element-ios/Riot/Modules/MediaPicker/Library/MediaAlbumContentViewController.m

/*
Copyright 2024 New Vector Ltd.
Copyright 2017 Vector Creations Ltd
Copyright 2015 OpenMarket Ltd

SPDX-License-Identifier: AGPL-3.0-only
Please see LICENSE in the repository root for full details.
 */

#import "MediaAlbumContentViewController.h"

#import <MobileCoreServices/MobileCoreServices.h>

#import "GeneratedInterface-Swift.h"

@interface MediaAlbumContentViewController ()
{
    /**
     Observe UIApplicationWillEnterForegroundNotification to refresh bubbles when app leaves the background state.
     */
    id UIApplicationWillEnterForegroundNotificationObserver;
    
    /**
     The current list of assets retrieved from collection.
     */
    PHFetchResult *assets;

    /**
     The currently selected media. Nil when the multiselection is not active.
     */
    NSMutableArray <PHAsset*> *selectedAssets;
    
    /**
     Observe kThemeServiceDidChangeThemeNotification to handle user interface theme change.
     */
    id kThemeServiceDidChangeThemeNotificationObserver;
}

@end

@implementation MediaAlbumContentViewController

#pragma mark - Class methods

+ (UINib *)nib
{
    return [UINib nibWithNibName:NSStringFromClass([MediaAlbumContentViewController class])
                          bundle:[NSBundle bundleForClass:[MediaAlbumContentViewController class]]];
}

+ (instancetype)mediaAlbumContentViewController
{
    return [[[self class] alloc] initWithNibName:NSStringFromClass([MediaAlbumContentViewController class])
                                          bundle:[NSBundle bundleForClass:[MediaAlbumContentViewController class]]];
}

#pragma mark -

- (void)finalizeInit
{
    [super finalizeInit];
    
    // Setup `MXKViewControllerHandling` properties
    self.enableBarTintColorStatusChange = NO;
    self.rageShakeManager = [RageShakeManager sharedManager];
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    // Register collection view cell class
    [self.assetsCollectionView registerClass:MXKMediaCollectionViewCell.class forCellWithReuseIdentifier:[MXKMediaCollectionViewCell defaultReuseIdentifier]];
    
    if (!_mediaTypes)
    {
        // Set default media type
        self.mediaTypes = @[(NSString *)kUTTypeImage];
    }
    
    MXWeakify(self);
    
    // Observe UIApplicationWillEnterForegroundNotification to refresh captures collection when app leaves the background state.
    UIApplicationWillEnterForegroundNotificationObserver = [[NSNotificationCenter defaultCenter] addObserverForName:UIApplicationWillEnterForegroundNotification object:nil queue:[NSOperationQueue mainQueue] usingBlock:^(NSNotification *notif) {
        
        MXStrongifyAndReturnIfNil(self);
        
        // Force a full refresh of the displayed collection
        self.assetsCollection = self->_assetsCollection;
        
    }];

    if (_allowsMultipleSelection)
    {
        self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:[VectorL10n mediaPickerSelect] style:UIBarButtonItemStylePlain target:self action:@selector(onSelect:)];
    }
    
    // Observe user interface theme change.
    kThemeServiceDidChangeThemeNotificationObserver = [[NSNotificationCenter defaultCenter] addObserverForName:kThemeServiceDidChangeThemeNotification object:nil queue:[NSOperationQueue mainQueue] usingBlock:^(NSNotification *notif) {
        
        MXStrongifyAndReturnIfNil(self);
        
        [self userInterfaceThemeDidChange];
        
    }];
    [self userInterfaceThemeDidChange];
}

- (void)userInterfaceThemeDidChange
{
    [ThemeService.shared.theme applyStyleOnNavigationBar:self.navigationController.navigationBar];

    self.assetsCollectionView.backgroundColor = ThemeService.shared.theme.backgroundColor;
    self.activityIndicator.backgroundColor = ThemeService.shared.theme.overlayBackgroundColor;

    [self setNeedsStatusBarAppearanceUpdate];
}

- (UIStatusBarStyle)preferredStatusBarStyle
{
    return ThemeService.shared.theme.statusBarStyle;
}

- (BOOL)prefersStatusBarHidden
{
    // Return the preferred value of the delegate if it is a view controller itself.
    // This is required to handle correctly the full screen mode when a media is selected.
    if ([self.delegate isKindOfClass:UIViewController.class])
    {
        return [(UIViewController*)self.delegate prefersStatusBarHidden];
    }
    
    // Keep visible the status bar by default.
    return NO;
}

- (void)destroy
{
    [super destroy];
    
    if (kThemeServiceDidChangeThemeNotificationObserver)
    {
        [[NSNotificationCenter defaultCenter] removeObserver:kThemeServiceDidChangeThemeNotificationObserver];
        kThemeServiceDidChangeThemeNotificationObserver = nil;
    }
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    
    self.navigationItem.title = _assetsCollection.localizedTitle;
    
    [self.assetsCollectionView reloadData];
}

- (void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
}

#pragma mark -

- (void)setMediaTypes:(NSArray *)mediaTypes
{
    _mediaTypes = mediaTypes;
    
    self.assetsCollection = _assetsCollection;
}

- (void)setAssetsCollection:(PHAssetCollection *)assetsCollection
{
    if (assetsCollection)
    {
        if (!_mediaTypes)
        {
            // Set default media type
            _mediaTypes = @[(NSString *)kUTTypeImage];
        }
        
        // Set up fetch options.
        PHFetchOptions *options = [[PHFetchOptions alloc] init];
        options.sortDescriptors = @[[NSSortDescriptor sortDescriptorWithKey:@"creationDate" ascending:NO]];
        if ([_mediaTypes indexOfObject:(NSString *)kUTTypeImage] != NSNotFound)
        {
            if ([_mediaTypes indexOfObject:(NSString *)kUTTypeMovie] != NSNotFound)
            {
                options.predicate = [NSPredicate predicateWithFormat:@"(mediaType == %d) || (mediaType == %d)", PHAssetMediaTypeImage, PHAssetMediaTypeVideo];
            }
            else
            {
                options.predicate = [NSPredicate predicateWithFormat:@"mediaType == %d",PHAssetMediaTypeImage];
            }
        }
        else if ([_mediaTypes indexOfObject:(NSString *)kUTTypeMovie] != NSNotFound)
        {
            options.predicate = [NSPredicate predicateWithFormat:@"mediaType == %d",PHAssetMediaTypeVideo];
        }
        
        assets = [PHAsset fetchAssetsInAssetCollection:assetsCollection options:options];
        
        MXLogDebug(@"[MediaAlbumVC] lists %tu assets", assets.count);
    }
    else
    {
        assets = nil;
    }
    
    _assetsCollection = assetsCollection;

    self.navigationItem.title = _assetsCollection.localizedTitle;
    
    [self.assetsCollectionView reloadData];
}

#pragma mark - UICollectionViewDataSource

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
    return assets.count;
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    MXKMediaCollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:[MXKMediaCollectionViewCell defaultReuseIdentifier] forIndexPath:indexPath];
    
    // Sanity check: cancel pending asynchronous request (if any)
    if (cell.tag)
    {
        [[PHImageManager defaultManager] cancelImageRequest:(PHImageRequestID)cell.tag];
        cell.tag = 0;
    }
    
    if (indexPath.item < assets.count)
    {
        PHAsset *asset = assets[indexPath.item];
        
        CGFloat collectionViewSquareSize = ((collectionView.frame.size.width - 6) / 4); // Here 6 = 3 * cell margin (= 2).
        CGSize cellSize = CGSizeMake(collectionViewSquareSize, collectionViewSquareSize);
        
        PHImageRequestOptions *option = [[PHImageRequestOptions alloc] init];
        option.synchronous = NO;
        cell.tag = [[PHImageManager defaultManager] requestImageForAsset:asset targetSize:cellSize contentMode:PHImageContentModeAspectFill options:option resultHandler:^(UIImage *result, NSDictionary *info) {
            
            cell.mxkImageView.imageView.contentMode = UIViewContentModeScaleAspectFill;
            cell.mxkImageView.image = result;
            cell.tag = 0;
            
        }];
        
        cell.bottomLeftIcon.image = AssetImages.videoIcon.image;
        cell.bottomLeftIcon.hidden = (asset.mediaType == PHAssetMediaTypeImage);

        cell.bottomRightIcon.image = AssetImages.selectionTick.image;
        cell.bottomRightIcon.tintColor = ThemeService.shared.theme.tintColor;
        cell.bottomRightIcon.hidden = !selectedAssets || (NSNotFound == [selectedAssets indexOfObject:asset]);

        // Disable user interaction in mxkImageView, in order to let collection handle user selection
        cell.mxkImageView.userInteractionEnabled = NO;
    }
    
    return cell;
}

#pragma mark - UICollectionViewDelegate

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
    if (indexPath.item < assets.count && self.delegate)
    {
        PHAsset *asset = assets[indexPath.item];

        // Are we in multiselection mode ?
        if (!selectedAssets)
        {
            // NO
            [self.delegate mediaAlbumContentViewController:self didSelectAsset:asset];
        }
        else
        {
            // YES. Toggle the selection of the cell
            MXKMediaCollectionViewCell *cell = (MXKMediaCollectionViewCell*)[collectionView cellForItemAtIndexPath:indexPath];

            if (NSNotFound == [selectedAssets indexOfObject:asset])
            {
                cell.bottomRightIcon.hidden = NO;
                [selectedAssets addObject:asset];
            }
            else
            {
                cell.bottomRightIcon.hidden = YES;
                [selectedAssets removeObject:asset];
            }

            self.navigationItem.rightBarButtonItem.enabled = (0 < selectedAssets.count);
        }
    }
}

- (void)collectionView:(UICollectionView *)collectionView didEndDisplayingCell:(nonnull UICollectionViewCell *)cell forItemAtIndexPath:(nonnull NSIndexPath *)indexPath
{
    // Check whether a asynchronous request is pending
    if (cell.tag)
    {
        [[PHImageManager defaultManager] cancelImageRequest:(PHImageRequestID)cell.tag];
        cell.tag = 0;
    }
}

#pragma mark - UICollectionViewDelegateFlowLayout

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
    if (indexPath.item < assets.count)
    {
        CGFloat collectionViewSquareSize = ((collectionView.frame.size.width - 6) / 4); // Here 6 = 3 * cell margin (= 2).
        CGSize cellSize = CGSizeMake(collectionViewSquareSize, collectionViewSquareSize);
        
        return cellSize;
    }
    return CGSizeZero;
}

#pragma mark - Actions

- (void)onSelect:(id)sender
{
    selectedAssets = [NSMutableArray array];

    // Update the nav buttons
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:[VectorL10n send] style:UIBarButtonItemStylePlain target:self action:@selector(onSelectionSend:)];
    self.navigationItem.rightBarButtonItem.enabled = NO;
    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemCancel target:self action:@selector(onSelectionCancel:)];
}

- (void)onSelectionSend:(id)sender
{
    if (selectedAssets.count > 1)
    {
        [self.delegate mediaAlbumContentViewController:self didSelectAssets:selectedAssets];
    }
    else
    {
        [self.delegate mediaAlbumContentViewController:self didSelectAsset:selectedAssets[0]];
    }
}

- (void)onSelectionCancel:(id)sender
{
    selectedAssets = nil;

    // Update the nav buttons
    self.navigationItem.rightBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:[VectorL10n mediaPickerSelect] style:UIBarButtonItemStylePlain target:self action:@selector(onSelect:)];
    self.navigationItem.rightBarButtonItem.enabled = YES;
    self.navigationItem.leftBarButtonItem = nil;

    // Do not use [UICollectionView reloadData] because it creates flickering
    // Unselecting manually the cells is more efficient
    for (MXKMediaCollectionViewCell *cell in self.assetsCollectionView.visibleCells)
    {
        cell.bottomRightIcon.hidden = YES;
    }
}

@end