Nothing Special   »   [go: up one dir, main page]
Skip to content

Instantly share code, notes, and snippets.

@thoretton-edwin

thoretton-edwin/GalleryImageViewCell.h

Last active April 7, 2016 12:18
Show Gist options
  • Save thoretton-edwin/2eaa6584edeba6290d47 to your computer and use it in GitHub Desktop.
Save thoretton-edwin/2eaa6584edeba6290d47 to your computer and use it in GitHub Desktop.
Download ZIP
Gallery with zoom & snap
Raw
constraint.text
View Hierarchy :
Collection
> ViewCell for landscape mode
>ScrollView
> ViewCell for portrait mode
>ScrollView
Constraints :
ScrollView :
- Align Center X & Y to ViewCell
- Equals W & H
Raw
example.m
////////////////////////////////////////////////////////////////////////////////////////////////////
- (void)viewDidLoad {
[super viewDidLoad];
//get asset of images
//_arrayOfAsset = data with images
UICollectionSnapFlowLayout* flowLayout = (UICollectionSnapFlowLayout*)self.collection.collectionViewLayout;
[flowLayout setScrollDirection:UICollectionViewScrollDirectionHorizontal];
flowLayout.sectionInset = UIEdgeInsetsMake(0, 0, 0, 0);
flowLayout.minimumLineSpacing = 0;
flowLayout.minimumInteritemSpacing = 0;
//auto play
[self play:nil];
}
-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section{
return _arrayOfAsset.count;
}
-(NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView{
return 1;
}
////////////////////////////////////////////////////////////////////////////////////////////////////
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath{
//UI
StopAudioViewCell *cell = nil;
if(UIDeviceOrientationIsLandscape([[UIDevice currentDevice] orientation])){
cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"LandscapeScrollCellID" forIndexPath:indexPath];
}
else{
cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"PortraitScrollCellID" forIndexPath:indexPath];
}
UIImage *orginalImg = //your image
if(cell.imageView){
[cell.imageView removeFromSuperview];
}
cell.scrollView.contentInset = UIEdgeInsetsZero;
cell.imageView = [[UIImageView alloc] initWithImage:orginalImg];
cell.imageView.contentMode = UIViewContentModeCenter;
cell.scrollView.contentSize = orginalImg.size;
float widthScale = cell.frame.size.width/ orginalImg.size.width;
float heightScale = cell.frame.size.height/ orginalImg.size.height;
CGFloat minimumZoomScale = MIN(widthScale,heightScale);
cell.scrollView.minimumZoomScale= minimumZoomScale;
cell.scrollView.maximumZoomScale=minimumZoomScale + 10;
cell.scrollView.delegate=cell;
cell.scrollView.zoomScale= minimumZoomScale;
cell.scrollView.bounds = cell.bounds;
cell.scrollView.contentInset = UIEdgeInsetsZero;
//We center the contentSize with UIEdgeInset when contentSize < CellSize
CGFloat top = 0, left = 0;
if(cell.bounds.size.width > cell.scrollView.contentSize.width){
left = (cell.bounds.size.width - cell.scrollView.contentSize.width)/2;
}
cell.scrollView.contentInset = UIEdgeInsetsMake(top, left, top, left);
if(cell.bounds.size.height > cell.scrollView.contentSize.height){
top = (cell.bounds.size.height - cell.scrollView.contentSize.height)/2;
}
cell.scrollView.contentInset = UIEdgeInsetsMake(top, left, top, left);
[cell.scrollView addSubview:cell.imageView];
return cell;
}
////////////////////////////////////////////////////////////////////////////////////////////////////
- (void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation
{
[self.collection reloadData];
[self.collection.collectionViewLayout invalidateLayout];
}
////////////////////////////////////////////////////////////////////////////////////////////////////
-(CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath{
return self.collection.frame.size;
}
-(UIEdgeInsets) collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section{
return UIEdgeInsetsMake(0,0,0,0);
}
Raw
GalleryImageViewCell.h
@interface GalleryImageViewCell : UICollectionViewCell <UIScrollViewDelegate>
@property (weak, nonatomic) IBOutlet UIScrollView *scrollContainer;
@property (weak, nonatomic) IBOutlet UIImageView *imageView;
@property (weak, nonatomic) IBOutlet NSLayoutConstraint *scrollHeightLayoutConstraint;
@property (weak, nonatomic) IBOutlet NSLayoutConstraint *scrollWidthLayoutConstraint;
@end
Raw
GalleryImageViewCell.m
#import "GalleryImageViewCell.h"
@implementation GalleryImageViewCell
- (UIView *)viewForZoomingInScrollView:(UIScrollView *)scrollView
{
return self.imageView;
}
-(void)scrollViewDidEndZooming:(UIScrollView *)scrollView withView:(UIView *)view atScale:(CGFloat)scale{
self.scrollView.contentInset = UIEdgeInsetsZero;
CGFloat top = 0, left = 0;
if(self.bounds.size.height > self.scrollView.contentSize.height){
top = (self.bounds.size.height - self.scrollView.contentSize.height)/2;
}
if(self.bounds.size.width > self.scrollView.contentSize.width){
left = (self.bounds.size.width - self.scrollView.contentSize.width)/2;
}
self.scrollView.contentInset = UIEdgeInsetsMake(top, left, top, left);
}
@end
Raw
UICollectionViewFlowLayoutCenterItem.m
#import "UICollectionSnapFlowLayout.h"
@implementation UICollectionSnapFlowLayout
-(CGPoint) targetContentOffsetForProposedContentOffset:(CGPoint)proposedContentOffset withScrollingVelocity:(CGPoint)velocity
{
CGSize collectionViewSize = self.collectionView.bounds.size;
CGFloat proposedContentOffsetCenterX = proposedContentOffset.x + self.collectionView.bounds.size.width * 0.5f;
CGRect proposedRect = self.collectionView.bounds;
// Comment out if you want the collectionview simply stop at the center of an item while scrolling freely
// proposedRect = CGRectMake(proposedContentOffset.x, 0.0, collectionViewSize.width, collectionViewSize.height);
UICollectionViewLayoutAttributes* candidateAttributes;
for (UICollectionViewLayoutAttributes* attributes in [self layoutAttributesForElementsInRect:proposedRect])
{
// == Skip comparison with non-cell items (headers and footers) == //
if (attributes.representedElementCategory != UICollectionElementCategoryCell)
{
continue;
}
// == First time in the loop == //
if(!candidateAttributes)
{
candidateAttributes = attributes;
continue;
}
if (fabsf(attributes.center.x - proposedContentOffsetCenterX) < fabsf(candidateAttributes.center.x - proposedContentOffsetCenterX))
{
candidateAttributes = attributes;
}
}
return CGPointMake(candidateAttributes.center.x - self.collectionView.bounds.size.width * 0.5f, proposedContentOffset.y);
}
@end
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment