My application consists of multiple pages by scrolling horizontally - done by having 2 swipe gesture recognizers over the whole ViewController. On every page I have a ViewTable with items that scroll vertically.
Unless I do a perfect horizontal swipe, the TableView takes over the recognition and does a slight vertical scroll on the table rows.
How do it change the scrolling recognition angle for TableView? Because the table's vertical scrolling is responding from touches around 10º ~ 170º. Whereas I'd like them to be 45º for each direction. How do I narrow that angle? So that my main left/right pages respond easier without having to try to do a perfect horizontal swipe.
I have not really made such a gesture but this is how I think this can be achieved. This is similar to ViewPager on Android. You can use a normal Gesture Recognizer over UITableView, calculate how much x and y displacements are there and then decide whether you want to handle the horizontal scroll yourself by shifting the page or pass the control down to UITableView.
But if you keep your Gesture Recognizer below UITableView, you will never get the control to act upon the gesture unless UITableView passes down to you.
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I essentially want a UITextView to scroll vertically but not ever be able to accidentally scroll the UIPageViewController when the gesture occurs within the UITextView.
I do still want the page turning gesture to work along the edges though:
I'm building an iOS layout which consists of a UITableView and a UIScrollView. The UIScrollView is inside a table cell of the UITableView and can be scrolled both horizontally and vertically. The diagram below shows this situation. If the user begins scrolling down/up on the UIScrollView the scrolling event should trigger setContentOffset of the table view, and not setContentOffset for the scroll view while the top of the scroll view will be on the dotted line (it's constant height). Then a scrolling touch event should trigger setContentOffset for the scroll view, not for the table view.
In another case: When the user starts scrolling on the table view, it should trigger setContentOffset for the table view, until the scroll view reaches the dotted line. Then the scroll view should handle setContentOffset.
My problem is how to transfer touch events between the table view and the scroll view during one sliding action.
This sounds like one of those cases where you want something quite specific and custom. So trying to do something clever with the gesture recognizers won't be enough.
The main problem is that the ways you can control gesture recognizers such as with gestureRecognizer:shouldReceiveTouch: and gestureRecognizerShouldBegin: only affect the start of the gesture (or for new touches, not ongoing ones), but you want a single ongoing gesture to transition between controlling each view. So for this reason I think you will need to place a large transparent view over your entire screen with a pan gesture recognizer on it and in your handlePan method decide which view you want to adjust and then call setContentOffset directly on that view. You can use the translation of the pan recognizer and the existing content offset to calculate the new one. I know this isn't very elegant, but I can't think of another way to achieve the effect you want.
I'm not sure if this is going to work, but you could try doing something like this:
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self.scrollView.panGestureRecognizer = self.tableView.panGestureRecognizer;
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[self.scrollView addGestureRecognizer:self.tableView.panGestureRecognizer];
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[self.tableView.panGestureRecognizer requireGestureRecognizerToFail:self.scrollView.panGestureRecognizer];
I have a UITableView and would like to have a custom way to delete my cells. When someone swipe on it, the cell would move horizontally on the side and disappear.
Exactly like the multitasking menu on iOS 7 (http://movies.apple.com/media/us/ios/ios7/f34c5445-5a9c-4b3a-9556-8efe89147559/shared_multitasking/shared_multitasking_2x.mp4), but instead of swiping vertically, it would be horizontal.
Does any one knows how to do that? Should I just detect a swipe and change the frame of my cell with a 1 sec animation? Or are there nice subclasses of UITableViewCell you would recommend?
I just threw together a very basic example of how to do this and posted it here: https://github.com/NSPostWhenIdle/MMSwipeToDeleteCollection. Don't expect to be able to drag and drop this into your project and have it work, because quite frankly it probably won't.
The basic idea to create something like this starts with a subclass of UICollectionViewCell that adds a gesture to the cell. In my example, I used a swipe gesture because I'm lazy :p and there is more overhead involved in setting up a pan gesture (which you'll want in your end product) because there is conflict between that pan gesture, and the pan gesture in the collection view's scroll view.
From there it's basically smooth sailing. When the gesture recognizer gets called you animate the cell out the top of the screen. If you set this up with a pan gesture, you'll need to configure this to drag the cell, and animate up or down upon completion, but in my swiping example, the cell moves to just out the top (of the 4 inch simulator, I used static values).
Then all that's left to do is some clean up. Once the cell has exited the screen you can safely delete it from your datasource and then from the collection view. (I used notification center do alert the collection view, but you should probably make a protocol) The only issue I had with this was that the cell animated back down while fading out as part of the stock deletion animation. Setting its alpha to 0 after it leaves the screen solves this problem.
I've been fighting with UIScrollView for a while now.
I have a scroll view which has multiple 'card' style views in it. I want the cards to move vertically, as in swiping up and down.
Imagine MobileSafari's tab view, but with swipe down to close tabs.
I can't figure out how to do this without it conflicting with the scroll view horizontal panning. I either get them both panning, or only one panning (vertical / horizontal).
What's the best practice to make this work perfectly, as in "if you're swiping vertically, stop horizontal swiping, and if you're swiping horizontally, stop vertical swiping".
Thank you!
Here's an illustration of what I want :
The scroll view has its own gesture recognizer: see its panGestureRecognizer property. If you add your own recognizer for detecting the vertical swipe, you can use requireGestureRecognizerToFail: or delegate methods to manage dependencies between the two recognizers.
I'm really confused by the intended behaviour of your app here. You are using swipe and panning interchangeably but they are different gesture recognizers.
Well one way to differentiate is to compare the x and y values of the translationInView: method of the gesture. If y > x, you have a vertical swipe/pan; x > y and you have a horizontal swipe/pan.
Make that gesture recognizer fail if the swipe/pan detected is not the type you are looking out for.
The main view of the iOS app "Piictu" is a vertical scrolling list of photo albums. The thumbnails of each album are displayed inline and scroll horizontally.
If you swipe down or up from any point the parent view scrolls vertically, even when the starting point of the gesture on an album thumbnail.
What's your best understanding of how this is done? A vertical swipe gesture recognizer on the parent view and a horizontal swipe gesture recognizer on the album child/sub views?
Or, is this perhaps a UIWebView?
Thanks!
It's a lot simpler than that, or at least it can be done a lot simpler: just nest scroll views. The outer one covers the whole screen and only allowing vertical scrolling. Each series of thumbnails is contained in another, smaller scroll view which only allows horizontal scrolling. I've used this technique myself for an app I was contracted to develop.