I want to implement a cross layout just like Wallapop app does on its main feed.
As you can see, it's composed of two groups of cells (Featured items, Items near you). The first group is scrolled horizontally, and the second group is scrolled vertically.
The first UIKit component that came to my mind to make that kind of layout is UICollectionView, having one section for each scrolling direction. Unfortunately UICollectionView current implementation is very limited, forcing the scroll in one direction only, no matter how many sections you declare.
So I wanted to give it a shot with vanilla UIKit components and that's what I got;
The problem with my solution is that the vertical UICollectionViewController (highlighted in green) is scrolling on its own and not pushing the horizontal UICollectionViewControllers upward.
I've also thought about using a single UICollectionViewController for the vertical cells, and setting an UIStackView with horizontal UICollectionViewControllers as needed for the horizontal cells, but it's a messy solution and doesn't scale very well, I even couldn't set a title for the vertical cells section If I opt this way.
Ideally, I want each group of scrollable cells to be it's own UIViewController in order to have a clear separation of concerns and modularity.
Is there a better way to implement a layout like the one I want with vanilla UIKit components?
The easiest and the most stable solution is to use the following view hierarchy:
Use one UICollectionView(1) instance
Horizontally scrollable sections can be implemented as Screen width UICollectionViewCell containing horizontally scrollable UICollectionView
Vertically scrollable sections should be just a regular section of UICollectionView(1)
Pros
UIKit only
Nothing extraordinary is needed - just a UICollectionViewFlowLayout everywhere
Cells are the same for Horizontally scrollable cells and Vertically scrollable cells
Good scalability and separation of concerns. Independent behaviors of Horizontal and Vertical sections each of which can have multiple data sources.
Cons
Horizontally scrollable sections should have fixed height. Otherwise scrolling behavior will be harder to maintain.
Arrow on the image means Uses!
You could use following way:
A collection view with two cell in it. First cell is for featured items and the second cell is for items near you. The first cell will cover full width and height required by your design.
For scalability use a Container View which embed a CollectionViewController which will responsible for showing featured item. This embedded CollectionViewController will scroll horizontally.
Items near you are straight forward direct cell of the initial collection view controller.
So your implementation of featured horizontal collection view remain in the embedded CollectionViewController and the items for cell remains in the primary CollectionViewController which also contain a loose connection (embedding into a container view) to the featured item.
It also does not suffer from the problem like scrolling vertically the items for sale does not scroll up the featured items.
Here is a screenshot which depicts the idea
Related
I would like to construct a view controller where one section of the view controller would be still and one section scrollable.
Both sections have headers where as well, one is still and one is moving along with the content in the section.
I do not want the cells in the section to be scrolled separately. All cells should move at the same time along with the header.
I have added an image to make my point little more clearer.
Use UICollection View for both view and disable scrolling for one view and enable scrolling for another view
you can probably add to your UIViewController view a UITableView on the left with fixed size (for example 150px) and vertical scroll disabled and a UICollectionView with horizontal flow and ,if needed a, with custom UICollectionViewLayout (but i think that you just need the classic UICollectionViewFlowLayout) for the right part that fits the remaining space.
Here you can find the component's documentation:
https://developer.apple.com/reference/uikit/uicollectionview
https://developer.apple.com/reference/uikit/uitableview
A question for the UICollectionView experts.
Imagine a collection view that looks like a table view (full width cells), and when you tap on one of them, new cells are inserted underneath that cell that are square cells, say half the width of the collection view, in 2 columns. Tapping the header again would appear to collapse the section.
Keeping in mind that I’m trying to use UICollectionViewFlowLayout instead of a custom UICollectionView.
Would you:
A) implement the tableview style cells as collection view supplementary views (headers), with a gesture recogniser that inserts the square cells?; or
B) implement the tableview style cells as one cell type, and the square cells as another cell type?; or
C) something else?
Personally I would go with option A. In the situation you're describing the full width item is really a section header that's function is to show/hide it's sections's cells.
From a data structure standpoint this is much easier to maintain with this approach. It can be handled with an array of arrays.
If they were all cells it would most likely be one large array, and would be more difficult to make the distinction between a full width cell and the half width cells.
I haven't worked with collection views a whole lot.
A client wants a horizontal collection view set up with paging enabled.
They want a single cell centered in the collection view, with the edges of neighboring cells peeking into the view to provide a visual cue that they can swipe to see other cells.
If I set up the collection view using paging and a default flow layout, as I page over each cell ends up shifted to the left a bit more.
I implement the UICollectionViewDelegateFlowLayout protocol's collectionView(_:layout:insetForSectionAtIndex:) method, I can set up section insets such that each cell is kept centered, but when I do that the neighboring cells don't appear, and ONLY the current cell is ever visible until you start scrolling.
I assume I need to do something with a custom flow layout, but I'm not sure what, exactly. Can somebody offer some guidance?
(I'm working in Swift 2.3, although I'm "bilingual", so answers in either Swift or Objective-C are fine.)
I am trying to implement something like this:
I have a UITableView with 1. "static" section, the total number of sections in the tableView can vary. I always want the first section (white area) to be visible to the user, the remaining sections should scroll underneath the first section. I have tried to implement this with two UITableViews, but since the (white area) can vary in size, I can't set a definite frame. I am using Storyboards with autolayout. At the moment the best solution I have come up with is the two UITableViews, but I need to find a way that I can resize the two tableViews according to the content of the white area and according to each other. The white area, one of the tableViews is containing a section with two rows, the first row is containing text that can vary in length and therefore needs dynamic resizing.
Any Idea how I can tackle this? Can I change the NSLayoutConstraints dynamically somehow?
If i understand correct, your first UIView rectangle if fixed, bottom table is scrollable.
To implement this, you should create typical UIViewController, add UIView and UITableView (programmatically or through an outlets). You should manage each view (tableView and UIView) separately.
I want to implement a UICollectionView with multiple sections which each section scrolls horizontally and independently like the attached image
I suggest you to use UITableView with customized UITableViewCells with UIScrollView as subview on its contentViews.
There are many samples, for example here
You can use multiple UICollectionViews in table cells. The tableView will scrolls vertically and The collection views can be configured to scroll horizontally by setting particular set of properties which will restrict them to scroll vertically, and they will only scroll horizontally. One constraint to consider is it is much more difficult to do animations that need to move from one table cell to another and you can't use a neat single change of collection view layout to animate all the items in your table view. But if these constraints aren't a problem then this is a relatively easy solution. I also tried it once. It worked for me. Hope that it works for you as well.