I have UIScrollView with other UIView elements inside. My other UIView elements are mostly segmented controls. If I click on a UISegmentedControl and hold for a second and then try to scroll, then no scrolling happens. I can only scroll when my finger touches and swipes immediately. I checked other iOS applications such as mail. The behavior was that you touch and hold on a mail, then it's highlighted, but as soon as finger moves away, the scrolling happens and highlighting is undone. How can I implement this behavior?
The issue was the property of UIScrollView. The property canCancelContentTouches was set to NO. Because of that, touch events were handled by subviews of scroll view and swiping didn't cause scrolling.
You can follow one of these steps:
If you are using UISegmentedControl over you UIScrollView, instead of that, add the UISegmentedControl over your controller's view.
If you want to use UISegmentedControl over your scrollView, then you have to create a custom scrollView by creating a subclass of UIScrollView and use an image view instead of UISegmentedControl adding the labels which can act as the segments. This is because your UISegmentControl itself is a touch handler and it breaks the UIResponder chain. So, the scrolling might face issues during the touch events.
Please let me know if any of these works. Thanks :)
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I am using a UIView subclass which can be resized by dragging on the borders and it is added as subview on a UIScrollView. I am also using a UIGestureRecognizer subclass to move the view on the UIScrollView such that the custom view remains visible and the scrollview autoscrolls.
This setup is working as intended but for one problem. Whenever the custom view is resized, the touches on UIScrollView are lost, i.e the scrollview does not recognise the tap or scroll on it unless the custom view is tapped or dragged once again. I have found that after resizing, neither custom UIView nor custom UIGestureRecognizer's touches began, cancelled or ended are called.
Where might the problem be?
There's a input toolbar appearing at bottom of screen, a UITextView which be contained becomes firstResponser when user wanna input something, and at this moment the input toolbar animates to the top of UIKeyboard.
What I want to do is to make input toolbar go back to the bottom when the tap event begins, so I implement a custom gesture TouchDownGestureRecognizer adding to a UITableView (list history messages). Then the problem appeared: The UITableView can't scroll when touchDown.
So how to recognize custom touchDown gesture and make scrollView scrollable Simultaneously?
Thanks in advance!
It seems that it is a little difficult to solve the problem by this way, so I do touch down stuff in the - (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView method.
I have a UIScrollView with an button just outside the content area of the scrollView. The user has to scroll up and hold the spring effect which one finger and push the button with another finger. The problem is that the touch on the button is never detected.
Please see the illustration below
The scroll view in it's initial state. the orange area is the scrollView, the white area the button
The user is now scrolling and holding with one finger to overcome the spring effect of the UIScrollView, and want to click the button
Any suggestions?
Check this out:
UIScrollView blocks all touches while zooming or scrolling
Make sure you have multitouch set to YES on the scrollview and also don't have any subviews with exclusive touch enabled.
I have a UIScrollView that contains several UIButtons. Each button is wired up to take an action when the user inputs a touch up event, so they are able to place their finger on the button and it will not be selected until it is raised. Currently, if I made a swipe gesture to scroll the UIScrollView quickly, then the scroll view moves as expected even if the gesture happens directly over a UIButton. HOWEVER, if I hold my finger down too long on a UIButton (about 1 second), the UIScrollView will no longer recognize the gesture and will not be able to scroll until the finger is lifted up.
I am wondering if their is a way to always have the UIScrollView recognize the scroll gesture? Note that this is not an issue if I touch the UiScrollView in a location without a UIButton - it then scrolls as expected.
It may worth a try to let your UIButton respond to UIControlEventTouchDown (maybe with an empty action). I'm not sure if this will work, but conceptually I think it should let the UIButton capture the touch immediately.
(Also make sure you don't enable delaysContentTouches on your scrollview.)
I found the answer to this here: UIScrollview with UIButtons - how to recreate springboard?
Essentially, I had to extend UIScrollView and override touchesShouldCancelInContentView, having it always return YES.
I have a rotating carousel menu made up of 6 UIViews that were added as subViews to self.view. When you rotate the carousel, some subviews are partially behind the subview closest to the user but the problem is that the subview closest to the user may not have been added after the one behind it so when I touch it, the one behind it gets triggered.
My question is, is there a way to programmatically use bringToFront whenever a subview is touched so that it will not matter whether or not it was added first or last to the view.
When you have 2 views responding to touch events and one is in front of the other, the other one will never receive the touch.
Instead of messing around with the event chain (aka subclassing UIView and overriding hitTest…) I'd suggest you reorder the views while spinning the carousel.
The view which appears to be in front should be the topmost view in the view hierarchy.