[PATCH libinput 3/6] touchpad: add a TOUCH_HOVERING state

Hans de Goede hdegoede at redhat.com
Mon Jan 5 03:19:44 PST 2015


Hi,

On 16-12-14 04:14, Peter Hutterer wrote:
> Some touchpads provide touch information while the finger hovers over the
> touchpad, i.e. before BTN_TOUCH. Add a touch state for those touchpads so we
> can ignore the touches until they actually start.
>
> The approach is now: instead of BEGIN we mark a new touch as HOVERING.
> Use the BTN_TOOL_FINGER, BTN_TOOL_DOUBLETAP information during
> tp_process_state() to mark any touches that are hovering as down or ended.
>
> i.e. provided BTN_TOUCH is down: if BTN_TOOL_FINGER is down, one hovering
> touch gets marked as down, if DOUBLETAP is down, two touches are marked as
> down, etc.
>
> When ending touches, switch them back into HOVERING if the BTN_TOOL_FINGER
> is still set, otherwise end them properly.
>
> https://bugs.freedesktop.org/show_bug.cgi?id=87197
>
> Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
> ---
>   src/evdev-mt-touchpad-edge-scroll.c |  1 +
>   src/evdev-mt-touchpad.c             | 81 ++++++++++++++++++++++++++++++++-----
>   src/evdev-mt-touchpad.h             |  8 +++-
>   3 files changed, 78 insertions(+), 12 deletions(-)
>
> diff --git a/src/evdev-mt-touchpad-edge-scroll.c b/src/evdev-mt-touchpad-edge-scroll.c
> index 616080f..55720f8 100644
> --- a/src/evdev-mt-touchpad-edge-scroll.c
> +++ b/src/evdev-mt-touchpad-edge-scroll.c
> @@ -294,6 +294,7 @@ tp_edge_scroll_handle_state(struct tp_dispatch *tp, uint64_t time)
>
>   		switch (t->state) {
>   		case TOUCH_NONE:
> +		case TOUCH_HOVERING:
>   			break;
>   		case TOUCH_BEGIN:
>   			tp_edge_scroll_handle_event(tp, t, SCROLL_EVENT_TOUCH);
> diff --git a/src/evdev-mt-touchpad.c b/src/evdev-mt-touchpad.c
> index c80d314..4898950 100644
> --- a/src/evdev-mt-touchpad.c
> +++ b/src/evdev-mt-touchpad.c
> @@ -180,24 +180,36 @@ tp_fake_finger_set(struct tp_dispatch *tp,
>   static inline void
>   tp_begin_touch(struct tp_dispatch *tp, struct tp_touch *t, uint64_t time)
>   {
> -	if (t->state == TOUCH_BEGIN || t->state == TOUCH_UPDATE)
> +	if (t->state == TOUCH_BEGIN ||
> +	    t->state == TOUCH_UPDATE ||
> +	    t->state == TOUCH_HOVERING)
>   		return;
>
> +	/* we begin the touch as hovering because until BTN_TOUCH happens we
> +	 * don't know if it's a touch down or not. And BTN_TOUCH may happen
> +	 * after ABS_MT_TRACKING_ID */
>   	tp_motion_history_reset(t);
>   	t->dirty = true;
> -	t->state = TOUCH_BEGIN;
> +	t->state = TOUCH_HOVERING;
>   	t->pinned.is_pinned = false;
>   	t->millis = time;
> -	tp->nfingers_down++;
> -	assert(tp->nfingers_down >= 1);
>   	tp->queued |= TOUCHPAD_EVENT_MOTION;
>   }
>
>   static inline void
>   tp_end_touch(struct tp_dispatch *tp, struct tp_touch *t, uint64_t time)
>   {
> -	if (t->state == TOUCH_END || t->state == TOUCH_NONE)
> +	switch (t->state) {
> +	case TOUCH_HOVERING:
> +		t->state = TOUCH_NONE;
> +	case TOUCH_NONE:
> +	case TOUCH_END:
>   		return;
> +	case TOUCH_BEGIN:
> +	case TOUCH_UPDATE:
> +		break;
> +
> +	}
>
>   	t->dirty = true;
>   	t->is_pointer = false;
> @@ -310,9 +322,6 @@ tp_process_fake_touch(struct tp_dispatch *tp,
>   		else
>   			tp_end_touch(tp, t, time);
>   	}
> -
> -	/* On mt the actual touch info may arrive after BTN_TOOL_FOO */
> -	assert(tp->has_mt || tp->nfingers_down == nfake_touches);
>   }
>
>   static void
> @@ -327,6 +336,7 @@ tp_process_key(struct tp_dispatch *tp,
>   			tp_process_button(tp, e, time);
>   			break;
>   		case BTN_TOUCH:
> +		case BTN_TOOL_FINGER:
>   		case BTN_TOOL_DOUBLETAP:
>   		case BTN_TOOL_TRIPLETAP:
>   		case BTN_TOOL_QUADTAP:
> @@ -543,12 +553,56 @@ tp_remove_scroll(struct tp_dispatch *tp)
>   }
>
>   static void
> +tp_unhover_touches(struct tp_dispatch *tp, uint64_t time)
> +{
> +	struct tp_touch *t;
> +	unsigned int nfake_touches;
> +	unsigned int i;
> +
> +	if (!tp->fake_touches && !tp->nfingers_down)
> +		return;
> +
> +	nfake_touches = tp_fake_finger_count(tp);
> +	if (tp->nfingers_down == nfake_touches &&
> +	    ((tp->nfingers_down == 0 && !tp_fake_finger_is_touching(tp)) ||
> +	     (tp->nfingers_down > 0 && tp_fake_finger_is_touching(tp))))
> +		return;
> +
> +	for (i = 0; i < tp->ntouches; i++) {
> +		t = tp_get_touch(tp, i);
> +
> +		/* if BTN_TOUCH is set, switch each hovering touch to BEGIN
> +		 * until nfingers_down matches nfake_touches (or end touches
> +		 * until that happens).
> +		 * if BTN_TOUCH is unset, end all touches, we're hovering
> +		 * all fingers now
> +		 */
> +		if (t->state == TOUCH_HOVERING) {
> +			if (tp_fake_finger_is_touching(tp)) {
> +				t->state = TOUCH_BEGIN;
> +				tp->nfingers_down++;
> +				assert(tp->nfingers_down >= 1);
> +			}
> +		} else if (tp->nfingers_down > nfake_touches ||
> +			   !tp_fake_finger_is_touching(tp)) {
> +			tp_end_touch(tp, t, time);

You're removing touches in the same order as you add them, I would expect
them to be removed in reverse order, I know the order has little meaning
in some cases, but still.


> +		}
> +
> +		if (tp_fake_finger_is_touching(tp) &&
> +		    tp->nfingers_down == nfake_touches)
> +			break;
> +	}
> +}
> +
> +static void
>   tp_process_state(struct tp_dispatch *tp, uint64_t time)
>   {
>   	struct tp_touch *t;
>   	struct tp_touch *first = tp_get_touch(tp, 0);
>   	unsigned int i;
>
> +	tp_unhover_touches(tp, time);
> +
>   	for (i = 0; i < tp->ntouches; i++) {
>   		t = tp_get_touch(tp, i);
>
> @@ -597,10 +651,15 @@ tp_post_process_state(struct tp_dispatch *tp, uint64_t time)
>   		if (!t->dirty)
>   			continue;
>
> -		if (t->state == TOUCH_END)
> -			t->state = TOUCH_NONE;
> -		else if (t->state == TOUCH_BEGIN)
> +		if (t->state == TOUCH_END) {
> +			if (!tp_fake_finger_is_touching(tp) &&
> +			    tp_fake_finger_count(tp) > 0)
> +				t->state = TOUCH_HOVERING;

You're hovering all fingers here, but what if in the same sync
some touches were ended with an ABS_MT_TRACKING_ID == -1 ?



> +			else
> +				t->state = TOUCH_NONE;
> +		} else if (t->state == TOUCH_BEGIN) {
>   			t->state = TOUCH_UPDATE;
> +		}
>
>   		t->dirty = false;
>   	}
> diff --git a/src/evdev-mt-touchpad.h b/src/evdev-mt-touchpad.h
> index 1450288..cdbf804 100644
> --- a/src/evdev-mt-touchpad.h
> +++ b/src/evdev-mt-touchpad.h
> @@ -53,6 +53,7 @@ enum touchpad_model {
>
>   enum touch_state {
>   	TOUCH_NONE = 0,
> +	TOUCH_HOVERING,
>   	TOUCH_BEGIN,
>   	TOUCH_UPDATE,
>   	TOUCH_END
> @@ -192,7 +193,12 @@ struct tp_dispatch {
>   	unsigned int real_touches;		/* number of slots */
>   	unsigned int ntouches;			/* no slots inc. fakes */
>   	struct tp_touch *touches;		/* len == ntouches */
> -	unsigned int fake_touches;		/* fake touch mask */
> +	/* bit 0: BTN_TOUCH
> +	 * bit 1: BTN_TOOL_FINGER
> +	 * bit 2: BTN_TOOL_DOUBLETAP
> +	 * ...
> +	 */
> +	unsigned int fake_touches;
>
>   	struct {
>   		int32_t margin_x;

This hunk should be in a previous patch.


Regards,

Hans


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