aura-x11: Add support for xmodmap'ed pointer buttons.

ui/base/x/events_x.cc

Index: ui/base/x/events_x.cc
diff --git a/ui/base/x/events_x.cc b/ui/base/x/events_x.cc
index 2c38267b45f9cad0ae87d9d22aa175592e0a898b..240fa73b3fbbd5ed0b6e4476e609174886377018 100644
--- a/ui/base/x/events_x.cc
+++ b/ui/base/x/events_x.cc
@@ -11,6 +11,7 @@
 #include "base/logging.h"
 #include "ui/base/keycodes/keyboard_code_conversion_x.h"
 #include "ui/base/touch/touch_factory.h"
+#include "ui/base/x/x11_util.h"
 #include "ui/gfx/point.h"
 
 #if !defined(TOOLKIT_USES_GTK)
@@ -70,11 +71,21 @@ int GetEventFlagsForButton(int button) {
   }
 }
 
+int GetMappedButton(int button) {
+  static unsigned char map[256];
+  static int count = 0;
+  if (!count)
+    count = XGetPointerMapping(ui::GetXDisplay(), map, arraysize(map));

[Daniel Erat, 2011/12/04 15:51:45]

i think that you need to refresh the cached copy of the mapping whenever chrome
receives a MappingNotify event with a request of MappingPointer:
http://tronche.com/gui/x/xlib/events/window-state-change/mapping.html

[sadrul, 2011/12/07 16:36:12]

Indeed. I thought about it, and assumed perhaps this isn't necessary (in light
of http://codereview.chromium.org/7019007/).

+  return button > 0 && button <= count ? map[button - 1] : button;
+}
+
 int GetButtonMaskForX2Event(XIDeviceEvent* xievent) {
   int buttonflags = 0;
   for (int i = 0; i < 8 * xievent->buttons.mask_len; i++) {
     if (XIMaskIsSet(xievent->buttons.mask, i)) {
-      buttonflags |= GetEventFlagsForButton(i);
+      int button = (xievent->sourceid == xievent->deviceid) ?
+                    GetMappedButton(i) : i;

[Daniel Erat, 2011/12/04 15:51:45]

nit: indent one less space?

[sadrul, 2011/12/07 17:06:52]

Done.

+      buttonflags |= GetEventFlagsForButton(button);
     }
   }
   return buttonflags;
@@ -185,15 +196,16 @@ EventType EventTypeFromNative(const base::NativeEvent& native_event) {
           static_cast<XIDeviceEvent*>(native_event->xcookie.data);
       if (TouchFactory::GetInstance()->IsTouchDevice(xievent->sourceid))
         return GetTouchEventType(native_event);
+      int button = EventButtonFromNative(native_event);
       switch (xievent->evtype) {
         case XI_ButtonPress:
-          if (xievent->detail >= kMinWheelButton &&
-              xievent->detail <= kMaxWheelButton)
+          if (button >= kMinWheelButton &&
+              button <= kMaxWheelButton)
             return ET_MOUSEWHEEL;
           return ET_MOUSE_PRESSED;
         case XI_ButtonRelease:
-          if (xievent->detail >= kMinWheelButton &&
-              xievent->detail <= kMaxWheelButton)
+          if (button >= kMinWheelButton &&
+              button <= kMaxWheelButton)
             return ET_MOUSEWHEEL;
           return ET_MOUSE_RELEASED;
         case XI_Motion:
@@ -233,8 +245,9 @@ int EventFlagsFromNative(const base::NativeEvent& native_event) {
           int flags = GetButtonMaskForX2Event(xievent) |
               GetEventFlagsFromXState(xievent->mods.effective);
           const EventType type = EventTypeFromNative(native_event);
+          int button = EventButtonFromNative(native_event);
           if ((type == ET_MOUSE_PRESSED || type == ET_MOUSE_RELEASED) && !touch)
-            flags |= GetEventFlagsForButton(xievent->detail);
+            flags |= GetEventFlagsForButton(button);
           return flags;
         }
         case XI_Motion:
@@ -281,6 +294,16 @@ gfx::Point EventLocationFromNative(const base::NativeEvent& native_event) {
   return gfx::Point();
 }
 
+int EventButtonFromNative(const base::NativeEvent& native_event) {
+  CHECK_EQ(GenericEvent, native_event->type);
+  XIDeviceEvent* xievent =
+      static_cast<XIDeviceEvent*>(native_event->xcookie.data);
+  int button = xievent->detail;
+
+  return (xievent->sourceid == xievent->deviceid) ?
+          GetMappedButton(button) : button;

[Daniel Erat, 2011/12/04 15:51:45]

nit: indent one less space?

[sadrul, 2011/12/07 17:06:52]

Done.

+}
+
 KeyboardCode KeyboardCodeFromNative(const base::NativeEvent& native_event) {
   return KeyboardCodeFromXKeyEvent(native_event);
 }
@@ -302,13 +325,10 @@ bool IsMouseEvent(const base::NativeEvent& native_event) {
 
 int GetMouseWheelOffset(const base::NativeEvent& native_event) {
   int button;
-  if (native_event->type == GenericEvent) {
-    XIDeviceEvent* xiev =
-        static_cast<XIDeviceEvent*>(native_event->xcookie.data);
-    button = xiev->detail;
-  } else {
+  if (native_event->type == GenericEvent)
+    button = EventButtonFromNative(native_event);
+  else
     button = native_event->xbutton.button;
-  }
   switch (button) {
     case 4:
 #if defined(OS_CHROMEOS)