Moving input device hotplug event processing outside of ui/display

ui/events/x/device_data_manager_x11.cc

Index: ui/events/x/device_data_manager_x11.cc
diff --git a/ui/events/x/device_data_manager_x11.cc b/ui/events/x/device_data_manager_x11.cc
index 97ffe3036f04eb5b757b5c8ac5338c41f58d91d9..6c26d90de83d11ee7ad5edd6e79cc5301dc0114f 100644
--- a/ui/events/x/device_data_manager_x11.cc
+++ b/ui/events/x/device_data_manager_x11.cc
@@ -13,6 +13,7 @@
 #include "base/sys_info.h"
 #include "ui/events/event_constants.h"
 #include "ui/events/event_switches.h"
+#include "ui/events/input_device_event_observer.h"
 #include "ui/events/x/device_list_cache_x.h"
 #include "ui/events/x/touch_factory_x11.h"
 #include "ui/gfx/display.h"
@@ -263,6 +264,10 @@ void DeviceDataManagerX11::UpdateDeviceList(Display* display) {
     if (possible_cmt && !not_cmt)
       cmt_devices_[deviceid] = true;
   }
+
+  FOR_EACH_OBSERVER(InputDeviceEventObserver,
+                    observers_,
+                    OnInputDeviceConfigurationChanged());
 }
 
 bool DeviceDataManagerX11::GetSlotNumber(const XIDeviceEvent* xiev, int* slot) {
@@ -659,4 +664,64 @@ bool DeviceDataManagerX11::TouchEventNeedsCalibrate(int touch_device_id) const {
   return false;
 }
 
+std::vector<TouchscreenDevice> DeviceDataManagerX11::GetTouchscreenDevices() {
+  std::vector<TouchscreenDevice> devices;
+  Display* display = gfx::GetXDisplay();
+
+  Atom valuator_x = XInternAtom(display, "Abs MT Position X", False);
+  Atom valuator_y = XInternAtom(display, "Abs MT Position Y", False);
+  if (valuator_x == None || valuator_y == None)
+    return devices;
+
+  XIDeviceList native_devices =
+      DeviceListCacheX::GetInstance()->GetXI2DeviceList(display);
+  for (int i = 0; i < native_devices.count; ++i) {
+    if (!native_devices[i].enabled || native_devices[i].use != XIFloatingSlave)
+      continue;  // Assume all touchscreens are floating slaves
+
+    double width = -1.0;
+    double height = -1.0;
+    bool is_direct_touch = false;
+
+    for (int j = 0; j < native_devices[i].num_classes; j++) {
+      XIAnyClassInfo* class_info = native_devices[i].classes[j];
+
+      if (class_info->type == XIValuatorClass) {
+        XIValuatorClassInfo* valuator_info =
+            reinterpret_cast<XIValuatorClassInfo*>(class_info);
+
+        if (valuator_x == valuator_info->label) {
+          // Ignore X axis valuator with unexpected properties
+          if (valuator_info->number == 0 && valuator_info->mode == Absolute &&
+              valuator_info->min == 0.0) {
+            width = valuator_info->max;
+          }
+        } else if (valuator_y == valuator_info->label) {
+          // Ignore Y axis valuator with unexpected properties
+          if (valuator_info->number == 1 && valuator_info->mode == Absolute &&
+              valuator_info->min == 0.0) {
+            height = valuator_info->max;
+          }
+        }
+      }
+#if defined(USE_XI2_MT)
+      if (class_info->type == XITouchClass) {
+        XITouchClassInfo* touch_info =
+            reinterpret_cast<XITouchClassInfo*>(class_info);
+        is_direct_touch = touch_info->mode == XIDirectTouch;
+      }
+#endif
+    }
+
+    // Touchscreens should have absolute X and Y axes, and be direct touch
+    // devices.
+    if (width > 0.0 && height > 0.0 && is_direct_touch) {
+      devices.push_back(TouchscreenDevice(native_devices[i].deviceid,
+                                          gfx::Size(width, height)));
+    }
+  }
+
+  return devices;
+}
+
 }  // namespace ui