Rotate screen in response to accelerator or device orientation sensors.

athena/screen/screen_manager_impl.cc

Index: athena/screen/screen_manager_impl.cc
diff --git a/athena/screen/screen_manager_impl.cc b/athena/screen/screen_manager_impl.cc
index 8522acfc7acd30404c8b2ce8aa0d88fad5963769..404996e688ea0f7ae21ab5e310045d3b452f7849 100644
--- a/athena/screen/screen_manager_impl.cc
+++ b/athena/screen/screen_manager_impl.cc
@@ -36,6 +36,11 @@ bool GrabsInput(aura::Window* container) {
   return params && params->grab_inputs;
 }
 
+bool IsRotationPortrait(gfx::Display::Rotation rotation) {
+  return rotation == gfx::Display::ROTATE_90 ||
+         rotation == gfx::Display::ROTATE_270;
+}
+
 // Returns the container which contains |window|.
 aura::Window* GetContainer(aura::Window* window) {
   // No containers for NULL or the root window itself.
@@ -199,9 +204,12 @@ class ScreenManagerImpl : public ScreenManager {
   virtual aura::Window* CreateContainer(const ContainerParams& params) OVERRIDE;
   virtual aura::Window* GetContext() OVERRIDE { return root_window_; }
   virtual void SetBackgroundImage(const gfx::ImageSkia& image) OVERRIDE;
+  virtual gfx::Display::Rotation GetRotation() OVERRIDE;
+  virtual void SetRotation(gfx::Display::Rotation rotation) OVERRIDE;
 
   aura::Window* root_window_;
   aura::Window* background_window_;
+  gfx::Display::Rotation rotation_;
 
   scoped_ptr<BackgroundController> background_controller_;
   scoped_ptr<aura::client::WindowTreeClient> window_tree_client_;
@@ -213,7 +221,8 @@ class ScreenManagerImpl : public ScreenManager {
 };
 
 ScreenManagerImpl::ScreenManagerImpl(aura::Window* root_window)
-    : root_window_(root_window) {
+    : root_window_(root_window),
+      rotation_(gfx::Display::ROTATE_0) {
   DCHECK(root_window_);
   DCHECK(!instance);
   instance = this;
@@ -322,6 +331,44 @@ void ScreenManagerImpl::SetBackgroundImage(const gfx::ImageSkia& image) {
   background_controller_->SetImage(image);
 }
 
+gfx::Display::Rotation ScreenManagerImpl::GetRotation() {
+  return rotation_;
+}
+
+void ScreenManagerImpl::SetRotation(gfx::Display::Rotation rotation) {
+  if (rotation == rotation_)
+    return;
+
+  gfx::Rect bounds(root_window_->bounds());
+  if (IsRotationPortrait(rotation) != IsRotationPortrait(rotation_)) {
+    bounds.set_size(gfx::Size(bounds.height(), bounds.width()));
+  }
+
+  rotation_ = rotation;
+  root_window_->SetBounds(bounds);
+  gfx::Transform transform;
+  switch (rotation) {
+    case gfx::Display::ROTATE_90:
+      transform.Translate(bounds.height(), 0);
+      transform.RotateAboutZAxis(90);
+      break;
+    case gfx::Display::ROTATE_180:
+      transform.Translate(bounds.width(), bounds.height());
+      transform.RotateAboutZAxis(180);
+      break;
+    case gfx::Display::ROTATE_270:
+      transform.Translate(0, bounds.width());
+      transform.RotateAboutZAxis(270);
+      break;
+    case gfx::Display::ROTATE_0:
+    default:
+      break;
+  }
+  // Note: This does not update the gfx::Display object. Code which relies
+  // on that may misbehave.
+  root_window_->layer()->SetTransform(transform);
+}
+
 }  // namespace
 
 ScreenManager::ContainerParams::ContainerParams(const std::string& n,