ResearchKit/ResearchKitUI/Common/Answer Format/ORKSurveyCardHeaderView.m

/*
 Copyright (c) 2018, Apple Inc. All rights reserved.
 
 Redistribution and use in source and binary forms, with or without modification,
 are permitted provided that the following conditions are met:
 
 1.  Redistributions of source code must retain the above copyright notice, this
 list of conditions and the following disclaimer.
 
 2.  Redistributions in binary form must reproduce the above copyright notice,
 this list of conditions and the following disclaimer in the documentation and/or
 other materials provided with the distribution.
 
 3.  Neither the name of the copyright holder(s) nor the names of any contributors
 may be used to endorse or promote products derived from this software without
 specific prior written permission. No license is granted to the trademarks of
 the copyright holders even if such marks are included in this software.
 
 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#import "ORKSurveyCardHeaderView.h"
#import "ORKSkin.h"
#import "ORKLearnMoreView.h"
#import "ORKTagLabel.h"
#import "ORKHelpers_Internal.h"

static const CGFloat HeaderViewLabelTopBottomPadding = 6.0;
static const CGFloat HeaderViewLabelTopPadding = 4.0;
static const CGFloat TagBottomPadding = 4.0;
static const CGFloat TagTopPadding = 8.0;
static const CGFloat HeaderViewBottomPadding = 24.0;
static const CGFloat SelectAllThatApplyTopPadding = 24.0;
static const CGFloat SelectAllThatApplyBottomPadding = 6.0;

NSString * const ORKSurveyCardHeaderViewTitleLabelAccessibilityIdentifier = @"ORKSurveyCardHeaderView_titleLabel";
NSString * const ORKSurveyCardHeaderViewProgressLabelAccessibilityIdentifier = @"ORKSurveyCardHeaderView_progressLabel";
NSString * const ORKSurveyCardHeaderViewDetailTextLabelAccessibilityIdentifier = @"ORKSurveyCardHeaderView_detailTextLabel";
NSString * const ORKSurveyCardHeaderViewSelectAllThatApplyLabelAccessibilityIdentifier = @"ORKSurveyCardHeaderView_selectAllThatApplyLabel";

@implementation ORKSurveyCardHeaderView {
    
    UIView *_headlineView;
    NSString *_title;
    UILabel *_titleLabel;
    NSString *_detailText;
    UILabel *_detailTextLabel;
    ORKLearnMoreView *_learnMoreView;
    NSString *_progressText;
    UILabel *_progressLabel;
    UILabel *_tagLabel;
    UILabel *_selectAllThatApplyLabel;
    BOOL _showBorder;
    BOOL _hasMultipleChoiceItem;
    BOOL _shouldIgnoreDarkMode;
    NSString *_tagText;
    CAShapeLayer *_headlineMaskLayer;
    NSMutableArray<NSLayoutConstraint *> *_headerViewConstraints;
    NSArray<NSLayoutConstraint *> *_learnMoreViewConstraints;
}

- (instancetype)initWithTitle:(NSString *)title {
    
    self = [super init];
    if (self) {
        _title = title;
        [self setupView];
    }
    return self;
}

- (instancetype)initWithTitle:(NSString *)title
                   detailText:(nullable NSString *)text
                learnMoreView:(nullable ORKLearnMoreView *)learnMoreView
                 progressText:(nullable NSString *)progressText
                      tagText:(nullable NSString *)tagText {
    
    return [self initWithTitle:title
                    detailText:text
                 learnMoreView:learnMoreView
                  progressText:progressText
                       tagText:tagText
                    showBorder:NO
         hasMultipleChoiceItem:NO
          shouldIgnoreDarkMode:NO];
}

- (instancetype)initWithTitle:(NSString *)title
                   detailText:(NSString *)text
                learnMoreView:(ORKLearnMoreView *)learnMoreView
                 progressText:(NSString *)progressText
                      tagText:(nullable NSString *)tagText
                   showBorder:(BOOL)showBorder
        hasMultipleChoiceItem:(BOOL)hasMultipleChoiceItem
         shouldIgnoreDarkMode:(BOOL)shouldIgnoreDarkMode {
    
    self = [super init];
    if (self) {
        [self configureWithTitle:title
                      detailText:text
                   learnMoreView:learnMoreView
                    progressText:progressText
                         tagText:tagText
                      showBorder:showBorder
           hasMultipleChoiceItem:hasMultipleChoiceItem
            shouldIgnoreDarkMode:shouldIgnoreDarkMode];
    }
    return self;
}

- (void)configureWithTitle:(NSString *)title
                detailText:(NSString *)text
             learnMoreView:(ORKLearnMoreView *)learnMoreView
              progressText:(NSString *)progressText
                   tagText:(NSString *)tagText
                showBorder:(BOOL)showBorder
     hasMultipleChoiceItem:(BOOL)hasMultipleChoiceItem
      shouldIgnoreDarkMode:(BOOL)shouldIgnoreDarkMode {
    _title = [title copy];
    _detailText = [text copy];
    _learnMoreView = learnMoreView;
    _progressText = [progressText copy];
    _showBorder = showBorder;
    _tagText = [tagText copy];
    _hasMultipleChoiceItem = hasMultipleChoiceItem;
    _shouldIgnoreDarkMode = shouldIgnoreDarkMode;
    [self setupView];
}

- (void)setupView {
    if (@available(iOS 14.0, *)) {
        [self setBackgroundConfiguration:[UIBackgroundConfiguration clearConfiguration]];
    } else {
        [self setBackgroundColor:[UIColor clearColor]];
    }
    [self setupHeaderView];
    [self setupConstraints];
}

- (void)setupHeaderView {
    [self setupHeadlineView];
    [self addSubview:_headlineView];
    
    if (_tagText) {
        [self setupTagLabel];
        [_headlineView addSubview:_tagLabel];
    }
    
    if (_progressText) {
        [self setUpProgressLabel];
        [_headlineView addSubview:_progressLabel];
    }
   
    [self setupTitleLabel];
    [_headlineView addSubview:_titleLabel];
    
    if (_detailText) {
        [self setUpDetailTextLabel];
        [_headlineView addSubview:_detailTextLabel];
    }
    
    if (_learnMoreView) {
        [_headlineView addSubview:_learnMoreView];
    }
    
    if (_hasMultipleChoiceItem) {
        [self setupSelectAllThatApplyLabel];
        [_headlineView addSubview:_selectAllThatApplyLabel];
    }
    
    if (_shouldIgnoreDarkMode) {
        self.overrideUserInterfaceStyle = UIUserInterfaceStyleLight;
    }
}

- (void)setupHeadlineView {
    if (!_headlineView) {
        _headlineView = [UIView new];
    }
}

- (void)setupTitleLabel {
    if (!_titleLabel) {
        _titleLabel = [UILabel new];
    }
    _titleLabel.text = _title;
    _titleLabel.numberOfLines = 0;
    _titleLabel.textColor = _shouldIgnoreDarkMode ? [UIColor blackColor] : [UIColor labelColor];
    _titleLabel.lineBreakMode = NSLineBreakByWordWrapping;
    _titleLabel.textAlignment = NSTextAlignmentNatural;
    [_titleLabel setFont:[ORKSurveyCardHeaderView titleLabelFont]];
}

- (void)setUpDetailTextLabel {
    if (!_detailTextLabel) {
        _detailTextLabel = [UILabel new];
    }
    _detailTextLabel.text = _detailText;
    _detailTextLabel.numberOfLines = 0;
    _detailTextLabel.lineBreakMode = NSLineBreakByWordWrapping;
    _detailTextLabel.textAlignment = NSTextAlignmentNatural;
    _detailTextLabel.accessibilityIdentifier = ORKSurveyCardHeaderViewDetailTextLabelAccessibilityIdentifier;
    [_detailTextLabel setFont:[ORKSurveyCardHeaderView detailTextLabelFont]];
}

- (void)setUpProgressLabel {
    if (!_progressLabel) {
        _progressLabel = [UILabel new];
    }
    _progressLabel.text = _progressText;
    _progressLabel.numberOfLines = 0;
    _progressLabel.textColor = _shouldIgnoreDarkMode ? [UIColor lightGrayColor] : [UIColor secondaryLabelColor];
    _progressLabel.textAlignment = NSTextAlignmentNatural;
    [_progressLabel setFont:[self progressLabelFont]];
}

- (void)setProgressText:(nullable NSString *)text {
    if (_progressText != text) {
        _progressText = [text copy];

        if (_progressText != nil) {
            if (_progressLabel == nil) {
                [self setUpProgressLabel];
                [_headlineView addSubview:_progressLabel];
                [self setupConstraints];
            } else {
                _progressLabel.text = _progressText;
            }
        } else {
            if (_progressLabel != nil) {
                [_progressLabel removeFromSuperview];
                _progressLabel = nil;
                [self setupConstraints];
            } else {
                // intentionally left empty
                // new text is nil, but _progressLabel is already nil
                // nothing to do
            }
        }
    }
}

- (void)prepareForReuse {
    [_headlineView removeFromSuperview];
    _headlineView = nil;
    
    [_titleLabel removeFromSuperview];
    _titleLabel = nil;
    _title = nil;
    
    [_detailTextLabel removeFromSuperview];
    _detailTextLabel = nil;
    _detailText = nil;
    
    [_learnMoreView removeFromSuperview];
    _learnMoreView = nil;
    
    [_progressLabel removeFromSuperview];
    _progressLabel = nil;
    _progressText = nil;
    
    [_tagLabel removeFromSuperview];
    _tagLabel = nil;
    _tagText = nil;
    
    [_selectAllThatApplyLabel removeFromSuperview];
    _selectAllThatApplyLabel = nil;
    
    _showBorder = NO;
    _hasMultipleChoiceItem = NO;
    _shouldIgnoreDarkMode = NO;
    
    [super prepareForReuse];
}

- (void)setupTagLabel {
    if (!_tagLabel) {
        _tagLabel = [ORKTagLabel new];
    }
    _tagLabel.text = _tagText;
}

- (void)setupSelectAllThatApplyLabel {
    if (!_selectAllThatApplyLabel) {
        _selectAllThatApplyLabel = [UILabel new];
    }
    
    _selectAllThatApplyLabel.text = ORKLocalizedString(@"AX_SELECT_ALL_THAT_APPLY", nil);
    _selectAllThatApplyLabel.accessibilityIdentifier = ORKSurveyCardHeaderViewSelectAllThatApplyLabelAccessibilityIdentifier;
    _selectAllThatApplyLabel.numberOfLines = 0;
    _selectAllThatApplyLabel.textColor = _shouldIgnoreDarkMode ? [UIColor lightGrayColor] : [UIColor secondaryLabelColor];
    _selectAllThatApplyLabel.textAlignment = NSTextAlignmentNatural;
    [_selectAllThatApplyLabel setFont:[self selectAllThatApplyFont]];
}

+ (UIFont *)titleLabelFont {
    UIFontDescriptor *descriptor = [UIFontDescriptor preferredFontDescriptorWithTextStyle:UIFontTextStyleBody];
    UIFontDescriptor *fontDescriptor = [descriptor fontDescriptorWithSymbolicTraits:(UIFontDescriptorTraitBold)];
    return [UIFont fontWithDescriptor:fontDescriptor size:[[fontDescriptor objectForKey: UIFontDescriptorSizeAttribute] doubleValue]];
}

+ (UIFont *)detailTextLabelFont {
    UIFontDescriptor *descriptor = [UIFontDescriptor preferredFontDescriptorWithTextStyle:UIFontTextStyleSubheadline];
    return [UIFont fontWithDescriptor:descriptor size:[[descriptor objectForKey: UIFontDescriptorSizeAttribute] doubleValue]];
}

- (UIFont *)progressLabelFont {
    UIFontDescriptor *descriptor = [UIFontDescriptor preferredFontDescriptorWithTextStyle:UIFontTextStyleFootnote];
    UIFontDescriptor *fontDescriptor = [descriptor fontDescriptorWithSymbolicTraits:(UIFontDescriptorTraitBold)];
    return [UIFont fontWithDescriptor:fontDescriptor size:[[fontDescriptor objectForKey: UIFontDescriptorSizeAttribute] doubleValue]];
}

- (UIFont *)selectAllThatApplyFont {
    UIFontDescriptor *descriptor = [UIFontDescriptor preferredFontDescriptorWithTextStyle:UIFontTextStyleFootnote];
    UIFontDescriptor *fontDescriptor = [descriptor fontDescriptorWithSymbolicTraits:(UIFontDescriptorTraitBold)];
    return [UIFont fontWithDescriptor:fontDescriptor size:[[fontDescriptor objectForKey: UIFontDescriptorSizeAttribute] doubleValue]];
}

- (void)layoutSubviews {
    [super layoutSubviews];
    
    if (_headlineView) {
        if (!_headlineMaskLayer) {
            _headlineMaskLayer = [CAShapeLayer layer];
        }
        for (CALayer *sublayer in [_headlineMaskLayer.sublayers mutableCopy]) {
            [sublayer removeFromSuperlayer];
        }
        [_headlineMaskLayer removeFromSuperlayer];
        
        _headlineMaskLayer.path = [UIBezierPath bezierPathWithRoundedRect: _headlineView.bounds byRoundingCorners: UIRectCornerTopLeft | UIRectCornerTopRight cornerRadii: (CGSize){ORKCardDefaultCornerRadii, ORKCardDefaultCornerRadii}].CGPath;
        
        CAShapeLayer *foreLayer = [CAShapeLayer layer];
        UIColor *fillColor = _shouldIgnoreDarkMode ? [UIColor whiteColor] : [UIColor secondarySystemGroupedBackgroundColor];
        UIColor *borderColor = _shouldIgnoreDarkMode ? [UIColor ork_midGrayTintColor] : UIColor.separatorColor;;
        
        [foreLayer setFillColor:[fillColor CGColor]];
        CGRect foreLayerBounds = CGRectMake(ORKCardDefaultBorderWidth, ORKCardDefaultBorderWidth, _headlineView.bounds.size.width - 2 * ORKCardDefaultBorderWidth, _headlineView.bounds.size.height - ORKCardDefaultBorderWidth);
        
        CGFloat foreLayerCornerRadii = ORKCardDefaultCornerRadii >= ORKCardDefaultBorderWidth ? ORKCardDefaultCornerRadii - ORKCardDefaultBorderWidth : ORKCardDefaultCornerRadii;
        
        foreLayer.path = [UIBezierPath bezierPathWithRoundedRect: foreLayerBounds byRoundingCorners: UIRectCornerTopLeft | UIRectCornerTopRight cornerRadii: (CGSize){foreLayerCornerRadii, foreLayerCornerRadii}].CGPath;
        foreLayer.zPosition = 0.0f;
        
        [_headlineMaskLayer addSublayer:foreLayer];
        
        if (_titleLabel.text) {
            CAShapeLayer *lineLayer = [CAShapeLayer layer];
            CGRect lineBounds = CGRectMake(0.0, _headlineView.bounds.size.height - 1.0, _headlineView.bounds.size.width, 0.5);
            lineLayer.path = [UIBezierPath bezierPathWithRect:lineBounds].CGPath;
            lineLayer.zPosition = 0.0f;
            [lineLayer setFillColor:[borderColor CGColor]];
            
            [_headlineMaskLayer addSublayer:lineLayer];
        }
        
        if (_showBorder) {
            [_headlineMaskLayer setFillColor:[borderColor CGColor]];
        } else {
            [_headlineMaskLayer setFillColor:[[UIColor clearColor] CGColor]];
        }
        
        [_headlineView.layer insertSublayer:_headlineMaskLayer atIndex:0];
    }
    
}

- (BOOL)useLearnMoreLeftAlignmentLayout {
    return ((_learnMoreView != nil) && ([_learnMoreView isTextLink] == NO));
}

- (void)setupConstraints {
    if (_headerViewConstraints) {
        [NSLayoutConstraint deactivateConstraints:_headerViewConstraints];
    }
    
    _headerViewConstraints = [NSMutableArray new];
    
    NSLayoutXAxisAnchor *trailingAnchor = [self useLearnMoreLeftAlignmentLayout] ? _learnMoreView.leadingAnchor : _headlineView.trailingAnchor;
    NSLayoutYAxisAnchor *lastYAxisAnchor = self.topAnchor;
    
    _headlineView.translatesAutoresizingMaskIntoConstraints = NO;
    
    if (_progressLabel) {
        _progressLabel.translatesAutoresizingMaskIntoConstraints = NO;
        
        [_headerViewConstraints addObject:[_progressLabel.topAnchor constraintEqualToAnchor:lastYAxisAnchor constant:ORKSurveyItemMargin]];
        [_headerViewConstraints addObject:[_progressLabel.leadingAnchor constraintEqualToAnchor:_titleLabel.leadingAnchor]];
        [_headerViewConstraints addObject:[_progressLabel.trailingAnchor constraintEqualToAnchor:trailingAnchor constant:-ORKSurveyItemMargin]];
        
        lastYAxisAnchor = _progressLabel.bottomAnchor;
    }
    
    if (_tagLabel) {
        CGFloat topPadding = _progressLabel ? TagTopPadding : ORKSurveyItemMargin;
        _tagLabel.translatesAutoresizingMaskIntoConstraints = NO;
        
        [_headerViewConstraints addObject:[_tagLabel.topAnchor constraintEqualToAnchor:lastYAxisAnchor constant:topPadding]];
        [_headerViewConstraints addObject:[_tagLabel.leadingAnchor constraintEqualToAnchor:_titleLabel.leadingAnchor]];
        
        [_headerViewConstraints addObject:[_tagLabel.trailingAnchor constraintLessThanOrEqualToAnchor:_headlineView.trailingAnchor constant:-ORKSurveyItemMargin]];
        lastYAxisAnchor = _tagLabel.bottomAnchor;
    }
    
    CGFloat titlePadding;
    if (_tagLabel) {
        titlePadding = TagBottomPadding;
    } else if (_progressLabel) {
        titlePadding = HeaderViewLabelTopPadding;
    } else {
        titlePadding = ORKSurveyItemMargin;
    }
    _titleLabel.translatesAutoresizingMaskIntoConstraints = NO;
    
    [_headerViewConstraints addObject:[_titleLabel.topAnchor constraintEqualToAnchor:lastYAxisAnchor constant:titlePadding]];
    [_headerViewConstraints addObject:[_titleLabel.leadingAnchor constraintEqualToAnchor:_headlineView.leadingAnchor constant:ORKSurveyItemMargin]];
    [_headerViewConstraints addObject:[_titleLabel.trailingAnchor constraintEqualToAnchor:[self useLearnMoreLeftAlignmentLayout] ? _learnMoreView.leadingAnchor : _headlineView.trailingAnchor constant:-ORKSurveyItemMargin]];
    
    lastYAxisAnchor = _titleLabel.bottomAnchor;
    NSLayoutYAxisAnchor *headlineViewBottomAnchor = _titleLabel.bottomAnchor;
    
    if (_detailTextLabel) {
        _detailTextLabel.translatesAutoresizingMaskIntoConstraints = NO;
        
        [_headerViewConstraints addObject:[_detailTextLabel.topAnchor constraintEqualToAnchor:_titleLabel.bottomAnchor constant:HeaderViewLabelTopBottomPadding]];
        [_headerViewConstraints addObject:[_detailTextLabel.leadingAnchor constraintEqualToAnchor:_titleLabel.leadingAnchor]];
        [_headerViewConstraints addObject:[_detailTextLabel.trailingAnchor constraintEqualToAnchor:[self useLearnMoreLeftAlignmentLayout] ? _learnMoreView.leadingAnchor : _headlineView.trailingAnchor constant:-ORKSurveyItemMargin]];

        lastYAxisAnchor = _detailTextLabel.bottomAnchor;
        headlineViewBottomAnchor = _detailTextLabel.bottomAnchor;
    }
    
    if (_learnMoreView) {
        [self setupLearnMoreViewConstraints];
        if ([_learnMoreView isTextLink] == YES) {
            [_learnMoreView setLearnMoreButtonFont:[UIFont preferredFontForTextStyle:UIFontTextStyleSubheadline]];
            [_learnMoreView setLearnMoreButtonTextAlignment:NSTextAlignmentLeft];
            
            [_headerViewConstraints addObject:[_learnMoreView.topAnchor constraintEqualToAnchor:_detailTextLabel ? _detailTextLabel.bottomAnchor : _titleLabel.bottomAnchor constant:HeaderViewLabelTopBottomPadding]];
            [_headerViewConstraints addObject:[_learnMoreView.leadingAnchor constraintEqualToAnchor:_titleLabel.leadingAnchor]];
            [_headerViewConstraints addObject:[_learnMoreView.trailingAnchor constraintEqualToAnchor:[self useLearnMoreLeftAlignmentLayout] ? _learnMoreView.leadingAnchor : _headlineView.trailingAnchor constant:-ORKSurveyItemMargin]];
            
            lastYAxisAnchor = _learnMoreView.bottomAnchor;
            headlineViewBottomAnchor = _learnMoreView.bottomAnchor;
        }
    }
    
    if (_selectAllThatApplyLabel) {
        _selectAllThatApplyLabel.translatesAutoresizingMaskIntoConstraints = NO;
        
        [_headerViewConstraints addObject:[_selectAllThatApplyLabel.topAnchor constraintEqualToAnchor:lastYAxisAnchor constant:SelectAllThatApplyTopPadding]];
        [_headerViewConstraints addObject:[_selectAllThatApplyLabel.leadingAnchor constraintEqualToAnchor:_titleLabel.leadingAnchor]];
        [_headerViewConstraints addObject:[_selectAllThatApplyLabel.trailingAnchor constraintEqualToAnchor:_titleLabel.trailingAnchor]];
        
        headlineViewBottomAnchor = _selectAllThatApplyLabel.bottomAnchor;
    }
    
    [_headerViewConstraints addObject:[_headlineView.topAnchor constraintEqualToAnchor:self.topAnchor constant:0.0]];
    [_headerViewConstraints addObject:[_headlineView.leadingAnchor constraintEqualToAnchor:self.leadingAnchor constant:ORKCardLeftRightMarginForWindow(self.window)]];
    [_headerViewConstraints addObject:[_headlineView.trailingAnchor constraintEqualToAnchor:self.trailingAnchor constant:-ORKCardLeftRightMarginForWindow(self.window)]];
    [_headerViewConstraints addObject:[_headlineView.bottomAnchor constraintEqualToAnchor: headlineViewBottomAnchor constant: _selectAllThatApplyLabel ? SelectAllThatApplyBottomPadding : HeaderViewBottomPadding]];
    
    
    [_headerViewConstraints addObject:[self.bottomAnchor constraintEqualToAnchor:_headlineView.bottomAnchor constant:0.0]];
    
    
    [NSLayoutConstraint activateConstraints:_headerViewConstraints];
}

- (void)setupLearnMoreViewConstraints {
    if (_learnMoreViewConstraints) {
        [NSLayoutConstraint deactivateConstraints:_learnMoreViewConstraints];
    }
    _learnMoreView.translatesAutoresizingMaskIntoConstraints = NO;

    if ([_learnMoreView isTextLink] == NO) {
        _learnMoreViewConstraints = @[
            [NSLayoutConstraint constraintWithItem:_learnMoreView
                                         attribute:NSLayoutAttributeTop
                                         relatedBy:NSLayoutRelationEqual
                                            toItem: _titleLabel ? : _headlineView
                                         attribute:NSLayoutAttributeTop
                                        multiplier:1.0
                                          constant:_titleLabel ? 0.0 : ORKSurveyItemMargin],
            [NSLayoutConstraint constraintWithItem:_learnMoreView
                                         attribute:NSLayoutAttributeTrailing
                                         relatedBy:NSLayoutRelationEqual
                                            toItem: _headlineView
                                         attribute:NSLayoutAttributeTrailing
                                        multiplier:1.0
                                          constant:-ORKSurveyItemMargin],
            [NSLayoutConstraint constraintWithItem:_learnMoreView
                                         attribute:NSLayoutAttributeWidth
                                         relatedBy:NSLayoutRelationEqual
                                            toItem: _learnMoreView
                                         attribute:NSLayoutAttributeHeight
                                        multiplier:1.0
                                          constant: 0.0]
        ];
    }
    
    [NSLayoutConstraint activateConstraints:_learnMoreViewConstraints];
}


@end