Move Screen Rotation from MaximizeModeController to ScreenOrientationController

ash/content/display/screen_orientation_controller_chromeos.cc

Index: ash/content/display/screen_orientation_controller_chromeos.cc
diff --git a/ash/content/display/screen_orientation_delegate_chromeos.cc b/ash/content/display/screen_orientation_controller_chromeos.cc
similarity index 36%
copy from ash/content/display/screen_orientation_delegate_chromeos.cc
copy to ash/content/display/screen_orientation_controller_chromeos.cc
index 892686470057c5708c69a7f0c3f39dee28bcb3ae..f36f1931b9c0e3c37fbe85a2a24f58b1b13ec7e9 100644
--- a/ash/content/display/screen_orientation_delegate_chromeos.cc
+++ b/ash/content/display/screen_orientation_controller_chromeos.cc
@@ -2,14 +2,16 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "ash/content/display/screen_orientation_delegate_chromeos.h"
+#include "ash/content/display/screen_orientation_controller_chromeos.h"
 
 #include "ash/ash_switches.h"
 #include "ash/display/display_info.h"
 #include "ash/display/display_manager.h"
 #include "ash/shell.h"
 #include "ash/wm/maximize_mode/maximize_mode_controller.h"
+#include "base/auto_reset.h"
 #include "base/command_line.h"
+#include "chromeos/accelerometer/accelerometer_reader.h"
 #include "content/public/browser/screen_orientation_provider.h"
 #include "content/public/browser/web_contents.h"
 #include "ui/aura/window.h"
@@ -18,6 +20,17 @@
 
 namespace {
 
+// The angle which the screen has to be rotated past before the display will
+// rotate to match it (i.e. 45.0f is no stickiness).
+const float kDisplayRotationStickyAngleDegrees = 60.0f;
+
+// The minimum acceleration in m/s^2 in a direction required to trigger screen
+// rotation. This prevents rapid toggling of rotation when the device is near
+// flat and there is very little screen aligned force on it. The value is
+// effectively the sine of the rise angle required times the acceleration due
+// to gravity, with the current value requiring at least a 25 degree rise.
+const float kMinimumAccelerationScreenRotation = 4.2f;
+
 blink::WebScreenOrientationLockType GetDisplayNaturalOrientation() {
   ash::DisplayManager* display_manager =
       ash::Shell::GetInstance()->display_manager();
@@ -47,32 +60,82 @@ blink::WebScreenOrientationLockType GetDisplayNaturalOrientation() {
 
 namespace ash {
 
-ScreenOrientationDelegate::ScreenOrientationDelegate()
+ScreenOrientationController::ScreenOrientationController()
     : locking_window_(NULL),
-      natural_orientation_(GetDisplayNaturalOrientation()) {
+      natural_orientation_(GetDisplayNaturalOrientation()),
+      ignore_display_configuration_updates_(false),
+      rotation_locked_(false),
+      user_rotation_(gfx::Display::ROTATE_0),
+      current_rotation_(gfx::Display::ROTATE_0) {
   content::ScreenOrientationProvider::SetDelegate(this);
+  Shell::GetInstance()->AddShellObserver(this);
 }
 
-ScreenOrientationDelegate::~ScreenOrientationDelegate() {
+ScreenOrientationController::~ScreenOrientationController() {
   content::ScreenOrientationProvider::SetDelegate(NULL);
+  Shell::GetInstance()->RemoveShellObserver(this);
+  Shell::GetInstance()->accelerometer_reader()->RemoveObserver(this);
+  Shell::GetInstance()->display_controller()->RemoveObserver(this);
+}
+
+void ScreenOrientationController::AddObserver(Observer* observer) {
+  observers_.AddObserver(observer);
+}
+
+void ScreenOrientationController::RemoveObserver(Observer* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+void ScreenOrientationController::SetRotationLocked(bool rotation_locked) {
+  if (rotation_locked_ == rotation_locked)
+    return;
+  rotation_locked_ = rotation_locked;
+  FOR_EACH_OBSERVER(Observer, observers_,
+                    OnRotationLockChanged(rotation_locked_));
+  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
+  if (!display_manager->HasInternalDisplay())
+    return;
+  base::AutoReset<bool> auto_ignore_display_configuration_updates(
+      &ignore_display_configuration_updates_, true);
+  display_manager->RegisterDisplayRotationProperties(rotation_locked_,
+                                                     current_rotation_);
+}
+
+void ScreenOrientationController::SetDisplayRotation(
+    gfx::Display::Rotation rotation) {
+  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
+  if (!display_manager->HasInternalDisplay())
+    return;
+  current_rotation_ = rotation;
+  base::AutoReset<bool> auto_ignore_display_configuration_updates(
+      &ignore_display_configuration_updates_, true);
+  display_manager->SetDisplayRotation(gfx::Display::InternalDisplayId(),
+                                      rotation);
+}
+
+void ScreenOrientationController::OnAccelerometerUpdated(
+    const ui::AccelerometerUpdate& update) {
+  if (rotation_locked_)
+    return;
+  if (!update.has(ui::ACCELEROMETER_SOURCE_SCREEN))
+    return;
+  // Ignore the reading if it appears unstable. The reading is considered
+  // unstable if it deviates too much from gravity
+  if (chromeos::AccelerometerReader::IsReadingStable(
+          update, ui::ACCELEROMETER_SOURCE_SCREEN)) {
+    HandleScreenRotation(update.get(ui::ACCELEROMETER_SOURCE_SCREEN));
+  }
 }
 
-bool ScreenOrientationDelegate::FullScreenRequired(
+bool ScreenOrientationController::FullScreenRequired(
     content::WebContents* web_contents) {
   return true;
 }
 
-void ScreenOrientationDelegate::Lock(
+void ScreenOrientationController::Lock(
     content::WebContents* web_contents,
     blink::WebScreenOrientationLockType lock_orientation) {
   aura::Window* requesting_window = web_contents->GetNativeView();
-
-  // TODO(jonross): Make ScreenOrientationDelegate responsible for rotation
-  // lock. Have MaximizeModeController, and TrayRotationLock both use it
-  // instead.
-  MaximizeModeController* controller =
-      Shell::GetInstance()->maximize_mode_controller();
-
   // TODO(jonross): Track one rotation lock per window. When the active window
   // changes apply any corresponding rotation lock.
   if (!locking_window_)
@@ -82,7 +145,7 @@ void ScreenOrientationDelegate::Lock(
 
   switch (lock_orientation) {
     case blink::WebScreenOrientationLockAny:
-      controller->SetRotationLocked(false);
+      SetRotationLocked(false);
       locking_window_ = NULL;
       break;
     case blink::WebScreenOrientationLockDefault:
@@ -108,7 +171,7 @@ void ScreenOrientationDelegate::Lock(
           blink::WebScreenOrientationLockLandscape);
       break;
     case blink::WebScreenOrientationLockNatural:
-      controller->LockRotation(gfx::Display::ROTATE_0);
+      LockRotation(gfx::Display::ROTATE_0);
       break;
     default:
       NOTREACHED();
@@ -116,7 +179,7 @@ void ScreenOrientationDelegate::Lock(
   }
 }
 
-bool ScreenOrientationDelegate::ScreenOrientationProviderSupported() {
+bool ScreenOrientationController::ScreenOrientationProviderSupported() {
   return Shell::GetInstance()
              ->maximize_mode_controller()
              ->IsMaximizeModeWindowManagerEnabled() &&
@@ -124,29 +187,73 @@ bool ScreenOrientationDelegate::ScreenOrientationProviderSupported() {
              switches::kAshEnableTouchViewTesting);
 }
 
-void ScreenOrientationDelegate::Unlock(content::WebContents* web_contents) {
+void ScreenOrientationController::Unlock(content::WebContents* web_contents) {
   aura::Window* requesting_window = web_contents->GetNativeView();
   if (requesting_window != locking_window_)
     return;
   locking_window_ = NULL;
-  Shell::GetInstance()->maximize_mode_controller()->SetRotationLocked(false);
+  SetRotationLocked(false);
+}
+
+void ScreenOrientationController::OnDisplayConfigurationChanged() {
+  if (ignore_display_configuration_updates_)
+    return;
+  gfx::Display::Rotation user_rotation =
+      Shell::GetInstance()
+          ->display_manager()
+          ->GetDisplayInfo(gfx::Display::InternalDisplayId())
+          .rotation();
+  if (user_rotation != current_rotation_) {
+    // A user may change other display configuration settings. When the user
+    // does change the rotation setting, then lock rotation to prevent the
+    // accelerometer from erasing their change.
+    SetRotationLocked(true);
+    user_rotation_ = current_rotation_ = user_rotation;
+  }
+}
+
+void ScreenOrientationController::OnMaximizeModeStarted() {
+  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
+  if (!display_manager->HasInternalDisplay())
+    return;
+  current_rotation_ = user_rotation_ =
+      display_manager->GetDisplayInfo(gfx::Display::InternalDisplayId())
+          .rotation();
+  LoadDisplayRotationProperties();
+  Shell::GetInstance()->accelerometer_reader()->AddObserver(this);
+  Shell::GetInstance()->display_controller()->AddObserver(this);
+}
+
+void ScreenOrientationController::OnMaximizeModeEnded() {
+  if (!Shell::GetInstance()->display_manager()->HasInternalDisplay())
+    return;
+  Shell::GetInstance()->accelerometer_reader()->RemoveObserver(this);
+  Shell::GetInstance()->display_controller()->RemoveObserver(this);
+  if (current_rotation_ != user_rotation_)
+    SetDisplayRotation(user_rotation_);
 }
 
-void ScreenOrientationDelegate::LockRotationToPrimaryOrientation(
+void ScreenOrientationController::LockRotation(
+    gfx::Display::Rotation rotation) {
+  SetRotationLocked(true);
+  SetDisplayRotation(rotation);
+}
+
+void ScreenOrientationController::LockRotationToPrimaryOrientation(
     blink::WebScreenOrientationLockType lock_orientation) {
-  Shell::GetInstance()->maximize_mode_controller()->LockRotation(
-      natural_orientation_ == lock_orientation ? gfx::Display::ROTATE_0
-                                               : gfx::Display::ROTATE_90);
+  LockRotation(natural_orientation_ == lock_orientation
+                   ? gfx::Display::ROTATE_0
+                   : gfx::Display::ROTATE_90);
 }
 
-void ScreenOrientationDelegate::LockRotationToSecondaryOrientation(
+void ScreenOrientationController::LockRotationToSecondaryOrientation(
     blink::WebScreenOrientationLockType lock_orientation) {
-  Shell::GetInstance()->maximize_mode_controller()->LockRotation(
-      natural_orientation_ == lock_orientation ? gfx::Display::ROTATE_180
-                                               : gfx::Display::ROTATE_270);
+  LockRotation(natural_orientation_ == lock_orientation
+                   ? gfx::Display::ROTATE_180
+                   : gfx::Display::ROTATE_270);
 }
 
-void ScreenOrientationDelegate::LockToRotationMatchingOrientation(
+void ScreenOrientationController::LockToRotationMatchingOrientation(
     blink::WebScreenOrientationLockType lock_orientation) {
   // TODO(jonross): Update MaximizeModeController to allow rotation between
   // two angles of an orientation (e.g. from ROTATE_0 to ROTATE_180, and from
@@ -158,23 +265,78 @@ void ScreenOrientationDelegate::LockToRotationMatchingOrientation(
   gfx::Display::Rotation rotation =
       display_manager->GetDisplayInfo(gfx::Display::InternalDisplayId())
           .rotation();
-  MaximizeModeController* controller =
-      Shell::GetInstance()->maximize_mode_controller();
   if (natural_orientation_ == lock_orientation) {
     if (rotation == gfx::Display::ROTATE_0 ||
         rotation == gfx::Display::ROTATE_180) {
-      controller->SetRotationLocked(true);
+      SetRotationLocked(true);
     } else {
-      controller->LockRotation(gfx::Display::ROTATE_0);
+      LockRotation(gfx::Display::ROTATE_0);
     }
   } else {
     if (rotation == gfx::Display::ROTATE_90 ||
         rotation == gfx::Display::ROTATE_270) {
-      controller->SetRotationLocked(true);
+      SetRotationLocked(true);
     } else {
-      controller->LockRotation(gfx::Display::ROTATE_90);
+      LockRotation(gfx::Display::ROTATE_90);
     }
   }
 }
 
+void ScreenOrientationController::HandleScreenRotation(
+    const gfx::Vector3dF& lid) {
+  gfx::Vector3dF lid_flattened(lid.x(), lid.y(), 0.0f);
+  float lid_flattened_length = lid_flattened.Length();
+  // When the lid is close to being flat, don't change rotation as it is too
+  // sensitive to slight movements.
+  if (lid_flattened_length < kMinimumAccelerationScreenRotation)
+    return;
+
+  // The reference vector is the angle of gravity when the device is rotated
+  // clockwise by 45 degrees. Computing the angle between this vector and
+  // gravity we can easily determine the expected display rotation.
+  static const gfx::Vector3dF rotation_reference(-1.0f, -1.0f, 0.0f);
+
+  // Set the down vector to match the expected direction of gravity given the
+  // last configured rotation. This is used to enforce a stickiness that the
+  // user must overcome to rotate the display and prevents frequent rotations
+  // when holding the device near 45 degrees.
+  gfx::Vector3dF down(0.0f, 0.0f, 0.0f);
+  if (current_rotation_ == gfx::Display::ROTATE_0)
+    down.set_y(-1.0f);
+  else if (current_rotation_ == gfx::Display::ROTATE_90)
+    down.set_x(-1.0f);
+  else if (current_rotation_ == gfx::Display::ROTATE_180)
+    down.set_y(1.0f);
+  else
+    down.set_x(1.0f);
+
+  // Don't rotate if the screen has not passed the threshold.
+  if (gfx::AngleBetweenVectorsInDegrees(down, lid_flattened) <
+      kDisplayRotationStickyAngleDegrees) {
+    return;
+  }
+
+  float angle = gfx::ClockwiseAngleBetweenVectorsInDegrees(
+      rotation_reference, lid_flattened, gfx::Vector3dF(0.0f, 0.0f, -1.0f));
+
+  gfx::Display::Rotation new_rotation = gfx::Display::ROTATE_90;
+  if (angle < 90.0f)
+    new_rotation = gfx::Display::ROTATE_0;
+  else if (angle < 180.0f)
+    new_rotation = gfx::Display::ROTATE_270;
+  else if (angle < 270.0f)
+    new_rotation = gfx::Display::ROTATE_180;
+
+  if (new_rotation != current_rotation_)
+    SetDisplayRotation(new_rotation);
+}
+
+void ScreenOrientationController::LoadDisplayRotationProperties() {
+  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
+  if (!display_manager->registered_internal_display_rotation_lock())
+    return;
+  SetDisplayRotation(display_manager->registered_internal_display_rotation());
+  SetRotationLocked(true);
+}
+
 }  // namespace ash