Skip to content

Instantly share code, notes, and snippets.

@DreamingInBinary

DreamingInBinary/LInk view

Created September 15, 2020 20:14
Show Gist options

  • Select an option

    Learn more about clone URLs
  • Save DreamingInBinary/73169994273255a9c9cd69aed73f9c7a to your computer and use it in GitHub Desktop.

Select an option

Learn more about clone URLs
Save DreamingInBinary/73169994273255a9c9cd69aed73f9c7a to your computer and use it in GitHub Desktop.
Download ZIP

Revisions

  1. Jordan Morgan created this gist Sep 15, 2020.
    287 changes: 287 additions & 0 deletions LInk view
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,287 @@
    //
    // SSListItemMediaTableViewCell.m
    // Spend Stack
    //
    // Created by Jordan Morgan on 2/23/18.
    // Copyright © 2018 Jordan Morgan. All rights reserved.
    //

    #import "SSListItemMediaTableViewCell.h"
    #import "SSListItemImageView.h"
    #import "SSListItemViewController.h"
    #import "UITableViewCell+Common.h"
    #import <LinkPresentation/LinkPresentation.h>

    @interface SSListItemMediaTableViewCell() <UIPointerInteractionDelegate>

    @property (strong, nonatomic, readwrite, nonnull) UIActivityIndicatorView *spinner;
    @property (strong, nonatomic, readwrite, nonnull) SSLabel *errorLabel;
    @property (strong, nonatomic, readwrite, nonnull) SSListItemImageView *mediaImageView;
    @property (strong, nonatomic, readwrite, nonnull) LPLinkView *linkView;
    @property (strong, nonatomic, readwrite, nonnull) LPMetadataProvider *provider;
    @property (nonatomic, getter=hasBegunMetadataFetch) BOOL beganMetadataFetch;

    @end

    @implementation SSListItemMediaTableViewCell

    #pragma mark - Custom Setters

    - (void)setViewMode:(AttachmentViewMode)viewMode
    {
    _viewMode = viewMode;
    if (_errorLabel) _errorLabel.text = viewMode == AttachmentViewModeLink ? ss_Localized(@"listEdit.noLink") : ss_Localized(@"listEdit.noImage");
    }

    #pragma mark - Initializers

    - (instancetype)initWithStyle:(UITableViewCellStyle)style reuseIdentifier:(NSString *)reuseIdentifier
    {
    self = [super initWithStyle:style reuseIdentifier:reuseIdentifier];

    if (self)
    {
    self.viewMode = AttachmentViewModeImage;

    self.mediaImageView = [SSListItemImageView new];
    self.mediaImageView.clipsToBounds = YES;
    self.mediaImageView.layer.cornerRadius = SSSpacingMargin;
    self.mediaImageView.contentMode = UIViewContentModeScaleAspectFill;
    self.mediaImageView.backgroundColor = [UIColor ssMutedColor];
    if (@available(iOS 13.4, *))[self.mediaImageView addPointerInteractionWithDelegate:self];

    self.linkView = [[LPLinkView alloc] initWithFrame:CGRectMake(0, 0, 1, 1)];
    self.linkView.hidden = YES;
    [self.linkView setContentHuggingPriority:UILayoutPriorityDefaultHigh forAxis:UILayoutConstraintAxisHorizontal];
    [self.linkView setContentHuggingPriority:UILayoutPriorityDefaultHigh forAxis:UILayoutConstraintAxisVertical];

    [self setupMetadataProvider];

    self.spinner = [[UIActivityIndicatorView alloc] initWithActivityIndicatorStyle:UIActivityIndicatorViewStyleMedium];
    self.spinner.hidden = YES;
    self.spinner.accessibilityLabel = ss_Localized(@"listEdit.loadingImage");

    self.errorLabel = [[SSLabel alloc] initWithTextStyle:UIFontTextStyleBody];
    self.errorLabel.text = ss_Localized(@"listEdit.noImage");
    self.errorLabel.hidden = YES;
    self.errorLabel.textAlignment = NSTextAlignmentCenter;

    __weak typeof(self) weakSelf = self;
    SSListItemImageViewTapHandler handler = ^ {
    if (weakSelf.mediaImageView.image == nil)
    {
    return;
    }

    SSListItemViewController *listItemVC = (SSListItemViewController *)[self closestViewController];
    if ([listItemVC isKindOfClass:[SSListItemViewController class]])
    {
    [listItemVC presentImageViewerWithImageView:weakSelf.mediaImageView];
    }
    };

    [self.mediaImageView configureImageViewForTapHandler:handler];

    [self.contentView addSubviews:@[self.mediaImageView, self.linkView, self.spinner, self.errorLabel]];

    self.selectionStyle = UITableViewCellSelectionStyleNone;
    self.dividerView.hidden = YES;

    [self setConstraints];
    }

    return self;
    }

    - (void)prepareForReuse
    {
    [super prepareForReuse];
    self.errorState = NO;
    }

    - (void)dealloc
    {
    if (self.provider)
    {
    [self.provider cancel];
    }
    }

    #pragma mark - Constraint Handling

    - (void)setConstraints
    {
    [super setConstraints];

    [self.mediaImageView mas_makeConstraints:^(MASConstraintMaker *make) {
    make.left.equalTo(self.contentView.mas_readableContentGuideLeft);
    make.right.equalTo(self.contentView.mas_readableContentGuideRight);
    make.top.equalTo(self.contentView.mas_top).with.offset(SSTopElementMargin);
    make.bottom.equalTo(self.contentView.mas_bottom).with.offset(SSBottomElementMargin);
    make.height.equalTo(self.mediaImageView.mas_width);
    }];

    [self.linkView mas_makeConstraints:^(MASConstraintMaker *make) {
    make.width.equalTo(self.contentView.mas_width);
    make.height.equalTo(self.contentView.mas_height);
    make.centerX.equalTo(self.contentView.mas_centerX);
    make.centerY.equalTo(self.contentView.mas_centerY);
    }];

    [self.spinner mas_makeConstraints:^(MASConstraintMaker *make) {
    make.edges.equalTo(self.mediaImageView);
    }];

    [self.errorLabel mas_makeConstraints:^(MASConstraintMaker *make) {
    make.edges.equalTo(self.mediaImageView).with.insets(UIEdgeInsetsMake(SSSpacingMargin, SSSpacingMargin, SSSpacingMargin, SSSpacingMargin));
    }];
    }

    #pragma mark - Pointer Interaction Delegate

    - (nullable UIPointerStyle *)pointerInteraction:(UIPointerInteraction *)interaction styleForRegion:(UIPointerRegion *)region API_AVAILABLE(ios(13.4))
    {
    if (interaction.view == nil) return nil;

    UITargetedPreview *targetedPreview = [[UITargetedPreview alloc] initWithView:interaction.view];

    UIPointerLiftEffect *hover = [UIPointerLiftEffect effectWithPreview:targetedPreview];
    UIPointerStyle *pointerStyle = [UIPointerStyle styleWithEffect:hover
    shape:nil];
    return pointerStyle;
    }

    #pragma mark - Public Methods

    - (void)setData:(SSListItem *)item list:(SSList * _Nonnull)list
    {
    [super setData:item list:list];

    if (self.viewMode == AttachmentViewModeImage)
    {
    self.linkView.hidden = YES;
    self.linkView.alpha = 0.0f;

    if (item.downsampledMediaImage)
    {
    self.spinner.hidden = YES;
    [self.spinner stopAnimating];

    self.errorLabel.hidden = YES;

    self.mediaImageView.hidden = NO;
    self.mediaImageView.alpha = 1.0f;
    self.mediaImageView.image = item.downsampledMediaImage;
    }
    else if (self.isInErrorState)
    {
    self.errorLabel.hidden = NO;

    self.spinner.hidden = YES;
    [self.spinner stopAnimating];

    self.mediaImageView.alpha = 0.0f;
    }
    else
    {
    self.spinner.hidden = NO;
    self.mediaImageView.alpha = 0.5f;

    self.errorLabel.hidden = YES;

    [self.spinner startAnimating];
    }
    }
    else
    {
    self.mediaImageView.hidden = YES;
    self.spinner.hidden = YES;
    [self.spinner stopAnimating];
    self.errorLabel.hidden = YES;

    if (self.hasBegunMetadataFetch == NO && item.linkMetadata == nil)
    {
    NSLog(@"Spend Stack: LinkView fetching link metadata.");
    if ([self linkViewHasPlaceholderMetadata] == NO)
    {
    self.linkView.metadata = [LPLinkMetadata new];
    }

    self.beganMetadataFetch = YES;
    self.spinner.hidden = NO;
    [self.spinner startAnimating];

    __weak typeof(self) weakSelf = self;
    [self.provider startFetchingMetadataForURL:[NSURL URLWithString:item.linkAttachment] completionHandler:^(LPLinkMetadata *metadata, NSError *error) {
    NSLog(@"Spend Stack: LinkView fetched link metadata: %@ and error: %@", metadata, error);
    dispatch_async(dispatch_get_main_queue(), ^ {
    if (weakSelf == nil || weakSelf.viewMode == AttachmentViewModeImage)
    {
    return;
    }

    weakSelf.spinner.hidden = YES;
    [weakSelf.spinner stopAnimating];

    if (metadata)
    {
    [self.listItem attachLink:metadata.originalURL.absoluteString metaData:metadata];
    // Update section header and cell
    [[NSNotificationCenter defaultCenter] postNotificationName:SS_ATTACHMENT_VIEW_MODE_CHANGED object:@(AttachmentViewModeLink)];
    }
    else
    {
    weakSelf.errorState = YES;
    weakSelf.errorLabel.hidden = NO;
    weakSelf.beganMetadataFetch = NO;
    [weakSelf setupMetadataProvider];
    }
    });
    }];
    }
    else if (item.linkMetadata && [self.linkView.metadata isKindOfClass:NSClassFromString(@"LPPlaceholderLinkMetadata")])
    {
    NSLog(@"Spend Stack: LinkView already have link metadata, showing link view.");
    [self positionLinkViewWithMetadata:item.linkMetadata];

    // In case they remove a link, and re-add a new one in the same viewing
    self.beganMetadataFetch = NO;
    [self setupMetadataProvider];
    }
    else
    {
    NSLog(@"Spend Stack: LinkView is in error state.");
    self.errorLabel.hidden = NO;
    self.errorState = YES;
    self.beganMetadataFetch = NO;
    [self setupMetadataProvider];
    }
    }
    }

    - (void)positionLinkViewWithMetadata:(LPLinkMetadata *)metadata
    {
    self.linkView = [[LPLinkView alloc] initWithMetadata:metadata];
    [self.contentView addSubview:self.linkView];

    [self.linkView mas_remakeConstraints:^(MASConstraintMaker *make) {
    make.left.equalTo(self.contentView.mas_readableContentGuideLeft);
    make.right.equalTo(self.contentView.mas_readableContentGuideRight);
    make.top.equalTo(self.contentView.mas_top).with.offset(SSTopElementMargin);
    make.bottom.equalTo(self.contentView.mas_bottom).with.offset(SSBottomElementMargin);
    make.height.equalTo(self.linkView.mas_width);
    }];
    }

    - (void)setupMetadataProvider
    {
    self.provider = [LPMetadataProvider new];
    self.provider.timeout = 10.0f;
    }

    - (BOOL)linkViewHasPlaceholderMetadata
    {
    return [self.linkView.metadata isKindOfClass:NSClassFromString(@"LPPlaceholderLinkMetadata")];
    }

    @end