Tablet-like power button behavior on Convertible/Tablet ChromeOS devices

ash/wm/tablet_power_button_controller.cc

+// 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 "ash/wm/tablet_power_button_controller.h"
+
+#include "ash/common/session/session_state_delegate.h"
+#include "ash/common/wm/maximize_mode/maximize_mode_controller.h"
+#include "ash/common/wm_shell.h"
+#include "ash/shell.h"
+#include "ash/wm/lock_state_controller.h"
+#include "chromeos/dbus/dbus_thread_manager.h"
+#include "chromeos/dbus/power_manager_client.h"
+
+namespace ash {
+
+namespace {
+
+// Amount of time the power button must be held to start the pre-shutdown
+// animation when in tablet mode.
+constexpr int kTabletShutdownTimeoutMs = 1000;
+
+}  // namespace
+
+TabletPowerButtonController::TestApi::TestApi(
+    TabletPowerButtonController* controller)
+    : controller_(controller) {}
+
+TabletPowerButtonController::TestApi::~TestApi() {}
+
+bool TabletPowerButtonController::TestApi::TabletPowerButtonTimerIsRunning()
+    const {
+  return controller_->tablet_power_button_timer_.IsRunning();
+}
+
+void TabletPowerButtonController::TestApi::TriggerTabletPowerButtonTimeout() {
+  controller_->OnTabletPowerButtonTimeout();
+  controller_->tablet_power_button_timer_.Stop();
+}
+
+TabletPowerButtonController::TabletPowerButtonController(
+    LockStateController* controller) {
+  controller_ = controller;
+  Shell::GetInstance()->PrependPreTargetHandler(this);
+  GetInitialBacklightsForcedOff();
+}
+
+TabletPowerButtonController::~TabletPowerButtonController() {
+  Shell::GetInstance()->RemovePreTargetHandler(this);
+}
+
+bool TabletPowerButtonController::ShouldHandlePowerButtonEvents() const {
+  return IsTabletModeSupported();
+}
+
+void TabletPowerButtonController::OnPowerButtonEvent(
+    bool down,
+    const base::TimeTicks& timestamp,
+    bool brightness_is_zero) {
+  if (down) {
+    power_button_down_while_screen_off_ = brightness_is_zero;
+    SetBacklightsForcedOff(false);
+    StartTabletPowerButtonTimer();
+  } else {
+    if (tablet_power_button_timer_.IsRunning()) {
+      tablet_power_button_timer_.Stop();
+      if (!power_button_down_while_screen_off_) {
+        SetBacklightsForcedOff(true);
+        LockScreenIfRequired();
+      }
+    }
+    power_button_down_while_screen_off_ = false;
+
+    // When power button is released, Cancel Shutdown animation whenever it is
+    // still cancellable.
+    if (controller_->CanCancelShutdownAnimation())
+      controller_->CancelShutdownAnimation();
+  }
+}
+
+void TabletPowerButtonController::OnKeyEvent(ui::KeyEvent* event) {
+  if (!IsTabletModeActive() && backlights_forced_off_)
+    SetBacklightsForcedOff(false);
+}
+
+void TabletPowerButtonController::OnMouseEvent(ui::MouseEvent* event) {
+  if (!IsTabletModeActive() && backlights_forced_off_)
+    SetBacklightsForcedOff(false);
+}
+
+void TabletPowerButtonController::SetBacklightsForcedOff(bool forced_off) {
+  if (backlights_forced_off_ == forced_off)
+    return;
+
+  chromeos::DBusThreadManager::Get()
+      ->GetPowerManagerClient()
+      ->SetBacklightsForcedOff(forced_off);
+  backlights_forced_off_ = forced_off;
+}
+
+void TabletPowerButtonController::GetInitialBacklightsForcedOff() {
+  chromeos::DBusThreadManager::Get()
+      ->GetPowerManagerClient()
+      ->GetBacklightsForcedOff(base::Bind(
+          &TabletPowerButtonController::OnGotInitialBacklightsForcedOff,
+          base::Unretained(this)));
+}
+
+void TabletPowerButtonController::OnGotInitialBacklightsForcedOff(
+    bool is_forced_off) {
+  backlights_forced_off_ = is_forced_off;
+}
+
+void TabletPowerButtonController::StartTabletPowerButtonTimer() {
+  tablet_power_button_timer_.Start(
+      FROM_HERE, base::TimeDelta::FromMilliseconds(kTabletShutdownTimeoutMs),
+      this, &TabletPowerButtonController::OnTabletPowerButtonTimeout);
+}
+
+void TabletPowerButtonController::OnTabletPowerButtonTimeout() {
+  controller_->StartShutdownAnimation();
+}
+
+void TabletPowerButtonController::LockScreenIfRequired() {
+  SessionStateDelegate* session_state_delegate =
+      WmShell::Get()->GetSessionStateDelegate();
+  if (session_state_delegate->ShouldLockScreenAutomatically() &&
+      session_state_delegate->CanLockScreen() &&
+      !session_state_delegate->IsUserSessionBlocked() &&
+      !controller_->LockRequested()) {
+    session_state_delegate->LockScreen();
+  }
+}
+
+bool TabletPowerButtonController::IsTabletModeSupported() const {
+  MaximizeModeController* maximize_mode_controller =
+      WmShell::Get()->maximize_mode_controller();
+  return maximize_mode_controller &&
+         maximize_mode_controller->CanEnterMaximizeMode();
+}
+
+bool TabletPowerButtonController::IsTabletModeActive() const {
+  MaximizeModeController* maximize_mode_controller =
+      WmShell::Get()->maximize_mode_controller();
+  return maximize_mode_controller &&
+         maximize_mode_controller->IsMaximizeModeWindowManagerEnabled();
+}
+
+}  // namespace ash