components/ActivityIndicator/src/private/MDCActivityIndicatorMotionSpec.m

// Copyright 2017-present the Material Components for iOS authors. 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.

#import "MDCActivityIndicatorMotionSpec.h"

@implementation MDCActivityIndicatorMotionSpec

+ (NSTimeInterval)pointCycleDuration {
  return 4.0 / 3.0;
}

+ (NSTimeInterval)pointCycleMinimumVariableDuration {
  return self.pointCycleDuration / 8;
}

+ (MDCActivityIndicatorMotionSpecIndeterminate)loopIndeterminate {
  NSTimeInterval pointCycleDuration = self.pointCycleDuration;
  MDMMotionCurve linear = MDMMotionCurveMakeBezier(0, 0, 1, 1);
  return (MDCActivityIndicatorMotionSpecIndeterminate){
      .outerRotation =
          {
              .duration = pointCycleDuration,
              .curve = linear,
          },
      .innerRotation =
          {
              .duration = pointCycleDuration,
              .curve = linear,
          },
      .strokeStart =
          {
              .delay = pointCycleDuration / 2,
              .duration = pointCycleDuration / 2,
              .curve = MDMMotionCurveMakeBezier((CGFloat)0.4, 0, (CGFloat)0.2, 1),
          },
      .strokeEnd =
          {
              .duration = pointCycleDuration,
              .curve = MDMMotionCurveMakeBezier((CGFloat)0.4, 0, (CGFloat)0.2, 1),
          },
  };
}

+ (MDCActivityIndicatorMotionSpecTransitionToDeterminate)willChangeToDeterminate {
  MDMMotionCurve linear = MDMMotionCurveMakeBezier(0, 0, 1, 1);
  return (MDCActivityIndicatorMotionSpecTransitionToDeterminate){
      // Transition timing is calculated at runtime - any duration/delay values provided here will
      // by scaled by the calculated duration.
      .innerRotation =
          {
              .duration = 1,
              .curve = linear,
          },
      .strokeEnd =
          {
              .duration = 1,
              .curve = MDMMotionCurveMakeBezier((CGFloat)0.4, 0, (CGFloat)0.2, 1),
          },
  };
}

+ (MDCActivityIndicatorMotionSpecTransitionToIndeterminate)willChangeToIndeterminate {
  return (MDCActivityIndicatorMotionSpecTransitionToIndeterminate){
      // Transition timing is calculated at runtime.
      .strokeStart =
          {
              .curve = MDMMotionCurveMakeBezier((CGFloat)0.4, 0, (CGFloat)0.2, 1),
          },
      .strokeEnd =
          {
              .curve = MDMMotionCurveMakeBezier((CGFloat)0.4, 0, (CGFloat)0.2, 1),
          },
  };
}

+ (MDCActivityIndicatorMotionSpecProgress)willChangeProgress {
  return (MDCActivityIndicatorMotionSpecProgress){
      .strokeEnd = {
          .duration = self.pointCycleDuration / 2,
          .curve = MDMMotionCurveMakeBezier((CGFloat)0.4, 0, (CGFloat)0.2, 1),
      }};
}

@end