Refactored gamepad polling to support dynamic sources

device/gamepad/gamepad_pad_state_provider.cc

Index: device/gamepad/gamepad_pad_state_provider.cc
diff --git a/device/gamepad/gamepad_data_fetcher.cc b/device/gamepad/gamepad_pad_state_provider.cc
similarity index 57%
copy from device/gamepad/gamepad_data_fetcher.cc
copy to device/gamepad/gamepad_pad_state_provider.cc
index 749a6f3df1aef6097aa88673201c6f4ee5ab7db1..892fd4d0c10c8828e73b9a118f0efa4c2638acc4 100644
--- a/device/gamepad/gamepad_data_fetcher.cc
+++ b/device/gamepad/gamepad_pad_state_provider.cc
@@ -1,33 +1,68 @@
-// Copyright (c) 2015 The Chromium Authors. All rights reserved.
+// Copyright 2016 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 "device/gamepad/gamepad_data_fetcher.h"
-
-#include <stddef.h>
-#include <string.h>
+#include "device/gamepad/gamepad_pad_state_provider.h"
 
 #include <cmath>
 
-#include "base/logging.h"
-#include "build/build_config.h"
+#include "device/gamepad/gamepad_data_fetcher.h"
+#include "third_party/WebKit/public/platform/WebGamepads.h"
+
+using blink::WebGamepad;
+using blink::WebGamepads;
+
+namespace device {
 
 namespace {
 
-#if !defined(OS_ANDROID)
 const float kMinAxisResetValue = 0.1f;
-#endif
 
 }  // namespace
 
-namespace device {
+GamepadPadStateProvider::GamepadPadStateProvider() {
+  pad_states_.reset(new PadState[WebGamepads::itemsLengthCap]);
 
-using blink::WebGamepad;
-using blink::WebGamepads;
+  for (unsigned i = 0; i < WebGamepads::itemsLengthCap; ++i)
+    ClearPadState(pad_states_.get()[i]);
+}
 
-#if !defined(OS_ANDROID)
-void GamepadDataFetcher::MapAndSanitizeGamepadData(PadState* pad_state,
-                                                   WebGamepad* pad) {
+GamepadPadStateProvider::~GamepadPadStateProvider() {}
+
+PadState* GamepadPadStateProvider::GetPadState(GamepadSource source,
+                                               int source_id) {
+  // Check to see if the device already has a reserved slot
+  PadState* empty_slot = nullptr;
+  for (size_t i = 0; i < WebGamepads::itemsLengthCap; ++i) {
+    PadState& state = pad_states_.get()[i];
+    if (state.source == source && state.source_id == source_id) {
+      // Retrieving the pad state marks this gamepad as active.
+      state.active_state = GAMEPAD_ACTIVE;
+      return &state;
+    }
+    if (!empty_slot && state.source == GAMEPAD_SOURCE_NONE)
+      empty_slot = &state;
+  }
+  if (empty_slot) {
+    empty_slot->source = source;
+    empty_slot->source_id = source_id;
+    empty_slot->active_state = GAMEPAD_NEWLY_ACTIVE;
+  }
+  return empty_slot;
+}
+
+void GamepadPadStateProvider::ClearPadState(PadState& state) {
+  memset(&state, 0, sizeof(PadState));
+}
+
+void GamepadPadStateProvider::InitializeDataFetcher(
+    GamepadDataFetcher* fetcher) {
+  fetcher->InitializeProvider(this);
+}
+
+void GamepadPadStateProvider::MapAndSanitizeGamepadData(PadState* pad_state,
+                                                        WebGamepad* pad,
+                                                        bool sanitize) {
   DCHECK(pad_state);
   DCHECK(pad);
 
@@ -43,6 +78,11 @@ void GamepadDataFetcher::MapAndSanitizeGamepadData(PadState* pad_state,
   else
     *pad = pad_state->data;
 
+  pad->connected = true;
+
+  if (!sanitize)
+    return;
+
   // About sanitization: Gamepads may report input event if the user is not
   // interacting with it, due to hardware problems or environmental ones (pad
   // has something heavy leaning against an axis.) This may cause user gestures
@@ -82,6 +122,5 @@ void GamepadDataFetcher::MapAndSanitizeGamepadData(PadState* pad_state,
     }
   }
 }
-#endif
 
-}  // namespace device
+}  // namespace device