I am looking to create a simple parallax scrolling effect on an image view that is embedded in a UIScrollView in swift (actually, I have the image embedded in a view that is, in turn, embedded in the UIScrollview). This is the layout I am working with:
As you can see from the screenshot above, the image is larger than the UIImageView to which it is assigned. When the user scrolls down the screen I would like other (vertical) portions of the image to become visible, such as in the example given in this tutorial. The tutorial, however, uses a collection view to display a mutable array of images and I could not figure out how to adapt it to my purposes. Does anyone have an idea as to how to accomplish this?
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I am trying to build an iOS app that will have the structure of Facebook's feed:
A vertical collection view that will have cells. Each cell will consist of image and text.
In fact, I am building my app with the help of this video by LetsBuildThatApp (this guy rocks by the way).
Currently, I am able to touch the image and animate it to full width, and also pan to dismiss it if velocity on Y-axis is more than a specific threshold.
What I want to achieve after that is to also be able to pinch/double tap to zoom. Like this:
I searched around and found some great articles on how to use UISCrollView to zoom. [Article1, Article2].
The problem is that I use autolayout to perform animations but these articles either use Storyboards or frames to position the image in the center of the scroll view [or at least this is how I understand it]. And also they don't involve any animations to start with.
Also, I don't want to present or push a view controller onto the navigation controller stack. I would rather animate the view on top of the base view as I do now.
Any idea on how to achieve this?
Thank you in advance!
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 am looking to achieve a similar effect to the Netflix app where at the top they have a scrollable header displaying different 'featured' movies.
As soon as the header start to scroll and the next image enters the view it downloads the image, also while being scrolled if you let go it snaps into place the image that was currently being shown the most.
I am not sure how to proceed and try to solve this problem. Any suggestions? should I look at using UIPageControl, or should I use a horizontal UICollectionView?
Thanks
You can implement it by using a horizon collection view，it can help you handle the reuse of imageViews!Or you can use a UIScrollView to contain a couple of subViews to display the image or three subViews and switch the image content
I'm trying to create a scroll view like the one used in the airbnb app.
At start the view display the image and under the image there is many subviews with info.
when scrolling the image start to shrink in a parallax way till it's gone.
Any ideas how to implement it ? I prefer to understand how it's done rater then using some github control
I'm using a UICollectionView (with horizontal layout) to manage a collection of images. The view controller that manages the collection view has the bottom toolbar visible with a play button to start a slideshow of the images in the collection. My question is what is the best way to implement a slideshow that involves a collection view? My initial thought was to try to make the collection view changing the visible cells with a UIView transition (transitionFromView or transitionWithView) with a cross dissolve option but I didn't get the effect I was expecting (maybe something wrong in my code). The other idea I had was to simply add a subview to the collection view to handle slideshow. This subview would have access to the data source and be able to iterate through the images. Don't know if this last option is a good way to approach the problem. Anyone has ever tried this and/or what would the recommendation be to solve this problem?
My idea is no need of collection view. In scrollview place imageview which display images. In timer Change the offset of scrollview. so it looks like automatically images are changing as like slide show.