Convert IgnoreAbsolute/RelativeAxes options into trinary state.

The Xen Virtual Pointer device exports both absolute and relative axes from
the kernel device. Which coordinates are used is a run-time decision and
depends on the host-specific configuration.
0a3657d2ee62f4086e9687218cb33835ba61a0b3 broke these devices, and they are
now unusable out-of-the-box as there is no configuration to cover them.

This patch converts the IgnoreAbsoluteAxes and the IgnoreRelativeAxes
configuration options into a trinary state.
1. If unset, configure the device as normal by trying to guess the right
   axis setup.
2. If set to true, ignore the specific axis type completely (except for
   wheel events).
3. If set to false, explicitly 'unignore' the axis type, alwas configuring
   it if it is present on the device. This setting introduces seemingly
   buggy behaviour (see Bug 21832)

1. and 2. replicate the current driver behaviour.
The result of 3. is that is that if a device has absolute axes and the
options set to false, both axes will be initialized (absolute last to get
clipping right). This requires axis labelling priorty to switch from
relative first to absolute first.

Relative events are forwarded into the server through the absolute axes,
the server scales this into the device absolute range and everyone is happy.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

1 files changed, 43 insertions, 10 deletions

diff --git a/src/evdev.c b/src/evdev.c
index 62d1bc7..0dff271 100644
--- a/src/evdev.c
+++ b/src/evdev.c
@@ -90,6 +90,8 @@
 #define EVDEV_TOUCHSCREEN	(1 << 6)
 #define EVDEV_CALIBRATED	(1 << 7) /* run-time calibrated? */
 #define EVDEV_TABLET		(1 << 8) /* device looks like a tablet? */
+#define EVDEV_UNIGNORE_ABSOLUTE (1 << 9) /* explicitly unignore abs axes */
+#define EVDEV_UNIGNORE_RELATIVE (1 << 10) /* explicitly unignore rel axes */
 
 #define MIN_KEYCODE 8
 #define GLYPHS_PER_KEY 2
@@ -1423,6 +1425,17 @@ EvdevInitButtonMapping(InputInfoPtr pInfo)
 }
 
 static void
+EvdevInitAnyClass(DeviceIntPtr device, EvdevPtr pEvdev)
+{
+    if (pEvdev->flags & EVDEV_RELATIVE_EVENTS &&
+        EvdevAddRelClass(device) == Success)
+        xf86Msg(X_INFO, "%s: initialized for relative axes.\n", device->name);
+    if (pEvdev->flags & EVDEV_ABSOLUTE_EVENTS &&
+        EvdevAddAbsClass(device) == Success)
+        xf86Msg(X_INFO, "%s: initialized for absolute axes.\n", device->name);
+}
+
+static void
 EvdevInitAbsClass(DeviceIntPtr device, EvdevPtr pEvdev)
 {
     if (EvdevAddAbsClass(device) == Success) {
@@ -1513,7 +1526,9 @@ EvdevInit(DeviceIntPtr device)
      * used and relative axes are ignored.
      */
 
-    if (pEvdev->flags & (EVDEV_TOUCHPAD | EVDEV_TOUCHSCREEN | EVDEV_TABLET))
+    if (pEvdev->flags & (EVDEV_UNIGNORE_RELATIVE | EVDEV_UNIGNORE_ABSOLUTE))
+        EvdevInitAnyClass(device, pEvdev);
+    else if (pEvdev->flags & (EVDEV_TOUCHPAD | EVDEV_TOUCHSCREEN | EVDEV_TABLET))
         EvdevInitTouchDevice(device, pEvdev);
     else if (pEvdev->flags & EVDEV_RELATIVE_EVENTS)
         EvdevInitRelClass(device, pEvdev);
@@ -1777,7 +1792,7 @@ EvdevProbe(InputInfoPtr pInfo)
 {
     int i, has_rel_axes, has_abs_axes, has_keys, num_buttons, has_scroll;
     int kernel24 = 0;
-    int ignore_rel, ignore_abs;
+    int ignore_abs = 0, ignore_rel = 0;
     EvdevPtr pEvdev = pInfo->private;
 
     if (pEvdev->grabDevice && ioctl(pInfo->fd, EVIOCGRAB, (void *)1)) {
@@ -1793,8 +1808,26 @@ EvdevProbe(InputInfoPtr pInfo)
         ioctl(pInfo->fd, EVIOCGRAB, (void *)0);
     }
 
-    ignore_rel = xf86SetBoolOption(pInfo->options, "IgnoreRelativeAxes", FALSE);
-    ignore_abs = xf86SetBoolOption(pInfo->options, "IgnoreAbsoluteAxes", FALSE);
+    /* Trinary state for ignoring axes:
+       - unset: do the normal thing.
+       - TRUE: explicitly ignore them.
+       - FALSE: unignore axes, use them at all cost if they're present.
+     */
+    if (xf86FindOption(pInfo->options, "IgnoreRelativeAxes"))
+    {
+        if (xf86SetBoolOption(pInfo->options, "IgnoreRelativeAxes", FALSE))
+            ignore_rel = TRUE;
+        else
+            pEvdev->flags |= EVDEV_UNIGNORE_RELATIVE;
+
+    }
+    if (xf86FindOption(pInfo->options, "IgnoreAbsoluteAxes"))
+    {
+        if (xf86SetBoolOption(pInfo->options, "IgnoreAbsoluteAxes", FALSE))
+           ignore_abs = TRUE;
+        else
+            pEvdev->flags |= EVDEV_UNIGNORE_ABSOLUTE;
+    }
 
     has_rel_axes = FALSE;
     has_abs_axes = FALSE;
@@ -2352,16 +2385,16 @@ static void EvdevInitAxesLabels(EvdevPtr pEvdev, int natoms, Atom *atoms)
     int labels_len = 0;
     char *misc_label;
 
-    if (pEvdev->flags & EVDEV_RELATIVE_EVENTS)
-    {
-        labels     = rel_labels;
-        labels_len = ArrayLength(rel_labels);
-        misc_label = AXIS_LABEL_PROP_REL_MISC;
-    } else if ((pEvdev->flags & EVDEV_ABSOLUTE_EVENTS))
+    if (pEvdev->flags & EVDEV_ABSOLUTE_EVENTS)
     {
         labels     = abs_labels;
         labels_len = ArrayLength(abs_labels);
         misc_label = AXIS_LABEL_PROP_ABS_MISC;
+    } else if ((pEvdev->flags & EVDEV_RELATIVE_EVENTS))
+    {
+        labels     = rel_labels;
+        labels_len = ArrayLength(rel_labels);
+        misc_label = AXIS_LABEL_PROP_REL_MISC;
     }
 
     memset(atoms, 0, natoms * sizeof(Atom));