EXP PagingScrollView

PagingScrollView.h

//
//  PagingCollectionView.h
//  PicCollage
//
//  Created by yyjim on 2/22/16.
//
//

#import <UIKit/UIKit.h>

@interface PagingScrollView : UIView

@property (nonatomic) CGFloat pagingWidth;
@property (nonatomic) CGFloat pagingHeight;

@property (nonatomic) UIScrollView *scrollView;
@end

PagingScrollView.m

//
//  PagingCollectionView.m
//  PicCollage
//
//  Created by yyjim on 2/22/16.
//
//

#import <Masonry/Masonry.h>

#import "PagingScrollView.h"

// =============================================================================

@interface PagingScrollView ()
@property (nonatomic) MASConstraint *widthContraint;
@property (nonatomic) MASConstraint *heightContraint;
@end

// =============================================================================

@implementation PagingScrollView

- (instancetype)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
    }
    return self;
}

- (void)setScrollView:(UIScrollView *)scrollView
{
    [_scrollView removeFromSuperview];
    _scrollView = scrollView;
    [self addSubview:_scrollView];
    
    [self.scrollView mas_makeConstraints:^(MASConstraintMaker *make) {
        make.center.equalTo(self);
        make.width.equalTo(@(self.pagingWidth)).priorityLow();
        make.height.equalTo(@(self.pagingHeight)).priorityLow();
        self.widthContraint  = make.width.equalTo(self.mas_width).priorityHigh();
        self.heightContraint = make.height.equalTo(self.mas_height).priorityHigh();
    }];
}

- (void)setPagingWidth:(CGFloat)pagingWidth
{
    if (_pagingWidth == pagingWidth) {
        return;
    }
    _pagingWidth = pagingWidth;
    
    if (_pagingWidth == 0) {
        [self.widthContraint activate];
    } else {
        [self.widthContraint deactivate];
        [self.scrollView mas_updateConstraints:^(MASConstraintMaker *make) {
            make.width.equalTo(@(_pagingWidth));
        }];
    }
}

- (void)setPagingHeight:(CGFloat)pagingHeight
{
    if (_pagingHeight == pagingHeight) {
        return;
    }

    _pagingHeight = pagingHeight;
    
    if (_pagingHeight == 0) {
        [self.heightContraint activate];
    } else {
        [self.heightContraint deactivate];
        [self.scrollView mas_updateConstraints:^(MASConstraintMaker *make) {
            make.height.equalTo(@(_pagingHeight));
        }];
    }
}

@end