Swift: UITableView scrolls slowly when embedded in ContainerView - ios

I have two container views controlled by a segment controller. When the selected index changes, one view is set hidden and the other one is set visible.
One view contains a tableview, and the other one is a Google Maps view. I tried to remove the Google Maps view completely to see if the scrolling in the tableview would be better, and that fixed the laggy scrolling. So I know that it is the hidden mapView that makes the tableview scroll slowly.
My question is: How can I keep both container views and still have smooth scrolling when the tableView is visible? Setting the container view with the mapView to hidden does not work.

If anyone else has this problem, try to follow this blog and add the views by code instead of using container views in IB. It fixed the problem, and the tableview now scrolls like a pro!
cocoacasts.com/managing-view-controllers-with-container-view-controllers/

Related

Swift: Did Tumblr add a UICollectionView in a UIScrollView?

I've been trying to replicate this effect for a couple days which was inspired by Tumblr.
I've previously asked questions on here with different approaches of the same problem but to no avail. I'm just curious as to how the engineers at Tumblr created a horizontal collection view, with two vertical collection views, and is able to scroll down without affecting the view above (without resetting the position of the view when you scroll vertically in a different tab).
Header Views
I tried this, but the header view was isolated and I had to scroll to the right to see the collectionView cells. This did not work.
Changing the topLayoutConstraint constant of my UIView (not cv header) with respect to the contentOffSet of the vertical collectionView.
This almost got the effect I wanted, except that when I scrolled horizontally, there was a huge gap between my collection view and if I scrolled in that new tab, the UIView would appear again because, again, topLayoutConstraint gets scrolled up depending on the contentOffSet of my vertical collectionView contentOffset.
Changing the position of the UICollectionView frame, and scrolling the super view up simultaneously with NSNotificationCenter.
Alas, this method did the same as method #2, except that the vertical collection view cells scrolled faster than the super view.
I ran out of options to make this work so I will show you in detail what's attempted to be replicated (also note the scroll bar on the right):
Note when I scroll down the first tab. I switch, and then scroll down further. Originally, as I've said, there would be a gap between the second main CV, and when I scrolled, the view would reposition as if were scrolling up again. On here, the view on top keeps going up. So I'm curious as to what method Tumblr engineers used to do this. UICollectionView inside UIScrollView? Other suggestions?
I believe there is no UICollectionView involved. It looks like UIPageViewController and each its page is a UITableView.
Perhaps the UIPageViewController sits in a UITableView as well - the header also moves up when you scroll. This main table has only one cell (and a header) which is occupied by the UIPageViewController.
Hope it helps.

indexed UITableView as Part scrollable Page

I'd like to implement an Interface that shows an indexed UITableView. In the table view I want a view displaying labels and image views related to the table view.
Together they should behave as if they were on one scrollable page.
First I tried to solve the problem with a tableHeaderView (not a section header). But the problem is that the section index overlaps the tableViewHeader.section index overlaps the table header view
If have seen approaches to solve a similar problem with a UISearchBar, but I can apply them to me problem
Then I tried to embed the tableview as a container view into a container viewtable view in a containerView
The problem here is that you can scroll the tableView inside of the container View, while the top view is still visible.
I also though about fading the index in when the content offset is equal to the height of the top view. But there seems to be no official way to get a hold of index bar view.
Any ideas?

Swift; is scrollView with tableView feasible?

I've have been trying for a while now, to implement a specific behavior in my app. On the initial view of my app, there must be a logo(imageView), a label and a textField. It should be possible to scroll down from the initial view, to a tableView. while the user scrolls down, the label in moved up in the window, to form a search field for the tableView. Then the scrollView should lock to the part with the tableView, and it should only be possible to scroll back up, if dragging elsewhere than the tableView.
What is best practice for doing as described?
The image show (only for illustration, i havn't been using story board when trying to implement it) an overview of the problem:
The way I've tried to do this so far, is by embedding the tableView in a scrollView (as seen on image), enabling paging on the scrollView, and than disabling scrolling on the scrollView, when the buttom part has been reached. I've added a gesture reconizer on the part with of the screen with the textField.
These two posts (Scrollview with embedded tableview and Use Pan Recognizer to Control ScrollView) descripe i further detail what i've tried so far.
But the question is more to, is there an alternate solution for making behaviour descriped above?
Maybe interactive animated transitioning between view controllers somehow?
YES there are! Implement a table view with a header view. And remove the scroll view.
self.tableView.tableHeaderView = topView
where topView will be the view wish as the UIImage, the label and textField

Create Shazam Type UI ios Swift

I am trying to recreate a UIView I have seen in multiple apps, mainly Shazam. The top half of the screen has some interactive buttons, and the bottom half looks like a tableView with custom cells. When the bottom half is panned/swiped up, the tableView scrolls over the top half with velocity, much like a scroll view.
I have been researching this and experimenting for a couple days now. I have gotten close, but not quite there.
My last approach was a view that had a tableView inside it. When the view was panned, the view would move to wherever the finger moved it to, but then would not have any velocity afterwards. Also when the tableView was panned/swiped down, it wouldn't move the whole view down.
Before that I tried a scrollView that took up the whole length of the screen. That gave the desired effect, but the button wasn’t tappable, and you could scroll the view in the button area, which is undesired.
Does it utilize ScrollViews or is it using a tableView that acts much like a ScrollView somehow.
Here is the Shazam UI/UX I am looking to recreate:
The top portion has interactive buttons, and doesn’t scroll. The bottom half shows content and when scrolled, covers up the top portion.
Below is what I have tried so far: This one is the panning view, which sort of works, but doesn’t have velocity and the tableView doesn’t scroll the view back down.
Any thoughts on a direction I can take from here is greatly appreciated. I am using Swift.
Cheers
This sort of thing is perhaps best done with a collection view and a custom layout — you can have some items for which you set layout attributes absolute to the view, and others relative to the scroll content offset.
There's a great (if wandering) discussion of this and other techniques in the Advanced User Interfaces with Collection Views talk from WWDC 2014.
This is actually simple than it seems at first. Here's how you can achieve this:
Create a UIViewController (not a UITableViewController).
Add some buttons to the top area of the screen.
Add a table view spanning the entire view controller's view. Make sure the table view is on top of the buttons added in the previous step.
Configure the top cell of the table view to be transparent (by setting its background color to Clear). Set the background color on the table view to Clear as well. This way it won't obscure the elements at the top of the screen, unless the table is scrolled up.
Because your table view is now transparent, you'll need to explicitly set the background color on the table cells other than the top one.
Profit!

UITableView Section Headers not visible when table in visible rect

I have a UIScrollView with 3 UITableViews stacked horizontally. I switch between these tableviews using a tab-controller on top. However, when I switch to the 2nd or 3rd tab and switch back quickly to 1st the section headers don't show. They display when I scroll the tableView. These are custom headers (jfyi). I tried calling setNeedsDisplay when the tableView is visible, but that does not help because as per Apple Docs :
If you simply change the geometry of the view, the view is typically not redrawn. Instead, its existing content is adjusted based on the value in the view’s contentMode property. Redisplaying the existing content improves performance by avoiding the need to redraw content that has not changed.
Since, only the geometry of the view is changing here, it does not help. Also this happens on all versions iOS 5~6.1 and on simulator and device. Thankfully, this does not crash the app, but its a problem nevertheless. Could someone help? I am attaching pictures for reference. First shows the problem, second: after scrolling the "head(er)less" tableview
EDIT:
I am using simple scrollRectToVisible:animated: to switch between tableviews. This does the trick but I just observed that when I set ...animated:NO all is okay. The problem happens when ...animated:YES
It seems the issue of displaying and scrolling taking place simultaneously for the respective tableview. So what you can do here is:
Remove the scroll animation
or
Just scroll the tableview to top on the tab press event
or
simply reload the tableView which is made visible

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