In iOS 8, We have a UIPageViewController which scrolls between different xViewControllers. Similar to what you see on several news sites, where you can scroll between headlines. When you start pushing one page off the screen, the next hugs it, and you can see the next page scroll from offscreen and into place
In the viewDidLoad Method of XviewController, we change the constraints of the image that is visible on the scrollable pages.
However when we scroll and see a preview of sorts, The preview doesn't have the formatting present in viewDidLoad, but will eventually call viewDidLoad and the formatting will snap into place once the image has settled in the center of the screen.
So what I'm curious of, is where is the preview ( image that scrolls into place ) generated? It's not generated by either of the UIPageViewDataSource methods
The code is privately owned, so I can't really share it.
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I have an iPad app similar to the iPad Keynote with a narrow overview on the left and a paged UICollectionView of my "slides" on the right. The collection view is using the default FlowLayout. Some of these slides are standard PDFs and some are embedded UIViewControllers that have been scaled (with a CGAffineTransform) and embedded in the cell. I'd like to smoothly animate the overview sidebar offscreen and zoom the current page cell to fullscreen. The collection view should allow paged swiping at whatever size. I'm using storyboards and autolayout.
I think I need to simultaneously animate about three things:
The collection view constraints (to the sidebar) to enlarge/shrink it
The flow layout's sizeForItemAt: value
The CGAffineTransform on the embedded view controller.
I have some pieces working (a single embedded View Controller "slide" that scales correctly) but cannot get the collectionView/cell resize dance to work correctly. The cell resize animation is jerky, or ends up with the wrong offset, or works for the leftmost cell but not for other cells.
I've tried most of the suggestions in the answers to this question but with no convincing success. I can't believe it's impossible but at this point I'm considering the smoke and mirrors approach of animating a static slide and hiding it after the animation completes. The attached video - ignoring the glitches - illustrates the kind of effect I'm after:
It's worth noting, on close inspection, that Keynote cheats somewhat when it comes to swiping between slides in edit mode, and manually manages the next slide sliding onscreen, so probably doesn't use a UICollectionView.
Has anyone done anything similar, or have any suggestions for things to try?
I managed to solve this. There's a proof-of-concept GitHub repo here.
There are a few moving parts:
There are two pieces of UIView scaling code. I suspect these could be combined with suitable delegate references as the nested view controllers are embedded. The first piece scales (statically) correctly when the Collection View cell is created. The second is an animated scale/translate when the sidebar size is changed.
I added a FlowLayout subclass to remove flicker as the collection's layout is invalidated during scaling.
The sidebar-related transform in the top-level VC uses most of the tricks in the book - invalidateLayout(), performBatchUpdates(...), layoutIfNeeded() etc. as well as animating the contentOffset to the correct value. Some manual tracking of the correct page/slide is required.
There's still a slight flicker occasionally at the start of resizing. This may not be an issue with my particular colour-scheme which will be black on dark gray. Bonus points if anyone can suggest how to track this down or alleviate it.
I have used the separate banner image and scroll view for category sections and tableview for records.
Need to make all things scrollable to topside and when the scroll position reached the top position category section would fixed at top position and the table view records would continue scrolling and once the scroll down all the object would displayed to their original position back to back well which is normally happen in android apps and whatsapp profile page.
Please share your answer if you have done like this.
Here is the link for DTParallaxTableView
QMBParallaxScrollViewController
This Library same you want MXSegmentedPager
May this helps lot.
I have implemented to a page to display multiple Viewcontroller via UIPageViewController. User can scroll horizontally to view a different ViewController (And I have dynamic number of VCs, depending on the data loaded from server) .
The problem is most of the user does not know that they can scroll horizontally . I would like to show to user when they come to my app first time that the page is horizontally scrollable. Just like the screenshot below
The easiest way is to show them the half-page scroll first so they realize that this page is scrollable. But I have searched through SO and found none of the solution. If I add gesture programmatically, the app might got rejected from appstore. So are there any easy way to do this?
I want to create a view in which I like to have animation such as the one present in iOS 8 Weather app.
I try to explain more what I have done. If anything is incorrect please guide me.
In the top I put a label for the temperature. (The big one)
Below that label, I put another label to show some text. In the Weather app, there is the horizontal scrollview showing the hourly forecast.
Next is the Table view.
What I want to achieve is that when I start scrolling, the first label disappear smoothly and the second one go to top of the screen and the TableView stretches to show more content.
When I scroll back to the top, I want the whole process to revert.
What is the best way to do this?
I've recently re-created the iOS8 Weather app's scrolling effect for an app I'm creating.
The complete code is too long to post here but for anyone who's interested, I've put it on GitHub. You can download and run the project to see how it looks. Improvements to the code are welcome:
UIScrollView with masked content.
It works like this:
You have one scrollview (the size of the screen), which contains a subview (the mask) which in turn has a subview (the content). We also add a large label to the top of the screen (in the Weather app, this displays the temperature).
Then you use the scrollViewDidScroll delegate method to keep the mask fixed to the screen as the user scrolls. You also use this method to stretch the mask upwards at first.
Fixing the mask to the screen means that the mask's subviews (our content) also becomes fixed. But we want it to scroll, so we do the opposite to the content of what we did to the mask (again, using scrollViewDidScroll).
We need the mask to actually behave as a mask, so we set clipsToBounds = YES on the mask.
Finally, we use the scrollview's offset during scroll to move and fade the big label at the top of the screen.
To make it behave exactly like the iOS8 Weather app, we need to also do the following:
Cancel any scroll touches that happen above the mask, i.e. over the large temperature display.
Ensure that the initial scroll that moves the temperature display is completed programatically if the user doesn't complete it.
Add a sideways-scrolling subview which is anchored to the top of the mask.
I haven't done these yet, though.
I am sure this is an easy question, but I am lost. I have MWPhotoBrowser and a bunch of photos loaded into the browser. Everything works beautifully, except if I click on an image in the browser and drag it around the screen it moves everywhere and repositions the image. Essentially I just want to stop if from dragging around all together.
Any recommendations ?
There were two issues causing this problem:
Autolayout was turned off. Since I wanted it to remain off I had to create a work around with #2.
The content appears to be sized to the View. In my case the view height was much larger than the available display area on the screen. To work around the issue I used another view sized to the viewable area and added the browser to that view rather than the super view.