Implement the gamepad API in the IPC proxy

content/browser/gamepad/gamepad_platform_data_fetcher_mac.mm

+// Copyright (c) 2012 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 "content/browser/gamepad/gamepad_platform_data_fetcher_mac.h"
+
+#include "base/mac/foundation_util.h"
+#include "base/memory/scoped_nsobject.h"
+#include "base/string16.h"
+#include "base/string_util.h"
+#include "base/utf_string_conversions.h"
+
+#include <IOKit/hid/IOHIDKeys.h>
+#import <Foundation/Foundation.h>
+
+namespace content {
+
+namespace {
+
+NSDictionary* DeviceMatching(uint32_t usage_page, uint32_t usage) {
+  return [NSDictionary dictionaryWithObjectsAndKeys:
+      [NSNumber numberWithUnsignedInt:usage_page],
+          base::mac::CFToNSCast(CFSTR(kIOHIDDeviceUsagePageKey)),
+      [NSNumber numberWithUnsignedInt:usage],
+          base::mac::CFToNSCast(CFSTR(kIOHIDDeviceUsageKey)),
+      nil];
+}
+
+float NormalizeAxis(CFIndex value, CFIndex min, CFIndex max) {
+  return (2.f * (value - min) / static_cast<float>(max - min)) - 1.f;
+}
+
+// http://www.usb.org/developers/hidpage
+const uint32_t kGenericDesktopUsagePage = 0x01;
+const uint32_t kButtonUsagePage = 0x09;
+const uint32_t kJoystickUsageNumber = 0x04;
+const uint32_t kGameUsageNumber = 0x05;
+const uint32_t kMultiAxisUsageNumber = 0x08;
+const uint32_t kAxisMinimumUsageNumber = 0x30;
+const uint32_t kAxisMaximumUsageNumber = 0x35;
+
+}  // namespace
+
+GamepadPlatformDataFetcherMac::GamepadPlatformDataFetcherMac()
+    : enabled_(true) {
+  memset(associated_, 0, sizeof(associated_));
+  hid_manager_ref_.reset(IOHIDManagerCreate(kCFAllocatorDefault,
+                                            kIOHIDOptionsTypeNone));
+  if (CFGetTypeID(hid_manager_ref_) != IOHIDManagerGetTypeID()) {
+    enabled_ = false;
+    return;
+  }
+
+  scoped_nsobject<NSArray> criteria([[NSArray alloc] initWithObjects:
+      DeviceMatching(kGenericDesktopUsagePage, kJoystickUsageNumber),
+      DeviceMatching(kGenericDesktopUsagePage, kGameUsageNumber),
+      DeviceMatching(kGenericDesktopUsagePage, kMultiAxisUsageNumber),
+      nil]);
+  IOHIDManagerSetDeviceMatchingMultiple(
+      hid_manager_ref_,
+      base::mac::NSToCFCast(criteria));
+
+  RegisterForNotifications();
+}
+
+void GamepadPlatformDataFetcherMac::RegisterForNotifications() {
+  // Register for plug/unplug notifications.
+  IOHIDManagerRegisterDeviceMatchingCallback(
+      hid_manager_ref_,
+      &DeviceAddCallback,
+      this);
+  IOHIDManagerRegisterDeviceRemovalCallback(
+      hid_manager_ref_,
+      DeviceRemoveCallback,
+      this);
+
+  // Register for value change notifications.
+  IOHIDManagerRegisterInputValueCallback(
+      hid_manager_ref_,
+      ValueChangedCallback,
+      this);
+
+  IOHIDManagerScheduleWithRunLoop(
+      hid_manager_ref_,
+      CFRunLoopGetMain(),
+      kCFRunLoopDefaultMode);
+
+  enabled_ = IOHIDManagerOpen(hid_manager_ref_,
+                              kIOHIDOptionsTypeNone) == kIOReturnSuccess;
+}
+
+void GamepadPlatformDataFetcherMac::UnregisterFromNotifications() {
+  IOHIDManagerUnscheduleFromRunLoop(
+      hid_manager_ref_,
+      CFRunLoopGetCurrent(),
+      kCFRunLoopDefaultMode);
+  IOHIDManagerClose(hid_manager_ref_, kIOHIDOptionsTypeNone);
+}
+
+void GamepadPlatformDataFetcherMac::PauseHint(bool pause) {
+  if (pause)
+    UnregisterFromNotifications();
+  else
+    RegisterForNotifications();
+}
+
+GamepadPlatformDataFetcherMac::~GamepadPlatformDataFetcherMac() {
+  UnregisterFromNotifications();
+}
+
+GamepadPlatformDataFetcherMac*
+GamepadPlatformDataFetcherMac::InstanceFromContext(
+    void* context) {
+  return reinterpret_cast<GamepadPlatformDataFetcherMac*>(context);
+}
+
+void GamepadPlatformDataFetcherMac::DeviceAddCallback(void* context,
+                                              IOReturn result,
+                                              void* sender,
+                                              IOHIDDeviceRef ref) {
+  InstanceFromContext(context)->DeviceAdd(ref);
+}
+
+void GamepadPlatformDataFetcherMac::DeviceRemoveCallback(void* context,
+                                                 IOReturn result,
+                                                 void* sender,
+                                                 IOHIDDeviceRef ref) {
+  InstanceFromContext(context)->DeviceRemove(ref);
+}
+
+void GamepadPlatformDataFetcherMac::ValueChangedCallback(void* context,
+                                                 IOReturn result,
+                                                 void* sender,
+                                                 IOHIDValueRef ref) {
+  InstanceFromContext(context)->ValueChanged(ref);
+}
+
+void GamepadPlatformDataFetcherMac::AddButtonsAndAxes(NSArray* elements,
+                                              size_t slot) {
+  WebKit::WebGamepad& pad = data_.items[slot];
+  AssociatedData& associated = associated_[slot];
+
+  pad.axesLength = 0;
+  pad.buttonsLength = 0;
+  pad.timestamp = 0;
+  memset(pad.axes, 0, sizeof(pad.axes));
+  memset(pad.buttons, 0, sizeof(pad.buttons));
+
+  for (id elem in elements) {
+    IOHIDElementRef element = reinterpret_cast<IOHIDElementRef>(elem);
+    uint32_t usagePage = IOHIDElementGetUsagePage(element);
+    uint32_t usage = IOHIDElementGetUsage(element);
+    if (IOHIDElementGetType(element) == kIOHIDElementTypeInput_Button &&
+        usagePage == kButtonUsagePage) {
+      uint32_t button_index = usage - 1;
+      if (button_index < WebKit::WebGamepad::buttonsLengthCap) {
+        associated.button_elements[button_index] = element;
+        pad.buttonsLength = std::max(pad.buttonsLength, button_index + 1);
+      }
+    }
+    else if (IOHIDElementGetType(element) == kIOHIDElementTypeInput_Misc) {
+      uint32_t axis_index = usage - kAxisMinimumUsageNumber;
+      if (axis_index < WebKit::WebGamepad::axesLengthCap) {
+        associated.axis_minimums[axis_index] =
+            IOHIDElementGetLogicalMin(element);
+        associated.axis_maximums[axis_index] =
+            IOHIDElementGetLogicalMax(element);
+        associated.axis_elements[axis_index] = element;
+        pad.axesLength = std::max(pad.axesLength, axis_index + 1);
+      }
+    }
+  }
+}
+
+void GamepadPlatformDataFetcherMac::DeviceAdd(IOHIDDeviceRef device) {
+  using WebKit::WebGamepad;
+  using WebKit::WebGamepads;
+  using base::mac::CFToNSCast;
+  using base::mac::CFCastStrict;
+  size_t slot;
+
+  if (!enabled_)
+    return;
+
+  // Find an index for this device.
+  for (slot = 0; slot < WebGamepads::itemsLengthCap; ++slot) {
+    // If we already have this device, and it's already connected, don't do
+    // anything now.
+    if (associated_[slot].device_ref == device && data_.items[slot].connected)
+      return;
+    if (!data_.items[slot].connected)
+      break;
+  }
+
+  // We can't handle this many connected devices.
+  if (slot == WebGamepads::itemsLengthCap)
+    return;
+
+  NSNumber* vendor_id = CFToNSCast(CFCastStrict<CFNumberRef>(
+      IOHIDDeviceGetProperty(device, CFSTR(kIOHIDVendorIDKey))));
+  NSNumber* product_id = CFToNSCast(CFCastStrict<CFNumberRef>(
+      IOHIDDeviceGetProperty(device, CFSTR(kIOHIDProductIDKey))));
+  NSString* product = CFToNSCast(CFCastStrict<CFStringRef>(
+      IOHIDDeviceGetProperty(device, CFSTR(kIOHIDProductKey))));
+  int vendor_int = [vendor_id intValue];
+  int product_int = [product_id intValue];
+
+  char vendor_as_str[5], product_as_str[5];
+  snprintf(vendor_as_str, sizeof(vendor_as_str), "%04x", vendor_int);
+  snprintf(product_as_str, sizeof(product_as_str), "%04x", product_int);
+  associated_[slot].mapper =
+      GetGamepadStandardMappingFunction(vendor_as_str, product_as_str);
+
+  NSString* ident = [NSString stringWithFormat:
+      @"%@ (%sVendor: %04x Product: %04x)",
+      product,
+      associated_[slot].mapper ? "STANDARD GAMEPAD " : "",
+      vendor_int,
+      product_int];
+  NSData* as16 = [ident dataUsingEncoding:NSUTF16StringEncoding];
+
+  const size_t kOutputLengthBytes = sizeof(data_.items[slot].id);
+  memset(&data_.items[slot].id, 0, kOutputLengthBytes);
+  [as16 getBytes:data_.items[slot].id
+          length:kOutputLengthBytes - sizeof(WebKit::WebUChar)];
+
+  base::mac::ScopedCFTypeRef<CFArrayRef> elements(
+      IOHIDDeviceCopyMatchingElements(device, NULL, kIOHIDOptionsTypeNone));
+  AddButtonsAndAxes(CFToNSCast(elements), slot);
+
+  associated_[slot].device_ref = device;
+  data_.items[slot].connected = true;
+  if (slot >= data_.length)
+    data_.length = slot + 1;
+}
+
+void GamepadPlatformDataFetcherMac::DeviceRemove(IOHIDDeviceRef device) {
+  using WebKit::WebGamepads;
+  size_t slot;
+  if (!enabled_)
+    return;
+
+  // Find the index for this device.
+  for (slot = 0; slot < WebGamepads::itemsLengthCap; ++slot) {
+    if (associated_[slot].device_ref == device && data_.items[slot].connected)
+      break;
+  }
+  DCHECK(slot < WebGamepads::itemsLengthCap);
+  // Leave associated device_ref so that it will be reconnected in the same
+  // location. Simply mark it as disconnected.
+  data_.items[slot].connected = false;
+}
+
+void GamepadPlatformDataFetcherMac::ValueChanged(IOHIDValueRef value) {
+  if (!enabled_)
+    return;
+
+  IOHIDElementRef element = IOHIDValueGetElement(value);
+  IOHIDDeviceRef device = IOHIDElementGetDevice(element);
+
+  // Find device slot.
+  size_t slot;
+  for (slot = 0; slot < data_.length; ++slot) {
+    if (data_.items[slot].connected && associated_[slot].device_ref == device)
+      break;
+  }
+  if (slot == data_.length)
+    return;
+
+  WebKit::WebGamepad& pad = data_.items[slot];
+  AssociatedData& associated = associated_[slot];
+
+  // Find and fill in the associated button event, if any.
+  for (size_t i = 0; i < pad.buttonsLength; ++i) {
+    if (associated.button_elements[i] == element) {
+      pad.buttons[i] = IOHIDValueGetIntegerValue(value) ? 1.f : 0.f;
+      pad.timestamp = std::max(pad.timestamp, IOHIDValueGetTimeStamp(value));
+      return;
+    }
+  }
+
+  // Find and fill in the associated axis event, if any.
+  for (size_t i = 0; i < pad.axesLength; ++i) {
+    if (associated.axis_elements[i] == element) {
+      pad.axes[i] = NormalizeAxis(IOHIDValueGetIntegerValue(value),
+                                  associated.axis_minimums[i],
+                                  associated.axis_maximums[i]);
+      pad.timestamp = std::max(pad.timestamp, IOHIDValueGetTimeStamp(value));
+      return;
+    }
+  }
+}
+
+void GamepadPlatformDataFetcherMac::GetGamepadData(
+    WebKit::WebGamepads* pads,
+    bool) {
+  if (!enabled_) {
+    pads->length = 0;
+    return;
+  }
+
+  // Copy to the current state to the output buffer, using the mapping
+  // function, if there is one available.
+  pads->length = data_.length;
+  for (size_t i = 0; i < WebKit::WebGamepads::itemsLengthCap; ++i) {
+    if (associated_[i].mapper)
+      associated_[i].mapper(data_.items[i], &pads->items[i]);
+    else
+      pads->items[i] = data_.items[i];
+  }
+}
+
+}  // namespace content