(fix landed) Reland of name MaximizeMode to TabletMode

ash/wm/tablet_mode/tablet_mode_controller.cc

Index: ash/wm/tablet_mode/tablet_mode_controller.cc
diff --git a/ash/wm/tablet_mode/tablet_mode_controller.cc b/ash/wm/tablet_mode/tablet_mode_controller.cc
new file mode 100644
index 0000000000000000000000000000000000000000..5525e4635472b90a3d184e5d35f3e4b0f67cdc5a
--- /dev/null
+++ b/ash/wm/tablet_mode/tablet_mode_controller.cc
@@ -0,0 +1,482 @@
+// 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 "ash/wm/tablet_mode/tablet_mode_controller.h"
+
+#include <utility>
+
+#include "ash/ash_switches.h"
+#include "ash/shell.h"
+#include "ash/shell_port.h"
+#include "ash/wm/tablet_mode/scoped_disable_internal_mouse_and_keyboard.h"
+#include "ash/wm/tablet_mode/tablet_mode_window_manager.h"
+#include "base/bind.h"
+#include "base/command_line.h"
+#include "base/metrics/histogram_macros.h"
+#include "base/time/default_tick_clock.h"
+#include "base/time/tick_clock.h"
+#include "chromeos/dbus/dbus_thread_manager.h"
+#include "ui/base/accelerators/accelerator.h"
+#include "ui/chromeos/accelerometer/accelerometer_util.h"
+#include "ui/display/display.h"
+#include "ui/events/event.h"
+#include "ui/events/keycodes/keyboard_codes.h"
+#include "ui/gfx/geometry/vector3d_f.h"
+
+namespace ash {
+
+namespace {
+
+// The hinge angle at which to enter tablet mode.
+const float kEnterTabletModeAngle = 200.0f;
+
+// The angle at which to exit tablet mode, this is specifically less than the
+// angle to enter tablet mode to prevent rapid toggling when near the angle.
+const float kExitTabletModeAngle = 160.0f;
+
+// Defines a range for which accelerometer readings are considered accurate.
+// When the lid is near open (or near closed) the accelerometer readings may be
+// inaccurate and a lid that is fully open may appear to be near closed (and
+// vice versa).
+const float kMinStableAngle = 20.0f;
+const float kMaxStableAngle = 340.0f;
+
+// The time duration to consider the lid to be recently opened.
+// This is used to prevent entering tablet mode if an erroneous accelerometer
+// reading makes the lid appear to be fully open when the user is opening the
+// lid from a closed position.
+const int kLidRecentlyOpenedDurationSeconds = 2;
+
+// When the device approaches vertical orientation (i.e. portrait orientation)
+// the accelerometers for the base and lid approach the same values (i.e.
+// gravity pointing in the direction of the hinge). When this happens abrupt
+// small acceleration perpendicular to the hinge can lead to incorrect hinge
+// angle calculations. To prevent this the accelerometer updates will be
+// smoothed over time in order to reduce this noise.
+// This is the minimum acceleration parallel to the hinge under which to begin
+// smoothing in m/s^2.
+const float kHingeVerticalSmoothingStart = 7.0f;
+// This is the maximum acceleration parallel to the hinge under which smoothing
+// will incorporate new acceleration values, in m/s^2.
+const float kHingeVerticalSmoothingMaximum = 8.7f;
+
+// The maximum deviation between the magnitude of the two accelerometers under
+// which to detect hinge angle in m/s^2. These accelerometers are attached to
+// the same physical device and so should be under the same acceleration.
+const float kNoisyMagnitudeDeviation = 1.0f;
+
+// The angle between chromeos::AccelerometerReadings are considered stable if
+// their magnitudes do not differ greatly. This returns false if the deviation
+// between the screen and keyboard accelerometers is too high.
+bool IsAngleBetweenAccelerometerReadingsStable(
+    const chromeos::AccelerometerUpdate& update) {
+  return std::abs(
+             ui::ConvertAccelerometerReadingToVector3dF(
+                 update.get(chromeos::ACCELEROMETER_SOURCE_ATTACHED_KEYBOARD))
+                 .Length() -
+             ui::ConvertAccelerometerReadingToVector3dF(
+                 update.get(chromeos::ACCELEROMETER_SOURCE_SCREEN))
+                 .Length()) <= kNoisyMagnitudeDeviation;
+}
+
+bool IsEnabled() {
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kAshEnableTouchView);
+}
+
+// Checks the command line to see which force tablet mode is turned on, if
+// any.
+TabletModeController::ForceTabletMode GetTabletMode() {
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(switches::kAshForceTabletMode)) {
+    std::string switch_value =
+        command_line->GetSwitchValueASCII(switches::kAshForceTabletMode);
+    if (switch_value == switches::kAshForceTabletModeClamshell)
+      return TabletModeController::ForceTabletMode::CLAMSHELL;
+
+    if (switch_value == switches::kAshForceTabletModeTouchView)
+      return TabletModeController::ForceTabletMode::TOUCHVIEW;
+  }
+  return TabletModeController::ForceTabletMode::NONE;
+}
+
+}  // namespace
+
+TabletModeController::TabletModeController()
+    : have_seen_accelerometer_data_(false),
+      can_detect_lid_angle_(false),
+      touchview_usage_interval_start_time_(base::Time::Now()),
+      tick_clock_(new base::DefaultTickClock()),
+      tablet_mode_switch_is_on_(false),
+      lid_is_closed_(false),
+      scoped_session_observer_(this),
+      weak_factory_(this) {
+  Shell::Get()->AddShellObserver(this);
+  ShellPort::Get()->RecordUserMetricsAction(
+      UMA_MAXIMIZE_MODE_INITIALLY_DISABLED);
+
+  // TODO(jonross): Do not create TabletModeController if the flag is
+  // unavailable. This will require refactoring
+  // IsTabletModeWindowManagerEnabled to check for the existance of the
+  // controller.
+  if (IsEnabled()) {
+    ShellPort::Get()->AddDisplayObserver(this);
+    chromeos::AccelerometerReader::GetInstance()->AddObserver(this);
+  }
+  chromeos::PowerManagerClient* power_manager_client =
+      chromeos::DBusThreadManager::Get()->GetPowerManagerClient();
+  power_manager_client->AddObserver(this);
+  power_manager_client->GetSwitchStates(base::Bind(
+      &TabletModeController::OnGetSwitchStates, weak_factory_.GetWeakPtr()));
+}
+
+TabletModeController::~TabletModeController() {
+  Shell::Get()->RemoveShellObserver(this);
+
+  if (IsEnabled()) {
+    ShellPort::Get()->RemoveDisplayObserver(this);
+    chromeos::AccelerometerReader::GetInstance()->RemoveObserver(this);
+  }
+  chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->RemoveObserver(
+      this);
+}
+
+bool TabletModeController::CanEnterTabletMode() {
+  // If we have ever seen accelerometer data, then HandleHingeRotation may
+  // trigger tablet mode at some point in the future.
+  // All TouchView-enabled devices can enter tablet mode.
+  return have_seen_accelerometer_data_ || IsEnabled();
+}
+
+// TODO(jcliang): Hide or remove EnableTabletModeWindowManager
+// (http://crbug.com/620241).
+void TabletModeController::EnableTabletModeWindowManager(bool should_enable) {
+  bool is_enabled = !!tablet_mode_window_manager_.get();
+  if (should_enable == is_enabled)
+    return;
+
+  if (should_enable) {
+    tablet_mode_window_manager_.reset(new TabletModeWindowManager());
+    // TODO(jonross): Move the tablet mode notifications from ShellObserver
+    // to TabletModeController::Observer
+    ShellPort::Get()->RecordUserMetricsAction(UMA_MAXIMIZE_MODE_ENABLED);
+    Shell::Get()->NotifyTabletModeStarted();
+
+    observers_.ForAllPtrs([](mojom::TouchViewObserver* observer) {
+      observer->OnTouchViewToggled(true);
+    });
+
+  } else {
+    tablet_mode_window_manager_->SetIgnoreWmEventsForExit();
+    Shell::Get()->NotifyTabletModeEnding();
+    tablet_mode_window_manager_.reset();
+    ShellPort::Get()->RecordUserMetricsAction(UMA_MAXIMIZE_MODE_DISABLED);
+    Shell::Get()->NotifyTabletModeEnded();
+
+    observers_.ForAllPtrs([](mojom::TouchViewObserver* observer) {
+      observer->OnTouchViewToggled(false);
+    });
+  }
+}
+
+bool TabletModeController::IsTabletModeWindowManagerEnabled() const {
+  return tablet_mode_window_manager_.get() != NULL;
+}
+
+void TabletModeController::AddWindow(aura::Window* window) {
+  if (IsTabletModeWindowManagerEnabled())
+    tablet_mode_window_manager_->AddWindow(window);
+}
+
+void TabletModeController::BindRequest(mojom::TouchViewManagerRequest request) {
+  bindings_.AddBinding(this, std::move(request));
+}
+
+void TabletModeController::OnAccelerometerUpdated(
+    scoped_refptr<const chromeos::AccelerometerUpdate> update) {
+  if (!AllowEnterExitTabletMode())
+    return;
+
+  have_seen_accelerometer_data_ = true;
+  can_detect_lid_angle_ =
+      update->has(chromeos::ACCELEROMETER_SOURCE_SCREEN) &&
+      update->has(chromeos::ACCELEROMETER_SOURCE_ATTACHED_KEYBOARD);
+
+  if (!can_detect_lid_angle_)
+    return;
+
+  if (!display::Display::HasInternalDisplay())
+    return;
+
+  if (!ShellPort::Get()->IsActiveDisplayId(
+          display::Display::InternalDisplayId())) {
+    return;
+  }
+
+  // Whether or not we enter tablet mode affects whether we handle screen
+  // rotation, so determine whether to enter tablet mode first.
+  if (ui::IsAccelerometerReadingStable(*update,
+                                       chromeos::ACCELEROMETER_SOURCE_SCREEN) &&
+      ui::IsAccelerometerReadingStable(
+          *update, chromeos::ACCELEROMETER_SOURCE_ATTACHED_KEYBOARD) &&
+      IsAngleBetweenAccelerometerReadingsStable(*update)) {
+    // update.has(chromeos::ACCELEROMETER_SOURCE_ATTACHED_KEYBOARD)
+    // Ignore the reading if it appears unstable. The reading is considered
+    // unstable if it deviates too much from gravity and/or the magnitude of the
+    // reading from the lid differs too much from the reading from the base.
+    HandleHingeRotation(update);
+  }
+}
+
+void TabletModeController::LidEventReceived(
+    chromeos::PowerManagerClient::LidState state,
+    const base::TimeTicks& time) {
+  if (!AllowEnterExitTabletMode())
+    return;
+
+  const bool open = state == chromeos::PowerManagerClient::LidState::OPEN;
+  if (open)
+    last_lid_open_time_ = time;
+  lid_is_closed_ = !open;
+  LeaveTabletMode();
+}
+
+void TabletModeController::TabletModeEventReceived(
+    chromeos::PowerManagerClient::TabletMode mode,
+    const base::TimeTicks& time) {
+  if (!AllowEnterExitTabletMode())
+    return;
+
+  const bool on = mode == chromeos::PowerManagerClient::TabletMode::ON;
+  tablet_mode_switch_is_on_ = on;
+  // Do not change if docked.
+  if (!display::Display::HasInternalDisplay() ||
+      !ShellPort::Get()->IsActiveDisplayId(
+          display::Display::InternalDisplayId())) {
+    return;
+  }
+  // The tablet mode switch activates at 300 degrees, so it is always reliable
+  // when |on|. However we wish to exit tablet mode at a smaller angle, so
+  // when |on| is false we ignore if it is possible to calculate the lid angle.
+  if (on && !IsTabletModeWindowManagerEnabled()) {
+    EnterTabletMode();
+  } else if (!on && IsTabletModeWindowManagerEnabled() &&
+             !can_detect_lid_angle_) {
+    LeaveTabletMode();
+  }
+}
+
+void TabletModeController::SuspendImminent() {
+  // The system is about to suspend, so record TouchView usage interval metrics
+  // based on whether TouchView mode is currently active.
+  RecordTouchViewUsageInterval(CurrentTouchViewIntervalType());
+}
+
+void TabletModeController::SuspendDone(const base::TimeDelta& sleep_duration) {
+  // We do not want TouchView usage metrics to include time spent in suspend.
+  touchview_usage_interval_start_time_ = base::Time::Now();
+}
+
+void TabletModeController::HandleHingeRotation(
+    scoped_refptr<const chromeos::AccelerometerUpdate> update) {
+  static const gfx::Vector3dF hinge_vector(1.0f, 0.0f, 0.0f);
+  gfx::Vector3dF base_reading(ui::ConvertAccelerometerReadingToVector3dF(
+      update->get(chromeos::ACCELEROMETER_SOURCE_ATTACHED_KEYBOARD)));
+  gfx::Vector3dF lid_reading(ui::ConvertAccelerometerReadingToVector3dF(
+      update->get(chromeos::ACCELEROMETER_SOURCE_SCREEN)));
+
+  // As the hinge approaches a vertical angle, the base and lid accelerometers
+  // approach the same values making any angle calculations highly inaccurate.
+  // Smooth out instantaneous acceleration when nearly vertical to increase
+  // accuracy.
+  float largest_hinge_acceleration =
+      std::max(std::abs(base_reading.x()), std::abs(lid_reading.x()));
+  float smoothing_ratio =
+      std::max(0.0f, std::min(1.0f, (largest_hinge_acceleration -
+                                     kHingeVerticalSmoothingStart) /
+                                        (kHingeVerticalSmoothingMaximum -
+                                         kHingeVerticalSmoothingStart)));
+
+  // We cannot trust the computed lid angle when the device is held vertically.
+  bool is_angle_reliable =
+      largest_hinge_acceleration <= kHingeVerticalSmoothingMaximum;
+
+  base_smoothed_.Scale(smoothing_ratio);
+  base_reading.Scale(1.0f - smoothing_ratio);
+  base_smoothed_.Add(base_reading);
+
+  lid_smoothed_.Scale(smoothing_ratio);
+  lid_reading.Scale(1.0f - smoothing_ratio);
+  lid_smoothed_.Add(lid_reading);
+
+  if (tablet_mode_switch_is_on_)
+    return;
+
+  // Ignore the component of acceleration parallel to the hinge for the purposes
+  // of hinge angle calculation.
+  gfx::Vector3dF base_flattened(base_smoothed_);
+  gfx::Vector3dF lid_flattened(lid_smoothed_);
+  base_flattened.set_x(0.0f);
+  lid_flattened.set_x(0.0f);
+
+  // Compute the angle between the base and the lid.
+  float lid_angle = 180.0f - gfx::ClockwiseAngleBetweenVectorsInDegrees(
+                                 base_flattened, lid_flattened, hinge_vector);
+  if (lid_angle < 0.0f)
+    lid_angle += 360.0f;
+
+  bool is_angle_stable = is_angle_reliable && lid_angle >= kMinStableAngle &&
+                         lid_angle <= kMaxStableAngle;
+
+  // Clear the last_lid_open_time_ for a stable reading so that there is less
+  // chance of a delay if the lid is moved from the close state to the fully
+  // open state very quickly.
+  if (is_angle_stable)
+    last_lid_open_time_ = base::TimeTicks();
+
+  // Toggle tablet mode on or off when corresponding thresholds are passed.
+  if (IsTabletModeWindowManagerEnabled() && is_angle_stable &&
+      lid_angle <= kExitTabletModeAngle) {
+    LeaveTabletMode();
+  } else if (!IsTabletModeWindowManagerEnabled() && !lid_is_closed_ &&
+             lid_angle >= kEnterTabletModeAngle &&
+             (is_angle_stable || !WasLidOpenedRecently())) {
+    EnterTabletMode();
+  }
+}
+
+void TabletModeController::EnterTabletMode() {
+  // Always reset first to avoid creation before destruction of a previous
+  // object.
+  event_blocker_ =
+      ShellPort::Get()->CreateScopedDisableInternalMouseAndKeyboard();
+
+  if (IsTabletModeWindowManagerEnabled())
+    return;
+  EnableTabletModeWindowManager(true);
+}
+
+void TabletModeController::LeaveTabletMode() {
+  event_blocker_.reset();
+
+  if (!IsTabletModeWindowManagerEnabled())
+    return;
+  EnableTabletModeWindowManager(false);
+}
+
+// Called after tablet mode has started, windows might still animate though.
+void TabletModeController::OnTabletModeStarted() {
+  RecordTouchViewUsageInterval(TOUCH_VIEW_INTERVAL_INACTIVE);
+}
+
+// Called after tablet mode has ended, windows might still be returning to
+// their original position.
+void TabletModeController::OnTabletModeEnded() {
+  RecordTouchViewUsageInterval(TOUCH_VIEW_INTERVAL_ACTIVE);
+}
+
+void TabletModeController::OnShellInitialized() {
+  force_tablet_mode_ = GetTabletMode();
+  if (force_tablet_mode_ == ForceTabletMode::TOUCHVIEW)
+    EnterTabletMode();
+}
+
+void TabletModeController::OnDisplayConfigurationChanged() {
+  if (!display::Display::HasInternalDisplay() ||
+      !ShellPort::Get()->IsActiveDisplayId(
+          display::Display::InternalDisplayId())) {
+    LeaveTabletMode();
+  } else if (tablet_mode_switch_is_on_ && !IsTabletModeWindowManagerEnabled()) {
+    // The internal display has returned, as we are exiting docked mode.
+    // The device is still in tablet mode, so trigger tablet mode, as this
+    // switch leads to the ignoring of accelerometer events. When the switch is
+    // not set the next stable accelerometer readings will trigger maximize
+    // mode.
+    EnterTabletMode();
+  }
+}
+
+void TabletModeController::RecordTouchViewUsageInterval(
+    TouchViewIntervalType type) {
+  if (!CanEnterTabletMode())
+    return;
+
+  base::Time current_time = base::Time::Now();
+  base::TimeDelta delta = current_time - touchview_usage_interval_start_time_;
+  switch (type) {
+    case TOUCH_VIEW_INTERVAL_INACTIVE:
+      UMA_HISTOGRAM_LONG_TIMES("Ash.TouchView.TouchViewInactive", delta);
+      total_non_touchview_time_ += delta;
+      break;
+    case TOUCH_VIEW_INTERVAL_ACTIVE:
+      UMA_HISTOGRAM_LONG_TIMES("Ash.TouchView.TouchViewActive", delta);
+      total_touchview_time_ += delta;
+      break;
+  }
+
+  touchview_usage_interval_start_time_ = current_time;
+}
+
+TabletModeController::TouchViewIntervalType
+TabletModeController::CurrentTouchViewIntervalType() {
+  if (IsTabletModeWindowManagerEnabled())
+    return TOUCH_VIEW_INTERVAL_ACTIVE;
+  return TOUCH_VIEW_INTERVAL_INACTIVE;
+}
+
+void TabletModeController::AddObserver(mojom::TouchViewObserverPtr observer) {
+  observer->OnTouchViewToggled(IsTabletModeWindowManagerEnabled());
+  observers_.AddPtr(std::move(observer));
+}
+
+bool TabletModeController::AllowEnterExitTabletMode() const {
+  return force_tablet_mode_ == ForceTabletMode::NONE;
+}
+
+void TabletModeController::OnChromeTerminating() {
+  // The system is about to shut down, so record TouchView usage interval
+  // metrics based on whether TouchView mode is currently active.
+  RecordTouchViewUsageInterval(CurrentTouchViewIntervalType());
+
+  if (CanEnterTabletMode()) {
+    UMA_HISTOGRAM_CUSTOM_COUNTS("Ash.TouchView.TouchViewActiveTotal",
+                                total_touchview_time_.InMinutes(), 1,
+                                base::TimeDelta::FromDays(7).InMinutes(), 50);
+    UMA_HISTOGRAM_CUSTOM_COUNTS("Ash.TouchView.TouchViewInactiveTotal",
+                                total_non_touchview_time_.InMinutes(), 1,
+                                base::TimeDelta::FromDays(7).InMinutes(), 50);
+    base::TimeDelta total_runtime =
+        total_touchview_time_ + total_non_touchview_time_;
+    if (total_runtime.InSeconds() > 0) {
+      UMA_HISTOGRAM_PERCENTAGE(
+          "Ash.TouchView.TouchViewActivePercentage",
+          100 * total_touchview_time_.InSeconds() / total_runtime.InSeconds());
+    }
+  }
+}
+
+void TabletModeController::OnGetSwitchStates(
+    chromeos::PowerManagerClient::LidState lid_state,
+    chromeos::PowerManagerClient::TabletMode tablet_mode) {
+  LidEventReceived(lid_state, base::TimeTicks::Now());
+  TabletModeEventReceived(tablet_mode, base::TimeTicks::Now());
+}
+
+bool TabletModeController::WasLidOpenedRecently() const {
+  if (last_lid_open_time_.is_null())
+    return false;
+
+  base::TimeTicks now = tick_clock_->NowTicks();
+  DCHECK(now >= last_lid_open_time_);
+  base::TimeDelta elapsed_time = now - last_lid_open_time_;
+  return elapsed_time.InSeconds() <= kLidRecentlyOpenedDurationSeconds;
+}
+
+void TabletModeController::SetTickClockForTest(
+    std::unique_ptr<base::TickClock> tick_clock) {
+  DCHECK(tick_clock_);
+  tick_clock_ = std::move(tick_clock);
+}
+
+}  // namespace ash