| /* |
| * Copyright 2015 Google Inc. All Rights Reserved. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #include "cobalt/cssom/timing_function.h" |
| |
| #include <algorithm> |
| |
| #include "base/lazy_instance.h" |
| #include "base/logging.h" |
| |
| namespace cobalt { |
| namespace cssom { |
| |
| namespace { |
| |
| struct NonTrivialStaticFields { |
| // Values for keyword timing values are provided by the specification: |
| // https://www.w3.org/TR/css3-transitions/#transition-timing-function-property |
| NonTrivialStaticFields() |
| : ease(new CubicBezierTimingFunction(0.25f, 0.1f, 0.25f, 1.0f)), |
| ease_in(new CubicBezierTimingFunction(0.42f, 0.0f, 1.0f, 1.0f)), |
| ease_in_out(new CubicBezierTimingFunction(0.42f, 0.0f, 0.58f, 1.0f)), |
| ease_out(new CubicBezierTimingFunction(0.0f, 0.0f, 0.58f, 1.0f)), |
| linear(new CubicBezierTimingFunction(0.0f, 0.0f, 1.0f, 1.0f)), |
| step_end(new SteppingTimingFunction(1, SteppingTimingFunction::kEnd)), |
| step_start( |
| new SteppingTimingFunction(1, SteppingTimingFunction::kStart)) {} |
| |
| const scoped_refptr<TimingFunction> ease; |
| const scoped_refptr<TimingFunction> ease_in; |
| const scoped_refptr<TimingFunction> ease_in_out; |
| const scoped_refptr<TimingFunction> ease_out; |
| const scoped_refptr<TimingFunction> linear; |
| const scoped_refptr<TimingFunction> step_end; |
| const scoped_refptr<TimingFunction> step_start; |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(NonTrivialStaticFields); |
| }; |
| |
| base::LazyInstance<NonTrivialStaticFields> non_trivial_static_fields = |
| LAZY_INSTANCE_INITIALIZER; |
| |
| } // namespace |
| |
| const scoped_refptr<TimingFunction>& TimingFunction::GetEase() { |
| return non_trivial_static_fields.Get().ease; |
| } |
| |
| const scoped_refptr<TimingFunction>& TimingFunction::GetEaseIn() { |
| return non_trivial_static_fields.Get().ease_in; |
| } |
| |
| const scoped_refptr<TimingFunction>& TimingFunction::GetEaseInOut() { |
| return non_trivial_static_fields.Get().ease_in_out; |
| } |
| |
| const scoped_refptr<TimingFunction>& TimingFunction::GetEaseOut() { |
| return non_trivial_static_fields.Get().ease_out; |
| } |
| |
| const scoped_refptr<TimingFunction>& TimingFunction::GetLinear() { |
| return non_trivial_static_fields.Get().linear; |
| } |
| |
| const scoped_refptr<TimingFunction>& TimingFunction::GetStepEnd() { |
| return non_trivial_static_fields.Get().step_end; |
| } |
| |
| const scoped_refptr<TimingFunction>& TimingFunction::GetStepStart() { |
| return non_trivial_static_fields.Get().step_start; |
| } |
| |
| float CubicBezierTimingFunction::Evaluate(float x) const { |
| return static_cast<float>(cubic_bezier_.Solve(x)); |
| } |
| |
| float SteppingTimingFunction::Evaluate(float x) const { |
| // number_of_steps_ must be greater than 0. This is DCHECK'd in the |
| // constructor. |
| int offset_amount = value_change_location_ == kStart ? 1 : 0; |
| return std::min(static_cast<int>(x * number_of_steps_ + offset_amount) / |
| static_cast<float>(number_of_steps_), |
| 1.0f); |
| } |
| |
| std::string CubicBezierTimingFunction::ToString() { |
| return base::StringPrintf("cubic-bezier(%.7g,%.7g,%.7g,%.7g)", |
| cubic_bezier_.x1(), cubic_bezier_.y1(), |
| cubic_bezier_.x2(), cubic_bezier_.y2()); |
| } |
| |
| std::string SteppingTimingFunction::ToString() { |
| std::string result = base::StringPrintf("steps(%d, ", number_of_steps_); |
| switch (value_change_location_) { |
| case kStart: { |
| result.append(kStartKeywordName); |
| break; |
| } |
| case kEnd: { |
| result.append(kEndKeywordName); |
| break; |
| } |
| } |
| result.push_back(')'); |
| return result; |
| } |
| |
| } // namespace cssom |
| } // namespace cobalt |