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//
// IFTTTAnimatedPagingScrollViewController.m
// JazzHands
//
// Created by Laura Skelton on 6/18/15.
// Copyright (c) 2015 IFTTT Inc. All rights reserved.
//
#import "IFTTTAnimatedPagingScrollViewController.h"
#import "IFTTTAnimator.h"
#import "IFTTTScrollViewPageConstraintAnimation.h"
@interface IFTTTAnimatedPagingScrollViewController ()
@property (nonatomic, strong) NSMutableArray *scrollViewPageConstraintAnimations;
@end
@implementation IFTTTAnimatedPagingScrollViewController
- (instancetype)init
{
if ((self = [super init])) {
[self commonInit];
}
return self;
}
- (instancetype)initWithCoder:(NSCoder *)aDecoder
{
if ((self = [super initWithCoder:aDecoder])) {
[self commonInit];
}
return self;
}
- (instancetype)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
if ((self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil])) {
[self commonInit];
}
return self;
}
- (void)commonInit
{
_scrollViewPageConstraintAnimations = [NSMutableArray array];
_animator = [IFTTTAnimator new];
_scrollView = [UIScrollView new];
_contentView = [UIView new];
[self updatePageOffset];
}
- (NSUInteger)numberOfPages
{
return 2;
}
- (void)viewDidLoad
{
[super viewDidLoad];
[self.view addSubview:self.scrollView];
self.scrollView.frame = self.view.bounds;
self.scrollView.pagingEnabled = YES;
self.scrollView.showsHorizontalScrollIndicator = NO;
self.scrollView.delegate = self;
[self.scrollView addSubview:self.contentView];
self.scrollView.translatesAutoresizingMaskIntoConstraints = NO;
self.contentView.translatesAutoresizingMaskIntoConstraints = NO;
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|[scrollView]|" options:0 metrics: 0 views:@{ @"scrollView" : self.scrollView }]];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[scrollView]|" options:0 metrics: 0 views:@{ @"scrollView" : self.scrollView }]];
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:self.scrollView attribute:NSLayoutAttributeLeft relatedBy:NSLayoutRelationEqual toItem:self.contentView attribute:NSLayoutAttributeLeft multiplier:1.f constant:0.f]];
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:self.scrollView attribute:NSLayoutAttributeRight relatedBy:NSLayoutRelationEqual toItem:self.contentView attribute:NSLayoutAttributeRight multiplier:1.f constant:0.f]];
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:self.scrollView attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem:self.contentView attribute:NSLayoutAttributeTop multiplier:1.f constant:0.f]];
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:self.scrollView attribute:NSLayoutAttributeBottom relatedBy:NSLayoutRelationEqual toItem:self.contentView attribute:NSLayoutAttributeBottom multiplier:1.f constant:0.f]];
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:self.contentView attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeWidth multiplier:(CGFloat)self.numberOfPages constant:0.f]];
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:self.contentView attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeHeight multiplier:1.f constant:0.f]];
}
- (void)viewDidAppear:(BOOL)animated
{
[super viewDidAppear:animated];
for (IFTTTScrollViewPageConstraintAnimation *animation in self.scrollViewPageConstraintAnimations) {
animation.pageWidth = self.pageWidth;
}
[self setPageOffset:self.pageOffset];
[self animateCurrentFrame];
}
#pragma mark - iOS8+ Resizing
- (void)viewWillTransitionToSize:(CGSize)size withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator
{
[super viewWillTransitionToSize:size withTransitionCoordinator:coordinator];
CGFloat newPageWidth = size.width;
for (IFTTTScrollViewPageConstraintAnimation *animation in self.scrollViewPageConstraintAnimations) {
animation.pageWidth = newPageWidth;
}
CGFloat futurePixelOffset = self.pageOffset * newPageWidth;
[coordinator animateAlongsideTransition:^(id<UIViewControllerTransitionCoordinatorContext> context) {
[self animateCurrentFrame];
[self.scrollView setContentOffset:CGPointMake(futurePixelOffset, 0.f)];
} completion:nil];
}
#pragma mark - iOS7 Orientation Change Resizing
- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration
{
CGFloat newPageWidth;
if ((UIInterfaceOrientationIsLandscape(self.interfaceOrientation)
&& UIInterfaceOrientationIsPortrait(toInterfaceOrientation))
|| (UIInterfaceOrientationIsPortrait(self.interfaceOrientation)
&& UIInterfaceOrientationIsLandscape(toInterfaceOrientation))) {
newPageWidth = CGRectGetHeight(self.scrollView.frame);
} else {
newPageWidth = CGRectGetWidth(self.scrollView.frame);
}
for (IFTTTScrollViewPageConstraintAnimation *animation in self.scrollViewPageConstraintAnimations) {
animation.pageWidth = newPageWidth;
}
CGFloat futurePixelOffset = self.pageOffset * newPageWidth;
[UIView animateWithDuration:duration animations:^{
[self animateCurrentFrame];
[self.scrollView setContentOffset:CGPointMake(futurePixelOffset, 0.f)];
} completion:^(BOOL finished){
[UIView animateWithDuration:0.1f
animations:^{
[self animateCurrentFrame];
}];
}];
}
#pragma mark - Page Offset
- (void)setPageOffset:(CGFloat)pageOffset
{
if (pageOffset < 0.f || pageOffset > (CGFloat) ([self numberOfPages] - 1)) {
return;
}
_pageOffset = pageOffset;
self.scrollView.contentOffset = CGPointMake(self.pageWidth * pageOffset, 0.f);
[self animateCurrentFrame];
}
- (void)updatePageOffset
{
if (self.pageWidth > 0.f) {
CGFloat currentOffset = self.scrollView.contentOffset.x;
currentOffset = currentOffset / self.pageWidth;
_pageOffset = currentOffset;
} else {
_pageOffset = 0.f;
}
}
#pragma mark - Scroll View
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
[self updatePageOffset];
[self animateCurrentFrame];
}
- (void)animateCurrentFrame
{
[self.animator animate:self.pageOffset];
}
- (CGFloat)pageWidth
{
return CGRectGetWidth(self.scrollView.frame);
}
#pragma mark - Keep View On Page Animations
- (void)keepView:(UIView *)view onPage:(CGFloat)page
{
[self keepView:view onPage:page withAttribute:IFTTTHorizontalPositionAttributeCenterX];
}
- (void)keepView:(UIView *)view onPage:(CGFloat)page withAttribute:(IFTTTHorizontalPositionAttribute)attribute
{
[self keepView:view onPage:page withAttribute:attribute offset:0.f];
}
- (void)keepView:(UIView *)view onPage:(CGFloat)page withAttribute:(IFTTTHorizontalPositionAttribute)attribute offset:(CGFloat)offset
{
view.translatesAutoresizingMaskIntoConstraints = NO;
[self.contentView addConstraint:[NSLayoutConstraint constraintWithItem:view
attribute:[self layoutAttributeFromPositionAttribute:attribute]
relatedBy:NSLayoutRelationEqual
toItem:self.contentView
attribute:NSLayoutAttributeCenterX
multiplier:[self multiplierForPage:page withAttribute:attribute]
constant:offset]];
}
- (void)keepView:(UIView *)view onPages:(NSArray *)pages
{
[self keepView:view onPages:pages atTimes:pages];
}
- (void)keepView:(UIView *)view onPages:(NSArray *)pages atTimes:(NSArray *)times
{
[self keepView:view onPages:pages atTimes:times withAttribute:IFTTTHorizontalPositionAttributeCenterX];
}
- (void)keepView:(UIView *)view onPages:(NSArray *)pages withAttribute:(IFTTTHorizontalPositionAttribute)attribute
{
[self keepView:view onPages:pages atTimes:pages withAttribute:attribute];
}
- (void)keepView:(UIView *)view onPages:(NSArray *)pages atTimes:(NSArray *)times withAttribute:(IFTTTHorizontalPositionAttribute)attribute
{
[self keepView:view onPages:pages atTimes:times withAttribute:attribute offset:0.f];
}
- (void)keepView:(UIView *)view onPages:(NSArray *)pages withAttribute:(IFTTTHorizontalPositionAttribute)attribute offset:(CGFloat)offset
{
[self keepView:view onPages:pages atTimes:pages withAttribute:attribute offset:offset];
}
- (void)keepView:(UIView *)view onPages:(NSArray *)pages atTimes:(NSArray *)times withAttribute:(IFTTTHorizontalPositionAttribute)attribute offset:(CGFloat)offset
{
NSAssert((pages.count == times.count), @"Make sure you set a time for each position.");
view.translatesAutoresizingMaskIntoConstraints = NO;
NSLayoutConstraint *xPositionConstraint = [NSLayoutConstraint constraintWithItem:view
attribute:[self layoutAttributeFromPositionAttribute:attribute]
relatedBy:NSLayoutRelationEqual
toItem:self.contentView
attribute:NSLayoutAttributeLeft
multiplier:1.f
constant:offset];
[self.contentView addConstraint:xPositionConstraint];
// TODO: set constraint type for animation initializer
IFTTTScrollViewPageConstraintAnimation *xPositionAnimation = [IFTTTScrollViewPageConstraintAnimation animationWithSuperview:self.contentView
constraint:xPositionConstraint
pageWidth:self.pageWidth
attribute:attribute];
for (NSUInteger i = 0; i < pages.count; i++) {
[xPositionAnimation addKeyframeForTime:(CGFloat)[(NSNumber *)times[i] floatValue]
page:(CGFloat)[(NSNumber *)pages[i] floatValue]];
}
[self.animator addAnimation:xPositionAnimation];
[self.scrollViewPageConstraintAnimations addObject:xPositionAnimation];
}
- (void)keepView:(UIView *)view onPages:(NSArray *)pages withAttribute:(IFTTTHorizontalPositionAttribute)attribute offsets:(NSArray *)offsets
{
[self keepView:view onPages:pages atTimes:pages withOffsets:offsets withAttribute:attribute];
}
- (void)keepView:(UIView *)view onPages:(NSArray *)pages atTimes:(NSArray *)times withOffsets:(NSArray *)offsets withAttribute:(IFTTTHorizontalPositionAttribute)attribute
{
NSAssert((pages.count == times.count) && (pages.count == offsets.count), @"Make sure you set a time and offset for each position.");
view.translatesAutoresizingMaskIntoConstraints = NO;
NSLayoutConstraint *xPositionConstraint = [NSLayoutConstraint constraintWithItem:view
attribute:[self layoutAttributeFromPositionAttribute:attribute]
relatedBy:NSLayoutRelationEqual
toItem:self.contentView
attribute:NSLayoutAttributeLeft
multiplier:1.f
constant:0.f];
[self.contentView addConstraint:xPositionConstraint];
// TODO: set constraint type for animation initializer
IFTTTScrollViewPageConstraintAnimation *xPositionAnimation = [IFTTTScrollViewPageConstraintAnimation animationWithSuperview:self.contentView
constraint:xPositionConstraint
pageWidth:self.pageWidth
attribute:attribute];
for (NSUInteger i = 0; i < pages.count; i++) {
[xPositionAnimation addKeyframeForTime:(CGFloat)[(NSNumber *)times[i] floatValue]
page:(CGFloat)[(NSNumber *)pages[i] floatValue]
constant:(CGFloat)[(NSNumber *)offsets[i] floatValue]];
}
[self.animator addAnimation:xPositionAnimation];
[self.scrollViewPageConstraintAnimations addObject:xPositionAnimation];
}
- (CGFloat)centerXMultiplierForPage:(CGFloat)page
{
return [self multiplierForPage:page withAttribute:IFTTTHorizontalPositionAttributeCenterX];
}
- (CGFloat)leftMultiplierForPage:(CGFloat)page
{
return [self multiplierForPage:page withAttribute:IFTTTHorizontalPositionAttributeLeft];
}
- (CGFloat)rightMultiplierForPage:(CGFloat)page
{
return [self multiplierForPage:page withAttribute:IFTTTHorizontalPositionAttributeRight];
}
- (CGFloat)multiplierForPage:(CGFloat)page withAttribute:(IFTTTHorizontalPositionAttribute)attribute
{
CGFloat offset;
switch (attribute) {
case IFTTTHorizontalPositionAttributeCenterX:
offset = 0.5;
break;
case IFTTTHorizontalPositionAttributeLeft:
offset = 0;
break;
case IFTTTHorizontalPositionAttributeRight:
offset = 1;
break;
}
return 2.f * (offset + page) / self.numberOfPages;
}
- (NSLayoutAttribute)layoutAttributeFromPositionAttribute:(IFTTTHorizontalPositionAttribute)attribute
{
NSLayoutAttribute layoutAttribute;
switch (attribute) {
case IFTTTHorizontalPositionAttributeCenterX:
layoutAttribute = NSLayoutAttributeCenterX;
break;
case IFTTTHorizontalPositionAttributeLeft:
layoutAttribute = NSLayoutAttributeLeft;
break;
case IFTTTHorizontalPositionAttributeRight:
layoutAttribute = NSLayoutAttributeRight;
break;
}
return layoutAttribute;
}
@end
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