Animated Rotation

views/animation/screen_rotation_setter.cc

Index: views/animation/screen_rotation_setter.cc
diff --git a/views/animation/screen_rotation_setter.cc b/views/animation/screen_rotation_setter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..9edd193b01ccb3c13144ba9ba769c21743b0edc5
--- /dev/null
+++ b/views/animation/screen_rotation_setter.cc
@@ -0,0 +1,69 @@
+// Copyright (c) 2011 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 "views/animation/screen_rotation_setter.h"
+
+#include "ui/gfx/compositor/layer.h"
+#include "ui/gfx/interpolated_transform.h"
+#include "views/view.h"
+
+namespace {
+
+static int SymmetricRound(float x) {
+  return static_cast<int>(
+    x > 0
+      ? std::floor(x + 0.5f)
+      : std::ceil(x - 0.5f));
+}
+
+} // namespace
+
+namespace views {
+
+ScreenRotationSetter::ScreenRotationSetter(views::View* view)
+    : rotation_(NULL),

[sky, 2011/08/25 03:00:13]

don't need rotation_

+      view_(view) {
+}
+
+void ScreenRotationSetter::Installed(ui::Layer* layer) OVERRIDE {
+}
+
+void ScreenRotationSetter::Uninstalled(ui::Layer* layer) OVERRIDE {
+}
+
+void ScreenRotationSetter::SetTransform(
+    ui::Layer* layer, const ui::Transform& transform) OVERRIDE {
+  float degrees;
+  if (!ui::InterpolatedTransform::FactorTRS(transform, NULL, &degrees, NULL))
+    return;
+
+  if (rotation_.get()) {
+    rotation_->UpdateTarget(SymmetricRound(degrees));
+  } else {
+    float old_degrees;
+    if (ui::InterpolatedTransform::FactorTRS(layer->transform(),
+                                             NULL, &old_degrees, NULL)) {
+      rotation_.reset(new views::ScreenRotation(view_,
+                                                SymmetricRound(old_degrees),
+                                                SymmetricRound(degrees)));
+      rotation_->set_listener(this);
+    }
+  }
+}
+
+void ScreenRotationSetter::SetBounds(
+    ui::Layer* layer, const gfx::Rect& bounds) {

[sky, 2011/08/25 03:00:13]

nit: each param on its own line.

+  // Ignore bounds changes during an animation.
+  if (rotation_.get() && !rotation_->done())
+    return;

[sky, 2011/08/25 03:00:13]

Don't you need to cache and apply the bounds change after the animation
completes?

+  layer->SetBounds(bounds);
+}
+
+void ScreenRotationSetter::OnScreenRotationCompleted(
+    views::ScreenRotation* rotation) {
+  DCHECK(rotation_.get() == rotation);

[sky, 2011/08/25 03:00:13]

nit: DCHECK_EQ

+  rotation_.reset();
+}
+
+} // namespace views