Hook up TABLET_MODE switch to maximize_mode_controller

ash/wm/maximize_mode/maximize_mode_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 "ash/wm/maximize_mode/maximize_mode_controller.h"
 
 #include <utility>
 
 #include "ash/accelerators/accelerator_controller.h"
 #include "ash/accelerators/accelerator_table.h"
@@ skipping 82 matching lines @@
              ui::ConvertAccelerometerReadingToVector3dF(
                  update.get(chromeos::ACCELEROMETER_SOURCE_SCREEN)).Length()) <=
          kNoisyMagnitudeDeviation;
 }
 #endif  // OS_CHROMEOS
 
 }  // namespace
 
 MaximizeModeController::MaximizeModeController()
     : have_seen_accelerometer_data_(false),
-      lid_open_past_180_(false),
       touchview_usage_interval_start_time_(base::Time::Now()),
       tick_clock_(new base::DefaultTickClock()),
+#if defined(OS_CHROMEOS)
+      tablet_mode_switch_is_on_(false),
+#endif
       lid_is_closed_(false) {
   Shell* shell = Shell::GetInstance();
   shell->AddShellObserver(this);
   shell->metrics()->RecordUserMetricsAction(
       ash::UMA_MAXIMIZE_MODE_INITIALLY_DISABLED);
 
 #if defined(OS_CHROMEOS)
   // TODO(jonross): Do not create MaximizeModeController if the flag is
   // unavailable. This will require refactoring
   // IsMaximizeModeWindowManagerEnabled to check for the existance of the
@@ skipping 85 matching lines @@
   // Whether or not we enter maximize mode affects whether we handle screen
   // rotation, so determine whether to enter maximize mode first.
   if (!update->has(chromeos::ACCELEROMETER_SOURCE_ATTACHED_KEYBOARD)) {
     if (first_accelerometer_update)
       EnterMaximizeMode();
   } else if (ui::IsAccelerometerReadingStable(
                  *update, chromeos::ACCELEROMETER_SOURCE_SCREEN) &&
              ui::IsAccelerometerReadingStable(
                  *update, chromeos::ACCELEROMETER_SOURCE_ATTACHED_KEYBOARD) &&
              IsAngleBetweenAccelerometerReadingsStable(*update)) {
+    if (tablet_mode_switch_is_on_)
+      return;
     // 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 MaximizeModeController::LidEventReceived(bool open,
                                               const base::TimeTicks& time) {
   if (open)
     last_lid_open_time_ = time;
   lid_is_closed_ = !open;
   LeaveMaximizeMode();
 }
 
+void MaximizeModeController::TabletModeEventReceived(
+    bool on,
+    const base::TimeTicks& time) {
+  tablet_mode_switch_is_on_ = on;
+  if (on && !IsMaximizeModeWindowManagerEnabled())
+    EnterMaximizeMode();
+}
+
 void MaximizeModeController::SuspendImminent() {
   // The system is about to suspend, so record TouchView usage interval metrics
   // based on whether TouchView mode is currently active.
   RecordTouchViewUsageInterval(CurrentTouchViewIntervalType());
 }
 
 void MaximizeModeController::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();
@@ skipping 12 matching lines @@
   // 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 =
+      std::abs(base_reading.x()) > 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);
 
   // 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 = lid_angle >= kMinStableAngle &&
+  bool is_angle_stable = !is_angle_reliable && lid_angle >= kMinStableAngle &&

[jonross, 2016/06/07 15:27:15]

On devices without a tablet mode switch, does this prevent entering maximize
mode? (Eg. on a veyron_minnie)

[jcliang, 2016/06/07 16:57:23]

Ah, there's a typo here. I forgot to invert the condition when I renamed the
variable. The boolean variable is_angle_reliable should be inverted in line 272
above and this should be

  bool is_angle_stable = is_angle_reliable && lid_angle >= kMinStableAngle &&
...

I'll fix this in the next patch roll. This is_angle_reliable only prevents state
transition when the device is vertical, so devices without tablet mode switch
should function just as before.

[jonross, 2016/06/07 22:04:42]

That SGTM

                          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 maximize mode on or off when corresponding thresholds are passed.
-  if (lid_open_past_180_ && is_angle_stable &&
+  if (IsMaximizeModeWindowManagerEnabled() && is_angle_stable &&
       lid_angle <= kExitMaximizeModeAngle) {
-    lid_open_past_180_ = false;
     LeaveMaximizeMode();
-  } else if (!lid_open_past_180_ && !lid_is_closed_ &&
+  } else if (!IsMaximizeModeWindowManagerEnabled() && !lid_is_closed_ &&
              lid_angle >= kEnterMaximizeModeAngle &&
              (is_angle_stable || !WasLidOpenedRecently())) {
-    lid_open_past_180_ = true;
     EnterMaximizeMode();
   }
 }
 #endif  // OS_CHROMEOS
 
 void MaximizeModeController::EnterMaximizeMode() {
   // Always reset first to avoid creation before destruction of a previous
   // object.
   event_blocker_.reset();
 #if defined(USE_X11)
@@ skipping 107 matching lines @@
   return elapsed_time.InSeconds() <= kLidRecentlyOpenedDurationSeconds;
 }
 
 void MaximizeModeController::SetTickClockForTest(
     std::unique_ptr<base::TickClock> tick_clock) {
   DCHECK(tick_clock_);
   tick_clock_ = std::move(tick_clock);
 }
 
 }  // namespace ash