Refine ForceUiTabletModeState

Previously, ForceUiTabletModeState uses kLockInTabletMode and
kLockInClamshellMode, and use forced_ui_mode_ to enforce the
tablet-mode state. However, this turns out not correct on
the handling of screen_orientation_controller.

To make ScreenOrientationController (and maybe some other entities)
work with testing situation, ForceUiTabletModeState should set
is_in_tablet_physical_state flag.

In this CL:
- change a simple 'force_physical_tablet_state' boolean to tri-state.
- introduce new TabletModeBehaviors for the new states.
- since it is considered to be 'physically tablet' status but
  we don't want to auto-rotate the screen due to accelerometer,
  create a new callback and add a mechanism to suppress the auto
  rotation.

This CL does not change all existing ash unit tests -- that will be done
in another CL.

Bug: b/161253230
Test: ScreenOrientationControllerTest, tast arc.WMNonresizableConversion, make sure the screen orientation
Change-Id: Ic48f8570df103fe58336faa675f9c1753bb63ee8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2310773
Commit-Queue: Jun Mukai <mukai@chromium.org>
Reviewed-by: Mitsuru Oshima <oshima@chromium.org>
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Cr-Commit-Position: refs/heads/master@{#791319}

ash/accelerometer/accelerometer_reader.cc

@@ -188,6 +188,8 @@ class AccelerometerFileReader
   void StartListenToTabletModeController();
   void StopListenToTabletModeController();
 
+  void SetEmitEvents(bool emit_events);
+
   // TabletModeObserver:
   void OnTabletPhysicalStateChanged() override;
 
@@ -261,6 +263,8 @@ class AccelerometerFileReader
   // reading to an AccelerometerUpdate and notifies observers.
   void ReadFileAndNotify();
 
+  void SetEmitEventsInternal(bool emit_events);
+
   // State of ChromeOS EC lid angle driver, if SUPPORTED, it means EC can handle
   // lid angle calculation.
   ECLidAngleDriver ec_lid_angle_driver_ = UNKNOWN;
@@ -271,6 +275,8 @@ class AccelerometerFileReader
   // True if periodical accelerometer read is on.
   bool accelerometer_read_on_ = false;
 
+  bool emit_events_ = true;
+
   // The time at which initialization re-tries should stop.
   base::TimeTicks initialization_timeout_;
 
@@ -541,6 +547,17 @@ void AccelerometerFileReader::StopListenToTabletModeController() {
   Shell::Get()->tablet_mode_controller()->RemoveObserver(this);
 }
 
+void AccelerometerFileReader::SetEmitEvents(bool emit_events) {
+  task_runner_->PostNonNestableTask(
+      FROM_HERE, base::BindOnce(&AccelerometerFileReader::SetEmitEventsInternal,
+                                this, emit_events));
+}
+
+void AccelerometerFileReader::SetEmitEventsInternal(bool emit_events) {
+  DCHECK(base::SequencedTaskRunnerHandle::IsSet());
+  emit_events_ = emit_events;
+}
+
 void AccelerometerFileReader::OnTabletPhysicalStateChanged() {
   // When CrOS EC lid angle driver is not present, accelerometer read is always
   // ON and can't be tuned. Thus AccelerometerFileReader no longer listens to
@@ -704,6 +721,9 @@ void AccelerometerFileReader::ReadFileAndNotify() {
     }
   }
 
+  if (!emit_events_)
+    return;
+
   observers_->Notify(FROM_HERE,
                      &AccelerometerReader::Observer::OnAccelerometerUpdated,
                      update_);
@@ -749,6 +769,10 @@ void AccelerometerReader::StopListenToTabletModeController() {
   accelerometer_file_reader_->StopListenToTabletModeController();
 }
 
+void AccelerometerReader::SetEnabled(bool enabled) {
+  accelerometer_file_reader_->SetEmitEvents(enabled);
+}
+
 AccelerometerReader::AccelerometerReader()
     : accelerometer_file_reader_(new AccelerometerFileReader()) {}
 

ash/accelerometer/accelerometer_reader.h

@@ -49,6 +49,11 @@ class ASH_EXPORT AccelerometerReader {
   void StartListenToTabletModeController();
   void StopListenToTabletModeController();
 
+  // Controls the availability of emitting acccelerometer reader events to
+  // its observers. This shouldn't be called normally, but Tast tests should
+  // be able to control the accelerometer feature.
+  void SetEnabled(bool enabled);
+
  protected:
   AccelerometerReader();
   virtual ~AccelerometerReader();

ash/display/screen_orientation_controller_unittest.cc

@@ -57,7 +57,7 @@ display::ManagedDisplayInfo CreateDisplayInfo(int64_t id,
 }
 
 void EnableTabletMode(bool enable) {
-  Shell::Get()->tablet_mode_controller()->SetEnabledForTest(enable);
+  Shell::Get()->tablet_mode_controller()->ForceUiTabletModeState(enable);
 }
 
 bool RotationLocked() {

ash/wm/tablet_mode/tablet_mode_controller.cc

@@ -213,7 +213,7 @@ constexpr TabletModeController::TabletModeBehavior kOnBySensor{
     /*observe_pointer_device_events=*/true,
     /*block_internal_input_device=*/true,
     /*always_show_overview_button=*/false,
-    /*force_physical_tablet_state=*/false,
+    TabletModeController::ForcePhysicalTabletState::kDefault,
 };
 
 // Defines the behavior that sticks to tablet mode. Used to implement the
@@ -224,7 +224,7 @@ constexpr TabletModeController::TabletModeBehavior kLockInTabletMode{
     /*observe_pointer_device_events=*/false,
     /*block_internal_input_device=*/false,
     /*always_show_overview_button=*/true,
-    /*force_physical_tablet_state=*/false,
+    TabletModeController::ForcePhysicalTabletState::kDefault,
 };
 
 // Defines the behavior that sticks to tablet mode. Used to implement the
@@ -235,7 +235,7 @@ constexpr TabletModeController::TabletModeBehavior kLockInClamshellMode{
     /*observe_pointer_device_events=*/false,
     /*block_internal_input_device=*/false,
     /*always_show_overview_button=*/false,
-    /*force_physical_tablet_state=*/false,
+    TabletModeController::ForcePhysicalTabletState::kDefault,
 };
 
 // Defines the behavior used for testing. It prevents the device from
@@ -246,7 +246,31 @@ constexpr TabletModeController::TabletModeBehavior kOnForTest{
     /*observe_pointer_device_events=*/true,
     /*block_internal_input_device=*/true,
     /*always_show_overview_button=*/false,
-    /*force_physical_tablet_state=*/true,
+    TabletModeController::ForcePhysicalTabletState::kForceTabletMode,
+};
+
+// Used for the testing API to forcibly enter into the tablet mode. It should
+// not observe hardware events as tests want to stick with the tablet mode, and
+// it should not block internal keyboard as some tests may want to use keyboard
+// events in the tablet mode.
+// TODO(mukai): consolidate this with kOnFOrTest.
+constexpr TabletModeController::TabletModeBehavior kOnForAutotest{
+    /*use_sensor=*/false,
+    /*observe_display_events=*/false,
+    /*observe_pointer_device_events=*/false,
+    /*block_internal_input_device=*/false,
+    /*always_show_overview_button=*/false,
+    TabletModeController::ForcePhysicalTabletState::kForceTabletMode,
+};
+
+// Used for the testing API to forcibly exit from the tablet mode.
+constexpr TabletModeController::TabletModeBehavior kOffForAutotest{
+    /*use_sensor=*/false,
+    /*observe_display_events=*/false,
+    /*observe_pointer_device_events=*/false,
+    /*block_internal_input_device=*/false,
+    /*always_show_overview_button=*/false,
+    TabletModeController::ForcePhysicalTabletState::kForceClamshellMode,
 };
 
 // Used for development purpose (currently debug shortcut shift-ctrl-alt). This
@@ -258,7 +282,7 @@ constexpr TabletModeController::TabletModeBehavior kOnForDev{
     /*observe_pointer_device_events=*/true,
     /*block_internal_input_device=*/false,
     /*always_show_overview_button=*/true,
-    /*force_physical_tablet_state=*/true,
+    TabletModeController::ForcePhysicalTabletState::kForceTabletMode,
 };
 
 using LidState = chromeos::PowerManagerClient::LidState;
@@ -531,19 +555,22 @@ void TabletModeController::ForceUiTabletModeState(
     base::Optional<bool> enabled) {
   if (!enabled.has_value()) {
     tablet_mode_behavior_ = kDefault;
-    forced_ui_mode_ = UiMode::kNone;
+    AccelerometerReader::GetInstance()->SetEnabled(true);
     if (!SetIsInTabletPhysicalState(CalculateIsInTabletPhysicalState()))
       UpdateUiTabletState();
     return;
   }
   if (*enabled) {
-    tablet_mode_behavior_ = kLockInTabletMode;
-    forced_ui_mode_ = UiMode::kTabletMode;
+    tablet_mode_behavior_ = kOnForAutotest;
   } else {
-    tablet_mode_behavior_ = kLockInClamshellMode;
-    forced_ui_mode_ = UiMode::kClamshell;
+    tablet_mode_behavior_ = kOffForAutotest;
   }
-  UpdateUiTabletState();
+  // We want to suppress the accelerometer to auto-rotate the screen based on
+  // the physical orientation, as it will confuse the test scenarios. Note that
+  // this should not block ScreenOrientationController as the screen may want
+  // to be rotated for other factors.
+  AccelerometerReader::GetInstance()->SetEnabled(false);
+  SetIsInTabletPhysicalState(CalculateIsInTabletPhysicalState());
 }
 
 void TabletModeController::SetEnabledForTest(bool enabled) {
@@ -1211,12 +1238,19 @@ void TabletModeController::OnScreenshotTaken(
 }
 
 bool TabletModeController::CalculateIsInTabletPhysicalState() const {
+  switch (tablet_mode_behavior_.force_physical_tablet_state) {
+    case ForcePhysicalTabletState::kDefault:
+      // Don't return forced result. Check the hardware configuration.
+      break;
+    case ForcePhysicalTabletState::kForceTabletMode:
+      return true;
+    case ForcePhysicalTabletState::kForceClamshellMode:
+      return false;
+  }
+
   if (!HasActiveInternalDisplay())
     return false;
 
-  if (tablet_mode_behavior_.force_physical_tablet_state)
-    return true;
-
   // For updated EC, the tablet mode switch activates at 200 degrees, and
   // deactivates at 160 degrees.
   // For old EC, the tablet mode switch activates at 300 degrees, so it's

ash/wm/tablet_mode/tablet_mode_controller.h

@@ -192,6 +192,15 @@ class ASH_EXPORT TabletModeController
   // Returns true if the system tray should have a overview button.
   bool ShouldShowOverviewButton() const;
 
+  // ForcePhysicalTabletState is to control physical tablet state. The default
+  // state is not to force the state, so the tablet-mode controller will observe
+  // device configurations.
+  enum class ForcePhysicalTabletState {
+    kDefault,
+    kForceTabletMode,
+    kForceClamshellMode,
+  };
+
   // Defines how the tablet mode controller controls the
   // tablet mode and its transition between clamshell mode.
   // This is defined as a public to define constexpr in cc.
@@ -201,7 +210,8 @@ class ASH_EXPORT TabletModeController
     bool observe_pointer_device_events = true;
     bool block_internal_input_device = false;
     bool always_show_overview_button = false;
-    bool force_physical_tablet_state = false;
+    ForcePhysicalTabletState force_physical_tablet_state =
+        ForcePhysicalTabletState::kDefault;
   };
 
  private: