Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
branch: ios5
Fetching contributors…

Cannot retrieve contributors at this time

file 748 lines (549 sloc) 24.666 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748
//
// SSCollectionView.m
// SSToolkit
//
// Created by Sam Soffes on 6/11/10.
// Copyright 2010-2011 Sam Soffes. All rights reserved.
//

#import "SSCollectionView.h"
#import "SSCollectionViewInternal.h"
#import "SSCollectionViewItem.h"
#import "SSCollectionViewItemInternal.h"
#import "SSCollectionViewItemTableViewCell.h"
#import "SSCollectionViewExtremityTableViewCell.h"
#import "SSDrawingUtilities.h"
#import "UIView+SSToolkitAdditions.h"

typedef enum {
SSCollectionViewCellTypeRow,
SSCollectionViewCellTypeHeader,
SSCollectionViewCellTypeFooter
} SSCollectionViewCellType;

static NSString *kSSCollectionViewSectionNumberOfItemsKey = @"SSCollectionViewSectionNumberOfItems";
static NSString *kSSCollectionViewSectionNumberOfRowsKey = @"SSCollectionViewSectionNumberOfRows";
static NSString *kSSCollectionViewSectionNumberOfItemsPerRowsKey = @"SSCollectionViewSectionNumberOfItemsPerRows";
static NSString *kSSCollectionViewSectionHeaderViewKey = @"SSCollectionViewSectionHeaderView";
static NSString *kSSCollectionViewSectionFooterViewKey = @"SSCollectionViewSectionFooterView";
static NSString *kSSCollectionViewSectionHeaderHeightKey = @"SSCollectionViewSectionHeaderHeight";
static NSString *kSSCollectionViewSectionFooterHeightKey = @"SSCollectionViewSectionFooterHeight";
static NSString *kSSCollectionViewSectionItemSizeKey = @"SSCollectionViewSectionItemSize";

@interface SSCollectionView (PrivateMethods)
- (void)_reuseItem:(SSCollectionViewItem *)item;
- (void)_reuseItems:(NSArray *)items;

- (CGSize)_itemSizeForSection:(NSUInteger)section;
- (NSUInteger)_numberOfItemsPerRowForSection:(NSUInteger)section;
- (NSUInteger)_numberOfRowsInSection:(NSUInteger)section;

- (NSArray *)_itemsForRowIndexPath:(NSIndexPath *)rowIndexPath;
- (NSIndexPath *)_cellIndexPathFromItemIndexPath:(NSIndexPath *)rowIndexPath;
- (SSCollectionViewCellType)_cellTypeForRowIndexPath:(NSIndexPath *)indexPath;
- (UIView *)_extremityViewForSection:(NSUInteger)section type:(SSCollectionViewCellType)type;

- (NSMutableDictionary *)_sectionInfoForIndex:(NSUInteger)section;
- (id)_sectionInfoItemForKey:(NSString *)key section:(NSUInteger)section;
- (void)_setSectionInfoItem:(id)object forKey:(NSString *)key section:(NSUInteger)section;
@end

@implementation SSCollectionView

#pragma mark -
#pragma mark Accessors

@synthesize dataSource = _dataSource;

- (void)setDataSource:(id<SSCollectionViewDataSource>)dataSource {
_dataSource = dataSource;

if (_delegate && _dataSource) {
[self reloadData];
}
}


@synthesize delegate = _delegate;

- (void)setDelegate:(id<SSCollectionViewDelegate>)delegate {
_delegate = delegate;

if (_delegate && _dataSource) {
[self reloadData];
}
}


@synthesize minimumColumnSpacing = _minimumColumnSpacing;
@synthesize rowSpacing = _rowSpacing;
@synthesize allowsSelection = _allowsSelection;

- (UIScrollView *)scrollView {
return _tableView;
}


- (UIView *)backgroundView {
return _tableView.backgroundView;
}


- (void)setBackgroundColor:(UIColor *)color {
[super setBackgroundColor:color];
_tableView.backgroundColor = color;
}


- (void)setBackgroundView:(UIView *)background {
_tableView.backgroundView = background;
}


@synthesize extremitiesStyle = _extremitiesStyle;

- (void)setExtremitiesStyle:(SSCollectionViewExtremitiesStyle)style {
if (_extremitiesStyle == style) {
return;
}

_extremitiesStyle = style;
[self reloadData];
}


#pragma mark -
#pragma mark NSObject

- (void)dealloc {
self.dataSource = nil;
self.delegate = nil;

[_visibleItems removeAllObjects];
[_visibleItems release];
_visibleItems = nil;

[_reuseableItems removeAllObjects];
[_reuseableItems release];
_reuseableItems = nil;

_tableView.dataSource = nil;
_tableView.delegate = nil;
[_tableView release];

[_sectionCache removeAllObjects];
[_sectionCache release];
_sectionCache = nil;

[super dealloc];
}


#pragma mark -
#pragma mark UIView

- (id)initWithFrame:(CGRect)frame {
    if ((self = [super initWithFrame:frame])) {
self.backgroundColor = [UIColor whiteColor];
self.opaque = YES;

_minimumColumnSpacing = 10.0f;
_rowSpacing = 20.0f;
_allowsSelection = YES;
_visibleItems = [[NSMutableSet alloc] init];
_reuseableItems = [[NSCache alloc] init];
_sectionCache = [[NSCache alloc] init];

_tableView = [[UITableView alloc] initWithFrame:CGRectSetZeroOrigin(frame)];
_tableView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
_tableView.dataSource = self;
_tableView.delegate = self;
_tableView.separatorStyle = UITableViewCellSeparatorStyleNone;
[self addSubview:_tableView];
    }
    return self;
}


- (void)setFrame:(CGRect)frame {
[super setFrame:frame];
[_tableView reloadData];
}


#pragma mark -
#pragma mark SSCollectionView

- (void)reloadData {
[_sectionCache removeAllObjects];
[_tableView reloadData];
}


- (SSCollectionViewItem *)dequeueReusableItemWithIdentifier:(NSString *)identifier {
if (!identifier) {
return nil;
}

NSMutableArray *items = [_reuseableItems objectForKey:identifier];
if (!items || [items count] == 0) {
return nil;
}

SSCollectionViewItem *item = [[items lastObject] retain];
[items removeObject:item];

[item prepareForReuse];
return [item autorelease];
}


- (SSCollectionViewItem *)itemPathForIndex:(NSIndexPath *)indexPath {
for (SSCollectionViewItem *item in _visibleItems) {
if ([item.indexPath isEqual:indexPath]) {
return item;
}
}

return nil;
}


- (NSIndexPath *)indexPathForItem:(SSCollectionViewItem *)item {
return item.indexPath;
}


- (void)selectItemAtIndexPath:(NSIndexPath *)indexPath animated:(BOOL)animated scrollPosition:(SSCollectionViewScrollPosition)scrollPosition {
// Notify delegate that it will select
if ([self.delegate respondsToSelector:@selector(collectionView:willSelectItemAtIndexPath:)]) {
[self.delegate collectionView:self willSelectItemAtIndexPath:indexPath];
}

// Select
SSCollectionViewItem *item = [self itemPathForIndex:indexPath];
[item setHighlighted:NO animated:NO];
[item setSelected:YES animated:YES];

// Scroll to position
if (scrollPosition == SSCollectionViewScrollPositionTop || scrollPosition == SSCollectionViewScrollPositionMiddle ||
scrollPosition == SSCollectionViewScrollPositionBottom) {
[self scrollToItemAtIndexPath:indexPath atScrollPosition:scrollPosition animated:animated];
}

// Notify delegate that it did selection
if ([self.delegate respondsToSelector:@selector(collectionView:didSelectItemAtIndexPath:)]) {
[self.delegate collectionView:self didSelectItemAtIndexPath:indexPath];
}
}


- (void)deselectItemAtIndexPath:(NSIndexPath *)indexPath animated:(BOOL)animated {
// Notify delegate that it will deselect
if ([self.delegate respondsToSelector:@selector(collectionView:willDeselectItemAtIndexPath:)]) {
[self.delegate collectionView:self willDeselectItemAtIndexPath:indexPath];
}

// Deselect
SSCollectionViewItem *item = [self itemPathForIndex:indexPath];
[item setHighlighted:NO animated:NO];
[item setSelected:NO animated:YES];

// Notify delegate that it did deselection
if ([self.delegate respondsToSelector:@selector(collectionView:didDeselectItemAtIndexPath:)]) {
[self.delegate collectionView:self didDeselectItemAtIndexPath:indexPath];
}
}


- (void)scrollToItemAtIndexPath:(NSIndexPath *)indexPath atScrollPosition:(SSCollectionViewScrollPosition)scrollPosition animated:(BOOL)animated {
NSIndexPath *cellIndexPath = [self _cellIndexPathFromItemIndexPath:indexPath];
[_tableView scrollToRowAtIndexPath:cellIndexPath atScrollPosition:(UITableViewScrollPosition)scrollPosition animated:animated];
}


- (void)reloadItemsAtIndexPaths:(NSArray *)indexPaths {
NSMutableArray *rowIndexPaths = [[NSMutableArray alloc] init];
for (NSIndexPath *itemIndexPath in indexPaths) {
NSIndexPath *rowIndexPath = [self _cellIndexPathFromItemIndexPath:itemIndexPath];
if (![rowIndexPaths containsObject:rowIndexPaths]) {
[rowIndexPaths addObject:rowIndexPath];
}
}

[_tableView reloadRowsAtIndexPaths:rowIndexPaths withRowAnimation:UITableViewRowAnimationFade];
[rowIndexPaths release];
}


- (NSUInteger)numberOfSections {
if ([_dataSource respondsToSelector:@selector(numberOfSectionsInCollectionView:)]) {
return [_dataSource numberOfSectionsInCollectionView:self];
}

return 1;
}


- (NSUInteger)numberOfItemsInSection:(NSUInteger)section {
NSNumber *items = [self _sectionInfoItemForKey:kSSCollectionViewSectionNumberOfItemsKey section:section];
if (!items) {
if ([_dataSource respondsToSelector:@selector(collectionView:numberOfItemsInSection:)] == NO) {
return 0;
}
items = [NSNumber numberWithUnsignedInteger:[_dataSource collectionView:self numberOfItemsInSection:section]];
[self _setSectionInfoItem:items forKey:kSSCollectionViewSectionNumberOfItemsKey section:section];
}
return [items unsignedIntegerValue];
}


- (CGRect)rectForSection:(NSUInteger)section {
return [_tableView rectForSection:(NSInteger)section];
}


- (CGRect)rectForHeaderInSection:(NSUInteger)section {
return [_tableView rectForSection:(NSInteger)section];
}


- (CGRect)rectForFooterInSection:(NSUInteger)section {
return [_tableView rectForFooterInSection:(NSInteger)section];
}


#pragma mark -
#pragma mark Private Methods

- (void)_reuseItem:(SSCollectionViewItem *)item {
[_visibleItems removeObject:item];

if (!item.reuseIdentifier) {
NSLog(@"[SSCollectionView] Your item identifier is nil. You should really provide a reuse identifier.");
return;
}

NSMutableArray *items = [_reuseableItems objectForKey:item.reuseIdentifier];
if (!items) {
[_reuseableItems setObject:[NSMutableArray array] forKey:item.reuseIdentifier];
}

[items addObject:item];
}


- (void)_reuseItems:(NSArray *)items {
for (SSCollectionViewItem *item in items) {
[self _reuseItem:item];
}
}


- (CGSize)_itemSizeForSection:(NSUInteger)section {
NSValue *size = [self _sectionInfoItemForKey:kSSCollectionViewSectionItemSizeKey section:section];
if (size) {
return [size CGSizeValue];
}

if ([_delegate respondsToSelector:@selector(collectionView:itemSizeForSection:)] == NO) {
[[NSException exceptionWithName:kSSCollectionViewMissingItemSizeExceptionName reason:kSSCollectionViewMissingItemSizeExceptionReason userInfo:nil] raise];
return CGSizeZero;
}

CGSize itemSize = [_delegate collectionView:self itemSizeForSection:section];
[self _setSectionInfoItem:[NSValue valueWithCGSize:itemSize] forKey:kSSCollectionViewSectionItemSizeKey section:section];

return itemSize;
}


- (NSUInteger)_numberOfItemsPerRowForSection:(NSUInteger)section {
NSNumber *items = [self _sectionInfoItemForKey:kSSCollectionViewSectionNumberOfItemsPerRowsKey section:section];
if (items) {
return [items unsignedIntegerValue];
}

CGSize itemSize = [self _itemSizeForSection:section];
NSUInteger itemsPerRow = (NSUInteger)floorf(self.frame.size.width / (itemSize.width + _minimumColumnSpacing));
[self _setSectionInfoItem:[NSNumber numberWithUnsignedInteger:itemsPerRow] forKey:kSSCollectionViewSectionNumberOfItemsPerRowsKey section:section];
return itemsPerRow;
}


- (NSUInteger)_numberOfRowsInSection:(NSUInteger)section {
NSNumber *numberOfRows = [self _sectionInfoItemForKey:kSSCollectionViewSectionNumberOfRowsKey section:section];
if (numberOfRows) {
return [numberOfRows unsignedIntegerValue];
}

        NSUInteger totalItems = [self numberOfItemsInSection:section];
        NSUInteger itemsPerRow = [self _numberOfItemsPerRowForSection:section];
        
        if (itemsPerRow == 0) {
            return 0;
        }
        
        NSUInteger rows = (NSUInteger)ceilf(totalItems / itemsPerRow);
        
        // Check for headers and footers
if (_extremitiesStyle == SSCollectionViewExtremitiesStyleScrolling) {
if ([self _sectionInfoItemForKey:kSSCollectionViewSectionHeaderViewKey section:section]) {
rows++;
}

if ([self _sectionInfoItemForKey:kSSCollectionViewSectionFooterViewKey section:section]) {
rows++;
}
}

[self _setSectionInfoItem:[NSNumber numberWithUnsignedInteger:rows] forKey:kSSCollectionViewSectionNumberOfRowsKey section:section];

return [numberOfRows unsignedIntegerValue];
}


- (CGFloat)_itemSpacingForSection:(NSUInteger)section {
CGSize itemSize = [self _itemSizeForSection:section];
NSUInteger itemsPerRow = [self _numberOfItemsPerRowForSection:section];
return roundf((self.frame.size.width - (itemSize.width * (CGFloat)itemsPerRow)) / (itemsPerRow + 1));
}


- (NSArray *)_itemsForRowIndexPath:(NSIndexPath *)rowIndexPath {
NSUInteger totalItems = [self numberOfItemsInSection:rowIndexPath.section];
NSUInteger itemsPerRow = [self _numberOfItemsPerRowForSection:rowIndexPath.section];

NSUInteger row = (NSUInteger)rowIndexPath.row;

// Check for header
if (_extremitiesStyle == SSCollectionViewExtremitiesStyleScrolling &&
[self _sectionInfoItemForKey:kSSCollectionViewSectionHeaderViewKey section:rowIndexPath.section]) {
row--;
}

NSUInteger startIndex = itemsPerRow * row;
NSUInteger endIndex = (NSUInteger)fmin(totalItems, startIndex + itemsPerRow);

NSMutableArray *items = [[NSMutableArray alloc] initWithCapacity:endIndex - startIndex];

for (NSUInteger i = startIndex; i < endIndex; i++) {
NSIndexPath *itemIndexPath = [NSIndexPath indexPathForRow:i inSection:rowIndexPath.section];
SSCollectionViewItem *item = [_dataSource collectionView:self itemForIndexPath:itemIndexPath];
if (item == nil) {
NSException *exception = [NSException exceptionWithName:kSSCollectionViewNilItemExceptionName
reason:kSSCollectionViewNilItemExceptionReason userInfo:nil];
[exception raise];
return nil;
}

item.tag = (NSInteger)i;
item.indexPath = itemIndexPath;
item.collectionView = self;
[_visibleItems addObject:item];
[items addObject:item];
}

return [items autorelease];
}


- (NSIndexPath *)_cellIndexPathFromItemIndexPath:(NSIndexPath *)rowIndexPath {
NSUInteger itemsPerRow = [self _numberOfItemsPerRowForSection:rowIndexPath.section];

// Avoid division by zero
if (itemsPerRow == 0) {
return nil;
}

NSUInteger row = (NSUInteger)floor(rowIndexPath.row / itemsPerRow);
return [NSIndexPath indexPathForRow:row inSection:rowIndexPath.section];
}


- (SSCollectionViewCellType)_cellTypeForRowIndexPath:(NSIndexPath *)indexPath {
// If extremity style is fixed, everything is a row
if (_extremitiesStyle == SSCollectionViewExtremitiesStyleFixed) {
return SSCollectionViewCellTypeRow;
}

// Check for header
if (indexPath.row == 0 && [self _sectionInfoItemForKey:kSSCollectionViewSectionHeaderViewKey section:indexPath.section]) {
return SSCollectionViewCellTypeHeader;
}

// Check for footer
BOOL hasFooter = ([self _sectionInfoItemForKey:kSSCollectionViewSectionFooterViewKey section:indexPath.section] != nil);
if (hasFooter && (NSUInteger)indexPath.row == [self _numberOfRowsInSection:indexPath.section] - 1) {
return SSCollectionViewCellTypeFooter;
}

return SSCollectionViewCellTypeRow;
}


- (UIView *)_extremityViewForSection:(NSUInteger)section type:(SSCollectionViewCellType)type {
// Note: It might be good for this method to check if the cache has been set and hit the delegate if not. For now,
// we are relying on UITableView to hit the delegate in the correct order.

// Header
if (type == SSCollectionViewCellTypeHeader) {
return [self _sectionInfoItemForKey:kSSCollectionViewSectionHeaderViewKey section:section];
}

// Footer
else if (type == SSCollectionViewCellTypeFooter) {
return [self _sectionInfoItemForKey:kSSCollectionViewSectionFooterViewKey section:section];
}

return nil;
}


- (NSMutableDictionary *)_sectionInfoForIndex:(NSUInteger)section {
NSNumber *sectionKey = [NSNumber numberWithUnsignedInteger:section];
NSMutableDictionary *dictionary = [_sectionCache objectForKey:sectionKey];
if (dictionary) {
return dictionary;
}

dictionary = [[NSMutableDictionary alloc] init];
[_sectionCache setObject:dictionary forKey:sectionKey];
[dictionary release];

return dictionary;
}


- (id)_sectionInfoItemForKey:(NSString *)key section:(NSUInteger)section {
NSDictionary *dictionary = [self _sectionInfoForIndex:section];
return [dictionary objectForKey:key];
}


- (void)_setSectionInfoItem:(id)object forKey:(NSString *)key section:(NSUInteger)section {
NSMutableDictionary *dictionary = [self _sectionInfoForIndex:section];
[dictionary setObject:object forKey:key];
}


#pragma mark -
#pragma mark UITableViewDataSource

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
return (NSInteger)[self numberOfSections];
}


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
return (NSInteger)[self _numberOfRowsInSection:(NSUInteger)section];
}


- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)rowIndexPath {
static NSString *itemCellIdentifier = @"SSCollectionViewItemTableViewCellIdentifier";
static NSString *extremityCellIdentifier = @"SSCollectionViewExtremityTableViewCellIdentifier";

SSCollectionViewCellType cellType = [self _cellTypeForRowIndexPath:rowIndexPath];

// Extremities
if (cellType != SSCollectionViewCellTypeRow) {
SSCollectionViewExtremityTableViewCell *cell = (SSCollectionViewExtremityTableViewCell *)[_tableView dequeueReusableCellWithIdentifier:extremityCellIdentifier];
if (!cell) {
cell = [[[SSCollectionViewExtremityTableViewCell alloc] initWithReuseIdentifier:extremityCellIdentifier] autorelease];
}

cell.extrimityView = [self _extremityViewForSection:rowIndexPath.section type:cellType];

return cell;
}

// Normal row
SSCollectionViewItemTableViewCell *cell = (SSCollectionViewItemTableViewCell *)[_tableView dequeueReusableCellWithIdentifier:itemCellIdentifier];
if (!cell) {
cell = [[[SSCollectionViewItemTableViewCell alloc] initWithReuseIdentifier:itemCellIdentifier] autorelease];
cell.collectionView = self;
}

cell.itemSize = [self _itemSizeForSection:rowIndexPath.section];
cell.itemSpacing = [self _itemSpacingForSection:rowIndexPath.section];
cell.items = [self _itemsForRowIndexPath:rowIndexPath];

return cell;
}


#pragma mark -
#pragma mark UITableViewDelegate

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)rowIndexPath {
// If scrolling extremity style, provide the height for the extermity
if (_extremitiesStyle == SSCollectionViewExtremitiesStyleScrolling) {
SSCollectionViewCellType cellType = [self _cellTypeForRowIndexPath:rowIndexPath];

// Header
if (cellType == SSCollectionViewCellTypeHeader) {
return [[self _sectionInfoItemForKey:kSSCollectionViewSectionHeaderHeightKey section:rowIndexPath.section] floatValue];
}

// Footer
else if (cellType == SSCollectionViewCellTypeFooter) {
return [[self _sectionInfoItemForKey:kSSCollectionViewSectionFooterHeightKey section:rowIndexPath.section] floatValue];
}
}

// Row
return [self _itemSizeForSection:rowIndexPath.section].height + _rowSpacing;
}


- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section {
// If scrolling extremity style, don't use table view's header since we will draw it in a cell
if (_extremitiesStyle == SSCollectionViewExtremitiesStyleScrolling) {
// Hit delegate and cache result for use later
if ([_delegate respondsToSelector:@selector(collectionView:viewForHeaderInSection:)]) {
UIView *view = [_delegate collectionView:self viewForHeaderInSection:(NSUInteger)section];
[self _setSectionInfoItem:view forKey:kSSCollectionViewSectionHeaderViewKey section:(NSUInteger)section];
}

return nil;
}

// If the collection view's delegate provides a header, forward it to the table view
if ([_delegate respondsToSelector:@selector(collectionView:viewForHeaderInSection:)]) {
return [_delegate collectionView:self viewForHeaderInSection:(NSUInteger)section];
}

// Default to none
return nil;
}


- (CGFloat)tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section {
// If scrolling extremity style, don't use table view's header since we will draw it in a cell
if (_extremitiesStyle == SSCollectionViewExtremitiesStyleScrolling) {

// Hit delegate and cache result for use later
if ([_delegate respondsToSelector:@selector(collectionView:heightForHeaderInSection:)]) {
CGFloat height = [_delegate collectionView:self heightForHeaderInSection:(NSUInteger)section];
[self _setSectionInfoItem:[NSNumber numberWithFloat:height] forKey:kSSCollectionViewSectionHeaderHeightKey section:(NSUInteger)section];
}
return 0.0f;
}

// If the collection view's delegate provides a header height, forward it to the table view
if ([_delegate respondsToSelector:@selector(collectionView:heightForHeaderInSection:)]) {
return [_delegate collectionView:self heightForHeaderInSection:(NSUInteger)section];
}

// Default to none
return 0.0f;
}


- (UIView *)tableView:(UITableView *)tableView viewForFooterInSection:(NSInteger)section {
// If scrolling extremity style, don't use table view's footer since we will draw it in a cell
if (_extremitiesStyle == SSCollectionViewExtremitiesStyleScrolling) {

// Hit delegate and cache result for use later
if ([_delegate respondsToSelector:@selector(collectionView:viewForFooterInSection:)]) {
UIView *view = [_delegate collectionView:self viewForFooterInSection:(NSUInteger)section];
[self _setSectionInfoItem:view forKey:kSSCollectionViewSectionFooterViewKey section:(NSUInteger)section];
}
return nil;
}

// If the collection view's delegate provides a footer, forward it to the table view
if ([_delegate respondsToSelector:@selector(collectionView:viewForFooterInSection:)]) {
return [_delegate collectionView:self viewForFooterInSection:(NSUInteger)section];
}

// Default to none
return nil;
}


- (CGFloat)tableView:(UITableView *)tableView heightForFooterInSection:(NSInteger)section {
// If scrolling extremity style, don't use table view's footer since we will draw it in a cell
if (_extremitiesStyle == SSCollectionViewExtremitiesStyleScrolling) {

// Hit delegate and cache result for use later
if ([_delegate respondsToSelector:@selector(collectionView:heightForFooterInSection:)]) {
CGFloat height = [_delegate collectionView:self heightForFooterInSection:(NSUInteger)section];
[self _setSectionInfoItem:[NSNumber numberWithFloat:height] forKey:kSSCollectionViewSectionFooterHeightKey section:(NSUInteger)section];
}
return 0.0f;
}

// If the collection view's delegate provides a footer height, forward it to the table view
if ([_delegate respondsToSelector:@selector(collectionView:heightForFooterInSection:)]) {
return [_delegate collectionView:self heightForFooterInSection:(NSUInteger)section];
}

// Default to none
return 0.0f;
}


#pragma mark -
#pragma mark UIScrollViewDelegate

- (void)scrollViewDidScroll:(UIScrollView *)aScrollView {
if ([_delegate respondsToSelector:@selector(scrollViewDidScroll:)]) {
[_delegate scrollViewDidScroll:aScrollView];
}
}


- (void)scrollViewWillBeginDragging:(UIScrollView *)aScrollView {
if ([_delegate respondsToSelector:@selector(scrollViewWillBeginDragging:)]) {
[_delegate scrollViewWillBeginDragging:aScrollView];
}
}


- (void)scrollViewDidEndDragging:(UIScrollView *)aScrollView willDecelerate:(BOOL)decelerate {
if ([_delegate respondsToSelector:@selector(scrollViewDidEndDragging:willDecelerate:)]) {
[_delegate scrollViewDidEndDragging:aScrollView willDecelerate:decelerate];
}
}


- (void)scrollViewWillBeginDecelerating:(UIScrollView *)aScrollView {
if ([_delegate respondsToSelector:@selector(scrollViewWillBeginDecelerating:)]) {
[_delegate scrollViewWillBeginDecelerating:aScrollView];
}
}


- (void)scrollViewDidEndDecelerating:(UIScrollView *)aScrollView {
if ([_delegate respondsToSelector:@selector(scrollViewDidEndDecelerating:)]) {
[_delegate scrollViewDidEndDecelerating:aScrollView];
}
}


- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)aScrollView {
if ([_delegate respondsToSelector:@selector(scrollViewDidEndScrollingAnimation:)]) {
[_delegate scrollViewDidEndScrollingAnimation:aScrollView];
}
}


- (BOOL)scrollViewShouldScrollToTop:(UIScrollView *)aScrollView {
if ([_delegate respondsToSelector:@selector(scrollViewShouldScrollToTop:)]) {
return [_delegate scrollViewShouldScrollToTop:aScrollView];
}

return YES;
}


- (void)scrollViewDidScrollToTop:(UIScrollView *)aScrollView {
if ([_delegate respondsToSelector:@selector(scrollViewDidScrollToTop:)]) {
[_delegate scrollViewDidScrollToTop:aScrollView];
}
}

@end
Something went wrong with that request. Please try again.