I have a UIScrollView that contains multiple UITableViews in it. The design is I have the UIScrollView to be the width of the view which is 320. The tableViews to be offset from the left with 10 pts and a width of 280, in which the next UITableView should be shown (or previewed) with 20 pts being shown.
I want that when I scroll the UIScrollView, it would only move by 290. Is there a method available for this in iOS or I would need a calculation to adjust the contentSize of the UIScrollView
If you enable paging, you will get the effect you are looking for, sans the smaller preview scroll.
One method to overcome this is to make the scrollview's frame smaller (290 points), and have its clipsToBounds property set to NO (so you get the preview of the next portion).
Another is to implement the scrollview's delegate method - (void)scrollViewWillEndDragging:(UIScrollView *)scrollView withVelocity:(CGPoint)velocity targetContentOffset:(inout CGPoint *)targetContentOffset and calculate where the scrollview should scroll according to velocity. The first method is simpler.
Related
My pure AutoLayout UITableViewCell looks like this in Interface Builder:
UITableViewCell
|-> UITableViewCell.contentView
|-> UIView (ScrollViewContainerView)
|-> UIScrollView
|-> left (fixed)
|-> center (fill remaining)
|-> right (fixed)
The UIScrollView contains a left, center, and right UIView. left and right are both fixed width, while center expands to fill the remainder of the UIView. The UIScrollView constraints are to align all edges to ScrollViewContainerView. ScrollViewContainerView constraints are to align all edges to the UITableViewCell.contentView. I have a constraint on center's width to be a multiple of ScrollViewContainerView's width, so the UIScrollView scrolls left and right, but the height is fixed and does not scroll. Note that the UIScrollView has been subclassed to include this code so that the UITableView can detect a tap on the cell to toggle selection.
The issue is that I currently can either scroll the UITableView containing these UITableViewCells up and down or I can scroll the UIScrollViews in the UITableViewCells left and right, not both.
When ScrollViewContainerView.userInteractionEnabled == YES, I can't scroll the UITableView up and down, but I can scroll the UIScrollView left and right. When ScrollViewContainerView.userInteractionEnabled == NO, I can scroll the UITableView up and down, but I can't scroll the UIScrollView left and right. userInteractionEnabled == YES on everything else in the above hierarchy.
I can get away with having ScrollViewContainerView as a sibling view to the UIScrollView (making the UIScrollView the direct descent of contentView -- can't get rid of this view completely, because I require it to get the dimensions for the UIScrollView frame). In that case, the opposite handling with userInteractionEnabled holds.
I know I've done this before in other projects before, but starting fresh again, I can't seem to figure out what step I'm missing. Currently using Xcode 6 6A215l targeting iOS 8, though I have reproduced the issue under Xcode 5 targeting iOS 7.
It sounds like the scrollview is causing your tableview to not allow userInteraction when being scrolled. I'm sure that if you called - (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView in the UIScrollView delegate (not sure for iOS 8), but you could just do
- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView {
if(scrollView.dragging == YES) {
self.<scrollViewName>.userInteractionEnabled = NO;
}
}
This is untested code, but it's just a bit of help to get you where you need to go.
Hope it helps!
I met some similar problem.
I have a scrollView in tableViewCell. All works fine.
Until one day, someone told me that the tableView can't scroll up/down when finger is touched on the scrollView in 6p. Just in 6p, not in 5, 5s,or6.
This makes me almost crazy.
Finally, I set the scrollView's height smaller than the height in storyboard.
Biu ~ It works~~~
Still, I don't know why.
#user2277872's answer put me on the right track to look at the output of the UIScrollView delegate methods of the UIScrollView in my UITableViewCell subclass. Putting an NSLog() in scrollViewWillBeginDragging: made me notice that the UIScrollView was receiving scrolling events while I was trying to scroll the UITableView. My UIScrollView had a contentSize larger than its frame in both directions, but I've forced that view to only scroll horizontal, so ignored the height and reset it. That force was my undoing and I should have known it at the time -- the correct solution is to fix the frame height. If the UIScrollView doesn't think there is more vertical content, it will correctly forward the swipe up/down gesture to the UITableView.
While I attempt to figure out why my contentSize is too large when it wasn't before (thinking I'm missing a clipToBounds somewhere), what I'm doing to force horizontal scrolling temporarily is (in the UITableViewCell's subclass):
- (void)drawRect:(CGRect)rect
{
[super drawRect:rect];
CGSize contentSize = self.scrollView.contentSize;
contentSize.height = self.frame.size.height;
self.scrollView.contentSize = contentSize;
}
EDIT: Actually, this is seemingly better than overriding drawRect. This would be in the UIScrollView subclass:
/*
* Lock to horizontal scrolling only.
*/
- (void)setContentSize:(CGSize)contentSize
{
[super setContentSize:CGSizeMake(contentSize.width, 1)];
}
The height struct member isn't too important, as long as it's guaranteed to be smaller than the frame.size.height of the UITableViewCell. Still hacky, still need to find why I could clip before and not now.
I have one UIImageView (building's floor map) and UIScrollView with gesture recognisers which allow me to scroll horizontally and vertically, zoom in/out. Everything works OK, but the building has two floors, so user should have the option to switch between them. I decided to use segmented control at the top of the map to provide this option.
If I put Segmented Control to the same UIScrollView, it scrolls vertically as well as horizontally. What I am asking is how to fix horizontal position of the Segmented Control, so it will be able to scroll only vertically with map.
I am trying to use this code to test, if it fixes the position of Segmented Control absolutely, but it seems to be that it doesn't.
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
CGRect frame = _floorSelector.frame;
frame.origin.y=50;
frame.origin.x= 160;
_floorSelector.frame = frame;
}
Where is the mistake? Thank you for replies!
I think the issue here is you are misunderstanding how scrolling is implemented in a UIScrollView, and how things are placed in its coordinate space.
When a UIScrollView is scrolled, the frames of its subviews are not changed. Relative to the scrollview, they remain in the same position while the contentOffset and bounds of the scroll view changes. In order to make a subview of a scroll view appear static while the rest of it scrolls, you must change its frame within the scrollview as the bounds change.
With that in mind, what you are doing now is just setting the same frame on that subview repeatedly, which is the same as not doing anything.
It sounds like what you want to do is something like this:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
CGRect frame = _floorSelector.frame;
frame.origin.x = 160 + scrollView.contentOffset.x;
_floorSelector.frame = frame;
}
Notice I do not change anything in the y axis because based on your question, the vertical scrolling doesn't need to be changed.
I have a UIScrollView that scrolls horizontally. I have about 10 views lined up horizontally in that scrollview. I want to find the view that contains the center point of the scrollview's frame (not contentView.frame) as it scrolls. I am thinking to use the - (void)scrollViewDidScroll:(UIScrollView *)scrollView UIScrollView delegate method, but I am not sure how to find this.
Thanks!
You can get the start-point of a frame of a view (myChildView) in the reference of another view (scrollView) using the following code:
CGPoint origin = [myChildView convertPoint:CGPointMake(myChildView.bounds.origin.x, myChildView.bounds.origin.y) toView:[self scrollView]];
Use the scrollViewDidScroll: delegate method to pick your views and perform the calculations there.
I have added 10 labels to to display 0 to 9 in UIScrollView, User can see only one label in UIScrollView visible part. User needs to scroll to see other labels. How to determine which label is currently visible in UIScrollView after scroll view decelerating.
Thanks in advance
Use the scroll view's contentOffset and calculate how many "pages" down they have scrolled by dividing the y offset by the content size height.
When scrolling is complete compare contentOffset value with labels positions or view to see which label is currently shown:
Use this method for getting scrolled position:
-(void)scrollViewDidScroll:(UIScrollView *)scrollView
{
NSLog(#"%f", scrollView.contentOffset.y);
//your logic to check shown label...
int currentVisiblePage = (scrollView.contentOffset.y / self.view.frame.size.height) + 1;
}
if you just want a single scrollable label, would be to use UITextView instead (reference). Disable editing, and you get a scrollable label.
(Taken almost verbatim from: how to add a scroll function to a UILabel)
For more detail:
UILabel inside of UIScrollView – programmatically
Sample code
AutoScrollLabel
This question already has answers here:
UICollectionView: paging like Safari tabs or App Store search
(6 answers)
Closed 9 years ago.
I've got a collection view whose content is scrolled horizontally and needs to be visible for the full width of the device. The collection view has clipsToBounds set to NO and it's frame is 600 wide with pagingEnabled set to YES.
The effect I'm looking for is that content would appear to slide under another view, however when the cell is scrolled outside the frame of the collection view then it is removed so that it can be reused.
Anyone know how I might get this to work, or achieve a similar effect?
Below is the simplest way that I've found to get this effect. It involves your collection view and an extra secret scroll view.
Set up your collection views
Set up your collection view and all its data source methods.
Frame the collection view; it should span the full width that you want to be visible.
Set the collection view's contentInset:
_collectionView.contentInset = UIEdgeInsetsMake(0, (self.view.frame.size.width-pageSize)/2, 0, (self.view.frame.size.width-pageSize)/2);
This helps offset the cells properly.
Set up your secret scrollview
Create a scrollview, place it wherever you like. You can set it to hidden if you like.
Set the size of the scrollview's bounds to the desired size of your page.
Set yourself as the delegate of the scrollview.
Set its contentSize to the expected content size of your collection view.
Move your gesture recognizer
Add the secret scrollview's gesture recognizer to the collection view, and disable the collection view's gesture recognizer:
[_collectionView addGestureRecognizer:_secretScrollView.panGestureRecognizer];
_collectionView.panGestureRecognizer.enabled = NO;
Delegate
- (void) scrollViewDidScroll:(UIScrollView *)scrollView {
CGPoint contentOffset = scrollView.contentOffset;
contentOffset.x = contentOffset.x - _collectionView.contentInset.left;
_collectionView.contentOffset = contentOffset;
}
As the scrollview moves, get its offset and set it to the offset of the collection view.
I blogged about this here, so check this link for updates: http://khanlou.com/2013/04/paging-a-overflowing-collection-view/