Allow gaming_seat to use ozone gamepad as back-end

components/exo/gaming_seat_ozone.cc

Index: components/exo/gaming_seat_ozone.cc
diff --git a/components/exo/gaming_seat_ozone.cc b/components/exo/gaming_seat_ozone.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c93e888a0806bc9e87e4d321e5670ba659390867
--- /dev/null
+++ b/components/exo/gaming_seat_ozone.cc
@@ -0,0 +1,112 @@
+// Copyright 2017 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 "components/exo/gaming_seat_ozone.h"
+#include "components/exo/gamepad_delegate.h"
+#include "components/exo/gaming_seat_delegate.h"
+#include "components/exo/shell_surface.h"
+#include "components/exo/surface.h"
+#include "ui/events/ozone/gamepad/gamepad_provider_ozone.h"
+
+namespace {
+constexpr int kMaxGamepadCount = 4;
+}  // namespace
+
+namespace exo {
+
+GamingSeatOzone::GamingSeatOzone(GamingSeatDelegate* delegate)
+    : delegate_(delegate),
+      gamepad_provider_(ui::GamepadProviderOzone::GetInstance()) {
+  auto* helper = WMHelper::GetInstance();
+  helper->AddFocusObserver(this);
+  OnWindowFocused(helper->GetFocusedWindow(), nullptr);
+}
+
+GamingSeatOzone::~GamingSeatOzone() {
+  gamepad_provider_->RemoveGamepadObserver(this);
+  delegate_->OnGamingSeatDestroying(this);
+  // Disconnect all the gamepads.
+  for (auto& entry : gamepads_) {
+    entry.second->OnRemoved();
+  }
+
+  WMHelper::GetInstance()->RemoveFocusObserver(this);
+}
+
+void GamingSeatOzone::OnGamepadDevicesUpdated() {
+  std::vector<ui::InputDevice> gamepad_devices =
+      gamepad_provider_->GetGamepadDevices();
+
+  std::map<int, GamepadDelegate*> old_gamepad_map;
+  old_gamepad_map.swap(gamepads_);
+
+  // Copy the "still connected gamepads".
+  for (auto& device : gamepad_devices) {
+    auto ite = old_gamepad_map.find(device.id);
+    if (ite != old_gamepad_map.end()) {
+      gamepads_[device.id] = ite->second;
+      old_gamepad_map.erase(ite);
+    }
+  }
+
+  // Send event for the disconected gamepads.
+  for (auto& entry : old_gamepad_map) {
+    entry.second->OnRemoved();
+  }
+
+  // Connect new connected gamepads if there is a slot.
+  for (auto& device : gamepad_devices) {
+    if (gamepads_.size() >= kMaxGamepadCount) {
+      break;
+    }
+    if (gamepads_.find(device.id) == gamepads_.end()) {
+      gamepads_[device.id] = delegate_->GamepadAdded();
+    }
+  }
+}
+
+void GamingSeatOzone::OnGamepadEvent(const ui::GamepadEvent& event) {
+  auto ite = gamepads_.find(event.device_id());
+  if (ite == gamepads_.end())
+    return;
+
+  switch (event.type()) {
+    case ui::GamepadEventType::BUTTON:
+      ite->second->OnButton(event.code(), event.value(), event.value());
+      break;
+    case ui::GamepadEventType::AXIS:
+      ite->second->OnAxis(event.code(), event.value());
+      break;
+    case ui::GamepadEventType::FRAME:
+      ite->second->OnFrame();
+      break;
+  }
+}
+
+void GamingSeatOzone::OnWindowFocused(aura::Window* gained_focus,
+                                      aura::Window* lost_focus) {
+  Surface* target = nullptr;
+  if (gained_focus) {
+    target = Surface::AsSurface(gained_focus);
+    if (!target) {
+      aura::Window* top_level_window = gained_focus->GetToplevelWindow();
+      if (top_level_window)
+        target = ShellSurface::GetMainSurface(top_level_window);
+    }
+  }
+
+  bool focused = target && delegate_->CanAcceptGamepadEventsForSurface(target);
+  Enable(focused);
+}
+
+void GamingSeatOzone::Enable(bool enable) {
+  if (enable) {
+    gamepad_provider_->AddGamepadObserver(this);
+    OnGamepadDevicesUpdated();
+  } else {
+    gamepad_provider_->RemoveGamepadObserver(this);
+  }
+}
+
+}  // namespace exo