Intorduce PowerButtonObserver API

athena/input/power_button_controller.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 "athena/input/power_button_controller.h"
+
+#include "athena/input/public/accelerator_manager.h"
+#include "chromeos/dbus/dbus_thread_manager.h"
+#include "ui/events/event_constants.h"
+
+namespace athena {
+namespace {
+
+// The amount of time that the power button must be held to be
+// treated as long press.
+const int kLongPressTimeoutMs = 1000;
+
+enum {
+  CMD_DEBUG_POWER_BUTTON_PRESSED,
+  CMD_DEBUG_POWER_BUTTON_RELEASED,
+};
+
+}  // namespace
+
+PowerButtonController::PowerButtonController()
+    : power_button_timeout_ms_(kLongPressTimeoutMs),
+      brightness_is_zero_(false) {
+  chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->AddObserver(
+      this);
+}
+
+PowerButtonController::~PowerButtonController() {
+  chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->RemoveObserver(
+      this);
+}
+
+void PowerButtonController::AddPowerButtonObserver(
+    PowerButtonObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void PowerButtonController::RemovePowerButtonObserver(
+    PowerButtonObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+void PowerButtonController::InstallAccelerators() {
+  const AcceleratorData accelerator_data[] = {
+      {TRIGGER_ON_PRESS,
+       ui::VKEY_P,
+       ui::EF_ALT_DOWN,
+       CMD_DEBUG_POWER_BUTTON_PRESSED,
+       AF_DEBUG | AF_NON_AUTO_REPEATABLE},
+      {TRIGGER_ON_RELEASE,
+       ui::VKEY_P,
+       ui::EF_ALT_DOWN,
+       CMD_DEBUG_POWER_BUTTON_RELEASED,
+       AF_DEBUG},
+  };
+  AcceleratorManager::Get()->RegisterAccelerators(
+      accelerator_data, arraysize(accelerator_data), this);
+}
+
+int PowerButtonController::SetPowerButtonTimeoutMsForTest(int timeout) {
+  int old_timeout = power_button_timeout_ms_;
+  power_button_timeout_ms_ = timeout;
+  return old_timeout;
+}
+
+void PowerButtonController::BrightnessChanged(int level, bool user_initiated) {
+  if (brightness_is_zero_)
+    zero_brightness_end_time_ = base::TimeTicks::Now();
+  brightness_is_zero_ = (level == 0);
+}
+
+void PowerButtonController::PowerButtonEventReceived(
+    bool down,
+    const base::TimeTicks& timestamp) {
+  // Ignore power button pressed while the screen is off
+  // (http://crbug.com/128451).
+  // TODO(oshima): This needs to be revisited for athena.
+  base::TimeDelta time_since_zero_brightness =
+      brightness_is_zero_
+          ? base::TimeDelta()
+          : (base::TimeTicks::Now() - zero_brightness_end_time_);
+  const int kShortTimeMs = 10;
+  if (time_since_zero_brightness.InMilliseconds() <= kShortTimeMs)
+    return;
+
+  if (down) {
+    FOR_EACH_OBSERVER(PowerButtonObserver,
+                      observers_,
+                      OnPowerButtonStateChanged(PowerButtonObserver::PRESSED));
+    timer_.Start(FROM_HERE,
+                 base::TimeDelta::FromMilliseconds(kLongPressTimeoutMs),
+                 this,
+                 &PowerButtonController::NotifyLongPress);
+  } else {
+    FOR_EACH_OBSERVER(PowerButtonObserver,
+                      observers_,
+                      OnPowerButtonStateChanged(PowerButtonObserver::RELEASED));
+    timer_.Stop();
+  }
+}
+
+bool PowerButtonController::IsCommandEnabled(int command_id) const {
+  return true;
+}
+
+bool PowerButtonController::OnAcceleratorFired(
+    int command_id,
+    const ui::Accelerator& accelerator) {
+  switch (command_id) {
+    case CMD_DEBUG_POWER_BUTTON_PRESSED:
+      PowerButtonEventReceived(true, base::TimeTicks());
+      break;
+    case CMD_DEBUG_POWER_BUTTON_RELEASED:
+      PowerButtonEventReceived(false, base::TimeTicks());
+      break;
+  }
+  return true;
+}
+
+void PowerButtonController::NotifyLongPress() {
+  FOR_EACH_OBSERVER(
+      PowerButtonObserver,
+      observers_,
+      OnPowerButtonStateChanged(PowerButtonObserver::LONG_PRESSED));
+}
+
+}  // namespace