XQuartz tablet mouse events are at the wrong location and other Xinput headaches

Jeremy Huddleston jeremyhu at apple.com
Tue Mar 13 02:23:46 PDT 2012 

Hey Peter,

I'm having an Xi week here in XQuartz.  I just received a bug report (http://xquartz.macosforge.org/trac/ticket/555) that tablet support has regressed in XQuartz in 1.12.0 from 1.11.4.  The DDX code in both versions is practically the same, so I think this might be a regression somewhere in DIX.  Does this sound related to anything you've heard about?

$ git diff origin/server-1.11-branch origin/server-1.12-branch hw/xquartz | diffstat
 GL/indirect.c            |    3 
 applewm.c                |    8 -
 bundle/Info.plist.cpp    |    4 
 mach-startup/Makefile.am |    7 +
 pseudoramiX.c            |   65 ++++------
 xpr/appledri.c           |   94 ++++++--------
 xpr/appledristr.h        |  298 ++++++++++++++++++++++++-----------------------
 xpr/dri.c                |    3 
 8 files changed, 239 insertions(+), 243 deletions(-)

---

In investigating http://bugs.winehq.org/show_bug.cgi?id=29844, I took a look at how our devices are initialized, and I am confused by Absolute vs Relative mode for a valuator axis and Absolute vs Relative axis label.  I know we discussed it in person back when this was made 2-3 years ago, but I've forgotten, and I need something in writing to job my memory. Our mouse pointer does:

axes_labels[0] = XIGetKnownProperty(AXIS_LABEL_PROP_REL_X);
...
InitValuatorAxisStruct(pPointer, 0, axes_labels[0], NO_AXIS_LIMITS, NO_AXIS_LIMITS, 0, 0, 0, Absolute);

whereas the tablet does:

axes_labels[0] = XIGetKnownProperty(AXIS_LABEL_PROP_ABS_X);
...
InitValuatorAxisStruct(pPointer, 0, axes_labels[0], 0, XQUARTZ_VALUATOR_LIMIT, 1, 0, 1, Absolute);

My understanding is that the mode (Absolute vs Relative) has to do with the data being presented as the current device state rather than the change in state from the previous input, but in looking at other code out there, it looks like AXIS_LABEL_PROP_ABS_X and AXIS_LABEL_PROP_REL_X are supposed to make that distinction.

"Absolute" and "Relative" are overloaded here, so that's making it difficult for me to reason through.  Absolute could mean the absolute value given (100 pixels) whereas relative could mean the relative positioning along a range (10% of the way from the left edge to the right edge).  Alternatively, it could mean the absolute value of the current state (100 pixels), or the relative change from the previous state (-2 pixels).

Can you please untangle the knots in my brain (doc/Xinput.xml is dated here, btw)?  Is it just the case that the pointer is incorrect and we should be doing:

axes_labels[0] = XIGetKnownProperty(AXIS_LABEL_PROP_ABS_X);
...
InitValuatorAxisStruct(pPointer, 0, axes_labels[0], NO_AXIS_LIMITS, NO_AXIS_LIMITS, 0, 0, 0, Absolute);

If so, can we overload that to also include relative change for the wine case:
axes_labels[0] = XIGetKnownProperty(AXIS_LABEL_PROP_ABS_X);
axes_labels[2] = XIGetKnownProperty(AXIS_LABEL_PROP_REL_X);
...
InitValuatorAxisStruct(pPointer, 0, axes_labels[0], NO_AXIS_LIMITS, NO_AXIS_LIMITS, 0, 0, 0, Absolute);
InitValuatorAxisStruct(pPointer, 2, axes_labels[2], NO_AXIS_LIMITS, NO_AXIS_LIMITS, 0, 0, 0, Relative);

---

And lastly, 'xinput list pointer' seems to be running into issues getting the atoms for the button labels here.  Are you seeing this?  I can't imagine that this is XQuartz-specific:

$ xinput list pointer
pointer                                 	id=7	[slave  pointer  (2)]
	Reporting 3 classes:
		Class originated from: 7. Type: XIButtonClass
		Buttons supported: 7
X Error of failed request:  BadAtom (invalid Atom parameter)
  Major opcode of failed request:  17 (X_GetAtomName)
  Atom id in failed request:  0xb0002
  Serial number of failed request:  23
  Current serial number in output stream:  23
		Button labels: "Button Middle" "Button Right" "Button Wheel Up" "Button Wheel Down" "Button Horiz Wheel Left" "Button Horiz Wheel Right"

Breaking on _XError in gdb:
Breakpoint 1, 0x000000010003636f in _XError ()(gdb) bt
#0  0x000000010003636f in _XError ()
#1  0x0000000100034300 in handle_error ()
#2  0x0000000100033e06 in _XReply ()
#3  0x000000010001ba5c in XGetAtomName ()
#4  0x0000000100001ba4 in print_classes_xi2 (display=0x100803200, classes=0x100204720, num_classes=3) at list.c:161
#5  0x000000010000252f in print_info_xi2 (display=0x100803200, dev=0x1002043e8, format=FORMAT_LONG) at list.c:284
#6  0x00000001000022c7 in list (display=0x100803200, argc=1, argv=0x7fff5fbff9d8, name=0x10000b556 "list", desc=0x10000b77b "[--short || --long || --name-only || --id-only] [<device name>...]") at list.c:380
#7  0x000000010000711d in main (argc=3, argv=0x7fff5fbff9c8) at xinput.c:386
(gdb) frame 4
#4  0x0000000100001ba4 in print_classes_xi2 (display=0x100803200, classes=0x100204720, num_classes=3) at list.c:161
161	                        name = (b->labels[j]) ? XGetAtomName(display, b->labels[j]) : NULL;
(gdb) list
156	                    printf("XIButtonClass\n");
157	                    printf("\t\tButtons supported: %d\n", b->num_buttons);
158	                    printf("\t\tButton labels:");
159	                    for (j = 0; j < b->num_buttons; j++)
160	                    {
161	                        name = (b->labels[j]) ? XGetAtomName(display, b->labels[j]) : NULL;
162	                        if (name)
163	                            printf(" \"%s\"", name);
164	                        else
165	                            printf(" None");
(gdb) print b->labels[0]
$17 = 117
(gdb) print b->labels[1]
$18 = 118
(gdb) print b->labels[2]
$19 = 119
(gdb) print b->labels[3]
$20 = 120
(gdb) print b->labels[4]
$21 = 121
(gdb) print b->labels[5]
$22 = 122
(gdb) print b->labels[6]
$23 = 720898
(gdb) print b->num_buttons
$24 = 7
(gdb) print b->labels[-1]
$25 = 498216206336

Based on xlsatoms, I'd expect 116-122 as the button atoms:
116	Button Left
117	Button Middle
118	Button Right
119	Button Wheel Up
120	Button Wheel Down
121	Button Horiz Wheel Left
122	Button Horiz Wheel Right

It works when the client is i386/Linux or i386/darwin and fails when x86_64/darwin, ppc/Linux, or ppc64/Linux ... is this possibly an inputproto issue?

$ arch -i386 /opt/X11/bin/xinput list pointer
pointer                                 	id=7	[slave  pointer  (2)]
	Reporting 3 classes:
		Class originated from: 7. Type: XIButtonClass
		Buttons supported: 7
		Button labels: "Button Left" "Button Middle" "Button Right" "Button Wheel Up" "Button Wheel Down" "Button Horiz Wheel Left" "Button Horiz Wheel Right"
		Button state:
		Class originated from: 7. Type: XIValuatorClass
		Detail for Valuator 0:
		  Label: Rel X
		  Range: -1.000000 - -1.000000
		  Resolution: 0 units/m
		  Mode: absolute
		  Current value: 665.000000
		Class originated from: 7. Type: XIValuatorClass
		Detail for Valuator 1:
		  Label: Rel Y
		  Range: -1.000000 - -1.000000
		  Resolution: 0 units/m
		  Mode: absolute
		  Current value: 12.000000


$ arch -x86_64 /opt/X11/bin/xinput list pointer
pointer                                 	id=7	[slave  pointer  (2)]
	Reporting 3 classes:
		Class originated from: 7. Type: XIButtonClass
		Buttons supported: 7
X Error of failed request:  BadAtom (invalid Atom parameter)
  Major opcode of failed request:  17 (X_GetAtomName)
  Atom id in failed request:  0xb0002
  Serial number of failed request:  23
  Current serial number in output stream:  23
		Button labels: "Button Middle" "Button Right" "Button Wheel Up" "Button Wheel Down" "Button Horiz Wheel Left" "Button Horiz Wheel Right"

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