events: Generalize IsTouchscreenInternal to any device type

This logic can also be used for keyboards, mice, touchpads, and tablets.

TEST=chrome on link_freon & rush_ryu
BUG=437539

Review URL: https://codereview.chromium.org/791743004

Cr-Commit-Position: refs/heads/master@{#308082}

ui/events/devices/device_util_linux.cc

@@ -14,12 +14,11 @@
 
 namespace ui {
 
-// We consider the touchscreen to be internal if it is an I2c device.
-bool IsTouchscreenInternal(const base::FilePath& path) {
+InputDeviceType GetInputDeviceTypeFromPath(const base::FilePath& path) {
   DCHECK(!base::MessageLoopForUI::IsCurrent());
   std::string event_node = path.BaseName().value();
   if (event_node.empty() || !StartsWithASCII(event_node, "event", false))
-    return false;
+    return InputDeviceType::INPUT_DEVICE_UNKNOWN;
 
   // Find sysfs device path for this device.
   base::FilePath sysfs_path =
@@ -29,19 +28,37 @@ bool IsTouchscreenInternal(const base::FilePath& path) {
 
   // Device does not exist.
   if (sysfs_path.empty())
-    return false;
+    return InputDeviceType::INPUT_DEVICE_UNKNOWN;
 
-  // Check all parent devices. If any of them is the "i2c" subsystem,
-  // consider the device internal. Otherwise consider it external.
-  const base::FilePath i2c_subsystem(FILE_PATH_LITERAL("/sys/bus/i2c"));
+  // Check ancestor devices for a known bus attachment.
   for (base::FilePath path = sysfs_path; path != base::FilePath("/");
        path = path.DirName()) {
-    if (base::MakeAbsoluteFilePath(
-          path.Append(FILE_PATH_LITERAL("subsystem"))) == i2c_subsystem)
-      return true;
+    std::string subsystem_path =
+        base::MakeAbsoluteFilePath(path.Append(FILE_PATH_LITERAL("subsystem")))
+            .value();
+    if (subsystem_path.empty())
+      continue;
+
+    // Internal bus attachments.
+    if (subsystem_path == "/sys/bus/pci")
+      return InputDeviceType::INPUT_DEVICE_INTERNAL;
+    if (subsystem_path == "/sys/bus/i2c")
+      return InputDeviceType::INPUT_DEVICE_INTERNAL;
+    if (subsystem_path == "/sys/bus/acpi")
+      return InputDeviceType::INPUT_DEVICE_INTERNAL;
+    if (subsystem_path == "/sys/bus/serio")
+      return InputDeviceType::INPUT_DEVICE_INTERNAL;
+    if (subsystem_path == "/sys/bus/platform")
+      return InputDeviceType::INPUT_DEVICE_INTERNAL;
+
+    // External bus attachments.
+    if (subsystem_path == "/sys/bus/usb")
+      return InputDeviceType::INPUT_DEVICE_EXTERNAL;
+    if (subsystem_path == "/sys/class/bluetooth")
+      return InputDeviceType::INPUT_DEVICE_EXTERNAL;
   }
 
-  return false;
+  return InputDeviceType::INPUT_DEVICE_UNKNOWN;
 }
 
 }  // namespace

ui/events/devices/device_util_linux.h

@@ -6,6 +6,7 @@
 #define UI_EVENTS_DEVICES_DEVICE_UTIL_LINUX_H_
 
 #include "ui/events/devices/events_devices_export.h"
+#include "ui/events/devices/input_device.h"
 
 namespace base {
 class FilePath;
@@ -13,8 +14,9 @@ class FilePath;
 
 namespace ui {
 
-// Returns true if the device described by |path| is an internal device.
-EVENTS_DEVICES_EXPORT bool IsTouchscreenInternal(const base::FilePath& path);
+// Finds device type (internal or external) based on device path.
+EVENTS_DEVICES_EXPORT InputDeviceType
+GetInputDeviceTypeFromPath(const base::FilePath& path);
 
 }  // namespace ui
 

ui/events/ozone/evdev/touch_event_converter_evdev.cc

@@ -80,7 +80,7 @@ TouchEventConverterEvdev::TouchEventConverterEvdev(
       syn_dropped_(false),
       is_type_a_(false),
       current_slot_(0),
-      is_internal_(IsTouchscreenInternal(path)) {
+      is_internal_(GetInputDeviceTypeFromPath(path) == INPUT_DEVICE_INTERNAL) {
 }
 
 TouchEventConverterEvdev::~TouchEventConverterEvdev() {

ui/events/platform/x11/x11_hotplug_event_handler.cc

@@ -299,9 +299,7 @@ void HandleTouchscreenDevicesInWorker(
     // Touchscreens should have absolute X and Y axes, and be direct touch
     // devices.
     if (max_x > 0.0 && max_y > 0.0 && is_direct_touch) {
-      InputDeviceType type = IsTouchscreenInternal(device_info.path)
-              ? InputDeviceType::INPUT_DEVICE_INTERNAL
-              : InputDeviceType::INPUT_DEVICE_EXTERNAL;
+      InputDeviceType type = GetInputDeviceTypeFromPath(device_info.path);
       // |max_x| and |max_y| are inclusive values, so we need to add 1 to get
       // the size.
       devices.push_back(TouchscreenDevice(