ResearchKit/ResearchKitUI/Common/Answer Format/Question Step Views/ORKSurveyAnswerCellForPicker.m

/*
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 may be used to endorse or promote products derived from this software without
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 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
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#import "ORKSurveyAnswerCellForPicker.h"

#import "ORKPicker.h"
#import "ORKDontKnowButton.h"

#import "ORKQuestionStep_Internal.h"
#import "ORKAnswerFormat_Internal.h"
#import "ORKHelpers_Internal.h"

static const CGFloat DividerViewTopPadding = 10.0;
static const CGFloat DontKnowButtonTopBottomPadding = 16.0;
static const CGFloat DontKnowButtonBottomPaddingOffset = 10.0;


@interface ORKSurveyAnswerCellForPicker () <ORKPickerDelegate, UIPickerViewDelegate> {
    BOOL _valueChangedDueUserAction;
}

@property (nonatomic, strong) id<ORKPicker> picker;

@end


@implementation ORKSurveyAnswerCellForPicker {
    ORKDontKnowButton *_dontKnowButton;
    UIView *_dividerView;
    BOOL _dontKnowButtonActive;
}

- (void)prepareView {
    [super prepareView];
    
    [self loadPicker];
    _valueChangedDueUserAction = NO;
}

- (void)loadPicker {
    if (_picker == nil) {
        _picker = [ORKPicker pickerWithAnswerFormat:[self.step impliedAnswerFormat] answer:self.answer delegate:self];
        _picker.pickerView.backgroundColor = UIColor.secondarySystemGroupedBackgroundColor;
        
        [self.picker pickerWillAppear];
        
        [self addSubview:_picker.pickerView];
        
        if ([self.step.answerFormat shouldShowDontKnowButton] && !_dontKnowButton) {
            [self setupDontKnowButton];
        }
        
        [self setupConstraintsForView:_picker.pickerView];
    }
}

- (void)setupDontKnowButton {
    if (!_dontKnowButton) {
        _dontKnowButton = [ORKDontKnowButton new];
        _dontKnowButton.customDontKnowButtonText = self.step.answerFormat.customDontKnowButtonText;
        [_dontKnowButton addTarget:self action:@selector(dontKnowButtonWasPressed) forControlEvents:UIControlEventTouchUpInside];
        [self addSubview:_dontKnowButton];
     }
     
     if (!_dividerView) {
         _dividerView = [UIView new];
         [_dividerView setBackgroundColor:[UIColor separatorColor]];
         [self addSubview:_dividerView];
     }
    
    _dontKnowButton.translatesAutoresizingMaskIntoConstraints = NO;
    _dividerView.translatesAutoresizingMaskIntoConstraints = NO;
    
    if (self.answer == [ORKDontKnowAnswer answer]) {
        [self dontKnowButtonWasPressed];
    }
}

- (void)dontKnowButtonWasPressed {
    if (![_dontKnowButton active]) {
        [_dontKnowButton setActive:YES];
        [self ork_setAnswer:[ORKDontKnowAnswer answer]];
        if (_picker) {
            [_picker setAnswer:nil];
        }
    }
}

- (void)setupConstraintsForView:(UIView *)view {
    if (view) {
        view.translatesAutoresizingMaskIntoConstraints = NO;

        [[view.centerXAnchor constraintEqualToAnchor:self.centerXAnchor] setActive:YES];
        [[view.topAnchor constraintEqualToAnchor:self.topAnchor] setActive:YES];
        
        if (_dontKnowButton) {
            CGFloat separatorHeight = 1.0 / [UIScreen mainScreen].scale;
            [[_dividerView.topAnchor constraintEqualToAnchor:view.bottomAnchor constant:DividerViewTopPadding] setActive:YES];
            [[_dividerView.leftAnchor constraintEqualToAnchor:self.leftAnchor] setActive:YES];
            [[_dividerView.rightAnchor constraintEqualToAnchor:self.rightAnchor] setActive:YES];
            [[_dividerView.heightAnchor constraintGreaterThanOrEqualToConstant:separatorHeight] setActive:YES];
            
            [[_dontKnowButton.topAnchor constraintEqualToAnchor:_dividerView.bottomAnchor constant:DontKnowButtonTopBottomPadding] setActive:YES];
            [[_dontKnowButton.centerXAnchor constraintEqualToAnchor:self.centerXAnchor] setActive:YES];
            [[_dontKnowButton.bottomAnchor constraintEqualToAnchor:self.bottomAnchor constant:-DontKnowButtonTopBottomPadding + DontKnowButtonBottomPaddingOffset] setActive:YES];
        } else {
            [[view.bottomAnchor constraintEqualToAnchor:self.bottomAnchor] setActive:YES];
        }
        
    }
}

- (void)answerDidChange {
    if (self.answer != [ORKDontKnowAnswer answer]) {
      [_picker setAnswer:self.answer];
    }
}

- (BOOL)isOptional {
    return self.step.isOptional;
}

- (void)valueChangedDueUserAction:(BOOL)userAction {
    if (userAction) {
        _valueChangedDueUserAction = userAction;
        if (_dontKnowButton && [_dontKnowButton active]) {
            [_dontKnowButton setActive:NO];
        }
    }
    
    [self ork_setAnswer:_picker.answer];
}

- (void)ork_setAnswer:(id)answer {
    // Override
    _answer = [answer copy];
    [self.delegate answerCell:self answerDidChangeTo:answer dueUserAction:_valueChangedDueUserAction];
}

- (void)picker:(id)picker answerDidChangeTo:(id)answer {
    [self valueChangedDueUserAction:YES];
}

+ (CGFloat)suggestedCellHeightForView:(UIView *)view {
    return 162.0 + 30.0;
}

#pragma mark UIPickerViewDelegate

- (CGFloat)pickerView:(UIPickerView *)pickerView rowHeightForComponent:(NSInteger)component {
    assert(pickerView == _picker.pickerView);
    return 32;
}

@end