Re-introduce v1 APIs. (#33)

This is a partial revert of commit 3a28e22.

This will allow us to gradually migrate clients to the new v2 APIs without immediately introducing a breaking change.

src/MDMMotionCurve.h

@@ -0,0 +1,194 @@
+/*
+ Copyright 2017-present The Material Motion 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 <CoreGraphics/CoreGraphics.h>
+#import <Foundation/Foundation.h>
+#import <QuartzCore/QuartzCore.h>
+
+/**
+ The possible kinds of motion curves that can be used to describe an animation.
+ */
+typedef NS_ENUM(NSUInteger, MDMMotionCurveType) {
+  /**
+   The value will be instantly set with no animation.
+   */
+  MDMMotionCurveTypeInstant,
+
+  /**
+   The value will be animated using a cubic bezier curve to model its velocity.
+   */
+  MDMMotionCurveTypeBezier,
+
+  /**
+   The value will be animated using a spring simulation.
+
+   A spring will treat the duration property of the motion timing as a suggestion and may choose to
+   ignore it altogether.
+   */
+  MDMMotionCurveTypeSpring,
+
+  /**
+   The default curve will be used.
+   */
+  MDMMotionCurveTypeDefault __deprecated_enum_msg("Use MDMMotionCurveTypeBezier instead."),
+
+} NS_SWIFT_NAME(MotionCurveType);
+
+/**
+ A generalized representation of a motion curve.
+ */
+struct MDMMotionCurve {
+  /**
+   The type defines how to interpret the data values.
+   */
+  MDMMotionCurveType type;
+
+  /**
+   The data values corresponding with this curve.
+   */
+  CGFloat data[4];
+} NS_SWIFT_NAME(MotionCurve);
+typedef struct MDMMotionCurve MDMMotionCurve;
+
+/**
+ Creates a bezier motion curve with the provided control points.
+
+ A cubic bezier has four control points in total. We assume that the first control point is 0, 0 and
+ the last control point is 1, 1. This method requires that you provide the second and third control
+ points.
+
+ See the documentation for CAMediaTimingFunction for more information.
+ */
+// clang-format off
+FOUNDATION_EXTERN
+MDMMotionCurve MDMMotionCurveMakeBezier(CGFloat p1x, CGFloat p1y, CGFloat p2x, CGFloat p2y)
+    NS_SWIFT_NAME(MotionCurveMakeBezier(p1x:p1y:p2x:p2y:));
+// clang-format on
+
+// clang-format off
+FOUNDATION_EXTERN
+MDMMotionCurve MDMMotionCurveFromTimingFunction(CAMediaTimingFunction * _Nonnull timingFunction)
+    NS_SWIFT_NAME(MotionCurve(fromTimingFunction:));
+// clang-format on
+
+/**
+ Creates a spring curve with the provided configuration.
+
+ Tension and friction map to Core Animation's stiffness and damping, respectively.
+
+ See the documentation for CASpringAnimation for more information.
+ */
+// clang-format off
+FOUNDATION_EXTERN MDMMotionCurve MDMMotionCurveMakeSpring(CGFloat mass,
+                                                          CGFloat tension,
+                                                          CGFloat friction)
+    NS_SWIFT_NAME(MotionCurveMakeSpring(mass:tension:friction:));
+// clang-format on
+
+/**
+ Creates a spring curve with the provided configuration.
+
+ Tension and friction map to Core Animation's stiffness and damping, respectively.
+
+ See the documentation for CASpringAnimation for more information.
+ */
+// clang-format off
+FOUNDATION_EXTERN
+MDMMotionCurve MDMMotionCurveMakeSpringWithInitialVelocity(CGFloat mass,
+                                                           CGFloat tension,
+                                                           CGFloat friction,
+                                                           CGFloat initialVelocity)
+    NS_SWIFT_NAME(MotionCurveMakeSpring(mass:tension:friction:initialVelocity:));
+// clang-format on
+
+/**
+ For cubic bezier curves, returns a reversed cubic bezier curve. For all other curve types, a copy
+ of the original curve is returned.
+ */
+// clang-format off
+FOUNDATION_EXTERN MDMMotionCurve MDMMotionCurveReversedBezier(MDMMotionCurve motionCurve)
+    NS_SWIFT_NAME(MotionCurveReversedBezier(fromMotionCurve:));
+// clang-format on
+
+/**
+ Named indices for the bezier motion curve's data array.
+ */
+typedef NS_ENUM(NSUInteger, MDMBezierMotionCurveDataIndex) {
+  MDMBezierMotionCurveDataIndexP1X,
+  MDMBezierMotionCurveDataIndexP1Y,
+  MDMBezierMotionCurveDataIndexP2X,
+  MDMBezierMotionCurveDataIndexP2Y
+} NS_SWIFT_NAME(BezierMotionCurveDataIndex);
+
+/**
+ Named indices for the spring motion curve's data array.
+ */
+typedef NS_ENUM(NSUInteger, MDMSpringMotionCurveDataIndex) {
+  MDMSpringMotionCurveDataIndexMass,
+  MDMSpringMotionCurveDataIndexTension,
+  MDMSpringMotionCurveDataIndexFriction,
+
+  /**
+   The initial velocity of the animation.
+
+   A value of zero indicates no initial velocity.
+   A positive value indicates movement toward the destination.
+   A negative value indicates movement away from the destination.
+
+   The value's units are dependent on the context and the value being animated.
+   */
+  MDMSpringMotionCurveDataIndexInitialVelocity
+} NS_SWIFT_NAME(SpringMotionCurveDataIndex);
+
+// Objective-C-specific macros
+
+#define _MDMBezier(p1x, p1y, p2x, p2y) \
+  ((MDMMotionCurve) {                   \
+    .type = MDMMotionCurveTypeBezier,  \
+    .data = { p1x,                     \
+              p1y,                     \
+              p2x,                     \
+              p2y }                    \
+  })
+
+#define _MDMSpring(mass, tension, friction) \
+  ((MDMMotionCurve) {                        \
+    .type = MDMMotionCurveTypeSpring,       \
+    .data = { mass,                         \
+              tension,                      \
+              friction }                    \
+  })
+
+#define _MDMSpringWithInitialVelocity(mass, tension, friction, initialVelocity) \
+  ((MDMMotionCurve) {                        \
+    .type = MDMMotionCurveTypeSpring,       \
+    .data = { mass,                         \
+              tension,                      \
+              friction,                     \
+              initialVelocity }             \
+  })
+
+/**
+ A linear bezier motion curve.
+ */
+#define MDMLinearMotionCurve _MDMBezier(0, 0, 1, 1)
+
+/**
+ Timing information for an iOS modal presentation slide animation.
+ */
+#define MDMModalMovementTiming { \
+  .delay = 0.000, .duration = 0.500, .curve = _MDMSpring(3, 1000, 500) \
+}

src/MDMMotionCurve.m

@@ -0,0 +1,51 @@
+/*
+ Copyright 2017-present The Material Motion 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 "MDMMotionCurve.h"
+
+MDMMotionCurve MDMMotionCurveMakeBezier(CGFloat p1x, CGFloat p1y, CGFloat p2x, CGFloat p2y) {
+  return _MDMBezier(p1x, p1y, p2x, p2y);
+}
+
+MDMMotionCurve MDMMotionCurveMakeSpring(CGFloat mass, CGFloat tension, CGFloat friction) {
+  return MDMMotionCurveMakeSpringWithInitialVelocity(mass, tension, friction, 0);
+}
+
+MDMMotionCurve MDMMotionCurveMakeSpringWithInitialVelocity(CGFloat mass,
+                                                           CGFloat tension,
+                                                           CGFloat friction,
+                                                           CGFloat initialVelocity) {
+  return _MDMSpringWithInitialVelocity(mass, tension, friction, initialVelocity);
+}
+
+MDMMotionCurve MDMMotionCurveFromTimingFunction(CAMediaTimingFunction *timingFunction) {
+  float pt1[2];
+  float pt2[2];
+  [timingFunction getControlPointAtIndex:1 values:pt1];
+  [timingFunction getControlPointAtIndex:2 values:pt2];
+  return MDMMotionCurveMakeBezier(pt1[0], pt1[1], pt2[0], pt2[1]);
+}
+
+MDMMotionCurve MDMMotionCurveReversedBezier(MDMMotionCurve motionCurve) {
+  MDMMotionCurve reversed = motionCurve;
+  if (motionCurve.type == MDMMotionCurveTypeBezier) {
+    reversed.data[0] = 1 - motionCurve.data[2];
+    reversed.data[1] = 1 - motionCurve.data[3];
+    reversed.data[2] = 1 - motionCurve.data[0];
+    reversed.data[3] = 1 - motionCurve.data[1];
+  }
+  return reversed;
+}

src/MDMMotionRepetition.h

@@ -0,0 +1,70 @@
+/*
+ Copyright 2017-present The Material Motion 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 <CoreGraphics/CoreGraphics.h>
+#import <Foundation/Foundation.h>
+
+/**
+ The possible kinds of repetition that can be used to describe an animation.
+ */
+typedef NS_ENUM(NSUInteger, MDMMotionRepetitionType) {
+  /**
+   The animation will be not be repeated.
+   */
+  MDMMotionRepetitionTypeNone,
+
+  /**
+   The animation will be repeated a given number of times.
+   */
+  MDMMotionRepetitionTypeCount,
+
+  /**
+   The animation will be repeated for a given number of seconds.
+   */
+  MDMMotionRepetitionTypeDuration,
+
+} NS_SWIFT_NAME(MotionReptitionType);
+
+/**
+ A generalized representation of a motion curve.
+ */
+struct MDMMotionRepetition {
+  /**
+   The type defines how to interpret the amount.
+   */
+  MDMMotionRepetitionType type;
+
+  /**
+   The amount of repetition.
+   */
+  double amount;
+
+  /**
+   Whether the animation should animate backwards after animating forwards.
+   */
+  BOOL autoreverses;
+
+} NS_SWIFT_NAME(MotionRepetition);
+typedef struct MDMMotionRepetition MDMMotionRepetition;
+
+// Objective-C-specific macros
+
+#define _MDMNoRepetition                 \
+  (MDMMotionRepetition) {                \
+    .type = MDMMotionRepetitionTypeNone, \
+    .amount = 0,                         \
+    .autoreverses = false                \
+  }

src/MDMMotionTiming.h

@@ -0,0 +1,48 @@
+/*
+ Copyright 2017-present The Material Motion 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 <CoreGraphics/CoreGraphics.h>
+#import <Foundation/Foundation.h>
+
+#import "MDMMotionCurve.h"
+#import "MDMMotionRepetition.h"
+
+/**
+ A representation of timing for an animation.
+ */
+struct MDMMotionTiming {
+  /**
+   The amount of time, in seconds, before this animation's value interpolation should begin.
+   */
+  CFTimeInterval delay;
+
+  /**
+   The amount of time, in seconds, over which this animation should interpolate between its values.
+   */
+  CFTimeInterval duration;
+
+  /**
+   The velocity and acceleration of the animation over time.
+   */
+  MDMMotionCurve curve;
+
+  /**
+   The repetition characteristics of the animation.
+   */
+  MDMMotionRepetition repetition;
+
+} NS_SWIFT_NAME(MotionTiming);
+typedef struct MDMMotionTiming MDMMotionTiming;

src/MotionInterchange.h

@@ -14,6 +14,7 @@
  limitations under the License.
  */
 
+// V2 APIs
 #import "CAMediaTimingFunction+MDMTimingCurve.h"
 #import "MDMAnimationTraits.h"
 #import "MDMRepetitionTraits.h"
@@ -22,3 +23,8 @@
 #import "MDMTimingCurve.h"
 #import "MDMSpringTimingCurve.h"
 #import "MDMSpringTimingCurveGenerator.h"
+
+// V1 APIs
+#import "MDMMotionCurve.h"
+#import "MDMMotionRepetition.h"
+#import "MDMMotionTiming.h"