Hook up TABLET_MODE switch to maximize_mode_controller

ash/wm/maximize_mode/maximize_mode_controller.cc

Index: ash/wm/maximize_mode/maximize_mode_controller.cc
diff --git a/ash/wm/maximize_mode/maximize_mode_controller.cc b/ash/wm/maximize_mode/maximize_mode_controller.cc
index 9d8b18dae29de82390b61d4e439eca666dfd59db..f74a31d72e3d4c360f171f2eac1f1f53642d54d2 100644
--- a/ash/wm/maximize_mode/maximize_mode_controller.cc
+++ b/ash/wm/maximize_mode/maximize_mode_controller.cc
@@ -100,9 +100,11 @@ bool IsAngleBetweenAccelerometerReadingsStable(
 
 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);
@@ -208,6 +210,8 @@ void MaximizeModeController::OnAccelerometerUpdated(
              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
@@ -224,6 +228,14 @@ void MaximizeModeController::LidEventReceived(bool 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.
@@ -256,6 +268,10 @@ void MaximizeModeController::HandleHingeRotation(
                                         (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);
@@ -277,7 +293,7 @@ void MaximizeModeController::HandleHingeRotation(
   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
@@ -287,14 +303,12 @@ void MaximizeModeController::HandleHingeRotation(
     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();
   }
 }