How to get UITableView header view to come before table cells in responder chain? - ios

I have a rather large table header view above my table view. I have a number of subviews in that header view. I am doing something a bit nonstandard where I am "sticking" some of those subviews (but not all) at the top of the table view.
My problem is that although visually the table view cells pass under the sticky table header subviews, it seems that the table view cells are "above" the table header view in terms of touch response. (For example: I have a button that is a subview of the table header view. When there are no cells underneath the button, the button works great and responds to touches. However, when the user scrolls the table view so that there are cells underneath the button, a touch on the button actually selects a hidden cell rather than push the button.) Can anyone give advice on how to "raise" the table header view above the table view cells, so that its subviews get first shot at touch handling?
I am using a table header view rather than a section header view due to the fact that I only want some of the subviews to stick (letting the others scroll up off the screen as usual). One of the subviews also can be expanded (and that expansion is animated) - to a height that is even bigger than the entire height of the screen. For these reasons, I didn't think using a section header view would be feasible. (If it is, please let me know, as I know that section header views are "above" table cells when it comes to touch response.)

You may try this, which would keep the desired header view on top of the others.
[yourView bringSubviewToFront:yourSubView];
This may be able to help as well:
http://www.iphonedevsdk.com/forum/iphone-sdk-development/5222-keeping-subview-front.html
Is this what you were looking for or did you want another approach?

Related

How to make header only stick on negative content offset - Swift

I have a tableView and I have a UIView as the tableView header. I want the header to move up the screen when I scroll down and act just like any normal cell. But when I have reached the top of the view, where if I scroll up it will just bounce back, I want the tableView header to stick to the top.
One example is like the Facebook app headers. They scroll when you scroll, but if you're at the top of the page and you scroll up, they wont scroll down, they stay stuck to the top.
How do I achieve this?
If you're using a normal tableView (not grouped style) and you only have one section, you can accomplish this by using the section header instead. The default behaviour of this type of tableView is as you described. You'll just have to provide a custom view for the section header that looks like your cell.
If this isn't a possibility, you'll need to take advantage of tableView being a subclass of scrollView, and implement the scrollViewDidScroll delegate method to check content offsets etc.

One section of the view controller is still and one section horizontally scrollable

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

How do I structure a table view to load halfway down a view?

I would like to make my UITableView load covering half of the window with a background view that starts visible, and as the window scrolls, is gradually covered by the table's cells.
Initially, I want to style is like so:
As the user scrolls, the cells will cover the background element.
The only way I could think to accomplish this would be to put the background element behind (and outside) a ScrollView (which is sized to fit over the background element and has a transparent background), put the TableView inside the ScrollView, and set the load coordinates to start the table far enough down. Is there a better way to accomplish my desired design?
I would prefer to avoid this layout because I would like to be able to easily add more cells dynamically as the user scrolls, ideally without having to deal with resizing the ScrollView.
You can take a view inside table view just above the table view cell and make its height whatever you want space in table view and make a outlet of that view. Then in view did load assign the view as table header view like this.
self.tableView.tableHeaderView = self.headerView;
This will be displayed exactly like you given and when user scrolls it will show the below cells and when you want you can change the frame of the header view and your header become invisible. You can do it whenever you want i mean if you want to change height on scrolling or if you want to change on adding more cells.

How should I approach structuring this view?

I'm having a hard time finding the best way to structure this design.
The top view has a minimum height and becomes sticky when it reaches this height. The bottom view hosts a paging controller with three views within. Each of these views hosts either a collection view or table view with vertical scrolling.
I'm really at a loss on how to approach this. Is the entire view scrollable and I should prevent scrolling on the second view until the top view has reached it's sticky height? Or are each of these views separate uitableviews and the pagingcontroller is just one cell? Should I even be using a pagingcontroller or should I use a scrollview with paging enabled? (the latter was a little rough interaction-wise)
Thank you!
Take a look at the Advanced User Interfaces using Collection View from WWDC this year. This view is very very very similar to the iTunes Connect app interface. The entire session video explains how they created that interface.
I used a similar method to this to create the keyboard in the Emojicate app.
I think what I'd do is actually fake the sticky header. So something like this...
Use only one collection view.
Create a "segmented data source" that contains three data sources. (See the video from WWDC about this)
When the segmented control is changed then update the collection view by changing its layout and (if you want) dataSource.
Make the entire top section a header on the collection view.
When the collection view scrolls past a certain point (when you want to sticky the header) then have a second view that is the compressed header and make it visible at the top of the screen. This is not attached to the collection view at all.
When the segmented control changes you can update the collection view by changing the "selected datasource". The datasource can also contain a UICollectionViewLayout that will update it.
Essentially, the tableview you are talking about is just a collection view where the cell width is equal to the screen width. i.e. fake a table view.
The sticky header isn't sticky at all. Just when it starts to go off screen you can put a fake header there instead.
It will require a duplicate (ish) view and some thinking about how to structure the data but I think this will be easier and less resource hungry than having multiple collection views and page controller and stuff.
If you want me to go through it in more detail let me know but it's a complex subject. Watch the video first.
I would make this part a navigation bar. Should be relatively easy. Just have to customize the back button with a barButtonItem and do a couple of labels in the titleView.
I would make the next part a Table View.
The tableView has 2 sections. The first section doesn't have a section header and the second section doesn't have any cells but just a section header.
First and only cell in this section:
And the rest would be the second section header's view:
This gives you the stickiness that you want because the section header will remain there even if you scroll past it and since the collection has only 2 sections the controls will always remain on top.
I think the collection/table paging part is the hardest part and I don't know clearly how it can be done. But I was thinking it could perhaps be a ContainerView. Each view of the container view would be either a tableview or a collectionview. You would have to add some code to handle the movement of the containerview relative to the second section header (possibly an autolayout constraint that attaches the containerview to the buttom of the first tableview that you implemented above).
I don't think having your tables/collections in a scrollview would be a good implementation. I think I have even read in documentation that developers should stay away from that (but I might be remembering it incorrectly).
I would have:
A "header view" with three subviews:
Fixed height top and bottom views (they stay visible at any size).
A middle view that appears/disappears as the superview grows/shrinks.
A scroll view (table or collection view are subclasses) on that partially covers the header view with a top inset set enough to reveal the underlying header view (the same way pull to refresh views are revealed).
The paging buttons could be set as table/collection view section header views.
Finally track the scroll view's scroll position to keep manually adjusting the header view height.
Another way to see this solution.
Two completely separated parts, a header view and a table view.
A simple header view (blue) that adjusts its subviews as its height changes. More precisely hides its middle subview (light blue) when it shrinks.
A table view that a) partially covers the header view in Interface builder but b) has a top inset as to avoid hiding the header view in the actual device (tableView.contentInset = UIEdgeInsetsMake(60.0f, 0.0f, 0.0f, 0.0f);).
The two parts are only "connected" by resizing the header view height as the table view scrolls up/down.

UITableView grouped with transparency above to reveal content behind it?

Is it possible to make a grouped UITableView transparent above and below it's content. I am not looking for a parallax-type solution, but I have a UITableView that I add to my view controller. When pulling down on the table view, I would like to display the view controller view (that the table view us a subview of).
Right now, when I add a UITableView with the same frame as my view controller's view and add it as a subview, when I drag down on the UITableView the header above the first cell is the same colour as my UITableView's background. Instead I would like for it to reveal the content behind it more and more as the user drags down.
Is this possible and how? Thanks.

Resources