Animated Rotation

views/animation/screen_rotation.h

+// 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.
+
+#ifndef VIEWS_ANIMATION_SCREEN_ROTATION_H_
+#define VIEWS_ANIMATION_SCREEN_ROTATION_H_
+#pragma once
+
+#include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/task.h"
+#include "ui/base/animation/animation_delegate.h"
+#include "ui/gfx/point.h"
+#include "ui/gfx/size.h"
+
+namespace ui {
+class SlideAnimation;
+class InterpolatedTransform;
+class Layer;
+class Transform;
+}
+
+namespace views {
+
+class View;
+class ScreenRotation;
+
+// Classes that wish to be notified when a screen rotation completes must
+// implement the screen rotation listener interface.
+class ScreenRotationListener {
+ public:
+  virtual void OnScreenRotationCompleted(ScreenRotation* rotation) = 0;
+};

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

Add a virtual destructor and make it public. This way it's clear ScreenRotation
doesn't own the listener.

+
+// A screen rotation represents a single transition from one screen orientation
+// to another. The  intended usage is that a new instance of the class is
+// created for every transition. It is possible to update the target orientation
+// in the middle of a transition.
+class ScreenRotation : public ui::AnimationDelegate {

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

These classes (ScreenRotation and ScreenRotationSetter) should live in touch. If
we really need them outside of touch we can promote them.

+ public:
+  ScreenRotation(View* view, float old_degrees, float new_degrees);
+  virtual ~ScreenRotation();
+
+  ScreenRotationListener* listener() { return listener_; }
+  void set_listener(ScreenRotationListener* listener) { listener_ = listener; }
+
+  // Called after the animation is finished and the view has completed painting
+  // in its final state.
+  void Finalize();
+
+  // Use this function to change the target orientation mid animation. The
+  // currently running transition will complete at the same time as it was going
+  // to originally, but in a different orientation.
+  void UpdateTarget(float degrees);

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

nit: Name this SetTarget.

+
+  // True if the animation is complete and finalized.
+  bool done() const { return done_; }
+
+ private:
+  // Implementation of ui::AnimationDelegate
+  virtual void AnimationEnded(const ui::Animation* anim) OVERRIDE;
+  virtual void AnimationProgressed(const ui::Animation* anim) OVERRIDE;
+
+  // Initializes |interpolated_transform_|, |new_origin_|, |new_size_|, and
+  // (if it has not already been initialized) |old_transform_|
+  void Init();
+
+  // Initializes the screen rotation and starts |animation_|.
+  void Start();
+
+  // Converts degrees to an angle in the range [-180, 180).
+  int NormalizeAngle(int degrees);
+
+  // This is the view that will be animated. The animation will operate mainly
+  // on |view_|'s layer, but it is used upon completion of the rotation to
+  // update the bounds.
+  View* view_;
+
+  // A ScreenRotation may be associated with a listener that is notified when
+  // the screen rotation completes.
+  ScreenRotationListener* listener_;
+
+  // The initial transform of the layer (not updated by |UpdateTarget|).
+  scoped_ptr<ui::Transform> old_transform_;
+
+  // The animation object that instigates stepping of the animation.
+  scoped_ptr<ui::SlideAnimation> animation_;
+
+  // Generates the intermediate transformation matrices used during the
+  // animation.
+  scoped_ptr<ui::InterpolatedTransform> interpolated_transform_;
+
+  // The original orientation (not updated by |UpdateTarget|.
+  float old_degrees_;
+
+  // The target orientation.
+  float new_degrees_;
+
+  // We keep track of the last step of the animation in case we change our
+  // target in the middle and have to create a new transition from last_t_ to 1
+  float last_t_;
+
+  // The target size for |view_|
+  gfx::Size new_size_;
+
+  // The target origin for |view_|
+  gfx::Point new_origin_;
+
+  // This is true if the rotation is completed and finalized.
+  bool done_;
+
+  // This is the duration of the transition in milliseconds
+  int duration_;
+
+  // This is used to post a task to update the bounds after the final call to
+  // SchedulePaint completes.
+  ScopedRunnableMethodFactory<ScreenRotation> method_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScreenRotation);
+};
+
+} // namespace views
+
+#endif // VIEWS_ANIMATION_SCREEN_ROTATION_H_