Get default scroll direction for UIScrollView Swift-CodePudding

I have an application that uses more UIScrollViews and extensions from it like UICollectionViews and UITableViews and for a little dynamism I have created some general functions to help me with some paddings / margins.

My functions are created as extensions for UIScrollView and I want to use them just when the scroll view is only vertical.

My Question

How can I find the scrolling direction of a UIScrollView?

I have found a lot of answers of how to find the scrolling direction, but I need when the UIScrollView is initialised to find the scrolling direction of it, if it's vertical or horizontal.

Thank you for your time!

CodePudding user response：

The only solution I can think of depends on the type of UIScrollView in question.

So first step check if it is a UIScrollView, UICollectionView or UITableView.

In the case of a UITableView

I think a fair assumption here is that the scrolling direction will be vertical

In the case of a UIScrollView

This one could be tricky but I guess here you would have to compare the content size with the frame as Desdenova suggested.

In the case of a UICollectionView

This data will lie in the in the layout of the UICollectionView.

For example, I set up a basic UICollectionView in Storyboard using a FlowLayout without any data in it.

Then I add this code somewhere appropriate

if let layout = collectionView.collectionViewLayout as? UICollectionViewFlowLayout
{
    if layout.scrollDirection == .horizontal {
        print("horizontal")
    }
    else {
        print("vertical")
    }
}

This prints out horizontal.

CodePudding user response：

For the UIScrollView you have to use the UIScrollViewDelegate scrollViewDidScroll which is helps you in UIScrollView's Scroll direction also for that you have to add some checks for the get the directions:

func scrollViewDidScroll(scrollView: UIScrollView!) {
    // Update ScrollView direction
    if self.lastContentOffset.y > scrollView.contentOffset.y && self.lastContentOffset.y < scrollView.contentOffset.y {
            // Vertical Scroll
    } else {
            // Horizontal Scroll
    }
}