Lock rotation when screen is manually rotated.

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 "ash/accelerators/accelerator_controller.h"
 #include "ash/accelerators/accelerator_table.h"
 #include "ash/accelerometer/accelerometer_controller.h"
 #include "ash/ash_switches.h"
@@ skipping 113 matching lines @@
     Shell::GetInstance()->accelerator_controller()->PerformAction(
         ash::TAKE_SCREENSHOT, ui::Accelerator());
   }
 }
 
 #endif  // OS_CHROMEOS
 
 }  // namespace
 
 MaximizeModeController::MaximizeModeController()
-    : rotation_locked_(false),
-      have_seen_accelerometer_data_(false) {
+    : accelerometer_setting_rotation_(false),
+      rotation_locked_(false),
+      have_seen_accelerometer_data_(false),
+      user_rotation_(gfx::Display::ROTATE_0) {
   Shell::GetInstance()->accelerometer_controller()->AddObserver(this);
 }
 
 MaximizeModeController::~MaximizeModeController() {
   Shell::GetInstance()->accelerometer_controller()->RemoveObserver(this);
 }
 
 bool MaximizeModeController::CanEnterMaximizeMode() {
   // If we have ever seen accelerometer data, then HandleHingeRotation may
   // trigger maximize mode at some point in the future.
@@ skipping 50 matching lines @@
   float angle = ClockwiseAngleBetweenVectorsInDegrees(base_flattened,
       lid_flattened, hinge_vector);
 
   // Toggle maximize mode on or off when corresponding thresholds are passed.
   // TODO(flackr): Make MaximizeModeController own the MaximizeModeWindowManager
   // such that observations of state changes occur after the change and shell
   // has fewer states to track.
   if (maximize_mode_engaged &&
       angle > kFullyOpenAngleErrorTolerance &&
       angle < kExitMaximizeModeAngle) {
-    Shell::GetInstance()->EnableMaximizeModeWindowManager(false);
-    event_blocker_.reset();
-    event_handler_.reset();
+    LeaveMaximizeMode();
   } else if (!maximize_mode_engaged &&
       angle > kEnterMaximizeModeAngle) {
-    Shell::GetInstance()->EnableMaximizeModeWindowManager(true);
-    event_blocker_.reset(new MaximizeModeEventBlocker);
-#if defined(OS_CHROMEOS)
-    event_handler_.reset(new ScreenshotActionHandler);
-#endif
+    EnterMaximizeMode();
   }
 }
 
 void MaximizeModeController::HandleScreenRotation(const gfx::Vector3dF& lid) {
   bool maximize_mode_engaged =
       Shell::GetInstance()->IsMaximizeModeWindowManagerEnabled();
 
+  if (!maximize_mode_engaged || rotation_locked_)
+    return;
+
   DisplayManager* display_manager =
       Shell::GetInstance()->display_manager();
   gfx::Display::Rotation current_rotation = display_manager->GetDisplayInfo(
       gfx::Display::InternalDisplayId()).rotation();
 
-  // If maximize mode is not engaged, ensure the screen is not rotated and
-  // do not rotate to match the current device orientation.
-  if (!maximize_mode_engaged) {
-    if (current_rotation != gfx::Display::ROTATE_0) {
-      // TODO(flackr): Currently this will prevent setting a manual rotation on
-      // the screen of a device with an accelerometer, this should only set it
-      // back to ROTATE_0 if it was last set by the accelerometer.
-      // Also, SetDisplayRotation will save the setting to the local store,
-      // this should be stored in a way that we can distinguish what the
-      // rotation was set by.
-      display_manager->SetDisplayRotation(gfx::Display::InternalDisplayId(),
-                                          gfx::Display::ROTATE_0);
-    }
-    rotation_locked_ = false;
-    return;
-  }
-
-  if (rotation_locked_)
-    return;
-
   // After determining maximize mode state, determine if the screen should
   // be rotated.
   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
@@ skipping 25 matching lines @@
       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;
 
-  // When exiting maximize mode return rotation to 0. When entering, rotate to
-  // match screen orientation.
-  if (new_rotation == gfx::Display::ROTATE_0 ||
-      maximize_mode_engaged) {
+  // When setting a new rotation set flag so that display configuration changes
+  // are not saved.
+  if (new_rotation != current_rotation) {
+    accelerometer_setting_rotation_ = true;

[flackr, 2014/05/23 15:30:58]

nit: use base::AutoReset.

     display_manager->SetDisplayRotation(gfx::Display::InternalDisplayId(),
                                         new_rotation);
+    accelerometer_setting_rotation_ = false;
   }
 }
 
+void MaximizeModeController::EnterMaximizeMode() {
+  // TODO(jonross): Listen for display configuration changes. If the user
+  // causes a rotation change a rotation lock should be applied.
+  // https://crbug.com/369505
+  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
+  user_rotation_ = display_manager->
+      GetDisplayInfo(gfx::Display::InternalDisplayId()).rotation();
+  rotation_locked_ =  user_rotation_ != gfx::Display::ROTATE_0;

[flackr, 2014/05/23 15:30:58]

I think the consensus was that we don't want to lock the rotation when maximize
mode is enabled with a non-zero rotation, just eventually lock it when you
manually set a rotation from within maximize mode, and persist the rotation that
you entered from when you exit.

[jonross, 2014/05/23 19:07:20]

Done.

+  Shell::GetInstance()->EnableMaximizeModeWindowManager(true);
+  event_blocker_.reset(new MaximizeModeEventBlocker);
+#if defined(OS_CHROMEOS)
+  event_handler_.reset(new ScreenshotActionHandler);
+#endif
+}
+
+void MaximizeModeController::LeaveMaximizeMode() {
+  DisplayManager* display_manager = Shell::GetInstance()->display_manager();
+  DisplayInfo info = display_manager->
+      GetDisplayInfo(gfx::Display::InternalDisplayId());
+  gfx::Display::Rotation current_rotation = info.rotation();
+  if (current_rotation != user_rotation_) {
+    display_manager->SetDisplayRotation(gfx::Display::InternalDisplayId(),
+                                        user_rotation_);
+  }
+  Shell::GetInstance()->EnableMaximizeModeWindowManager(false);
+  event_blocker_.reset();
+  event_handler_.reset();
+}
+
 }  // namespace ash