components/MaskedTransition/src/private/MDCMaskedTransition.m - external/github.com/material-components/material-components-ios - Git at Google

 /*
  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 <CoreGraphics/CoreGraphics.h>
 #import <QuartzCore/QuartzCore.h>

 #import "MDCMaskedTransition.h"

 #import <MotionAnimator/MotionAnimator.h>

 #import "MDCMaskedPresentationController.h"
 #import "MDCMaskedTransitionMotionForContext.h"
 #import "MDCMaskedTransitionMotionSpecs.h"

 // Math utilities

 static inline CGPoint CenterOfFrame(CGRect frame) {
   return CGPointMake(CGRectGetMidX(frame), CGRectGetMidY(frame));
 }

 static inline CGPoint AnchorPointFromPosition(CGPoint position, CGRect bounds) {
   return CGPointMake(position.x / CGRectGetWidth(bounds), position.y / CGRectGetHeight(bounds));
 }

 static inline CGRect FrameCenteredAround(CGPoint position, CGSize size) {
   return CGRectMake(position.x - size.width / 2,
                     position.y - size.height / 2,
                     size.width,
                     size.height);
 }

 static inline CGFloat LengthOfVector(CGVector vector) {
   return (CGFloat)hypot(vector.dx, vector.dy);
 }

 // TODO: Pull this out to MotionTransitioning.
 static void
 PrepareTransitionWithContext(id<UIViewControllerContextTransitioning> transitionContext,
                              MDMTransitionDirection direction) {
   UIViewController *fromViewController =
       [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
   UIView *fromView = [transitionContext viewForKey:UITransitionContextFromViewKey];
   if (fromView == nil) {
     fromView = fromViewController.view;
   }
   if (fromView != nil && fromView == fromViewController.view) {
     CGRect finalFrame = [transitionContext finalFrameForViewController:fromViewController];
     if (!CGRectIsEmpty(finalFrame)) {
       fromView.frame = finalFrame;
     }
   }

   UIViewController *toViewController =
       [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
   UIView *toView = [transitionContext viewForKey:UITransitionContextToViewKey];
   if (toView == nil) {
     toView = toViewController.view;
   }
   if (toView != nil && toView == toViewController.view) {
     CGRect finalFrame = [transitionContext finalFrameForViewController:toViewController];
     if (!CGRectIsEmpty(finalFrame)) {
       toView.frame = finalFrame;
     }

     if (toView.superview == nil) {
       switch (direction) {
         case MDMTransitionDirectionForward:
           [transitionContext.containerView addSubview:toView];
           break;

         case MDMTransitionDirectionBackward:
           [transitionContext.containerView insertSubview:toView atIndex:0];
           break;
       }
     }
   }
 }

 // TODO: Pull this out to MotionTransitioning.
 static NSArray <UIViewController *> *
 OrderedViewControllersWithTransitionContext(id<UIViewControllerContextTransitioning> transitionContext,
                                             MDMTransitionDirection direction) {

   UIViewController *fromViewController =
       [transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
   UIViewController *toViewController =
       [transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];

   if (direction == MDMTransitionDirectionForward) {
     return @[fromViewController, toViewController];
   } else {
     return @[toViewController, fromViewController];
   }
 }

 @implementation MDCMaskedTransition {
   UIView *_sourceView;
   CGFloat _initialSourceViewAlpha;
   MDMTransitionDirection _direction;
 }

 - (instancetype)initWithSourceView:(UIView *)sourceView
                          direction:(MDMTransitionDirection)direction {
   self = [super init];
   if (self) {
     _sourceView = sourceView;
     _direction = direction;
   }
   return self;
 }

 #pragma mark - UIViewControllerAnimatedTransitioning

 - (NSTimeInterval)transitionDuration:(id<UIViewControllerContextTransitioning>)transitionContext {
   NSArray<UIViewController *> *viewControllers =
       OrderedViewControllersWithTransitionContext(transitionContext, _direction);
   NSAssert([viewControllers count] == 2,
            @"Expected two view controllers to be involved in a transition.");
   if ([viewControllers count] != 2) {
     return 0;
   }
   UIViewController *presentedViewController = viewControllers[1];
   MDCMaskedTransitionMotionSpec motionSpecification =
       MDCMaskedTransitionMotionSpecForContext(transitionContext.containerView,
                                               presentedViewController);

   MDCMaskedTransitionMotionTiming motion = ((_direction == MDMTransitionDirectionForward)
                                             ? motionSpecification.expansion
                                             : motionSpecification.collapse);

   return motion.overallDuration;
 }

 - (void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext {
   PrepareTransitionWithContext(transitionContext, _direction);
   NSArray<UIViewController *> *viewControllers =
       OrderedViewControllersWithTransitionContext(transitionContext, _direction);
   NSAssert([viewControllers count] == 2,
            @"Expected two view controllers to be involved in a transition.");
   if ([viewControllers count] != 2) {
     [transitionContext completeTransition:YES];
     return;
   }
   UIViewController *presentedViewController = viewControllers[1];

   MDCMaskedTransitionMotionSpec motionSpecification =
       MDCMaskedTransitionMotionSpecForContext(transitionContext.containerView,
                                               presentedViewController);

   // Cache original state.
   // We're going to reparent the fore view, so keep this information for later.
   UIView *originalSuperview = presentedViewController.view.superview;
   const CGRect originalFrame = presentedViewController.view.frame;
   UIView *originalSourceSuperview = _sourceView.superview;
   const CGRect originalSourceFrame = _sourceView.frame;
   UIColor *originalSourceBackgroundColor = _sourceView.backgroundColor;

   // Reparent the fore view into a masked view.
   UIView *maskedView = [[UIView alloc] initWithFrame:presentedViewController.view.frame];
   {
     CGRect reparentedFrame = presentedViewController.view.frame;
     reparentedFrame.origin = CGPointZero;
     presentedViewController.view.frame = reparentedFrame;

     maskedView.layer.cornerRadius = presentedViewController.view.layer.cornerRadius;
     maskedView.clipsToBounds = presentedViewController.view.clipsToBounds;
   }
   [transitionContext.containerView addSubview:maskedView];

   UIView *floodFillView = [[UIView alloc] initWithFrame:presentedViewController.view.bounds];
   floodFillView.backgroundColor = _sourceView.backgroundColor;

   // TODO(featherless): Profile whether it's more performant to fade the flood fill out or to
   // fade the fore view in (what we're currently doing).
   [maskedView addSubview:floodFillView];
   [maskedView addSubview:presentedViewController.view];

   // All frames are assumed to be relative to the container view unless named otherwise.
   const CGRect initialSourceFrame = [_sourceView convertRect:_sourceView.bounds
                                                       toView:transitionContext.containerView];
   const CGRect finalMaskedFrame = originalFrame;
   CGRect initialMaskedFrame;
   CGPoint corner;
   const CGPoint initialSourceCenter = CenterOfFrame(initialSourceFrame);
   if (motionSpecification.isCentered) {
     initialMaskedFrame = FrameCenteredAround(initialSourceCenter, originalFrame.size);
     // Bottom right
     corner = CGPointMake(CGRectGetMaxX(initialMaskedFrame), CGRectGetMaxY(initialMaskedFrame));

   } else {
     initialMaskedFrame = CGRectMake(CGRectGetMinX(transitionContext.containerView.bounds),
                                     CGRectGetMinY(initialSourceFrame) - 20,
                                     CGRectGetWidth(originalFrame),
                                     CGRectGetHeight(originalFrame));
     if (CGRectGetMidX(initialSourceFrame) < CGRectGetMidX(initialMaskedFrame)) {
       // Middle-right
       corner = CGPointMake(CGRectGetMaxX(initialMaskedFrame), CGRectGetMidY(initialMaskedFrame));
     } else {
       // Middle-left
       corner = CGPointMake(CGRectGetMinX(initialMaskedFrame), CGRectGetMidY(initialMaskedFrame));
     }
   }

   maskedView.frame = initialMaskedFrame;
   const CGRect initialSourceFrameInMask = [maskedView convertRect:initialSourceFrame
                                                          fromView:transitionContext.containerView];

   const CGFloat initialRadius = CGRectGetWidth(_sourceView.bounds) / 2;
   const CGFloat finalRadius = LengthOfVector(CGVectorMake(initialSourceCenter.x - corner.x,
                                                           initialSourceCenter.y - corner.y));
   const CGFloat finalScale = finalRadius / initialRadius;

   CAShapeLayer *shapeLayer = [[CAShapeLayer alloc] init];
   {
     // Ensures that we transform from the center of the source view's frame.
     shapeLayer.anchorPoint = AnchorPointFromPosition(CenterOfFrame(initialSourceFrameInMask),
                                                      maskedView.layer.bounds);
     shapeLayer.frame = maskedView.layer.bounds;
     shapeLayer.path = [[UIBezierPath bezierPathWithOvalInRect:initialSourceFrameInMask] CGPath];
   }
   maskedView.layer.mask = shapeLayer;

   _sourceView.frame = initialSourceFrameInMask;
   _sourceView.backgroundColor = nil;
   [maskedView addSubview:_sourceView];

   [CATransaction begin];
   [CATransaction setCompletionBlock:^{
     presentedViewController.view.frame = originalFrame;
     [originalSuperview addSubview:presentedViewController.view];

     self->_sourceView.frame = originalSourceFrame;
     self->_sourceView.backgroundColor = originalSourceBackgroundColor;
     if (motionSpecification.shouldSlideWhenCollapsed
         && transitionContext.presentationStyle != UIModalPresentationCustom) {
       // If we're going to slide when collapsed then this transition won't be invoked. If we also
       // don't have a presentation controller (because of the presentation style) then we need to
       // restore the source view's visibility somehow. This is the only place I could think of to
       // do so, but it unfortunately means if the presented view controller is somehow presented
       // such that the source view is still visible then the source view will appear to flash back
       // into existence at the end of the transition, breaking the illusion of continuity.
       self->_sourceView.alpha = 1;
     }
     [originalSourceSuperview addSubview:self->_sourceView];

     [maskedView removeFromSuperview];

     [transitionContext completeTransition:YES]; // Hand off back to UIKit
   }];

   MDCMaskedTransitionMotionTiming motion = ((_direction == MDMTransitionDirectionForward)
                                             ? motionSpecification.expansion
                                             : motionSpecification.collapse);

   MDMMotionAnimator *animator = [[MDMMotionAnimator alloc] init];
   animator.shouldReverseValues = _direction == MDMTransitionDirectionBackward;

   if (_direction == MDMTransitionDirectionForward) {
     _initialSourceViewAlpha = _sourceView.alpha;
   }

   [animator animateWithTiming:motion.iconFade
                       toLayer:_sourceView.layer
                    withValues:@[ @(_initialSourceViewAlpha), @0 ]
                       keyPath:MDMKeyPathOpacity];

   [animator animateWithTiming:motion.contentFade
                       toLayer:presentedViewController.view.layer
                    withValues:@[ @0, @1 ]
                       keyPath:MDMKeyPathOpacity];

   // TODO(featherless): Support shadow + elevation changes. May need companion transition for this?

   {
     UIColor *initialColor = floodFillView.backgroundColor;
     if (!initialColor) {
       initialColor = [UIColor clearColor];
     }
     UIColor *finalColor = presentedViewController.view.backgroundColor;
     if (!finalColor) {
       finalColor = [UIColor whiteColor];
     }
     [animator animateWithTiming:motion.floodBackgroundColor
                         toLayer:floodFillView.layer
                      withValues:@[ initialColor, finalColor ]
                         keyPath:MDMKeyPathBackgroundColor];
   }

   {
     void (^completion)(void) = nil;
     if (_direction == MDMTransitionDirectionForward) {
       completion = ^{
         // Upon completion of the animation we want all of the content to be visible, so we jump
         // to a full bounds mask.
         shapeLayer.transform = CATransform3DIdentity;
         shapeLayer.path = [[UIBezierPath bezierPathWithRect:presentedViewController.view.bounds]
                            CGPath];
       };
     }
     [animator animateWithTiming:motion.maskTransformation
                         toLayer:shapeLayer
                      withValues:@[ @1, @(finalScale) ]
                         keyPath:MDMKeyPathScale
                      completion:completion];
   }

   [animator animateWithTiming:motion.horizontalMovement
                       toLayer:maskedView.layer
                    withValues:@[ @(CGRectGetMidX(initialMaskedFrame)),
                                  @(CGRectGetMidX(finalMaskedFrame)) ]
                       keyPath:MDMKeyPathX];

   [animator animateWithTiming:motion.verticalMovement
                       toLayer:maskedView.layer
                    withValues:@[ @(CGRectGetMidY(initialMaskedFrame)),
                                  @(CGRectGetMidY(finalMaskedFrame)) ]
                       keyPath:MDMKeyPathY];

   [CATransaction commit];
 }

 @end
	/*
	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 <CoreGraphics/CoreGraphics.h>
	#import <QuartzCore/QuartzCore.h>

	#import "MDCMaskedTransition.h"

	#import <MotionAnimator/MotionAnimator.h>

	#import "MDCMaskedPresentationController.h"
	#import "MDCMaskedTransitionMotionForContext.h"
	#import "MDCMaskedTransitionMotionSpecs.h"

	// Math utilities

	static inline CGPoint CenterOfFrame(CGRect frame) {
	return CGPointMake(CGRectGetMidX(frame), CGRectGetMidY(frame));
	}

	static inline CGPoint AnchorPointFromPosition(CGPoint position, CGRect bounds) {
	return CGPointMake(position.x / CGRectGetWidth(bounds), position.y / CGRectGetHeight(bounds));
	}

	static inline CGRect FrameCenteredAround(CGPoint position, CGSize size) {
	return CGRectMake(position.x - size.width / 2,
	position.y - size.height / 2,
	size.width,
	size.height);
	}

	static inline CGFloat LengthOfVector(CGVector vector) {
	return (CGFloat)hypot(vector.dx, vector.dy);
	}

	// TODO: Pull this out to MotionTransitioning.
	static void
	PrepareTransitionWithContext(id<UIViewControllerContextTransitioning> transitionContext,
	MDMTransitionDirection direction) {
	UIViewController *fromViewController =
	[transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
	UIView *fromView = [transitionContext viewForKey:UITransitionContextFromViewKey];
	if (fromView == nil) {
	fromView = fromViewController.view;
	}
	if (fromView != nil && fromView == fromViewController.view) {
	CGRect finalFrame = [transitionContext finalFrameForViewController:fromViewController];
	if (!CGRectIsEmpty(finalFrame)) {
	fromView.frame = finalFrame;
	}
	}

	UIViewController *toViewController =
	[transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];
	UIView *toView = [transitionContext viewForKey:UITransitionContextToViewKey];
	if (toView == nil) {
	toView = toViewController.view;
	}
	if (toView != nil && toView == toViewController.view) {
	CGRect finalFrame = [transitionContext finalFrameForViewController:toViewController];
	if (!CGRectIsEmpty(finalFrame)) {
	toView.frame = finalFrame;
	}

	if (toView.superview == nil) {
	switch (direction) {
	case MDMTransitionDirectionForward:
	[transitionContext.containerView addSubview:toView];
	break;

	case MDMTransitionDirectionBackward:
	[transitionContext.containerView insertSubview:toView atIndex:0];
	break;
	}
	}
	}
	}

	// TODO: Pull this out to MotionTransitioning.
	static NSArray <UIViewController >
	OrderedViewControllersWithTransitionContext(id<UIViewControllerContextTransitioning> transitionContext,
	MDMTransitionDirection direction) {

	UIViewController *fromViewController =
	[transitionContext viewControllerForKey:UITransitionContextFromViewControllerKey];
	UIViewController *toViewController =
	[transitionContext viewControllerForKey:UITransitionContextToViewControllerKey];

	if (direction == MDMTransitionDirectionForward) {
	return @[fromViewController, toViewController];
	} else {
	return @[toViewController, fromViewController];
	}
	}

	@implementation MDCMaskedTransition {
	UIView *_sourceView;
	CGFloat _initialSourceViewAlpha;
	MDMTransitionDirection _direction;
	}

	- (instancetype)initWithSourceView:(UIView *)sourceView
	direction:(MDMTransitionDirection)direction {
	self = [super init];
	if (self) {
	_sourceView = sourceView;
	_direction = direction;
	}
	return self;
	}

	#pragma mark - UIViewControllerAnimatedTransitioning

	- (NSTimeInterval)transitionDuration:(id<UIViewControllerContextTransitioning>)transitionContext {
	NSArray<UIViewController > viewControllers =
	OrderedViewControllersWithTransitionContext(transitionContext, _direction);
	NSAssert([viewControllers count] == 2,
	@"Expected two view controllers to be involved in a transition.");
	if ([viewControllers count] != 2) {
	return 0;
	}
	UIViewController *presentedViewController = viewControllers[1];
	MDCMaskedTransitionMotionSpec motionSpecification =
	MDCMaskedTransitionMotionSpecForContext(transitionContext.containerView,
	presentedViewController);

	MDCMaskedTransitionMotionTiming motion = ((_direction == MDMTransitionDirectionForward)
	? motionSpecification.expansion
	: motionSpecification.collapse);

	return motion.overallDuration;
	}

	- (void)animateTransition:(id<UIViewControllerContextTransitioning>)transitionContext {
	PrepareTransitionWithContext(transitionContext, _direction);
	NSArray<UIViewController > viewControllers =
	OrderedViewControllersWithTransitionContext(transitionContext, _direction);
	NSAssert([viewControllers count] == 2,
	@"Expected two view controllers to be involved in a transition.");
	if ([viewControllers count] != 2) {
	[transitionContext completeTransition:YES];
	return;
	}
	UIViewController *presentedViewController = viewControllers[1];

	MDCMaskedTransitionMotionSpec motionSpecification =
	MDCMaskedTransitionMotionSpecForContext(transitionContext.containerView,
	presentedViewController);

	// Cache original state.
	// We're going to reparent the fore view, so keep this information for later.
	UIView *originalSuperview = presentedViewController.view.superview;
	const CGRect originalFrame = presentedViewController.view.frame;
	UIView *originalSourceSuperview = _sourceView.superview;
	const CGRect originalSourceFrame = _sourceView.frame;
	UIColor *originalSourceBackgroundColor = _sourceView.backgroundColor;

	// Reparent the fore view into a masked view.
	UIView *maskedView = [[UIView alloc] initWithFrame:presentedViewController.view.frame];
	{
	CGRect reparentedFrame = presentedViewController.view.frame;
	reparentedFrame.origin = CGPointZero;
	presentedViewController.view.frame = reparentedFrame;

	maskedView.layer.cornerRadius = presentedViewController.view.layer.cornerRadius;
	maskedView.clipsToBounds = presentedViewController.view.clipsToBounds;
	}
	[transitionContext.containerView addSubview:maskedView];

	UIView *floodFillView = [[UIView alloc] initWithFrame:presentedViewController.view.bounds];
	floodFillView.backgroundColor = _sourceView.backgroundColor;

	// TODO(featherless): Profile whether it's more performant to fade the flood fill out or to
	// fade the fore view in (what we're currently doing).
	[maskedView addSubview:floodFillView];
	[maskedView addSubview:presentedViewController.view];

	// All frames are assumed to be relative to the container view unless named otherwise.
	const CGRect initialSourceFrame = [_sourceView convertRect:_sourceView.bounds
	toView:transitionContext.containerView];
	const CGRect finalMaskedFrame = originalFrame;
	CGRect initialMaskedFrame;
	CGPoint corner;
	const CGPoint initialSourceCenter = CenterOfFrame(initialSourceFrame);
	if (motionSpecification.isCentered) {
	initialMaskedFrame = FrameCenteredAround(initialSourceCenter, originalFrame.size);
	// Bottom right
	corner = CGPointMake(CGRectGetMaxX(initialMaskedFrame), CGRectGetMaxY(initialMaskedFrame));

	} else {
	initialMaskedFrame = CGRectMake(CGRectGetMinX(transitionContext.containerView.bounds),
	CGRectGetMinY(initialSourceFrame) - 20,
	CGRectGetWidth(originalFrame),
	CGRectGetHeight(originalFrame));
	if (CGRectGetMidX(initialSourceFrame) < CGRectGetMidX(initialMaskedFrame)) {
	// Middle-right
	corner = CGPointMake(CGRectGetMaxX(initialMaskedFrame), CGRectGetMidY(initialMaskedFrame));
	} else {
	// Middle-left
	corner = CGPointMake(CGRectGetMinX(initialMaskedFrame), CGRectGetMidY(initialMaskedFrame));
	}
	}

	maskedView.frame = initialMaskedFrame;
	const CGRect initialSourceFrameInMask = [maskedView convertRect:initialSourceFrame
	fromView:transitionContext.containerView];

	const CGFloat initialRadius = CGRectGetWidth(_sourceView.bounds) / 2;
	const CGFloat finalRadius = LengthOfVector(CGVectorMake(initialSourceCenter.x - corner.x,
	initialSourceCenter.y - corner.y));
	const CGFloat finalScale = finalRadius / initialRadius;

	CAShapeLayer *shapeLayer = [[CAShapeLayer alloc] init];
	{
	// Ensures that we transform from the center of the source view's frame.
	shapeLayer.anchorPoint = AnchorPointFromPosition(CenterOfFrame(initialSourceFrameInMask),
	maskedView.layer.bounds);
	shapeLayer.frame = maskedView.layer.bounds;
	shapeLayer.path = [[UIBezierPath bezierPathWithOvalInRect:initialSourceFrameInMask] CGPath];
	}
	maskedView.layer.mask = shapeLayer;

	_sourceView.frame = initialSourceFrameInMask;
	_sourceView.backgroundColor = nil;
	[maskedView addSubview:_sourceView];

	[CATransaction begin];
	[CATransaction setCompletionBlock:^{
	presentedViewController.view.frame = originalFrame;
	[originalSuperview addSubview:presentedViewController.view];

	self->_sourceView.frame = originalSourceFrame;
	self->_sourceView.backgroundColor = originalSourceBackgroundColor;
	if (motionSpecification.shouldSlideWhenCollapsed
	&& transitionContext.presentationStyle != UIModalPresentationCustom) {
	// If we're going to slide when collapsed then this transition won't be invoked. If we also
	// don't have a presentation controller (because of the presentation style) then we need to
	// restore the source view's visibility somehow. This is the only place I could think of to
	// do so, but it unfortunately means if the presented view controller is somehow presented
	// such that the source view is still visible then the source view will appear to flash back
	// into existence at the end of the transition, breaking the illusion of continuity.
	self->_sourceView.alpha = 1;
	}
	[originalSourceSuperview addSubview:self->_sourceView];

	[maskedView removeFromSuperview];

	[transitionContext completeTransition:YES]; // Hand off back to UIKit
	}];

	MDCMaskedTransitionMotionTiming motion = ((_direction == MDMTransitionDirectionForward)
	? motionSpecification.expansion
	: motionSpecification.collapse);

	MDMMotionAnimator *animator = [[MDMMotionAnimator alloc] init];
	animator.shouldReverseValues = _direction == MDMTransitionDirectionBackward;

	if (_direction == MDMTransitionDirectionForward) {
	_initialSourceViewAlpha = _sourceView.alpha;
	}

	[animator animateWithTiming:motion.iconFade
	toLayer:_sourceView.layer
	withValues:@[ @(_initialSourceViewAlpha), @0 ]
	keyPath:MDMKeyPathOpacity];

	[animator animateWithTiming:motion.contentFade
	toLayer:presentedViewController.view.layer
	withValues:@[ @0, @1 ]
	keyPath:MDMKeyPathOpacity];

	// TODO(featherless): Support shadow + elevation changes. May need companion transition for this?

	{
	UIColor *initialColor = floodFillView.backgroundColor;
	if (!initialColor) {
	initialColor = [UIColor clearColor];
	}
	UIColor *finalColor = presentedViewController.view.backgroundColor;
	if (!finalColor) {
	finalColor = [UIColor whiteColor];
	}
	[animator animateWithTiming:motion.floodBackgroundColor
	toLayer:floodFillView.layer
	withValues:@[ initialColor, finalColor ]
	keyPath:MDMKeyPathBackgroundColor];
	}

	{
	void (^completion)(void) = nil;
	if (_direction == MDMTransitionDirectionForward) {
	completion = ^{
	// Upon completion of the animation we want all of the content to be visible, so we jump
	// to a full bounds mask.
	shapeLayer.transform = CATransform3DIdentity;
	shapeLayer.path = [[UIBezierPath bezierPathWithRect:presentedViewController.view.bounds]
	CGPath];
	};
	}
	[animator animateWithTiming:motion.maskTransformation
	toLayer:shapeLayer
	withValues:@[ @1, @(finalScale) ]
	keyPath:MDMKeyPathScale
	completion:completion];
	}

	[animator animateWithTiming:motion.horizontalMovement
	toLayer:maskedView.layer
	withValues:@[ @(CGRectGetMidX(initialMaskedFrame)),
	@(CGRectGetMidX(finalMaskedFrame)) ]
	keyPath:MDMKeyPathX];

	[animator animateWithTiming:motion.verticalMovement
	toLayer:maskedView.layer
	withValues:@[ @(CGRectGetMidY(initialMaskedFrame)),
	@(CGRectGetMidY(finalMaskedFrame)) ]
	keyPath:MDMKeyPathY];

	[CATransaction commit];
	}

	@end