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 <set>
+
+#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 is_read_only() const = 0;

[spang, 2014/10/08 19:09:15]

IsReadOnly()

(lower case with underscores is for trivial accessors, never virtuals)

[Shecky Lin, 2014/10/09 09:19:31]

Done.

+
+ 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 is_allocated() 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 is_read_only() 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 is_allocated() const OVERRIDE { return is_allocated_; }

[spang, 2014/10/08 19:09:15]

same here.. if it's virtual please use mixed case: IsAllocated()

[Shecky Lin, 2014/10/09 09:19:31]

Done.

+
+  // 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"};
+
+// Max number of devices that we track.
+const ui::GesturePropertyProvider::DeviceId kMaxDeviceNum = 0xffff;
+
+// 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->is_allocated() << ", "
+     << property->is_read_only() << "), ";
+
+  // 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 {
+
+// 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);

[spang, 2014/10/08 19:09:15]

Do we actually use the path for any matches?

I think depending on path is inherently racy - they are assigned in probe order
so the particular path assigned is not stable.

[Shecky Lin, 2014/10/09 09:19:31]

Yes, we do. If you search for "MatchDevicePath" under the xorg-conf directory in
the CrOS tree, you may probably see dozens of example. It is mainly used to rule
out malicious devices that are not actually input ones (e.g., whose device node
doesn't start with /dev/input/event*). We wouldn't specify a node index in the
conf file because just like you said, the index is dependent on the probe order
and isn't stable.

[spang, 2014/10/09 17:20:48]

Ah.. ok. We only open devices that match /dev/input/event* in the first place,
so if that's the only match used then it doesn't make any difference in our
case.

+  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() : device_id_counter_(0) {
+  LoadDeviceConfigurations();
+}
+
+GesturePropertyProvider::~GesturePropertyProvider() {
+}
+
+void GesturePropertyProvider::GetDeviceIdsByType(
+    const DeviceType type,
+    std::vector<DeviceId>* device_ids) {
+  device_ids->clear();
+  DeviceIdMap::iterator it = device_ids_map_.begin();
+  for (; it != device_ids_map_.end(); ++it)
+    if (IsDeviceOfType(it->first, type))
+      device_ids->push_back(it->second);
+}
+
+GesturesProp* GesturePropertyProvider::GetProperty(const DeviceId device_id,
+                                                   const std::string& name) {
+  return FindProperty(device_id, name);
+}
+
+GesturePropertyProvider::DeviceId GesturePropertyProvider::GetDeviceId(
+    const DevicePtr device,
+    const bool do_create) {
+  DeviceIdMap::iterator it = device_ids_map_.find(device);
+  if (it != device_ids_map_.end())
+    return it->second;
+  if (!do_create)
+    return -1;
+
+  // Insert a new one if not exists.
+  // TODO(sheckylin): Replace this id generation scheme with a better one.
+  // The current way may result in memory leaks.
+  DeviceId id = device_id_counter_;
+  device_ids_map_[device] = id;
+  properties_maps_.set(id,
+                       scoped_ptr<ScopedPropertyMap>(new ScopedPropertyMap));
+  device_id_counter_ = (device_id_counter_ + 1) % kMaxDeviceNum;
+
+  // Apply default property values for the device.
+  SetupDefaultProperties(id, device);
+  return id;
+}
+
+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.
+  ScopedDeviceScopedPropertyMap::iterator it = properties_maps_.find(device_id);
+  if (it != properties_maps_.end())
+    it->second->set(name, scoped_ptr<GesturesProp>(property));
+}
+
+void GesturePropertyProvider::DeleteProperty(const DeviceId device_id,
+                                             const std::string& name) {
+  ScopedDeviceScopedPropertyMap::iterator it = properties_maps_.find(device_id);
+  if (it != properties_maps_.end())
+    it->second->erase(name);
+}
+
+GesturesProp* GesturePropertyProvider::FindProperty(const DeviceId device_id,
+                                                    const std::string& name) {
+  ScopedDeviceScopedPropertyMap::const_iterator ia =
+      properties_maps_.find(device_id);
+  if (ia == properties_maps_.end())
+    return NULL;
+  ScopedPropertyMap::const_iterator ib = ia->second->find(name);
+  if (ib == ia->second->end())
+    return NULL;
+  return ib->second;
+}
+
+GesturesProp* GesturePropertyProvider::GetDefaultProperty(
+    const DeviceId device_id,
+    const std::string& name) {
+  ScopedDevicePropertyMap::const_iterator ia =
+      default_properties_maps_.find(device_id);
+  if (ia == default_properties_maps_.end())
+    return NULL;
+  PropertyMap::const_iterator ib = ia->second->find(name);
+  if (ib == ia->second->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)

[spang, 2014/10/08 19:09:15]

whitespace: if ()

I use "git clang-format" to fix whitespace issues automatically.

[Shecky Lin, 2014/10/09 09:19:31]

Nice tip. Thanks!

+              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.
+  scoped_ptr<PropertyMap> property_map(new PropertyMap);
+  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;
+      }
+    }
+  }
+  default_properties_maps_.set(device_id, property_map.Pass());
+}
+
+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* property = new GesturesStringProp(
+      name, value, init, PreCreateProperty(device_data, name));
+
+  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);
+  GesturePropertyProvider::DevicePtr device = GetDevicePointer(device_data);
+  GesturePropertyProvider::DeviceId device_id =
+      provider->GetDeviceId(device, false);
+  if (device_id < 0)
+    return;
+
+  // 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(device_id, 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;
+}
+
+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* property = new PROPTYPE(
+      name, count, value, init, PreCreateProperty(device_data, name));
+
+  PostCreateProperty(device_data, name, property);
+  return property;
+}
+
+GesturesProp* GesturesPropFunctionsWrapper::PreCreateProperty(
+    void* device_data,
+    const char* name) {
+  GesturePropertyProvider* provider = GetPropertyProvider(device_data);
+  GesturePropertyProvider::DevicePtr device = GetDevicePointer(device_data);
+
+  // Create a new PropertyMap for the device if not exists already.
+  GesturePropertyProvider::DeviceId device_id =
+      provider->GetDeviceId(device, true);
+
+  // 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, property);
+  }
+
+  // Return the found default property from conf files (could be NULL).
+  return provider->GetDefaultProperty(device_id, name);
+}
+
+void GesturesPropFunctionsWrapper::PostCreateProperty(void* device_data,
+                                                      const char* name,
+                                                      GesturesProp* property) {
+  GesturePropertyProvider* provider = GetPropertyProvider(device_data);
+  GesturePropertyProvider::DevicePtr device = GetDevicePointer(device_data);
+
+  // Add the property to the gesture property provider. The gesture property
+  // provider will own it from now on.
+  provider->AddProperty(provider->GetDeviceId(device, false), 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();
+}
+
+/* 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