touchui: support XInput2 MT

base/message_pump_x.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/message_pump_x.h"
 
 #include <gdk/gdkx.h>
 #include <X11/extensions/XInput2.h>
 
 #include "base/basictypes.h"
@@ skipping 52 matching lines @@
     return;
 
   int event, err;
 
   if (!XQueryExtension(display, "XInputExtension", &xiopcode, &event, &err)) {
     VLOG(1) << "X Input extension not available.";
     xiopcode = -1;
     return;
   }
 
+#if defined(USE_XI2_1)
+  int major = 2, minor = 1;
+#else
   int major = 2, minor = 0;
+#endif
   if (XIQueryVersion(display, &major, &minor) == BadRequest) {
-    VLOG(1) << "XInput2 not supported in the server.";
+    VLOG(1) << "XInput" << major << "." << minor

[Daniel Kurtz, 2011/09/08 23:09:58]

This will actually print the server's supported version, not 2.1:

http://www.x.org/releases/X11R7.5/doc/man/man3/XIQueryVersion.3.html

[ningxin.hu, 2011/09/09 05:08:54]

Thanks. I will revert this change.

+            << "not supported in the server.";
     xiopcode = -1;
     return;
   }

[Daniel Kurtz, 2011/09/08 23:09:58]

Save the server's reported version (returned in major, minor), and, if it is
2.0, use the (#ifndef USE_XI2_1) way to pass multitouch events.

[ningxin.hu, 2011/09/09 05:08:54]

Thanks for the suggestion. Since ubuntu supports multitouch in its XI2.1 and
Xorg will support multitouch in XI2.2, we properly cannot use minor version to
detect MT support simplely. 

So I propose to still use 'use_xi2_mt' gyp switch to turn on the XI2 MT support
when on ubuntu 11.04 or later xorg XI2.2.

 }
 
 }  // namespace
 
 namespace base {
 
 MessagePumpX::MessagePumpX() : MessagePumpGlib(),
     x_source_(NULL),
     gdksource_(NULL),
     dispatching_event_(false),
@@ skipping 191 matching lines @@
 }
 
 MessagePumpObserver::EventStatus
     MessagePumpObserver::WillProcessXEvent(XEvent* xev) {
   return EVENT_CONTINUE;
 }
 
 COMPILE_ASSERT(XLASTEvent >= LASTEvent, XLASTEvent_too_small);
 
 }  // namespace base