I've just vertical scrolling a few times in the past, but now I'm trying to implement horizontal scrolling but when I run it it doesn't scroll.
What is the problem with it?
P.S. is it possible to design and layout views using a storyboard for scrolling? In this example the blue view is still visible within the screen representation, so its ok to deal with, but suppose I wanted to add another view which is further to the right and thus not visible within the screen representation? Is there anyway of visually designing a scroll view where you can see all the entirity within the storyboard what it will look like?
You don't have a trailing constraint on the scroll view's direct subview, so the scroll view cannot compute the correct contentSize.
Also, it's easier to understand the constraints in the document outline if you give each view a unique label. You have two views labelled “View” so it's difficult to be sure which constraints connect to which “View”.
Related
I have the following autolayout-driven setup:
Main viewController, with a scrollview inside it. Scrollview pinned to superview edges. This one scrolls up and down.
A few normal, fixed size views at the top of the scrollview
Another scrollview. This one scrolls left and right. The second scrollview contains a couple of tableviews, side by side. The idea is that the user can switch between them. They both contain a handful of cells, all the same width as the screen and 72pts tall.
The problem I'm trying to solve is that the tableview contents are not the same size. The left one has say, 6 cells, and the right one has 3.
My first approach was to dynamically change the second scrollview height to match which ever tableview was currently visible. What ended up happening was that switching between the two tableviews (by doing setContentOffset:animated:) went extremely wrong if animated was set to true - it would adjust the content offset so everything was offscreen. In fact it would set the content offset to and then as I switched, about a dozen times, then it'd reset. It was weird, I gave up.
Now I'm trying to just adjust the content inset of the main scrollview to offset the gap in the content of the current tableview, and it's also being weird. When I set the bottom content inset in viewDidLoad, it works fine. When I set it at the time the tableview becomes current, it does nothing.
What gives? What scenarios would lead to these view interactions not behaving properly?
Use different tableViewController for each table.
Embed them in pageViewController.
Add those few normal, fixed size views at the top of the pageViewControllers view.
Conform scrollViewDelegate in pageViewController.
Pass scrollViewDidScroll from tableViews to pageViewController.
Set tableViews inset to match those fixed size views at top.
Change height according to the scroll.
This is the way you can achieve the functionality you want.
I hope it helps.
I have a scroll view which works fine. Almost. I'm building in Any/Any. The problem is that the scroll view won't scroll past the view controller. I have a switch that is mostly in the view controller window, but the rest is off the box (not really sure how to describe it; it's in the view in the scroll view, but the view is longer than the view controller so part of it is hidden).
The scroll view will scroll down until it hits the part where the view controller would end if you were looking at it in Xcode. There is some more stuff under the switch (labels and another switch). To view these you have to forcefully scroll down. Xcode shows no constraint errors (little red circle with white arrow).
Hopefully this makes sense
A ScrollView needs to know the height and width of the content it is holding in order to know how much to scroll and which direction. Here is a quick read on how ScrollViews work in iOS: https://www.objc.io/issues/3-views/scroll-view/
You can set this programmatically using the contentSize property, but this requires you to know and or calculate the contentSize, which is pretty tedious in most cases.
The correct way of defining the contentSize in iOS is to define AutoLayout constraints in your View. Here is an excellent tutorial on doing just that:
https://www.natashatherobot.com/ios-autolayout-scrollview/
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!
I am trying to find the way to implement a scroll view on my viewController screen, which allows the user to scroll between different pages of controls and have the controls around it, outside the scroll view, react to whatever data or actions take place in the scroll view.
All the tutorials I have found is adding a scroll view that shows a carousel of images, or programmatically adding coloured frames. Very little control interaction.
But none that shows how to create 2-3 pages of controls (buttons and labels), and how to integrate it with the parent view (so the parent view and scroll view talk to each other in one view).
So for now, what would be the first step to create a scroll view with 2 'pages' of controls? Has anyone come across any good resources for this? How is the best way to achieve this?
Thanks!
Add Scroll View. Add top,left,right, bottom constraint to scroll view. Set horizontal only in storyboard.
Add a view inside scroll view. Now add height constraint from this view to super view. (Not the scroll view.) Specify some width and add width constraint.
I suggest you to use UIPageViewController for this type of scrolling.
I suggest you go for UICollectionViewLayout and enable paging to true. Using this will give you the finest control of each page and the horizontal as well as vertical scroll.
So, what I need: 3 pages (with swipe support): two of them just fit the screen, third one must have vertical scrolling.
1) Can you provide what bunch of controls I need to use: ScrollView with vertical scrolling inside parent ScrollView with paging enabled? Or ScrollView with PageControl?
2) How to adjust vertical ScrollView. I've read bunch of question here, and tried to do that by myself.
I tried to add 4 constraints for ScrollView (pin it to parent edges), then I add child UIView, also pin it to Scroll edges. Then I add some rectangles to child view, and using different settings I got: just horizontal view, horizontal+vertical scroll, only vertical scroll but with top space from UINavigationBar and with clipped some height from child rectangles (I can't scroll to them).
Can someone provide some example of how to do that? I prefer IB for constraints, but if it's necessary to calculate some math in code - it's ok.
Thanks
When paging between view's like that, I would suggest using a UIPageController (You can easily get a sample application by creating a new project and selecting "Page Based Application"). Change the transition style from Page Curl to Scrolling and there is the functionality you need for paging between view controllers. Now you just can place a scroll view in your third view controller and make sure the attributes are as follows. DirectionLockEnabled is the key to what you are trying to do, as it determines if scrolling is disabled in a particular direction (this case horizontal scrolling). Using this type of solution, it is then really easy to set constraints because you're setting constraints for 3 separate view controllers rather than 3 views within a scroll view
edit: disable "Shows Horizontal Indicator" Checkbox also