I'm using a UIView subclass in my Today widget. The view makes use of swiping gestures. However, these gestures either scroll the whole Notification Center up and down, or make the Notification Center switch from Today to Notifications.
Is there any way to prevent the touch events to be bubbled up to the Notification Center scroll view? Using [self setExclusiveTouch:YES]; in the subclass did not solve it unfortunately.
Is there any way to prevent the touch events to be bubbled up to the Notification Center scroll view? Using [self setExclusiveTouch:YES]; in the subclass did not solve it unfortunately.
No. Because of the remote view hosting that your Today widget is being presented inside, [self setExclusiveTouch:YES] doesn't quite do what you want.
The rough architecture in iOS 8.0 is:
[User touch creates a UITouch]
|
v
Notification Center (UIScrollView)
|
v
UIRemoteView container
(presents your UIView)
[crosses process boundary]
|
v
your Today widget's UIView
Think of the touch as basically becoming cloned when it crosses the process boundary. Your view's exclusive touch desires are only relevant in your widget's process space/window, and don't propagate back outwards to the Notification Center which is hosting you remotely.
Apples official advise as mentioned in another answer:
Avoid putting a scroll view inside a widget. It’s difficult for users
to scroll within a widget without inadvertently scrolling the Today
view.
This is pretty poorly written advice from Apple. It is perfectly fine to use a scroll view in a Today widget but you must disable scrolling so that it doesn't interfere. Apple even use a UITableView in their WWDC talk.
Basically it advises you not to interfere with the Notification Centers existing gestures.
The existing gestures happen to be scrolling in all four directions so you are pretty limited on what you can do with gestures in a widget.
What sort of gesture are you trying to achieve? You mentioned swiping but if you do that you're going to interfere with the existing gestures and break things. This sort of behaviour wouldn't be allowed in a widget as it would effect the UX of the operating system itself.
Maybe you should look into taking a different approach to handle your action?
According to Apple's App Extensions Programming Guide:
"Avoid putting a scroll view inside a widget. It’s difficult for users to scroll within a widget without inadvertently scrolling the Today view."
Related
Edit: I am editing my initial question (see below for history) as I am getting new information.
I figured out that when the swipe motion starts from inside the button bounds, we never receive TouchesEnded or TouchesCancelled, only TouchesMoved. However, if I can react on WillEnddragging, it would be great. Is it possible to cancel a gesture on WillEndDragging and also pass this cancel down the children chain?
History:
I am using Xamarin Forms and I have the following issue
I have custom controls part of native scrolling views, like ScrollView or CollectionView, that remain in "clicked" state after the finger enters them but then initiates a scroll gesture.
I had a similar issue on UWP in the past and managed to solve it with the UIElement.PointerCaptureLost event.
Sorry if I am wasting your time on trivial stuff, but I am really stuck and I greatly appreciate your help.
I have tried different approaches suggested, including setting DelaysContentTouches to NO, and playing around with CanCancelContentTouches and overriding TouchesShouldCancelInContentView to always return NO, in a ScrollView custom renderer.
I have had a read of
Allow UIScrollView and its subviews to both respond to a touch
and
UIScrollView sending touches to subviews
Maybe the accepted answer here helps, but I am not sure how to get the tag of my custom view.
What I am expecting is my custom controls to receive the cancelled touch event (or something similar) as happens in both Android and Windows
This was easier than it looked. Solved by adding a UIGestureRecognizerDelegate to my UIGestureRecognizer class and in the delegate I overwrote ShouldRecognizeSimultaneously to return true.
I am working on the IOS application, related to voice over, my Question is : When accessibility voice over was enabled how can i get the swipe gestures left, right, top and down, what re the function for detecting these in swift?
First of all, you need to let VoiceOver know that about your view (or another element). So if you are in a view controller, this should work: self.view.isAccessibilityElement = true
Second, you need to let VoiceOver know that your view will handle user interactions on its own: self.view.accessibilityTraits = UIAccessibilityTraitAllowsDirectInteraction. After that your view should start getting gestures notifications.
Here's another relevant answer: https://stackoverflow.com/a/20712889/2219578
It isn't possible to catch the left, right, top and bottom VoiceOver gestures : I've seen neither a protocol nor a kind of notification for this.
However, you can detect a scrolling action and be aware of the element focus provided by VoiceOver.
I'm using Ember-Gestures which implements Hammer.js in a Cordova app to implement some simple gesture controls.
I'm running into a major problem whereby any gesture that triggers an animation (transition, transform, SVG animations), if the screen is scrolling any amount, that animation will freeze and be at its end state when scrolling is complete. In particular, I have an element on a vertically scrollable page which should (ideally) be able to be pinched in and out to expand it into multiple elements or back into one.
I'm familiar that as an optimization iOS freezes all animation during scroll. However, since pinch and swipe gestures can both slightly scroll the screen, this is terrible for user experience because elaborate transitions can be completely frozen if the user swipes, for example, slightly up and to the left rather than just directly left.
I've tried a few solutions to enable rendering during scroll like those here, but these don't seem to work on contemporary versions of iOS. I've also tried the hammerJS e.preventDefault() method to freeze scrolling during gestures called through the Ember-gestures extension, so my method looks like:
swipeLeft(e) {
e.originalEvent.gesture.srcEvent.preventDefault()
// Do stuff
},
...but this doesn't have any appreciable effect. (Maybe there's something wrong here? gesture had no preventDefault() method itself, and ember-gestures seems to try to abstract some of this away.
Is there any way I can either keep animations rendering during scrolling (this seems unlikely), or alternately STOP a page from scrolling right before performing an animation (and prevent scroll while it's executing)?
Alternately is there any way I can add constraints to what is interpreted as a "pinch" or "swipe" gesture such that those that would also be interpreted as scroll gestures are excluded.
My solution here ended up being to add event handlers such that when the screen is touched with multiple fingers, the body is set to fixed position such that it's unscrollable for the duration of the touch (with the fixed position removed when touch is ended). I added the handlers to the pinchStart and pinchEnd events
I suspect there might be a more elegant solution out there, but for the purpose of disabling accidental scrolling while pinching so that D3.js animations won't freeze midway, this was a quick and effective fix.
When I demo my touch apps to remote teams the people on the other end dont know where I am touching. To remedy this, I have been working on an event intercepting view/window that can display touches over applications. No matter how may variations on nextResponder I call, I am unable to react to the touch and pass it along to the controllers underneath. Specifically scroll views dont react nor do buttons.
Is there a way to take an event, get its position, then pass it along to what ever component would have been responding to it initially (the controller underneath)?
Update:
I am making some progress with a UIView. The new view is always returning NO to pointInside.This works great for when the touch starts, but it doesnt track moves or releases. Is there a strategy to adding gesture recognizers to the touch in order to track its event lifecycle?
Joe
You could try creating your own subclass of UIApplication that overrides sendEvent:. Your implementation should call [super sendEvent:event] as well as process the event as needed.
Update your main.m and pass the name of you custom UIApplication class as the 3rd parameter to the call of UIApplicationMain.
After some more due diligence, I found my oversight. In the layer that was on top and displaying the touches, user interaction needed to be set to false. Once I set that to false, I was able to use that layer for display while catching events on the layers below. The project still isn't done but I am one step closer.
Take care,
Joe
I've got a UIView which the user drags on and off of the screen (like a drawer).
The UIView has a bunch of buttons, some always visible, others hidden until the user 'opens' the drawer.
For some reason, the UIButtons that are 'off screen' on the initial UIView presentation aren't being passed events when they're later moved onto screen.
While the others receive all the events all the time.
Seems buggy to me, I would have thought the SDK would handle all this itself?
I've got a very simple example which you can take a look at: http://cl.ly/2r1c0k2p361B3B1A461L
Thanks in advance.
After a bit more research, it had to do with the views clipping boundaries.
The buttons were being drawn, but were essentially out of the views frame, so no events were registered.
More details on this question: Programmatically Created UIButtons Below Screen Not Working?