ozone: evdev: Add gamepad support

ui/events/ozone/evdev/event_device_info.cc

 // Copyright 2013 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 "ui/events/ozone/evdev/event_device_info.h"
 
 #include <linux/input.h>
 
 #include "base/files/file_path.h"
 #include "base/logging.h"
@@ skipping 409 matching lines @@
 }
 
 bool EventDeviceInfo::HasTablet() const {
   return HasAbsXY() && HasPointer() && HasStylus();
 }
 
 bool EventDeviceInfo::HasTouchscreen() const {
   return HasAbsXY() && HasDirect();
 }
 
+bool EventDeviceInfo::HasGamepad() const {
+  if (!HasEventType(EV_KEY))
+    return false;
+
+  // If the device has gamepad button, it will be considered
+  // as a gamepad. Note: this WILL have false positives and false negatives. A
+  // concrete solution will use ID_INPUT_JOYSTICK with some patch remving false

[spang, 2017/04/21 05:38:46]

typo: removing

[jkwang, 2017/04/25 21:16:41]

Done.

+  // positives.
+  for (int key = BTN_JOYSTICK; key <= BTN_THUMBR; ++key)

[spang, 2017/05/03 22:00:37]

Please add braces around all multiline blocks. The outer block here has two
lines.

[jkwang, 2017/05/05 00:07:45]

Done.

+    if (HasKeyEvent(key))
+      return true;
+
+  return false;
+}
+
 EventDeviceInfo::LegacyAbsoluteDeviceType
 EventDeviceInfo::ProbeLegacyAbsoluteDevice() const {
   if (!HasAbsXY())
     return LegacyAbsoluteDeviceType::LADT_NONE;
 
   // Treat internal stylus devices as touchscreens.
   if (device_type_ == INPUT_DEVICE_INTERNAL && HasStylus())
     return LegacyAbsoluteDeviceType::LADT_TOUCHSCREEN;
 
   if (HasStylus())
     return LegacyAbsoluteDeviceType::LADT_TABLET;
 
   if (HasKeyEvent(BTN_TOOL_FINGER) && HasKeyEvent(BTN_TOUCH))
     return LegacyAbsoluteDeviceType::LADT_TOUCHPAD;
 
   if (HasKeyEvent(BTN_TOUCH))
     return LegacyAbsoluteDeviceType::LADT_TOUCHSCREEN;
 
   // ABS_Z mitigation for extra device on some Elo devices.
   if (HasKeyEvent(BTN_LEFT) && !HasAbsEvent(ABS_Z))
     return LegacyAbsoluteDeviceType::LADT_TOUCHSCREEN;
 
   return LegacyAbsoluteDeviceType::LADT_NONE;
 }
 
 }  // namespace ui