session-ios/Signal/src/ViewControllers/ConversationView/Cells/OWSMessageCell.m

//
//  Copyright (c) 2018 Open Whisper Systems. All rights reserved.
//

#import "OWSMessageCell.h"
#import "OWSExpirationTimerView.h"
#import "OWSMessageBubbleView.h"
#import "Signal-Swift.h"

NS_ASSUME_NONNULL_BEGIN

@interface OWSMessageCell ()

// The nullable properties are created as needed.
// The non-nullable properties are so frequently used that it's easier
// to always keep one around.

// The cell's contentView contains:
//
// * MessageView (message)
// * dateHeaderLabel (above message)
// * footerView (below message)
// * failedSendBadgeView ("trailing" beside message)

@property (nonatomic) OWSMessageBubbleView *messageBubbleView;
@property (nonatomic) UILabel *dateHeaderLabel;
@property (nonatomic, nullable) UIImageView *failedSendBadgeView;
@property (nonatomic) UIView *footerView;
@property (nonatomic) UILabel *footerLabel;
@property (nonatomic, nullable) OWSExpirationTimerView *expirationTimerView;

@property (nonatomic, nullable) NSMutableArray<NSLayoutConstraint *> *viewConstraints;
@property (nonatomic) BOOL isPresentingMenuController;

@end

@implementation OWSMessageCell

// `[UIView init]` invokes `[self initWithFrame:...]`.
- (instancetype)initWithFrame:(CGRect)frame
{
    if (self = [super initWithFrame:frame]) {
        [self commontInit];
    }

    return self;
}

- (void)commontInit
{
    OWSAssert(!self.messageBubbleView);

    _viewConstraints = [NSMutableArray new];

    self.layoutMargins = UIEdgeInsetsZero;
    self.contentView.layoutMargins = UIEdgeInsetsZero;

    self.messageBubbleView = [OWSMessageBubbleView new];
    [self.contentView addSubview:self.messageBubbleView];

    self.footerView = [UIView containerView];
    [self.contentView addSubview:self.footerView];

    self.dateHeaderLabel = [UILabel new];
    self.dateHeaderLabel.font = self.dateHeaderDateFont;
    self.dateHeaderLabel.textAlignment = NSTextAlignmentCenter;
    self.dateHeaderLabel.textColor = [UIColor lightGrayColor];
    [self.contentView addSubview:self.dateHeaderLabel];

    self.footerLabel = [UILabel new];
    self.footerLabel.font = UIFont.ows_dynamicTypeCaption1Font;
    self.footerLabel.textColor = [UIColor lightGrayColor];
    [self.footerView addSubview:self.footerLabel];

    // Hide these views by default.
    self.dateHeaderLabel.hidden = YES;
    self.footerLabel.hidden = YES;

    [self.messageBubbleView autoPinEdge:ALEdgeTop toEdge:ALEdgeBottom ofView:self.dateHeaderLabel];

    [self.footerView autoPinEdgeToSuperviewEdge:ALEdgeBottom];
    [self.footerView autoPinWidthToSuperview];

    self.contentView.userInteractionEnabled = YES;

    UILongPressGestureRecognizer *longPress =
        [[UILongPressGestureRecognizer alloc] initWithTarget:self action:@selector(handleLongPressGesture:)];
    [self.contentView addGestureRecognizer:longPress];

    PanDirectionGestureRecognizer *panGesture = [[PanDirectionGestureRecognizer alloc]
        initWithDirection:(self.isRTL ? PanDirectionLeft : PanDirectionRight)target:self
                   action:@selector(handlePanGesture:)];
    [self addGestureRecognizer:panGesture];
}

+ (NSString *)cellReuseIdentifier
{
    return NSStringFromClass([self class]);
}

- (BOOL)shouldHaveFailedSendBadge
{
    if (![self.viewItem.interaction isKindOfClass:[TSOutgoingMessage class]]) {
        return NO;
    }
    TSOutgoingMessage *outgoingMessage = (TSOutgoingMessage *)self.viewItem.interaction;
    return outgoingMessage.messageState == TSOutgoingMessageStateUnsent;
}

- (UIImage *)failedSendBadge
{
    UIImage *image = [UIImage imageNamed:@"message_send_failure"];
    OWSAssert(image);
    OWSAssert(image.size.width == self.failedSendBadgeSize && image.size.height == self.failedSendBadgeSize);
    return image;
}

- (CGFloat)failedSendBadgeSize
{
    return 20.f;
}

#pragma mark - Convenience Accessors

- (OWSMessageCellType)cellType
{
    return self.viewItem.messageCellType;
}

- (TSMessage *)message
{
    OWSAssert([self.viewItem.interaction isKindOfClass:[TSMessage class]]);

    return (TSMessage *)self.viewItem.interaction;
}

- (BOOL)isIncoming
{
    return self.viewItem.interaction.interactionType == OWSInteractionType_IncomingMessage;
}

- (BOOL)isOutgoing
{
    return self.viewItem.interaction.interactionType == OWSInteractionType_OutgoingMessage;
}

#pragma mark - Load

- (void)loadForDisplay
{
    OWSAssert(self.viewItem);
    OWSAssert(self.viewItem.interaction);
    OWSAssert([self.viewItem.interaction isKindOfClass:[TSMessage class]]);
    OWSAssert(self.contentWidth > 0);
    OWSAssert(self.messageBubbleView);

    self.messageBubbleView.viewItem = self.viewItem;
    self.messageBubbleView.contentWidth = self.contentWidth;
    self.messageBubbleView.cellMediaCache = self.delegate.cellMediaCache;
    [self.messageBubbleView configureViews];
    [self.messageBubbleView loadContent];

    if (self.shouldHaveFailedSendBadge) {
        self.failedSendBadgeView = [UIImageView new];
        self.failedSendBadgeView.image =
            [self.failedSendBadge imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];
        self.failedSendBadgeView.tintColor = [UIColor ows_destructiveRedColor];
        [self.contentView addSubview:self.failedSendBadgeView];

        [self.viewConstraints addObjectsFromArray:@[
            [self.messageBubbleView autoPinLeadingToSuperviewMargin],
            [self.failedSendBadgeView autoPinLeadingToTrailingEdgeOfView:self.messageBubbleView],
            [self.failedSendBadgeView autoAlignAxis:ALAxisHorizontal toSameAxisOfView:self.messageBubbleView],
            [self.failedSendBadgeView autoPinTrailingToSuperviewMargin],
            [self.failedSendBadgeView autoSetDimension:ALDimensionWidth toSize:self.failedSendBadgeSize],
            [self.failedSendBadgeView autoSetDimension:ALDimensionHeight toSize:self.failedSendBadgeSize],
        ]];
    } else {
        [self.viewConstraints addObjectsFromArray:@[
            [self.messageBubbleView autoPinLeadingToSuperviewMargin],
            [self.messageBubbleView autoPinTrailingToSuperviewMargin],
        ]];
    }

    [self updateDateHeader];
    [self updateFooter];
}

// * If cell is visible, lazy-load (expensive) view contents.
// * If cell is not visible, eagerly unload view contents.
- (void)ensureMediaLoadState
{
    OWSAssert(self.messageBubbleView);

    if (!self.isCellVisible) {
        [self.messageBubbleView unloadContent];
    } else {
        [self.messageBubbleView loadContent];
    }
}

- (void)updateDateHeader
{
    OWSAssert(self.contentWidth > 0);

    static NSDateFormatter *dateHeaderDateFormatter = nil;
    static NSDateFormatter *dateHeaderTimeFormatter = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        dateHeaderDateFormatter = [NSDateFormatter new];
        [dateHeaderDateFormatter setLocale:[NSLocale currentLocale]];
        [dateHeaderDateFormatter setDoesRelativeDateFormatting:YES];
        [dateHeaderDateFormatter setDateStyle:NSDateFormatterMediumStyle];
        [dateHeaderDateFormatter setTimeStyle:NSDateFormatterNoStyle];
        
        dateHeaderTimeFormatter = [NSDateFormatter new];
        [dateHeaderTimeFormatter setLocale:[NSLocale currentLocale]];
        [dateHeaderTimeFormatter setDoesRelativeDateFormatting:YES];
        [dateHeaderTimeFormatter setDateStyle:NSDateFormatterNoStyle];
        [dateHeaderTimeFormatter setTimeStyle:NSDateFormatterShortStyle];
    });

    if (self.viewItem.shouldShowDate) {
        NSDate *date = self.viewItem.interaction.dateForSorting;
        NSString *dateString = [dateHeaderDateFormatter stringFromDate:date];
        NSString *timeString = [dateHeaderTimeFormatter stringFromDate:date];

        NSAttributedString *attributedText = [NSAttributedString new];
        attributedText = [attributedText rtlSafeAppend:dateString
                                            attributes:@{
                                                NSFontAttributeName : self.dateHeaderDateFont,
                                                NSForegroundColorAttributeName : [UIColor lightGrayColor],
                                            }
                                         referenceView:self];
        attributedText = [attributedText rtlSafeAppend:@" "
                                            attributes:@{
                                                NSFontAttributeName : self.dateHeaderDateFont,
                                            }
                                         referenceView:self];
        attributedText = [attributedText rtlSafeAppend:timeString
                                            attributes:@{
                                                NSFontAttributeName : self.dateHeaderTimeFont,
                                                NSForegroundColorAttributeName : [UIColor lightGrayColor],
                                            }
                                         referenceView:self];

        self.dateHeaderLabel.attributedText = attributedText;
        self.dateHeaderLabel.hidden = NO;

        [self.viewConstraints addObjectsFromArray:@[
            // Date headers should be visually centered within the conversation view,
            // so they need to extend outside the cell's boundaries.
            [self.dateHeaderLabel autoSetDimension:ALDimensionWidth toSize:self.contentWidth],
            (self.isIncoming ? [self.dateHeaderLabel autoPinEdgeToSuperviewEdge:ALEdgeLeading]
                             : [self.dateHeaderLabel autoPinEdgeToSuperviewEdge:ALEdgeTrailing]),
            [self.dateHeaderLabel autoPinEdgeToSuperviewEdge:ALEdgeTop],
            [self.dateHeaderLabel autoSetDimension:ALDimensionHeight toSize:self.dateHeaderHeight],
        ]];
    } else {
        self.dateHeaderLabel.hidden = YES;
        [self.viewConstraints addObjectsFromArray:@[
            [self.dateHeaderLabel autoSetDimension:ALDimensionHeight toSize:0],
            [self.dateHeaderLabel autoPinEdgeToSuperviewEdge:ALEdgeTop],
        ]];
    }
}

- (BOOL)shouldShowFooter
{
    BOOL shouldShowFooter = NO;

    if (self.message.shouldStartExpireTimer) {
        shouldShowFooter = YES;
    } else if (self.isOutgoing) {
        shouldShowFooter = !self.viewItem.shouldHideRecipientStatus;
    } else if (self.viewItem.isGroupThread) {
        shouldShowFooter = YES;
    } else {
        shouldShowFooter = NO;
    }

    return shouldShowFooter;
}

- (CGFloat)footerHeight
{
    if (!self.shouldShowFooter) {
        return 0.f;
    }

    return ceil(MAX(kExpirationTimerViewSize, self.footerLabel.font.lineHeight));
}

- (CGFloat)footerVSpacing
{
    return 1.f;
}

- (void)updateFooter
{
    OWSAssert(self.viewItem.interaction.interactionType == OWSInteractionType_IncomingMessage
        || self.viewItem.interaction.interactionType == OWSInteractionType_OutgoingMessage);

    TSMessage *message = self.message;
    BOOL hasExpirationTimer = message.shouldStartExpireTimer;
    NSAttributedString *attributedText = nil;
    if (self.isOutgoing) {
        if (!self.viewItem.shouldHideRecipientStatus || hasExpirationTimer) {
            TSOutgoingMessage *outgoingMessage = (TSOutgoingMessage *)message;
            NSString *statusMessage =
                [MessageRecipientStatusUtils statusMessageWithOutgoingMessage:outgoingMessage referenceView:self];
            attributedText = [[NSAttributedString alloc] initWithString:statusMessage attributes:@{}];
        }
    } else if (self.viewItem.isGroupThread) {
        TSIncomingMessage *incomingMessage = (TSIncomingMessage *)self.viewItem.interaction;
        attributedText = [self.delegate attributedContactOrProfileNameForPhoneIdentifier:incomingMessage.authorId];
    }
    
    if (!hasExpirationTimer &&
        !attributedText) {
        self.footerLabel.hidden = YES;
        [self.viewConstraints addObjectsFromArray:@[
            [self.footerView autoPinEdge:ALEdgeTop toEdge:ALEdgeBottom ofView:self.messageBubbleView],
            [self.footerView autoSetDimension:ALDimensionHeight toSize:0],
        ]];
        return;
    }

    [self.viewConstraints addObject:[self.footerView autoPinEdge:ALEdgeTop
                                                          toEdge:ALEdgeBottom
                                                          ofView:self.messageBubbleView
                                                      withOffset:self.footerVSpacing]];

    if (hasExpirationTimer) {
        uint64_t expirationTimestamp = message.expiresAt;
        uint32_t expiresInSeconds = message.expiresInSeconds;
        self.expirationTimerView = [[OWSExpirationTimerView alloc] initWithExpiration:expirationTimestamp
                                                               initialDurationSeconds:expiresInSeconds];
        [self.footerView addSubview:self.expirationTimerView];
    }
    if (attributedText) {
        self.footerLabel.attributedText = attributedText;
        self.footerLabel.hidden = NO;
    }

    if (hasExpirationTimer &&
        attributedText) {
        [self.viewConstraints addObjectsFromArray:@[
            [self.expirationTimerView autoVCenterInSuperview],
            [self.footerLabel autoVCenterInSuperview],
            (self.isIncoming ? [self.expirationTimerView autoPinLeadingToSuperviewMargin]
                             : [self.expirationTimerView autoPinTrailingToSuperviewMargin]),
            (self.isIncoming ? [self.footerLabel autoPinLeadingToTrailingEdgeOfView:self.expirationTimerView offset:0.f]
                             : [self.footerLabel autoPinTrailingToLeadingEdgeOfView:self.expirationTimerView offset:0.f]),
            [self.footerView autoSetDimension:ALDimensionHeight toSize:self.footerHeight],
        ]];
    } else if (hasExpirationTimer) {
        [self.viewConstraints addObjectsFromArray:@[
            [self.expirationTimerView autoVCenterInSuperview],
            (self.isIncoming ? [self.expirationTimerView autoPinLeadingToSuperviewMargin]
                             : [self.expirationTimerView autoPinTrailingToSuperviewMargin]),
            [self.footerView autoSetDimension:ALDimensionHeight toSize:self.footerHeight],
        ]];
    } else if (attributedText) {
        [self.viewConstraints addObjectsFromArray:@[
            [self.footerLabel autoVCenterInSuperview],
            (self.isIncoming ? [self.footerLabel autoPinLeadingToSuperviewMargin]
                             : [self.footerLabel autoPinTrailingToSuperviewMargin]),
            [self.footerView autoSetDimension:ALDimensionHeight toSize:self.footerHeight],
        ]];
    } else {
        OWSFail(@"%@ Cell unexpectedly has neither expiration timer nor footer text.", self.logTag);
    }
}

- (UIFont *)dateHeaderDateFont
{
    return UIFont.ows_dynamicTypeCaption1Font.ows_medium;
}

- (UIFont *)dateHeaderTimeFont
{
    return UIFont.ows_dynamicTypeCaption1Font;
}

#pragma mark - Measurement

- (CGSize)cellSizeForViewWidth:(int)viewWidth contentWidth:(int)contentWidth
{
    OWSAssert(self.viewItem);
    OWSAssert([self.viewItem.interaction isKindOfClass:[TSMessage class]]);
    OWSAssert(self.messageBubbleView);

    self.messageBubbleView.viewItem = self.viewItem;
    self.messageBubbleView.contentWidth = self.contentWidth;
    self.messageBubbleView.cellMediaCache = self.delegate.cellMediaCache;
    CGSize messageBubbleSize = [self.messageBubbleView sizeForContentWidth:contentWidth];

    CGSize cellSize = messageBubbleSize;

    OWSAssert(cellSize.width > 0 && cellSize.height > 0);

    cellSize.height += self.dateHeaderHeight;
    if (self.shouldShowFooter) {
        cellSize.height += self.footerVSpacing;
        cellSize.height += self.footerHeight;
    }

    if (self.shouldHaveFailedSendBadge) {
        cellSize.width += self.failedSendBadgeSize;
    }

    cellSize = CGSizeCeil(cellSize);

    return cellSize;
}

- (CGFloat)dateHeaderHeight
{
    if (self.viewItem.shouldShowDate) {
        // Add 5pt spacing above and below the date header.
        return (CGFloat)ceil(MAX(self.dateHeaderDateFont.lineHeight, self.dateHeaderTimeFont.lineHeight) + 10.f);
    } else {
        return 0.f;
    }
}

#pragma mark -

- (void)prepareForReuse
{
    [super prepareForReuse];

    [NSLayoutConstraint deactivateConstraints:self.viewConstraints];
    self.viewConstraints = [NSMutableArray new];

    [self.messageBubbleView prepareForReuse];
    [self.messageBubbleView unloadContent];

    self.dateHeaderLabel.text = nil;
    self.dateHeaderLabel.hidden = YES;
    [self.failedSendBadgeView removeFromSuperview];
    self.failedSendBadgeView = nil;
    self.footerLabel.text = nil;
    self.footerLabel.hidden = YES;

    [self.expirationTimerView clearAnimations];
    [self.expirationTimerView removeFromSuperview];
    self.expirationTimerView = nil;

    [self hideMenuControllerIfNecessary];
}

#pragma mark - Notifications

- (void)setIsCellVisible:(BOOL)isCellVisible {
    BOOL didChange = self.isCellVisible != isCellVisible;

    [super setIsCellVisible:isCellVisible];

    if (!didChange) {
        return;
    }

    [self ensureMediaLoadState];

    if (isCellVisible) {
        if (self.message.shouldStartExpireTimer) {
            [self.expirationTimerView ensureAnimations];
        } else {
            [self.expirationTimerView clearAnimations];
        }
    } else {
        [self.expirationTimerView clearAnimations];

        [self hideMenuControllerIfNecessary];
    }
}

#pragma mark - Gesture recognizers

- (void)handleLongPressGesture:(UILongPressGestureRecognizer *)sender
{
    OWSAssert(self.delegate);

    if (sender.state != UIGestureRecognizerStateBegan) {
        return;
    }

    if (self.viewItem.interaction.interactionType == OWSInteractionType_OutgoingMessage) {
        TSOutgoingMessage *outgoingMessage = (TSOutgoingMessage *)self.viewItem.interaction;
        if (outgoingMessage.messageState == TSOutgoingMessageStateUnsent) {
            // Ignore long press on unsent messages.
            return;
        } else if (outgoingMessage.messageState == TSOutgoingMessageStateAttemptingOut) {
            // Ignore long press on outgoing messages being sent.
            return;
        }
    }

    CGPoint locationInMessageBubble = [sender locationInView:self.messageBubbleView];
    switch ([self.messageBubbleView gestureLocationForLocation:locationInMessageBubble]) {
        case OWSMessageGestureLocation_Default:
        case OWSMessageGestureLocation_OversizeText: {
            CGPoint location = [sender locationInView:self];
            [self showTextMenuController:location];
            break;
        }
        case OWSMessageGestureLocation_Media: {
            CGPoint location = [sender locationInView:self];
            [self showMediaMenuController:location];
            break;
        }
        case OWSMessageGestureLocation_QuotedReply: {
            CGPoint location = [sender locationInView:self];
            [self showDefaultMenuController:location];
            break;
        }
    }
}

- (void)handlePanGesture:(UIPanGestureRecognizer *)panRecognizer
{
    OWSAssert(self.delegate);

    [self.delegate didPanWithGestureRecognizer:panRecognizer viewItem:self.viewItem];
}

#pragma mark - UIMenuController

- (void)showTextMenuController:(CGPoint)fromLocation
{
    [self showMenuController:fromLocation menuItems:self.viewItem.textMenuControllerItems];
}

- (void)showMediaMenuController:(CGPoint)fromLocation
{
    [self showMenuController:fromLocation menuItems:self.viewItem.mediaMenuControllerItems];
}

- (void)showDefaultMenuController:(CGPoint)fromLocation
{
    [self showMenuController:fromLocation menuItems:self.viewItem.defaultMenuControllerItems];
}

- (void)showMenuController:(CGPoint)fromLocation menuItems:(NSArray *)menuItems
{
    if (menuItems.count < 1) {
        OWSFail(@"%@ No menu items to present.", self.logTag);
        return;
    }

    // We don't want taps on messages to hide the keyboard,
    // so we only let messages become first responder
    // while they are trying to present the menu controller.
    self.isPresentingMenuController = YES;

    [self becomeFirstResponder];

    if ([UIMenuController sharedMenuController].isMenuVisible) {
        [[UIMenuController sharedMenuController] setMenuVisible:NO animated:NO];
    }

    // We use custom action selectors so that we can control
    // the ordering of the actions in the menu.
    [UIMenuController sharedMenuController].menuItems = menuItems;
    CGRect targetRect = CGRectMake(fromLocation.x, fromLocation.y, 1, 1);
    [[UIMenuController sharedMenuController] setTargetRect:targetRect inView:self];
    [[UIMenuController sharedMenuController] setMenuVisible:YES animated:YES];
}

- (BOOL)canPerformAction:(SEL)action withSender:(nullable id)sender
{
    return [self.viewItem canPerformAction:action];
}

- (void)copyTextAction:(nullable id)sender
{
    [self.viewItem copyTextAction];
}

- (void)copyMediaAction:(nullable id)sender
{
    [self.viewItem copyMediaAction];
}

- (void)shareTextAction:(nullable id)sender
{
    [self.viewItem shareTextAction];
}

- (void)shareMediaAction:(nullable id)sender
{
    [self.viewItem shareMediaAction];
}

- (void)saveMediaAction:(nullable id)sender
{
    [self.viewItem saveMediaAction];
}

- (void)deleteAction:(nullable id)sender
{
    [self.viewItem deleteAction];
}

- (void)metadataAction:(nullable id)sender
{
    OWSAssert([self.viewItem.interaction isKindOfClass:[TSMessage class]]);

    [self.delegate showMetadataViewForViewItem:self.viewItem];
}

- (void)replyAction:(nullable id)sender
{
    OWSAssert([self.viewItem.interaction isKindOfClass:[TSMessage class]]);

    [self.delegate conversationCell:self didTapReplyForViewItem:self.viewItem];
}

- (BOOL)canBecomeFirstResponder
{
    return self.isPresentingMenuController;
}

- (void)didHideMenuController:(NSNotification *)notification
{
    self.isPresentingMenuController = NO;
}

- (void)setIsPresentingMenuController:(BOOL)isPresentingMenuController
{
    if (_isPresentingMenuController == isPresentingMenuController) {
        return;
    }

    _isPresentingMenuController = isPresentingMenuController;

    if (isPresentingMenuController) {
        [[NSNotificationCenter defaultCenter] addObserver:self
                                                 selector:@selector(didHideMenuController:)
                                                     name:UIMenuControllerDidHideMenuNotification
                                                   object:nil];
    } else {
        [[NSNotificationCenter defaultCenter] removeObserver:self
                                                        name:UIMenuControllerDidHideMenuNotification
                                                      object:nil];
    }
}

- (void)hideMenuControllerIfNecessary
{
    if (self.isPresentingMenuController) {
        [[UIMenuController sharedMenuController] setMenuVisible:NO animated:NO];
    }
    self.isPresentingMenuController = NO;
}

- (void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
}

@end

NS_ASSUME_NONNULL_END