is currently inactive, a new tracking id is > * assigned to the slot. > */ > void input_mt_report_state(struct input_dev *dev, bool active); > > Since all tracking-capable drivers we have seen so far have a contact id with > the same semantics as the slot id, it makes sense to have the above function to > remove the need for individual drivers to assign tracking ids. > > With the input core (or input-mt.c) controlling the tracking id, it is easy to > add more goodness, such as I agree that centralizing the common code is a good way to go. > /** > * input_mt_report_pointer_emulation() - common pointer emulation > * @dev: input device with allocated MT slots > * > * Performs legacy pointer emulation via BTN_TOUCH, etc. > */ > void input_mt_report_pointer_emulation(struct input_dev *dev); > > Since the input device knows the MT state and what buttons and abs axes are in > use, it can provide the right set of data to emit to emulate pointer and touch > events. The track-oldest-contact logic can be readily implemented. Are we going to do the tocuh and pen aribtration in input-mt.c? I need to understand this to make my patches. Sounds a bit complicated if we do the aribtration here, considering the differences between pen and tocuh. If not, we will need to tell input_mt_report_pointer_emulation if another tool (such as pen) has already sent pointer events. That is input_mt_report_pointer_emulation is only called when needed. Ping -- 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
