Attachment 128234 Details for Bug 92772 – 0001-Calculate-the-required-scroll-distance-based-on-the-.patch

[patch] 0001-Calculate-the-required-scroll-distance-based-on-the-.patch

0001-Calculate-the-required-scroll-distance-based-on-the-.patch (text/plain), 4.82 KB, created by Peter Hutterer on 2016-11-28 04:27:11 UTC

(hide)

Description:

Filename:

MIME Type:

Creator: Peter Hutterer

Created: 2016-11-28 04:27:11 UTC

Size: 4.82 KB

patch

obsolete

>From 5e819a9df3835469d1ffe842edc63bb7c11b57b6 Mon Sep 17 00:00:00 2001
>From: Peter Hutterer <peter.hutterer@who-t.net>
>Date: Mon, 28 Nov 2016 14:09:06 +1000
>Subject: [PATCH xf86-input-libinput] Calculate the required scroll distance
> based on the angle
>
>For a mouse with a click angle of 15 degrees things are unchanged. For devices
>with angles less than 10, the current code scrolled way too fast. Because the
>angle wasn't used anywhere, each tick would count as full scroll wheel event,
>a slight movement of the wheel would thus scroll as much as a large movement
>on a normal mouse.
>
>Fix this by taking the actual click angle of the device into account. We
>calculate some multiple of the angle that's close enough to the default 15
>degrees of the wheel and then require that many click events to hit the full
>scroll distance. For example, a mouse with a click angle of 3 degrees now
>requires 5 clicks to trigger a full legacy scroll button event.
>
>XI2.1 clients get the intermediate events (i.e. in this case five times
>one-fifth of the scroll distance) and can thus scroll smoothly, or more
>specifically in smaller events than usual.
>
>https://bugs.freedesktop.org/show_bug.cgi?id=92772
>
>Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
>---
> src/xf86libinput.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 58 insertions(+), 4 deletions(-)
>
>diff --git a/src/xf86libinput.c b/src/xf86libinput.c
>index 747e84b..c558092 100644
>--- a/src/xf86libinput.c
>+++ b/src/xf86libinput.c
>@@ -124,8 +124,12 @@ struct xf86libinput {
> 	uint32_t capabilities;
> 
> 	struct {
>+		/* The distances set in the XI 2.1 ScrollClass */
> 		int vdist;
> 		int hdist;
>+
>+		double vdist_factor;
>+		double hdist_factor;
> 	} scroll;
> 
> 	struct {
>@@ -1320,6 +1324,53 @@ xf86libinput_handle_key(InputInfoPtr pInfo, struct libinput_event_keyboard *even
> 	xf86PostKeyboardEvent(dev, key, is_press);
> }
> 
>+static inline double
>+get_scroll_factor(struct xf86libinput *driver_data,
>+		  struct libinput_event_pointer *event,
>+		  enum libinput_pointer_axis axis)
>+{
>+	double *factor;
>+	double f;
>+	double angle;
>+	int discrete;
>+
>+	switch (axis) {
>+	case LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL:
>+		factor = &driver_data->scroll.hdist_factor;
>+		break;
>+	case LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL:
>+		factor = &driver_data->scroll.vdist_factor;
>+		break;
>+	default:
>+		return 0.0;
>+	}
>+
>+	/* We assume the scroll click angle of the device never changes */
>+	if (*factor != 0.0)
>+		return *factor;
>+
>+	/* Calculate the angle per single scroll event */
>+	angle = libinput_event_pointer_get_axis_value(event, axis);
>+	discrete = libinput_event_pointer_get_axis_value_discrete(event, axis);
>+	angle /= discrete;
>+
>+	/* We only do magic for click angles smaller than 10 degrees */
>+	if (angle >= 10) {
>+		*factor = 1.0;
>+		return 1.0;
>+	}
>+
>+	/* Figure out something that gets close to 15 degrees (the general
>+	 * wheel default) with a number of clicks. This formula gives us
>+	 * between 14 and and 18 degrees for the range of 1-9.
>+	 */
>+	f = 13/(int)angle + 1;
>+
>+	*factor = f;
>+
>+	return f;
>+}
>+
> static void
> xf86libinput_handle_axis(InputInfoPtr pInfo, struct libinput_event_pointer *event)
> {
>@@ -1329,6 +1380,7 @@ xf86libinput_handle_axis(InputInfoPtr pInfo, struct libinput_event_pointer *even
> 	double value;
> 	enum libinput_pointer_axis axis;
> 	enum libinput_pointer_axis_source source;
>+	double scroll_factor;
> 
> 	if ((driver_data->capabilities & CAP_POINTER) == 0)
> 		return;
>@@ -1349,7 +1401,8 @@ xf86libinput_handle_axis(InputInfoPtr pInfo, struct libinput_event_pointer *even
> 	if (libinput_event_pointer_has_axis(event, axis)) {
> 		if (source == LIBINPUT_POINTER_AXIS_SOURCE_WHEEL) {
> 			value = libinput_event_pointer_get_axis_value_discrete(event, axis);
>-			value *= driver_data->scroll.vdist;
>+			scroll_factor = get_scroll_factor(driver_data, event, axis);
>+			value *= driver_data->scroll.vdist/scroll_factor;
> 		} else {
> 			value = libinput_event_pointer_get_axis_value(event, axis);
> 		}
>@@ -1363,7 +1416,8 @@ xf86libinput_handle_axis(InputInfoPtr pInfo, struct libinput_event_pointer *even
> 	if (libinput_event_pointer_has_axis(event, axis)) {
> 		if (source == LIBINPUT_POINTER_AXIS_SOURCE_WHEEL) {
> 			value = libinput_event_pointer_get_axis_value_discrete(event, axis);
>-			value *= driver_data->scroll.hdist;
>+			scroll_factor = get_scroll_factor(driver_data, event, axis);
>+			value *= driver_data->scroll.vdist/scroll_factor;
> 		} else {
> 			value = libinput_event_pointer_get_axis_value(event, axis);
> 		}
>@@ -2928,8 +2982,8 @@ xf86libinput_pre_init(InputDriverPtr drv,
> 
> 	pInfo->private = driver_data;
> 	driver_data->pInfo = pInfo;
>-	driver_data->scroll.vdist = 15;
>-	driver_data->scroll.hdist = 15;
>+	driver_data->scroll.vdist = 100;
>+	driver_data->scroll.hdist = 100;
> 	driver_data->path = path;
> 	driver_data->shared_device = shared_device;
> 	xorg_list_append(&driver_data->shared_device_link,
>-- 
>2.9.3
>

Actions: View | Splinter Review

Attachments on bug 92772: 127323 | 127324 | 128174 | 128233 | 128234 | 128256 | 128980

Use of freedesktop.org services, including Bugzilla, is subject to our Code of Conduct. How we collect and use information is described in our Privacy Policy.