I have an application in which I have implemented the system transitions between views UIPageViewController offers. The problem I have is that in each view images placed indicating the Frame where they have to be affixed. If this frame outside the screen, when I make the transition to pass page, the pieces of the images protruding frames page are shown. I know the best way for do this is edit the image erasing this piece, but the problem is that this images with I have the problem, are dynamically set in place for each size of screen
The best way to this is setting view.clipsToBounds = true.
Related
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.
Let's say I have a complex UIView, which is initially on the screen with quite small frame, let's say 80x80.
One of its subviews is an UIImageView displaying an image whose actual resolution is 1024x1024.
When the user tap the UIView i want the view to zoom in almost full screen so that the user can better see the image.
I know already how to scale a UIView to zoom in, my question is the following.
What's the best way to zoom in this view without pixellating the image?
I thought of these options:
I can actually set the frame of the UIView to the full screen size, and normally scale it down, so I'm sure that when it's zoomed in, it will be perfectly detailed. This solution anyway have a strong performance issue, cause moving around many of these scaled down views, will be quite an hit on the CPU/GPU.
I can do it just as I described, so small frame and scale > 1 to zoom in, but in this case will the image be displayed without pixellating?
I can actually set the frame to redisplay the view at the big/small size. In this case the detail will be good, but I have a performance hit here too, because my UIView have around 15 subviews that need complex calculation to relayout, so it's not so "fast" to set the frame.
Which is the best solution? Or do anybody have any other better solution?
Why dont you just have thumbnail representations that are 80x80, and when the user taps on any thumbnail, you transition from your current view containing all the thumbnails to a new view with the +transitionFromView:toView:duration:options:completion: method and simply display a UIImageView with the full resolution image loaded into that new view :)
I have created a small app using a ScrollView w/ paging and a series of UIImageViews each representing a page. It acts similar to the Photos.app.
I want to be able to pan and zoom individually for each image (page of a scrollview).
What would be the most sound approach to do this? Should I replace the UIImageView page with a scrollview with a UIImage inside it? I would then have a main scroll view where each page of the scrollview had a scrollview with an image inside it that could be pinched,etc.
It seems like a messy approach. I am looking for a clean approach. Any suggestions?
Well, as far as I know the approach you suggest is the way it is done. I have used this to create a PDF viewer and once everything is in place it doesn't feel too messy.
You might want to use CATiledLayer as your inner (per-page) scrollview's layer (instead of CALayer) if these images you have are really big (which could well be the case since otherwise zooming in on them would not bring you much but pixelation, but this is just an assumption on my part).
Checkout UIPageViewController. This controller manages a view controllers for each page and transitions between them using effects like page curl or scroll.
In your case you would create a view controller that manages a scrollview for zoom & pan for each page.
I've got a scrollview that allows the user to scroll between different pages and then tap on one to have it expand so that they can read the page in full, a little like how one changes tabs in Safari on the iPhone. Changing the frame size of each sub view is a bit of a pain when rotating as the scroll position is getting lost as the content size of the sub view has to change too. I was wondering if there was a more effective way of
resizing the views for entering 'viewing' mode or rotating the device.
The solution to your first problem is when you want to expand the view, pull it out of the scrollView then add it to self.view.subviews with an appropriate frame, then animate the frame to fill the screen. When done with it do the reverse, shrink it, then when its back to the appropriate size stick it back in the scrollView.
If for some reason this does not work - the scrollview is showing other stuff that gets moved when you remove the view, then instead of just removing your view from it, create a simple UIView of the same size as the view you will expand, and essentially replace the view you pull out with the "placeholder" view.
I need to implement a zoomable UIPageViewController in iOS 5 when in a two pages layout mode (in other words, when the Spine Location is set to Mid).
Using a scrollview for each page works fine when only one page is displayed. But when two pages are diplayed side-by-side in landscape mode, how can one seamless synch the pages and align the borders during the zoom animation?
One possible solution would be to put the UIPageViewController inside a bigger UIScrollView controller, but this yelds a blurred image because the two scrollviews inside the pages are not updated with a higer resolution area of the source images when the parent is zoomed.
It seems that is impossible to zoom inside a UIPageViewController when in two page mode. Is there someone who found a solution to this?
Thanks in advance.
I am still testing, but I have this.
I used the pageviewcontroller template.
I changed the scene to show a image instead a month (inside a UIImageView).
used a UIPinchGestureRecognizer to zoom the image and an UIPanGestureRecognizer to move the image once it is zoomed and it works.
The only problem is sometimes the page swipe is recognised instead the pan, so it changes the page instead moving the inside image.
And it only zooms a page at a time, I marked clip subviews in the view of the dataViewController, so 2 pages remains the same size even when you zoom in the other.