Attachment 28684 Details for Bug 20529 – 0001-Restrict-wheel-emulation-to-a-single-axis-at-a-time.patch

[patch] 0001-Restrict-wheel-emulation-to-a-single-axis-at-a-time.patch

0001-Restrict-wheel-emulation-to-a-single-axis-at-a-time.patch (text/plain), 3.55 KB, created by Peter Hutterer on 2009-08-16 16:53:53 UTC

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Creator: Peter Hutterer

Created: 2009-08-16 16:53:53 UTC

Size: 3.55 KB

patch

obsolete

>From 3b40645a10a119529610405c8ef0373cf4eabd7c Mon Sep 17 00:00:00 2001
>From: Peter Hutterer <peter.hutterer@who-t.net>
>Date: Mon, 17 Aug 2009 09:41:11 +1000
>Subject: [PATCH] Restrict wheel emulation to a single axis at a time.
>
>Wheel emulation works for both horizontal and vertical axes. Thus, if a
>device doesn't move in perfect straight line, scroll events build up on the
>respective other axis.
>
>In some clients, scroll wheel events have specific meanings other than
>scrolling (e.g. mplayer). In these clients, erroneous scrolling events come
>at a high cost.
>
>Thus, if a scroll wheel event is generated for one axis, reset the inertia
>of the other axis to 0, avoiding the buildup of these erroneous scrolling
>events.
>
>Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
>---
> src/emuWheel.c |   28 +++++++++++++++++++++-------
> 1 files changed, 21 insertions(+), 7 deletions(-)
>
>diff --git a/src/emuWheel.c b/src/emuWheel.c
>index 9bff731..e5adcc6 100644
>--- a/src/emuWheel.c
>+++ b/src/emuWheel.c
>@@ -54,7 +54,7 @@ static Atom prop_wheel_button   = 0;
> 
> /* Local Funciton Prototypes */
> static BOOL EvdevWheelEmuHandleButtonMap(InputInfoPtr pInfo, WheelAxisPtr pAxis, char *axis_name);
>-static void EvdevWheelEmuInertia(InputInfoPtr pInfo, WheelAxisPtr axis, int value);
>+static int EvdevWheelEmuInertia(InputInfoPtr pInfo, WheelAxisPtr axis, int value);
> 
> /* Filter mouse button events */
> BOOL
>@@ -98,7 +98,7 @@ BOOL
> EvdevWheelEmuFilterMotion(InputInfoPtr pInfo, struct input_event *pEv)
> {
>     EvdevPtr pEvdev = (EvdevPtr)pInfo->private;
>-    WheelAxisPtr pAxis = NULL;
>+    WheelAxisPtr pAxis = NULL, pOtherAxis = NULL;
>     int value = pEv->value;
>     int ms;
> 
>@@ -119,19 +119,28 @@ EvdevWheelEmuFilterMotion(InputInfoPtr pInfo, struct input_event *pEv)
> 	switch(pEv->code) {
> 	case REL_X:
> 	    pAxis = &(pEvdev->emulateWheel.X);
>+	    pOtherAxis = &(pEvdev->emulateWheel.Y);
> 	    break;
> 
> 	case REL_Y:
> 	    pAxis = &(pEvdev->emulateWheel.Y);
>+	    pOtherAxis = &(pEvdev->emulateWheel.X);
> 	    break;
> 
> 	default:
> 	    break;
> 	}
> 
>-	/* If we found REL_X or REL_Y, emulate a mouse wheel */
>+	/* If we found REL_X or REL_Y, emulate a mouse wheel.
>+           Reset the inertia of the other axis when a scroll event was sent
>+           to avoid the buildup of erroneous scroll events if the user
>+           doesn't move in a perfectly straight line.
>+         */
> 	if (pAxis)
>-	    EvdevWheelEmuInertia(pInfo, pAxis, value);
>+	{
>+	    if (EvdevWheelEmuInertia(pInfo, pAxis, value))
>+		pOtherAxis->traveled_distance = 0;
>+	}
> 
> 	/* Eat motion events while emulateWheel button pressed. */
> 	return TRUE;
>@@ -140,17 +149,20 @@ EvdevWheelEmuFilterMotion(InputInfoPtr pInfo, struct input_event *pEv)
>     return FALSE;
> }
> 
>-/* Simulate inertia for our emulated mouse wheel */
>-static void
>+/* Simulate inertia for our emulated mouse wheel.
>+   Returns the number of wheel events generated.
>+ */
>+static int
> EvdevWheelEmuInertia(InputInfoPtr pInfo, WheelAxisPtr axis, int value)
> {
>     EvdevPtr pEvdev = (EvdevPtr)pInfo->private;
>     int button;
>     int inertia;
>+    int rc = 0;
> 
>     /* if this axis has not been configured, just eat the motion */
>     if (!axis->up_button)
>-	return;
>+	return rc;
> 
>     axis->traveled_distance += value;
> 
>@@ -166,7 +178,9 @@ EvdevWheelEmuInertia(InputInfoPtr pInfo, WheelAxisPtr axis, int value)
>     while(abs(axis->traveled_distance) > pEvdev->emulateWheel.inertia) {
> 	axis->traveled_distance -= inertia;
> 	EvdevQueueButtonClicks(pInfo, button, 1);
>+	rc++;
>     }
>+    return rc;
> }
> 
> /* Handle button mapping here to avoid code duplication,
>-- 
>1.6.3.rc1.2.g0164.dirty
>

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