1// Copyright (c) 2012 The Chromium Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#include "ash/rotator/screen_rotation.h"
6
7#include "base/time/time.h"
8#include "ui/compositor/layer.h"
9#include "ui/gfx/interpolated_transform.h"
10#include "ui/gfx/rect.h"
11#include "ui/gfx/transform.h"
12
13namespace ash {
14
15namespace {
16
17const int k90DegreeTransitionDurationMs = 350;
18const int k180DegreeTransitionDurationMs = 550;
19const int k360DegreeTransitionDurationMs = 750;
20
21base::TimeDelta GetTransitionDuration(int degrees) {
22  if (degrees == 360)
23    return base::TimeDelta::FromMilliseconds(k360DegreeTransitionDurationMs);
24  if (degrees == 180)
25    return base::TimeDelta::FromMilliseconds(k180DegreeTransitionDurationMs);
26  if (degrees == 0)
27    return base::TimeDelta::FromMilliseconds(0);
28  return base::TimeDelta::FromMilliseconds(k90DegreeTransitionDurationMs);
29}
30
31}  // namespace
32
33ScreenRotation::ScreenRotation(int degrees, ui::Layer* layer)
34    : ui::LayerAnimationElement(LayerAnimationElement::TRANSFORM,
35                                GetTransitionDuration(degrees)),
36      degrees_(degrees) {
37  InitTransform(layer);
38}
39
40ScreenRotation::~ScreenRotation() {
41}
42
43void ScreenRotation::InitTransform(ui::Layer* layer) {
44  // No rotation required, use the identity transform.
45  if (degrees_ == 0) {
46    interpolated_transform_.reset(
47        new ui::InterpolatedConstantTransform(gfx::Transform()));
48    return;
49  }
50
51  // Use the target transform/bounds in case the layer is already animating.
52  const gfx::Transform& current_transform = layer->GetTargetTransform();
53  const gfx::Rect& bounds = layer->GetTargetBounds();
54
55  gfx::Point old_pivot;
56  gfx::Point new_pivot;
57
58  int width = bounds.width();
59  int height = bounds.height();
60
61  switch (degrees_) {
62    case 90:
63      new_origin_ = new_pivot = gfx::Point(width, 0);
64      break;
65    case -90:
66      new_origin_ = new_pivot = gfx::Point(0, height);
67      break;
68    case 180:
69    case 360:
70      new_pivot = old_pivot = gfx::Point(width / 2, height / 2);
71      new_origin_.SetPoint(width, height);
72      break;
73  }
74
75  // Convert points to world space.
76  current_transform.TransformPoint(&old_pivot);
77  current_transform.TransformPoint(&new_pivot);
78  current_transform.TransformPoint(&new_origin_);
79
80  scoped_ptr<ui::InterpolatedTransform> rotation(
81      new ui::InterpolatedTransformAboutPivot(
82          old_pivot,
83          new ui::InterpolatedRotation(0, degrees_)));
84
85  scoped_ptr<ui::InterpolatedTransform> translation(
86      new ui::InterpolatedTranslation(
87          gfx::Point(0, 0),
88          gfx::Point(new_pivot.x() - old_pivot.x(),
89                     new_pivot.y() - old_pivot.y())));
90
91  float scale_factor = 0.9f;
92  scoped_ptr<ui::InterpolatedTransform> scale_down(
93      new ui::InterpolatedScale(1.0f, scale_factor, 0.0f, 0.5f));
94
95  scoped_ptr<ui::InterpolatedTransform> scale_up(
96      new ui::InterpolatedScale(1.0f, 1.0f / scale_factor, 0.5f, 1.0f));
97
98  interpolated_transform_.reset(
99      new ui::InterpolatedConstantTransform(current_transform));
100
101  scale_up->SetChild(scale_down.release());
102  translation->SetChild(scale_up.release());
103  rotation->SetChild(translation.release());
104  interpolated_transform_->SetChild(rotation.release());
105}
106
107void ScreenRotation::OnStart(ui::LayerAnimationDelegate* delegate) {
108}
109
110bool ScreenRotation::OnProgress(double t,
111                                ui::LayerAnimationDelegate* delegate) {
112  delegate->SetTransformFromAnimation(interpolated_transform_->Interpolate(t));
113  return true;
114}
115
116void ScreenRotation::OnGetTarget(TargetValue* target) const {
117  target->transform = interpolated_transform_->Interpolate(1.0);
118}
119
120void ScreenRotation::OnAbort(ui::LayerAnimationDelegate* delegate) {
121}
122
123}  // namespace ash
124