ozone: evdev: Add gesture property provider

ui/events/ozone/evdev/libgestures_glue/gesture_property_provider.cc

+// Copyright 2014 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/libgestures_glue/gesture_property_provider.h"
+
+#include <gestures/gestures.h>
+#include <libevdev/libevdev.h>
+
+#include <fnmatch.h>
+#include <stdint.h>
+#include <string.h>
+#include <algorithm>
+#include <iostream>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/containers/hash_tables.h"
+#include "base/files/file_enumerator.h"
+#include "base/files/file_util.h"
+#include "base/logging.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_split.h"
+#include "base/strings/string_tokenizer.h"
+#include "base/strings/string_util.h"
+#include "base/strings/stringize_macros.h"
+#include "base/strings/stringprintf.h"
+#include "ui/events/ozone/evdev/libgestures_glue/gesture_interpreter_libevdev_cros.h"
+
+// Severity level for general info logging purpose.
+#define GPROP_LOG DVLOG
+#define INFO_SEVERITY 1
+
+/* Implementation of GesturesProp declared in gestures.h
+ *
+ * libgestures requires that this be in the top level namespace.
+ * */
+class GesturesProp {
+ public:
+  typedef ui::GesturePropertyProvider::PropertyType PropertyType;
+
+  GesturesProp(const std::string& name,
+               const PropertyType type,
+               const size_t count)
+      : name_(name),
+        type_(type),
+        count_(count),
+        get_(NULL),
+        set_(NULL),
+        handler_data_(NULL) {}
+  virtual ~GesturesProp() {}
+
+  // Variant-ish interfaces for accessing the property value. Each type of
+  // property should override the corresponding interfaces for it.
+  virtual std::vector<int> GetIntValue() const {
+    NOTREACHED();
+    return std::vector<int>();
+  }
+  virtual bool SetIntValue(const std::vector<int>& value) {
+    NOTREACHED();
+    return false;
+  }
+  virtual std::vector<int16_t> GetShortValue() const {
+    NOTREACHED();
+    return std::vector<int16_t>();
+  }
+  virtual bool SetShortValue(const std::vector<int16_t>& value) {
+    NOTREACHED();
+    return false;
+  }
+  virtual std::vector<bool> GetBoolValue() const {
+    NOTREACHED();
+    return std::vector<bool>();
+  }
+  virtual bool SetBoolValue(const std::vector<bool>& value) {
+    NOTREACHED();
+    return false;
+  }
+  virtual std::string GetStringValue() const {
+    NOTREACHED();
+    return std::string();
+  }
+  virtual bool SetStringValue(const std::string& value) {
+    NOTREACHED();
+    return false;
+  }
+  virtual std::vector<double> GetDoubleValue() const {
+    NOTREACHED();
+    return std::vector<double>();
+  }
+  virtual bool SetDoubleValue(const std::vector<double>& value) {
+    NOTREACHED();
+    return false;
+  }
+
+  // Set property access handlers.
+  void SetHandlers(GesturesPropGetHandler get,
+                   GesturesPropSetHandler set,
+                   void* data) {
+    get_ = get;
+    set_ = set;
+    handler_data_ = data;
+  }
+
+  // Accessors.
+  const std::string& name() const { return name_; }
+  PropertyType type() const { return type_; }
+  size_t count() const { return count_; }
+  virtual bool IsReadOnly() const = 0;
+
+ protected:
+  void OnGet() const {
+    // We don't have the X server now so there is currently nothing to do when
+    // the get handler returns true.
+    // TODO(sheckylin): Re-visit this if we use handlers that modifies the
+    // property.
+    if (get_)
+      get_(handler_data_);
+  }
+
+  void OnSet() const {
+    // Call the property set handler if available.
+    if (set_)
+      set_(handler_data_);
+  }
+
+ private:
+  // For logging purpose.
+  friend std::ostream& operator<<(std::ostream& os,
+                                  const GesturesProp& property);
+
+  // Interfaces for getting internal pointers and stuff.
+  virtual const char** GetStringWritebackPtr() const {
+    NOTREACHED();
+    return NULL;
+  }
+  virtual bool IsAllocated() const {
+    NOTREACHED();
+    return false;
+  }
+
+  // Property name, type and number of elements.
+  std::string name_;
+  PropertyType type_;
+  size_t count_;
+
+  // Handler function pointers and the data to be passed to them when the
+  // property is accessed.
+  GesturesPropGetHandler get_;
+  GesturesPropSetHandler set_;
+  void* handler_data_;
+
+  DISALLOW_COPY_AND_ASSIGN(GesturesProp);
+};
+
+template <typename T>
+class TypedGesturesProp : public GesturesProp {
+ public:
+  TypedGesturesProp(const std::string& name,
+                    const PropertyType type,
+                    const size_t count,
+                    T* value)
+      : GesturesProp(name, type, count),
+        value_(value),
+        is_read_only_(false),
+        is_allocated_(false) {
+    Init();
+  }
+  virtual ~TypedGesturesProp() override {
+    if (is_allocated_)
+      delete[] value_;
+  }
+
+  // Accessors.
+  virtual bool IsReadOnly() const override { return is_read_only_; }
+
+ protected:
+  // Functions for setting/getting numerical properties.
+  //
+  // These two functions calls the set/get handler and should only be used in
+  // Get*Value/Set*Value functions.
+  template <typename U>
+  std::vector<U> GetNumericalPropertyValue() const {
+    // Nothing should be modified so it is OK to call the get handler first.
+    OnGet();
+    return this->template GetNumericalValue<U>();
+  }
+
+  template <typename U>
+  bool SetNumericalPropertyValue(const std::vector<U>& value) {
+    // Set the value only if not read-only and the vector size matches.
+    //
+    // As per the legacy guideline, all read-only properties (created with NULL)
+    // can't be modified. If we want to change this in the future, re-think
+    // about the different cases here (e.g., should we allow setting an array
+    // value of different size?).
+    if (is_read_only_ || value.size() != count())
+      return false;
+    bool ret = this->template SetNumericalValue(value);
+    OnSet();
+    return ret;
+  }
+
+  // Initialize a numerical property's value. Note that a (numerical) default
+  // property's value is always stored in double.
+  void InitializeNumericalProperty(const T* init,
+                                   const GesturesProp* default_property) {
+    if (IsDefaultPropertyUsable(default_property)) {
+      GPROP_LOG(INFO_SEVERITY) << "Default property found. Using its value ...";
+      this->template SetNumericalValue(default_property->GetDoubleValue());
+    } else {
+      // To work with the interface exposed by the gesture lib, we have no
+      // choice but to trust that the init array has sufficient size.
+      std::vector<T> temp(init, init + count());
+      this->template SetNumericalValue(temp);
+    }
+  }
+
+  // Data pointer.
+  T* value_;
+
+  // If the flag is on, it means the GesturesProp is created by passing a NULL
+  // data pointer to the creator functions. We define the property as a
+  // read-only one and that no value change will be allowed for it. Note that
+  // the flag is different from is_allocated in that StringProperty will always
+  // allocate no matter it is created with NULL or not.
+  bool is_read_only_;
+
+ private:
+  // Initialize the object.
+  void Init() {
+    // If no external data pointer is passed, we have to create our own.
+    if (!value_) {
+      value_ = new T[GesturesProp::count()];
+      is_read_only_ = true;
+      is_allocated_ = true;
+    }
+  }
+
+  // Low-level functions for setting/getting numerical properties.
+  template <typename U>
+  std::vector<U> GetNumericalValue() const {
+    // We do type-casting because the numerical types may not totally match.
+    // For example, we store bool as GesturesPropBool to be compatible with the
+    // gesture library. Also, all parsed xorg-conf property values are stored
+    // as double because we can't identify their original type lexically.
+    // TODO(sheckylin): Handle value out-of-range (e.g., double to int).
+    std::vector<U> result(count());
+    for (size_t i = 0; i < count(); ++i)
+      result[i] = static_cast<U>(value_[i]);
+    return result;
+  }
+
+  template <typename U>
+  bool SetNumericalValue(const std::vector<U>& value) {
+    for (size_t i = 0; i < count(); ++i)
+      value_[i] = static_cast<T>(value[i]);
+    return true;
+  }
+
+  // Check if a default property usable for (numerical) initialization.
+  bool IsDefaultPropertyUsable(const GesturesProp* default_property) const {
+    // We currently assumed that we won't specify any array property in the
+    // configuration files. The code needs to be updated if the assumption
+    // becomes invalid in the future.
+    return (count() == 1 && default_property &&
+            default_property->type() != PropertyType::PT_STRING);
+  }
+
+  // Accessors.
+  virtual bool IsAllocated() const override { return is_allocated_; }
+
+  // If the flag is on, it means the memory that the data pointer points to is
+  // allocated here. We will need to free the memory by ourselves when the
+  // GesturesProp is destroyed.
+  bool is_allocated_;
+};
+
+class GesturesIntProp : public TypedGesturesProp<int> {
+ public:
+  GesturesIntProp(const std::string& name,
+                  const size_t count,
+                  int* value,
+                  const int* init,
+                  const GesturesProp* default_property)
+      : TypedGesturesProp<int>(name, PropertyType::PT_INT, count, value) {
+    InitializeNumericalProperty(init, default_property);
+  }
+  virtual std::vector<int> GetIntValue() const override {
+    return this->template GetNumericalPropertyValue<int>();
+  }
+  virtual bool SetIntValue(const std::vector<int>& value) override {
+    return this->template SetNumericalPropertyValue(value);
+  }
+};
+
+class GesturesShortProp : public TypedGesturesProp<short> {
+ public:
+  GesturesShortProp(const std::string& name,
+                    const size_t count,
+                    short* value,
+                    const short* init,
+                    const GesturesProp* default_property)
+      : TypedGesturesProp<short>(name, PropertyType::PT_SHORT, count, value) {
+    InitializeNumericalProperty(init, default_property);
+  }
+  virtual std::vector<int16_t> GetShortValue() const override {
+    return this->template GetNumericalPropertyValue<int16_t>();
+  }
+  virtual bool SetShortValue(const std::vector<int16_t>& value) override {
+    return this->template SetNumericalPropertyValue(value);
+  }
+};
+
+class GesturesBoolProp : public TypedGesturesProp<GesturesPropBool> {
+ public:
+  GesturesBoolProp(const std::string& name,
+                   const size_t count,
+                   GesturesPropBool* value,
+                   const GesturesPropBool* init,
+                   const GesturesProp* default_property)
+      : TypedGesturesProp<GesturesPropBool>(name,
+                                            PropertyType::PT_BOOL,
+                                            count,
+                                            value) {
+    InitializeNumericalProperty(init, default_property);
+  }
+  virtual std::vector<bool> GetBoolValue() const override {
+    return this->template GetNumericalPropertyValue<bool>();
+  }
+  virtual bool SetBoolValue(const std::vector<bool>& value) override {
+    return this->template SetNumericalPropertyValue(value);
+  }
+};
+
+class GesturesDoubleProp : public TypedGesturesProp<double> {
+ public:
+  GesturesDoubleProp(const std::string& name,
+                     const size_t count,
+                     double* value,
+                     const double* init,
+                     const GesturesProp* default_property)
+      : TypedGesturesProp<double>(name, PropertyType::PT_REAL, count, value) {
+    InitializeNumericalProperty(init, default_property);
+  }
+  virtual std::vector<double> GetDoubleValue() const override {
+    return this->template GetNumericalPropertyValue<double>();
+  }
+  virtual bool SetDoubleValue(const std::vector<double>& value) override {
+    return this->template SetNumericalPropertyValue(value);
+  }
+};
+
+class GesturesStringProp : public TypedGesturesProp<std::string> {
+ public:
+  // StringProperty's memory is always allocated on this side instead of
+  // externally in the gesture lib as the original one will be destroyed right
+  // after the constructor call (check the design of StringProperty). To do
+  // this, we call the TypedGesturesProp constructor with NULL pointer so that
+  // it always allocates.
+  GesturesStringProp(const std::string& name,
+                     const char** value,
+                     const char* init,
+                     const GesturesProp* default_property)
+      : TypedGesturesProp<std::string>(name, PropertyType::PT_STRING, 1, NULL),
+        write_back_(NULL) {
+    InitializeStringProperty(value, init, default_property);
+  }
+  virtual std::string GetStringValue() const override {
+    OnGet();
+    return *value_;
+  }
+  virtual bool SetStringValue(const std::string& value) override {
+    if (is_read_only_)
+      return false;
+    *value_ = value;
+
+    // Write back the pointer in case it may change (e.g., string
+    // re-allocation).
+    if (write_back_)
+      *(write_back_) = value_->c_str();
+    OnSet();
+    return true;
+  }
+
+ private:
+  // Initialize the object.
+  void InitializeStringProperty(const char** value,
+                                const char* init,
+                                const GesturesProp* default_property) {
+    // Initialize the property value similar to the numerical types.
+    if (IsDefaultPropertyUsable(default_property)) {
+      GPROP_LOG(INFO_SEVERITY) << "Default property found. Using its value ...";
+      *value_ = default_property->GetStringValue();
+    } else {
+      *value_ = init;
+    }
+
+    // If the provided pointer is not NULL, replace its content
+    // (val_ of StringProperty) with the address of our allocated string.
+    // Note that we don't have to do this for the other data types as they will
+    // use the original data pointer if possible and it is unnecessary to do so
+    // if the pointer is NULL.
+    if (value) {
+      *value = value_->c_str();
+      write_back_ = value;
+      // Set the read-only flag back to false.
+      is_read_only_ = false;
+    }
+  }
+
+  // Re-write the function with different criteria as we want string properties
+  // now.
+  bool IsDefaultPropertyUsable(const GesturesProp* default_property) const {
+    return (default_property &&
+            default_property->type() == PropertyType::PT_STRING);
+  }
+
+  virtual const char** GetStringWritebackPtr() const override {
+    return write_back_;
+  }
+
+  // In some cases, we don't directly use the data pointer provided by the
+  // creators due to its limitation and instead use our own types (e.g., in
+  // the case of string). We thus need to store the write back pointer so that
+  // we can update the value in the gesture lib if the property value gets
+  // changed.
+  const char** write_back_;
+};
+
+// Anonymous namespace for utility functions and internal constants.
+namespace {
+
+// The path that we will look for conf files.
+const char kConfigurationFilePath[] = "/etc/gesture";
+
+// We support only match types that have already been used. One should change
+// this if we start using new types in the future. Note that most unsupported
+// match types are either useless in CrOS or inapplicable to the non-X
+// environment.
+const char* kSupportedMatchTypes[] = {"MatchProduct",
+                                      "MatchDevicePath",
+                                      "MatchUSBID",
+                                      "MatchIsPointer",
+                                      "MatchIsTouchpad",
+                                      "MatchIsTouchscreen"};
+const char* kUnsupportedMatchTypes[] = {"MatchVendor",
+                                        "MatchOS",
+                                        "MatchPnPID",
+                                        "MatchDriver",
+                                        "MatchTag",
+                                        "MatchLayout",
+                                        "MatchIsKeyboard",
+                                        "MatchIsJoystick",
+                                        "MatchIsTablet"};
+
+// Special keywords for boolean values.
+const char* kTrue[] = {"on", "true", "yes"};
+const char* kFalse[] = {"off", "false", "no"};
+
+// Check if a device falls into one device type category.
+bool IsDeviceOfType(const ui::GesturePropertyProvider::DevicePtr device,
+                    const ui::GesturePropertyProvider::DeviceType type) {
+  EvdevClass evdev_class = device->info.evdev_class;
+  switch (type) {
+    case ui::GesturePropertyProvider::DT_MOUSE:
+      return (evdev_class == EvdevClassMouse ||
+              evdev_class == EvdevClassMultitouchMouse);
+      break;
+    case ui::GesturePropertyProvider::DT_TOUCHPAD:
+      // Note that the behavior here is different from the inputcontrol script
+      // which actually returns touchscreen devices as well.
+      return (evdev_class == EvdevClassTouchpad);
+      break;
+    case ui::GesturePropertyProvider::DT_TOUCHSCREEN:
+      return (evdev_class == EvdevClassTouchscreen);
+      break;
+    case ui::GesturePropertyProvider::DT_MULTITOUCH:
+      return (evdev_class == EvdevClassTouchpad ||
+              evdev_class == EvdevClassTouchscreen ||
+              evdev_class == EvdevClassMultitouchMouse);
+      break;
+    case ui::GesturePropertyProvider::DT_MULTITOUCH_MOUSE:
+      return (evdev_class == EvdevClassMultitouchMouse);
+      break;
+    case ui::GesturePropertyProvider::DT_ALL:
+      return true;
+      break;
+    default:
+      NOTREACHED();
+      break;
+  }
+  return false;
+}
+
+// Trick to get the device path from a file descriptor.
+std::string GetDeviceNodePath(
+    const ui::GesturePropertyProvider::DevicePtr device) {
+  std::string proc_symlink = "/proc/self/fd/" + base::IntToString(device->fd);
+  base::FilePath path;
+  if (!base::ReadSymbolicLink(base::FilePath(proc_symlink), &path))
+    return std::string();
+  return path.value();
+}
+
+// Check if a match criteria is currently implemented. Note that we didn't
+// implemented all of them as some are inapplicable in the non-X world.
+bool IsMatchTypeSupported(const std::string& match_type) {
+  for (size_t i = 0; i < arraysize(kSupportedMatchTypes); ++i)
+    if (match_type == kSupportedMatchTypes[i])
+      return true;
+  for (size_t i = 0; i < arraysize(kUnsupportedMatchTypes); ++i) {
+    if (match_type == kUnsupportedMatchTypes[i]) {
+      LOG(ERROR) << "Unsupported gestures input class match type: "
+                 << match_type;
+      return false;
+    }
+  }
+  return false;
+}
+
+// Check if a match criteria is a device type one.
+bool IsMatchDeviceType(const std::string& match_type) {
+  return StartsWithASCII(match_type, "MatchIs", true);
+}
+
+// Parse a boolean value keyword (e.g., on/off, true/false).
+int ParseBooleanKeyword(const std::string& value) {
+  for (size_t i = 0; i < arraysize(kTrue); ++i)
+    if (LowerCaseEqualsASCII(value, kTrue[i]))
+      return 1;
+  for (size_t i = 0; i < arraysize(kFalse); ++i)
+    if (LowerCaseEqualsASCII(value, kFalse[i]))
+      return -1;
+  return 0;
+}
+
+// Log the value of an array property.
+template <typename T>
+void LogArrayProperty(std::ostream& os, const std::vector<T>& value) {
+  os << "(";
+  for (size_t i = 0; i < value.size(); ++i) {
+    if (i > 0)
+      os << ", ";
+    os << value[i];
+  }
+  os << ")";
+}
+
+// Property type logging function.
+std::ostream& operator<<(std::ostream& out,
+                         const ui::GesturePropertyProvider::PropertyType type) {
+  std::string s;
+#define TYPE_CASE(TYPE)                     \
+  case (ui::GesturePropertyProvider::TYPE): \
+    s = #TYPE;                              \
+    break;
+  switch (type) {
+    TYPE_CASE(PT_INT);
+    TYPE_CASE(PT_SHORT);
+    TYPE_CASE(PT_BOOL);
+    TYPE_CASE(PT_STRING);
+    TYPE_CASE(PT_REAL);
+    default:
+      NOTREACHED();
+      break;
+  }
+#undef TYPE_CASE
+  return out << s;
+}
+
+}  // namespace
+
+// GesturesProp logging function.
+std::ostream& operator<<(std::ostream& os, const GesturesProp& prop) {
+  const GesturesProp* property = &prop;
+
+  // Output the property content.
+  os << "\"" << property->name() << "\", " << property->type() << ", "
+     << property->count() << ", (" << property->IsAllocated() << ", "
+     << property->IsReadOnly() << "), ";
+
+  // Only the string property has the write back pointer.
+  if (property->type() == ui::GesturePropertyProvider::PT_STRING)
+    os << property->GetStringWritebackPtr();
+  else
+    os << "NULL";
+
+  // Output the property values.
+  os << ", ";
+  switch (property->type()) {
+    case ui::GesturePropertyProvider::PT_INT:
+      LogArrayProperty(os, property->GetIntValue());
+      break;
+    case ui::GesturePropertyProvider::PT_SHORT:
+      LogArrayProperty(os, property->GetShortValue());
+      break;
+    case ui::GesturePropertyProvider::PT_BOOL:
+      LogArrayProperty(os, property->GetBoolValue());
+      break;
+    case ui::GesturePropertyProvider::PT_STRING:
+      os << "\"" << property->GetStringValue() << "\"";
+      break;
+    case ui::GesturePropertyProvider::PT_REAL:
+      LogArrayProperty(os, property->GetDoubleValue());
+      break;
+    default:
+      LOG(ERROR) << "Unknown gesture property type: " << property->type();
+      NOTREACHED();
+      break;
+  }
+  return os;
+}
+
+namespace ui {
+namespace internal {
+
+// Mapping table from a property name to its corresponding GesturesProp
+// object pointer.
+typedef base::hash_map<std::string, GesturesProp*> PropertiesMap;
+typedef base::ScopedPtrHashMap<std::string, GesturesProp> ScopedPropertiesMap;
+
+// Struct holding properties of a device.
+//
+// Note that we can't define it in GesturePropertyProvider as a nested class
+// because ScopedPtrHashMap will require us to expose the GestureProp's
+// destructor so that it can instantiate the object. This is something we
+// don't want to do.
+struct GestureDevicePropertyData {
+  GestureDevicePropertyData() {}
+
+  // Properties owned and being used by the device.
+  ScopedPropertiesMap properties;
+
+  // Unowned default properties (owned by the configuration file). Their values
+  // will be applied when a property of the same name is created. These are
+  // usually only a small portion of all properties in use.
+  PropertiesMap default_properties;
+};
+
+// Base class for device match criterias in conf files.
+// Check the xorg-conf spec for more detailed information.
+class MatchCriteria {
+ public:
+  typedef ui::GesturePropertyProvider::DevicePtr DevicePtr;
+  explicit MatchCriteria(const std::string& arg);
+  virtual ~MatchCriteria() {}
+  virtual bool Match(const DevicePtr device) = 0;
+
+ protected:
+  std::vector<std::string> args_;
+};
+
+// Match a device based on its evdev name string.
+class MatchProduct : public MatchCriteria {
+ public:
+  explicit MatchProduct(const std::string& arg);
+  virtual ~MatchProduct() {}
+  virtual bool Match(const DevicePtr device);
+};
+
+// Math a device based on its device node path.
+class MatchDevicePath : public MatchCriteria {
+ public:
+  explicit MatchDevicePath(const std::string& arg);
+  virtual ~MatchDevicePath() {}
+  virtual bool Match(const DevicePtr device);
+};
+
+// Math a USB device based on its USB vid and pid.
+// Mostly used for external mice and touchpads.
+class MatchUSBID : public MatchCriteria {
+ public:
+  explicit MatchUSBID(const std::string& arg);
+  virtual ~MatchUSBID() {}
+  virtual bool Match(const DevicePtr device);
+
+ private:
+  bool IsValidPattern(const std::string& pattern);
+  std::vector<std::string> vid_patterns_;
+  std::vector<std::string> pid_patterns_;
+};
+
+// Generic base class for device type math criteria.
+class MatchDeviceType : public MatchCriteria {
+ public:
+  explicit MatchDeviceType(const std::string& arg);
+  virtual ~MatchDeviceType() {}
+  virtual bool Match(const DevicePtr device) = 0;
+
+ protected:
+  bool value_;
+  bool is_valid_;
+};
+
+// Check if a device is a pointer device.
+class MatchIsPointer : public MatchDeviceType {
+ public:
+  explicit MatchIsPointer(const std::string& arg);
+  virtual ~MatchIsPointer() {}
+  virtual bool Match(const DevicePtr device);
+};
+
+// Check if a device is a touchpad.
+class MatchIsTouchpad : public MatchDeviceType {
+ public:
+  explicit MatchIsTouchpad(const std::string& arg);
+  virtual ~MatchIsTouchpad() {}
+  virtual bool Match(const DevicePtr device);
+};
+
+// Check if a device is a touchscreen.
+class MatchIsTouchscreen : public MatchDeviceType {
+ public:
+  explicit MatchIsTouchscreen(const std::string& arg);
+  virtual ~MatchIsTouchscreen() {}
+  virtual bool Match(const DevicePtr device);
+};
+
+// Struct for sections in xorg conf files.
+struct ConfigurationSection {
+  typedef ui::GesturePropertyProvider::DevicePtr DevicePtr;
+  ConfigurationSection() {}
+  bool Match(const DevicePtr device);
+  std::string identifier;
+  ScopedVector<MatchCriteria> criterias;
+  ScopedVector<GesturesProp> properties;
+};
+
+MatchCriteria::MatchCriteria(const std::string& arg) {
+  // TODO(sheckylin): Should we trim all tokens here?
+  Tokenize(arg, "|", &args_);
+  if (args_.empty()) {
+    LOG(ERROR) << "Empty match pattern found, will evaluate to the default "
+                  "value (true): \"" << arg << "\"";
+  }
+}
+
+MatchProduct::MatchProduct(const std::string& arg) : MatchCriteria(arg) {
+}
+
+bool MatchProduct::Match(const DevicePtr device) {
+  if (args_.empty())
+    return true;
+  std::string name(device->info.name);
+  for (size_t i = 0; i < args_.size(); ++i)
+    if (name.find(args_[i]) != std::string::npos)
+      return true;
+  return false;
+}
+
+MatchDevicePath::MatchDevicePath(const std::string& arg) : MatchCriteria(arg) {
+}
+
+bool MatchDevicePath::Match(const DevicePtr device) {
+  if (args_.empty())
+    return true;
+
+  // Check if the device path matches any pattern.
+  std::string path = GetDeviceNodePath(device);
+  if (path.empty())
+    return false;
+  for (size_t i = 0; i < args_.size(); ++i)
+    if (fnmatch(args_[i].c_str(), path.c_str(), FNM_NOESCAPE) == 0)
+      return true;
+  return false;
+}
+
+MatchUSBID::MatchUSBID(const std::string& arg) : MatchCriteria(arg) {
+  // Check each pattern and split valid ones into vids and pids.
+  for (size_t i = 0; i < args_.size(); ++i) {
+    if (!IsValidPattern(args_[i])) {
+      LOG(ERROR) << "Invalid USB ID: " << args_[i];
+      continue;
+    }
+    std::vector<std::string> tokens;
+    base::SplitString(args_[i], ':', &tokens);
+    vid_patterns_.push_back(base::StringToLowerASCII(tokens[0]));
+    pid_patterns_.push_back(base::StringToLowerASCII(tokens[1]));
+  }
+  if (vid_patterns_.empty()) {
+    LOG(ERROR) << "No valid USB ID pattern found, will be ignored: \"" << arg
+               << "\"";
+  }
+}
+
+bool MatchUSBID::Match(const DevicePtr device) {
+  if (vid_patterns_.empty())
+    return true;
+  std::string vid = base::StringPrintf("%04x", device->info.id.vendor);
+  std::string pid = base::StringPrintf("%04x", device->info.id.product);
+  for (size_t i = 0; i < vid_patterns_.size(); ++i) {
+    if (fnmatch(vid_patterns_[i].c_str(), vid.c_str(), FNM_NOESCAPE) == 0 &&
+        fnmatch(pid_patterns_[i].c_str(), pid.c_str(), FNM_NOESCAPE) == 0) {
+      return true;
+    }
+  }
+  return false;
+}
+
+bool MatchUSBID::IsValidPattern(const std::string& pattern) {
+  // Each USB id should be in the lsusb format, i.e., xxxx:xxxx. We choose to do
+  // a lazy check here: if the pattern contains wrong characters not in the hex
+  // number range, it won't be matched anyway.
+  int number_of_colons = 0;
+  size_t pos_of_colon = 0;
+  for (size_t i = 0; i < pattern.size(); ++i)
+    if (pattern[i] == ':')
+      ++number_of_colons, pos_of_colon = i;
+  return (number_of_colons == 1) && (pos_of_colon != 0) &&
+         (pos_of_colon != pattern.size() - 1);
+}
+
+MatchDeviceType::MatchDeviceType(const std::string& arg)
+    : MatchCriteria(arg), value_(true), is_valid_(false) {
+  // Default value of a match criteria is true.
+  if (args_.empty())
+    args_.push_back("on");
+
+  // We care only about the first argument.
+  int value = ParseBooleanKeyword(args_[0]);
+  if (value) {
+    is_valid_ = true;
+    value_ = value > 0;
+  }
+  if (!is_valid_) {
+    LOG(ERROR)
+        << "No valid device class boolean keyword found, will be ignored: \""
+        << arg << "\"";
+  }
+}
+
+MatchIsPointer::MatchIsPointer(const std::string& arg) : MatchDeviceType(arg) {
+}
+
+bool MatchIsPointer::Match(const DevicePtr device) {
+  if (!is_valid_)
+    return true;
+  return (value_ == (device->info.evdev_class == EvdevClassMouse ||
+                     device->info.evdev_class == EvdevClassMultitouchMouse));
+}
+
+MatchIsTouchpad::MatchIsTouchpad(const std::string& arg)
+    : MatchDeviceType(arg) {
+}
+
+bool MatchIsTouchpad::Match(const DevicePtr device) {
+  if (!is_valid_)
+    return true;
+  return (value_ == (device->info.evdev_class == EvdevClassTouchpad));
+}
+
+MatchIsTouchscreen::MatchIsTouchscreen(const std::string& arg)
+    : MatchDeviceType(arg) {
+}
+
+bool MatchIsTouchscreen::Match(const DevicePtr device) {
+  if (!is_valid_)
+    return true;
+  return (value_ == (device->info.evdev_class == EvdevClassTouchscreen));
+}
+
+bool ConfigurationSection::Match(DevicePtr device) {
+  for (size_t i = 0; i < criterias.size(); ++i)
+    if (!criterias[i]->Match(device))
+      return false;
+  return true;
+}
+
+}  // namespace internal
+
+GesturePropertyProvider::GesturePropertyProvider() {
+  LoadDeviceConfigurations();
+}
+
+GesturePropertyProvider::~GesturePropertyProvider() {
+}
+
+void GesturePropertyProvider::GetDeviceIdsByType(
+    const DeviceType type,
+    std::vector<DeviceId>* device_ids) {
+  device_ids->clear();
+  DeviceMap::const_iterator it = device_map_.begin();
+  for (; it != device_map_.end(); ++it)
+    if (IsDeviceOfType(it->second, type))
+      device_ids->push_back(it->first);
+}
+
+GesturesProp* GesturePropertyProvider::GetProperty(const DeviceId device_id,
+                                                   const std::string& name) {
+  return FindProperty(device_id, name);
+}
+
+void GesturePropertyProvider::RegisterDevice(const DeviceId id,
+                                             const DevicePtr device) {
+  DeviceMap::const_iterator it = device_map_.find(id);
+  if (it != device_map_.end())
+    return;
+
+  // Setup data-structures.
+  device_map_[id] = device;
+  device_data_map_.set(id,
+                       scoped_ptr<internal::GestureDevicePropertyData>(
+                           new internal::GestureDevicePropertyData));
+
+  // Gather default property values for the device from the parsed conf files.
+  SetupDefaultProperties(id, device);
+  return;
+}
+
+void GesturePropertyProvider::UnregisterDevice(const DeviceId id) {
+  DeviceMap::const_iterator it = device_map_.find(id);
+  if (it == device_map_.end())
+    return;
+  device_data_map_.erase(id);
+  device_map_.erase(it);
+}
+
+void GesturePropertyProvider::AddProperty(const DeviceId device_id,
+                                          const std::string& name,
+                                          GesturesProp* property) {
+  // The look-up should never fail because ideally a property can only be
+  // created with GesturesPropCreate* functions from the gesture lib side.
+  // Therefore, we simply return on failure.
+  internal::GestureDevicePropertyData* device_data =
+      device_data_map_.get(device_id);
+  if (device_data)
+    device_data->properties.set(name, scoped_ptr<GesturesProp>(property));
+}
+
+void GesturePropertyProvider::DeleteProperty(const DeviceId device_id,
+                                             const std::string& name) {
+  internal::GestureDevicePropertyData* device_data =
+      device_data_map_.get(device_id);
+  if (device_data)
+    device_data->properties.erase(name);
+}
+
+GesturesProp* GesturePropertyProvider::FindProperty(const DeviceId device_id,
+                                                    const std::string& name) {
+  internal::GestureDevicePropertyData* device_data =
+      device_data_map_.get(device_id);
+  if (!device_data)
+    return NULL;
+  return device_data->properties.get(name);
+}
+
+GesturesProp* GesturePropertyProvider::GetDefaultProperty(
+    const DeviceId device_id,
+    const std::string& name) {
+  internal::GestureDevicePropertyData* device_data =
+      device_data_map_.get(device_id);
+  if (!device_data)
+    return NULL;
+  internal::PropertiesMap::const_iterator ib =
+      device_data->default_properties.find(name);
+  if (ib == device_data->default_properties.end())
+    return NULL;
+  return ib->second;
+}
+
+void GesturePropertyProvider::LoadDeviceConfigurations() {
+  // Enumerate conf files and sort them lexicographically.
+  std::set<base::FilePath> files;
+  base::FileEnumerator file_enum(base::FilePath(kConfigurationFilePath),
+                                 false,
+                                 base::FileEnumerator::FILES,
+                                 "*.conf");
+  for (base::FilePath path = file_enum.Next(); !path.empty();
+       path = file_enum.Next()) {
+    files.insert(path);
+  }
+  GPROP_LOG(INFO_SEVERITY) << files.size() << " conf files were found";
+
+  // Parse conf files one-by-one.
+  for (std::set<base::FilePath>::iterator file_iter = files.begin();
+       file_iter != files.end();
+       ++file_iter) {
+    GPROP_LOG(INFO_SEVERITY) << "Parsing conf file: " << (*file_iter).value();
+    std::string content;
+    if (!base::ReadFileToString(*file_iter, &content)) {
+      LOG(ERROR) << "Can't loading gestures conf file: "
+                 << (*file_iter).value();
+      continue;
+    }
+    ParseXorgConfFile(content);
+  }
+}
+
+void GesturePropertyProvider::ParseXorgConfFile(const std::string& content) {
+  // To simplify the parsing work, we made some assumption about the conf file
+  // format which doesn't exist in the original xorg-conf spec. Most important
+  // ones are:
+  // 1. All keywords and names are now case-sensitive. Also, underscores are not
+  //    ignored.
+  // 2. Each entry takes up one and exactly one line in the file.
+  // 3. No negation of the option value even if the option name is prefixed with
+  //    "No" as it may cause problems for option names that does start with "No"
+  //    (e.g., "Non-linearity").
+
+  // Break the content into sections, lines and then pieces.
+  // Sections are delimited by the "EndSection" keyword.
+  // Lines are delimited by "\n".
+  // Pieces are delimited by all white-spaces.
+  std::vector<std::string> sections;
+  base::SplitStringUsingSubstr(content, "EndSection", &sections);
+  for (size_t i = 0; i < sections.size(); ++i) {
+    // Create a new configuration section.
+    configurations_.push_back(new internal::ConfigurationSection());
+    internal::ConfigurationSection* config = configurations_.back();
+
+    // Break the section into lines.
+    base::StringTokenizer lines(sections[i], "\n");
+    bool is_input_class_section = true;
+    bool has_checked_section_type = false;
+    while (is_input_class_section && lines.GetNext()) {
+      // Parse the line w.r.t. the xorg-conf format.
+      std::string line(lines.token());
+
+      // Skip empty lines.
+      if (line.empty())
+        continue;
+
+      // Treat all whitespaces as delimiters.
+      base::StringTokenizer pieces(line, base::kWhitespaceASCII);
+      pieces.set_quote_chars("\"");
+      bool is_parsing = false;
+      bool has_error = false;
+      bool next_is_section_type = false;
+      bool next_is_option_name = false;
+      bool next_is_option_value = false;
+      bool next_is_match_criteria = false;
+      bool next_is_identifier = false;
+      std::string match_type, option_name;
+      while (pieces.GetNext()) {
+        std::string piece(pieces.token());
+
+        // Skip empty pieces.
+        if (piece.empty())
+          continue;
+
+        // See if we are currently parsing an entry or are still looking for
+        // one.
+        if (is_parsing) {
+          // Stop parsing the current line if the format is wrong.
+          if (piece.size() <= 2 || piece[0] != '\"' ||
+              piece[piece.size() - 1] != '\"') {
+            LOG(ERROR) << "Error parsing line: " << lines.token();
+            has_error = true;
+            if (next_is_section_type)
+              is_input_class_section = false;
+            break;
+          }
+
+          // Parse the arguments. Note that we don't break even if a whitespace
+          // string is passed. It will just be handled in various ways based on
+          // the entry type.
+          std::string arg;
+          base::TrimWhitespaceASCII(
+              piece.substr(1, piece.size() - 2), base::TRIM_ALL, &arg);
+          if (next_is_section_type) {
+            // We only care about InputClass sections.
+            if (arg != "InputClass") {
+              has_error = true;
+              is_input_class_section = false;
+            } else {
+              GPROP_LOG(INFO_SEVERITY) << "New InputClass section found";
+              has_checked_section_type = true;
+            }
+            break;
+          } else if (next_is_identifier) {
+            GPROP_LOG(INFO_SEVERITY) << "Identifier: " << arg;
+            config->identifier = arg;
+            next_is_identifier = false;
+            break;
+          } else if (next_is_option_name) {
+            // TODO(sheckylin): Support option "Ignore".
+            option_name = arg;
+            next_is_option_value = true;
+            next_is_option_name = false;
+          } else if (next_is_option_value) {
+            GesturesProp* property = CreateDefaultProperty(option_name, arg);
+            if (property)
+              config->properties.push_back(property);
+            next_is_option_value = false;
+            break;
+          } else if (next_is_match_criteria) {
+            // Skip all match types that are not supported.
+            if (IsMatchTypeSupported(match_type)) {
+              internal::MatchCriteria* criteria =
+                  CreateMatchCriteria(match_type, arg);
+              if (criteria)
+                config->criterias.push_back(criteria);
+            }
+            next_is_match_criteria = false;
+            break;
+          }
+        } else {
+          // If the section type hasn't been decided yet, look for it.
+          // Otherwise, look for valid entries according to the spec.
+          if (has_checked_section_type) {
+            if (piece == "Driver") {
+              // TODO(sheckylin): Support "Driver" so that we can force a device
+              // not to use the gesture lib.
+              NOTIMPLEMENTED();
+              break;
+            } else if (piece == "Identifier") {
+              is_parsing = true;
+              next_is_identifier = true;
+              continue;
+            } else if (piece == "Option") {
+              is_parsing = true;
+              next_is_option_name = true;
+              continue;
+            } else if (piece.size() > 5 && piece.compare(0, 5, "Match") == 0) {
+              match_type = piece;
+              is_parsing = true;
+              next_is_match_criteria = true;
+              continue;
+            }
+          } else if (piece == "Section") {
+            is_parsing = true;
+            next_is_section_type = true;
+            continue;
+          }
+
+          // If none of the above is found, check if the current piece starts a
+          // comment.
+          if (piece.empty() || piece[0] != '#') {
+            LOG(ERROR) << "Error parsing line: " << lines.token();
+            has_error = true;
+          }
+          break;
+        }
+      }
+
+      // The value of a boolean option is skipped (default is true).
+      if (!has_error && (next_is_option_value || next_is_match_criteria)) {
+        if (next_is_option_value) {
+          GesturesProp* property = CreateDefaultProperty(option_name, "on");
+          if (property)
+            config->properties.push_back(property);
+        } else if (IsMatchTypeSupported(match_type) &&
+                   IsMatchDeviceType(match_type)) {
+          internal::MatchCriteria* criteria =
+              CreateMatchCriteria(match_type, "on");
+          if (criteria)
+            config->criterias.push_back(criteria);
+        }
+      }
+    }
+
+    // Remove useless config sections.
+    if (!is_input_class_section ||
+        (config->criterias.empty() && config->properties.empty())) {
+      configurations_.pop_back();
+    }
+  }
+}
+
+internal::MatchCriteria* GesturePropertyProvider::CreateMatchCriteria(
+    const std::string& match_type,
+    const std::string& arg) {
+  GPROP_LOG(INFO_SEVERITY) << "Creating match criteria: (" << match_type << ", "
+                           << arg << ")";
+  if (match_type == "MatchProduct")
+    return new internal::MatchProduct(arg);
+  if (match_type == "MatchDevicePath")
+    return new internal::MatchDevicePath(arg);
+  if (match_type == "MatchUSBID")
+    return new internal::MatchUSBID(arg);
+  if (match_type == "MatchIsPointer")
+    return new internal::MatchIsPointer(arg);
+  if (match_type == "MatchIsTouchpad")
+    return new internal::MatchIsTouchpad(arg);
+  if (match_type == "MatchIsTouchscreen")
+    return new internal::MatchIsTouchscreen(arg);
+  NOTREACHED();
+  return NULL;
+}
+
+GesturesProp* GesturePropertyProvider::CreateDefaultProperty(
+    const std::string& name,
+    const std::string& value) {
+  // Our parsing rule:
+  // 1. No hex or oct number is accepted.
+  // 2. All numbers will be stored as double.
+  // 3. Array elements can be separated by both white-spaces or commas.
+  // 4. A token is treated as numeric either if it is one of the special
+  //    keywords for boolean values (on, true, yes, off, false, no) or if
+  //    base::StringToDouble succeeds.
+  // 5. The property is treated as numeric if and only if all of its elements
+  //    (if any) are numerics. Otherwise, it will be treated as a string.
+  // 6. A string property will be trimmed before storing its value.
+  GPROP_LOG(INFO_SEVERITY) << "Creating default property: (" << name << ", "
+                           << value << ")";
+
+  // Parse elements one-by-one.
+  std::string delimiters(base::kWhitespaceASCII);
+  delimiters.append(",");
+  base::StringTokenizer tokens(value, delimiters);
+  bool is_all_numeric = true;
+  std::vector<double> numbers;
+  while (tokens.GetNext()) {
+    // Skip empty tokens.
+    std::string token(tokens.token());
+    if (token.empty())
+      continue;
+
+    // Check if it is a boolean keyword.
+    int bool_result = ParseBooleanKeyword(token);
+    if (bool_result) {
+      numbers.push_back(bool_result > 0);
+      continue;
+    }
+
+    // Check if it is a number.
+    double real_result;
+    bool success = base::StringToDouble(token, &real_result);
+    if (!success) {
+      is_all_numeric = false;
+      break;
+    }
+    numbers.push_back(real_result);
+  }
+
+  // Create the GesturesProp. Array properties need to contain at least one
+  // number and may contain numbers only.
+  GesturesProp* property = NULL;
+  if (is_all_numeric && numbers.size()) {
+    property = new GesturesDoubleProp(
+        name, numbers.size(), NULL, numbers.data(), NULL);
+  } else {
+    property = new GesturesStringProp(name, NULL, value.c_str(), NULL);
+  }
+
+  GPROP_LOG(INFO_SEVERITY) << "Prop: " << *property;
+  // The function will always succeed for now but it may change later if we
+  // specify some name or args as invalid.
+  return property;
+}
+
+void GesturePropertyProvider::SetupDefaultProperties(const DeviceId device_id,
+                                                     const DevicePtr device) {
+  GPROP_LOG(INFO_SEVERITY) << "Setting up default properties for (" << device
+                           << ", " << device_id << ", " << device->info.name
+                           << ")";
+
+  // Go through all parsed sections.
+  internal::PropertiesMap& property_map =
+      device_data_map_.get(device_id)->default_properties;
+  for (size_t i = 0; i < configurations_.size(); ++i) {
+    if (configurations_[i]->Match(device)) {
+      GPROP_LOG(INFO_SEVERITY) << "Conf section \""
+                               << configurations_[i]->identifier
+                               << "\" is matched";
+      for (size_t j = 0; j < configurations_[i]->properties.size(); j++) {
+        GesturesProp* property = configurations_[i]->properties[j];
+        // We can't use insert here because a property may be set for several
+        // times along the way.
+        property_map[property->name()] = property;
+      }
+    }
+  }
+}
+
+GesturesProp* GesturesPropFunctionsWrapper::CreateInt(void* device_data,
+                                                      const char* name,
+                                                      int* value,
+                                                      size_t count,
+                                                      const int* init) {
+  return CreateProperty<int, GesturesIntProp>(
+      device_data, name, value, count, init);
+}
+
+GesturesProp* GesturesPropFunctionsWrapper::CreateShort(void* device_data,
+                                                        const char* name,
+                                                        short* value,
+                                                        size_t count,
+                                                        const short* init) {
+  return CreateProperty<short, GesturesShortProp>(
+      device_data, name, value, count, init);
+}
+
+GesturesProp* GesturesPropFunctionsWrapper::CreateBool(
+    void* device_data,
+    const char* name,
+    GesturesPropBool* value,
+    size_t count,
+    const GesturesPropBool* init) {
+  return CreateProperty<GesturesPropBool, GesturesBoolProp>(
+      device_data, name, value, count, init);
+}
+
+GesturesProp* GesturesPropFunctionsWrapper::CreateReal(void* device_data,
+                                                       const char* name,
+                                                       double* value,
+                                                       size_t count,
+                                                       const double* init) {
+  return CreateProperty<double, GesturesDoubleProp>(
+      device_data, name, value, count, init);
+}
+
+GesturesProp* GesturesPropFunctionsWrapper::CreateString(void* device_data,
+                                                         const char* name,
+                                                         const char** value,
+                                                         const char* init) {
+  GesturesProp* default_property = NULL;
+  if (!PreCreateProperty(device_data, name, &default_property))
+    return NULL;
+  GesturesProp* property =
+      new GesturesStringProp(name, value, init, default_property);
+
+  PostCreateProperty(device_data, name, property);
+  return property;
+}
+
+void GesturesPropFunctionsWrapper::RegisterHandlers(
+    void* device_data,
+    GesturesProp* property,
+    void* handler_data,
+    GesturesPropGetHandler get,
+    GesturesPropSetHandler set) {
+  // Sanity checks
+  if (!device_data || !property)
+    return;
+
+  property->SetHandlers(get, set, handler_data);
+}
+
+void GesturesPropFunctionsWrapper::Free(void* device_data,
+                                        GesturesProp* property) {
+  if (!property)
+    return;
+  GesturePropertyProvider* provider = GetPropertyProvider(device_data);
+
+  // No need to manually delete the prop pointer as it is implicitly handled
+  // with scoped ptr.
+  GPROP_LOG(3) << "Freeing Property: \"" << property->name() << "\"";
+  provider->DeleteProperty(GetDeviceId(device_data), property->name());
+}
+
+bool GesturesPropFunctionsWrapper::InitializeDeviceProperties(
+    void* device_data,
+    GestureDeviceProperties* properties) {
+  if (!device_data)
+    return false;
+  GesturePropertyProvider::DevicePtr device = GetDevicePointer(device_data);
+
+  /* Create Device Properties */
+
+  // Read Only properties.
+  CreateString(
+      device_data, "Device Node", NULL, GetDeviceNodePath(device).c_str());
+  short vid = static_cast<short>(device->info.id.vendor);
+  CreateShort(device_data, "Device Vendor ID", NULL, 1, &vid);
+  short pid = static_cast<short>(device->info.id.product);
+  CreateShort(device_data, "Device Product ID", NULL, 1, &pid);
+
+  // Useable trackpad area. If not configured in .conf file,
+  // use x/y valuator min/max as reported by kernel driver.
+  CreateIntSingle(device_data,
+                  "Active Area Left",
+                  &properties->area_left,
+                  Event_Get_Left(device));
+  CreateIntSingle(device_data,
+                  "Active Area Right",
+                  &properties->area_right,
+                  Event_Get_Right(device));
+  CreateIntSingle(device_data,
+                  "Active Area Top",
+                  &properties->area_top,
+                  Event_Get_Top(device));
+  CreateIntSingle(device_data,
+                  "Active Area Bottom",
+                  &properties->area_bottom,
+                  Event_Get_Bottom(device));
+
+  // Trackpad resolution (pixels/mm). If not configured in .conf file,
+  // use x/y resolution as reported by kernel driver.
+  CreateIntSingle(device_data,
+                  "Vertical Resolution",
+                  &properties->res_y,
+                  Event_Get_Res_Y(device));
+  CreateIntSingle(device_data,
+                  "Horizontal Resolution",
+                  &properties->res_x,
+                  Event_Get_Res_X(device));
+
+  // Trackpad orientation minimum/maximum. If not configured in .conf file,
+  // use min/max as reported by kernel driver.
+  CreateIntSingle(device_data,
+                  "Orientation Minimum",
+                  &properties->orientation_minimum,
+                  Event_Get_Orientation_Minimum(device));
+  CreateIntSingle(device_data,
+                  "Orientation Maximum",
+                  &properties->orientation_maximum,
+                  Event_Get_Orientation_Maximum(device));
+
+  // Log dump property. Will call Event_Dump_Debug_Log when its value is being
+  // set.
+  GesturesProp* dump_debug_log_prop = CreateBoolSingle(
+      device_data, "Dump Debug Log", &properties->dump_debug_log, false);
+  RegisterHandlers(
+      device_data, dump_debug_log_prop, device, NULL, Event_Dump_Debug_Log);
+
+  // Whether to do the gesture recognition or just passing the multi-touch data
+  // to upper layers.
+  CreateBoolSingle(device_data,
+                   "Raw Touch Passthrough",
+                   &properties->raw_passthrough,
+                   false);
+  return true;
+}
+
+void GesturesPropFunctionsWrapper::UnregisterDevice(void* device_data) {
+  GesturePropertyProvider* provider = GetPropertyProvider(device_data);
+  provider->UnregisterDevice(GetDeviceId(device_data));
+}
+
+template <typename T, class PROPTYPE>
+GesturesProp* GesturesPropFunctionsWrapper::CreateProperty(void* device_data,
+                                                           const char* name,
+                                                           T* value,
+                                                           size_t count,
+                                                           const T* init) {
+  // Create the property. Use the default property value if possible.
+  GesturesProp* default_property = NULL;
+  if (!PreCreateProperty(device_data, name, &default_property))
+    return NULL;
+  GesturesProp* property =
+      new PROPTYPE(name, count, value, init, default_property);
+
+  // Start tracking the property in the provider.
+  PostCreateProperty(device_data, name, property);
+  return property;
+}
+
+bool GesturesPropFunctionsWrapper::PreCreateProperty(
+    void* device_data,
+    const char* name,
+    GesturesProp** default_property) {
+  GesturePropertyProvider* provider = GetPropertyProvider(device_data);
+  GesturePropertyProvider::DeviceId device_id = GetDeviceId(device_data);
+
+  // Register the device in the property provider if not yet.
+  provider->RegisterDevice(device_id, GetDevicePointer(device_data));
+
+  // First, see if the GesturesProp already exists.
+  GPROP_LOG(3) << "Creating Property: \"" << name << "\"";
+  GesturesProp* property = provider->FindProperty(device_id, name);
+
+  // If so, delete it as we can't reuse the data structure (newly-created
+  // property may have different data type and count, which are fixed upon
+  // creation via the template mechanism).
+  if (property) {
+    LOG(WARNING) << "Gesture property \"" << name
+                 << "\" re-created. This shouldn't happen at the normal usage.";
+    Free(device_data, property);
+  }
+
+  // Return the found default property from conf files (could be NULL).
+  *default_property = provider->GetDefaultProperty(device_id, name);
+  return true;
+}
+
+void GesturesPropFunctionsWrapper::PostCreateProperty(void* device_data,
+                                                      const char* name,
+                                                      GesturesProp* property) {
+  // Add the property to the gesture property provider. The gesture property
+  // provider will own it from now on.
+  GesturePropertyProvider* provider = GetPropertyProvider(device_data);
+  provider->AddProperty(GetDeviceId(device_data), name, property);
+
+  // Log the creation.
+  GPROP_LOG(INFO_SEVERITY) << "Created active prop: " << *property;
+}
+
+GesturesProp* GesturesPropFunctionsWrapper::CreateIntSingle(void* device_data,
+                                                            const char* name,
+                                                            int* value,
+                                                            int init) {
+  return CreateInt(device_data, name, value, 1, &init);
+}
+
+GesturesProp* GesturesPropFunctionsWrapper::CreateBoolSingle(
+    void* device_data,
+    const char* name,
+    GesturesPropBool* value,
+    GesturesPropBool init) {
+  return CreateBool(device_data, name, value, 1, &init);
+}
+
+GesturePropertyProvider* GesturesPropFunctionsWrapper::GetPropertyProvider(
+    void* device_data) {
+  return static_cast<GestureInterpreterLibevdevCros*>(device_data)
+      ->property_provider();
+}
+
+GesturePropertyProvider::DevicePtr
+GesturesPropFunctionsWrapper::GetDevicePointer(void* device_data) {
+  return static_cast<GestureInterpreterLibevdevCros*>(device_data)->evdev();
+}
+
+GesturePropertyProvider::DeviceId GesturesPropFunctionsWrapper::GetDeviceId(
+    void* device_data) {
+  return static_cast<GestureInterpreterLibevdevCros*>(device_data)->id();
+}
+
+/* Global GesturesPropProvider
+ *
+ * Used by PropRegistry in GestureInterpreter to forward property value
+ * creations from there.
+ * */
+const GesturesPropProvider kGesturePropProvider = {
+    GesturesPropFunctionsWrapper::CreateInt,
+    GesturesPropFunctionsWrapper::CreateShort,
+    GesturesPropFunctionsWrapper::CreateBool,
+    GesturesPropFunctionsWrapper::CreateString,
+    GesturesPropFunctionsWrapper::CreateReal,
+    GesturesPropFunctionsWrapper::RegisterHandlers,
+    GesturesPropFunctionsWrapper::Free};
+
+}  // namespace ui