Detect if label touches navigation bar - swift

I am trying to make view that is scrollable. That viewcontroller contains also navbar. Now my goal is to resize my view if the title in that view touches the navbar. How should I do it?
This is how my view looks like(note that the navBar is just transparent):
What I want after the title collision:
I know that I can achieve it in scrollViewDidScroll delegate function, but how?

Well you can track label position using convertRect: method as
func scrollViewDidScroll(_ scrollView: UIScrollView) {
let labelTop = label.rectCorrespondingToWindow.minY
let navBottom = self.navigationController?.navigationBar.rectCorrespondingToWindow.maxY
if navBottom == labelTop {
// do what you want to do
}
}
extension UIView{
var rectCorrespondingToWindow:CGRect{
return self.convert(self.bounds, to: nil)
}
}

Related

how to have UITableView's pinned headers hide after scrolling

I want to have my tableViewHeaders visible as the user scrolls by pinning to the top which is the current behaviour in my tableView. However, when the tableView stops scrolling, I want to remove these 'pinned' headers. I am achieving this in my collectionView project using the following in my scrollView delegate methods:
if let cvl = chatCollectionView.collectionViewLayout as? UICollectionViewFlowLayout {
cvl.sectionHeadersPinToVisibleBounds = false
cvl.invalidateLayout()
}
Is there a similar way to hide a tableView's 'pinned' (sticky) headers? I am using a tableViewController.
This is my solution to this issue. I wonder if there is a simpler way to do this though.
Please note, this will only work if your header is a UITableViewHeaderFooterView. Not if you are using a UITableViewCell for a header. If you are using a UITableViewCell, tableView.headerView(forSection: indexPathForVisibleRow.section) will return nil.
In order to hide the pinned headers when the tableView stops scrolling and have them re-appear when the tableView starts scrolling again, override these four scrollView delegate methods.
In the first two (scrollViewWillBeginDragging and scrollViewWillBeginDecelerating), get the section header for the first section of the visible rows and make sure it is not hidden.
In the second two delegate methods, do a check to see that for each of the visible rows, the header frame for that row is not overlapping the frame for the row cell. If it is, then this is a pinned header and we hide it after a delay. We need to ensure that the scrollView is not still dragging before removing the pinned header as will be the case when the user lifts their finger but the scroll view continues to scroll. Also because of the time delay, we check that the scrollView is not dragging before removing it in case the user starts scrolling again less than 0.5 seconds after the scroll stops.
override func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
showPinnedHeaders()
}
override func scrollViewWillBeginDecelerating(_ scrollView: UIScrollView) {
showPinnedHeaders()
}
override func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
removePinnedHeaders()
}
override func scrollViewDidEndDragging(_ scrollView: UIScrollView, willDecelerate decelerate: Bool) {
removePinnedHeaders()
}
private func showPinnedHeaders() {
for section in 0..<totalNumberOfSectionsInYourTableView {
tableView.headerView(forSection: section)?.isHidden = false
}
}
private func removePinnedHeaders() {
if let indexPathsForVisibleRows = tableView.indexPathsForVisibleRows {
if indexPathsForVisibleRows.count > 0 {
for indexPathForVisibleRow in indexPathsForVisibleRows {
if let header = tableView.headerView(forSection: indexPathForVisibleRow.section) {
if let cell = tableView.cellForRow(at: indexPathForVisibleRow) {
if header.frame.intersects(cell.frame) {
let seconds = 0.5
let delay = seconds * Double(NSEC_PER_SEC)
let dispatchTime = DispatchTime.now() + Double(Int64(delay)) / Double(NSEC_PER_SEC)
DispatchQueue.main.asyncAfter(deadline: dispatchTime, execute: {
if !self.tableView.isDragging && header.frame.intersects(cell.frame) {
header.isHidden = true
}
})
}
}
}
}
}
}
}
Additionally add removePinnedHeaders() to viewDidAppear() and any other rotation or keyboard frame change methods that will scroll your tableView.

How to Make the scroll of a TableView inside ScrollView behave naturally

I need to do this app that has a weird configuration.
As shown in the next image, the main view is a UIScrollView. Then inside it should have a UIPageView, and each page of the PageView should have a UITableView.
I've done all this so far. But my problem is that I want the scrolling to behave naturally.
The next is what I mean naturally. Currently when I scroll on one of the UITableViews, it scrolls the tableview (not the scrollview). But I want it to scroll the ScrollView unless the scrollview cannot scroll cause it got to its top or bottom (In that case I'd like it to scroll the tableview).
For example, let's say my scrollview is currently scrolled to the top. Then I put my finger over the tableview (of the current page being shown) and start scrolling down. I this case, I want the scrollview to scroll (no the tableview). If I keep scrolling down my scrollview and it reaches the bottom, if I remove my finger from the display and put it back over the tebleview and scroll down again, I want my tableview to scroll down now because the scrollview reached its bottom and it's not able to keep scrolling.
Do you guys have any idea about how to implement this scrolling?
I'm REALLY lost with this. Any help will be greatly appreciate it :(
Thanks!
The solution to simultaneously handling the scroll view and the table view revolves around the UIScrollViewDelegate. Therefore, have your view controller conform to that protocol:
class ViewController: UIViewController, UIScrollViewDelegate {
I’ll represent the scroll view and table view as outlets:
#IBOutlet weak var scrollView: UIScrollView!
#IBOutlet weak var tableView: UITableView!
We’ll also need to track the height of the scroll view content as well as the screen height. You’ll see why later.
let screenHeight = UIScreen.mainScreen().bounds.height
let scrollViewContentHeight = 1200 as CGFloat
A little configuration is needed in viewDidLoad::
override func viewDidLoad() {
super.viewDidLoad()
scrollView.contentSize = CGSizeMake(scrollViewContentWidth, scrollViewContentHeight)
scrollView.delegate = self
tableView.delegate = self
scrollView.bounces = false
tableView.bounces = false
tableView.scrollEnabled = false
}
where I’ve turned off bouncing to keep things simple. The key settings are the delegates for the scroll view and the table view and having the table view scrolling being turned off at first.
These are necessary so that the scrollViewDidScroll: delegate method can handle reaching the bottom of the scroll view and reaching the top of the table view. Here is that method:
func scrollViewDidScroll(scrollView: UIScrollView) {
let yOffset = scrollView.contentOffset.y
if scrollView == self.scrollView {
if yOffset >= scrollViewContentHeight - screenHeight {
scrollView.scrollEnabled = false
tableView.scrollEnabled = true
}
}
if scrollView == self.tableView {
if yOffset <= 0 {
self.scrollView.scrollEnabled = true
self.tableView.scrollEnabled = false
}
}
}
What the delegate method is doing is detecting when the scroll view has reached its bottom. When that has happened the table view can be scrolled. It is also detecting when the table view reaches the top where the scroll view is re-enabled.
I created a GIF to demonstrate the results:
Modified Daniel's answer to make it more efficient and bug free.
#IBOutlet weak var scrollView: UIScrollView!
#IBOutlet weak var tableView: UITableView!
#IBOutlet weak var tableHeight: NSLayoutConstraint!
override func viewDidLoad() {
super.viewDidLoad()
//Set table height to cover entire view
//if navigation bar is not translucent, reduce navigation bar height from view height
tableHeight.constant = self.view.frame.height-64
self.tableView.isScrollEnabled = false
//no need to write following if checked in storyboard
self.scrollView.bounces = false
self.tableView.bounces = true
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 20
}
func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
let label = UILabel(frame: CGRect(x: 0, y: 0, width: tableView.frame.width, height: 30))
label.text = "Section 1"
label.textAlignment = .center
label.backgroundColor = .yellow
return label
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
cell.textLabel?.text = "Row: \(indexPath.row+1)"
return cell
}
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if scrollView == self.scrollView {
tableView.isScrollEnabled = (self.scrollView.contentOffset.y >= 200)
}
if scrollView == self.tableView {
self.tableView.isScrollEnabled = (tableView.contentOffset.y > 0)
}
}
Complete project can be seen here:
https://gitlab.com/vineetks/TableScroll.git
After many trials and errors, this is what worked best for me. The solution has to solve two needs 1) determine who's scrolling property should be used; tableView or scrollView? 2) make sure that the tableView doesn't give authority to the scrollView until it has reached the top of it's table/content.
In order to see if the scrollview should be used for scrolling vs the tableview, i checked to see if the UIView right above my tableview was within frame. If the UIView is within frame, it's safe to say the scrollView should have authority to scroll. If the UIView is not within frame, that means that the tableView is taking up the entire window, and therefor should have authority to scroll.
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if scrollView.bounds.intersects(UIView.frame) == true {
//the UIView is within frame, use the UIScrollView's scrolling.
if tableView.contentOffset.y == 0 {
//tableViews content is at the top of the tableView.
tableView.isUserInteractionEnabled = false
tableView.resignFirstResponder()
print("using scrollView scroll")
} else {
//UIView is in frame, but the tableView still has more content to scroll before resigning its scrolling over to ScrollView.
tableView.isUserInteractionEnabled = true
scrollView.resignFirstResponder()
print("using tableView scroll")
}
} else {
//UIView is not in frame. Use tableViews scroll.
tableView.isUserInteractionEnabled = true
scrollView.resignFirstResponder()
print("using tableView scroll")
}
}
hope this helps someone!
None of the answers here worked perfectly for me. Each one had it's owned nuanced problem (needing to do a repeated swipe when one scrollview hit it's bottom, or the scroll indicator not looking correct, etc), so figured I'd throw in another answer.
Ole Begemann has a great write up on doing this exactly https://oleb.net/blog/2014/05/scrollviews-inside-scrollviews/
Despite being an old post, the concepts still apply to the current APIs. Additionally, there is a maintained (Xcode 9 compatible) Objective-C implementation of his approach https://github.com/eyeem/OLEContainerScrollView
If you are facing problem with the nested scrolling issue , here tis the simplest solution for it .
go to your design screen
select your scroll view and then disable bounce on scroll
if your view uses table view inside scroll view then disable bounce on scroll of the table view as well
run and check it is solved
check how to disable bounce on scroll of a scroll view
check how to disable bounce on scroll of a tableview view
I was struggling with this problem, too. There is a very simple solution.
In interface builder:
create simple ViewController
add a simple View, it will be our header, and constrain it to superview
it's the red view on the example below
I have added 12px from top, left and right, and set fixed height to 128px
embed a PageViewController, making sure it is constrained to the superview, and not the header
Now, here comes the fun part: for each page you add, make sure its tableView has an offset from top. Thats it. You can do if with this code, for example (assuming you use UITableViewController as a page):
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
let tables = viewControllers.compactMap { $0 as? UITableViewController }
tables.forEach {
$0.tableView.contentInset = UIEdgeInsets(top: headerView.bounds.height, left: 0, bottom: 0, right: 0)
$0.tableView.contentOffset = CGPoint(x: 0, y: -headerView.bounds.height)
}
}
No messy scroll inside scroll inside table view, no mangling with delegates, no duplicated scrolls, perfectly natural behavior. If you can't see the header, it is probably because of the tableView background color. You have to set it to clear, for the header to be visible from under the tableView.
I think there are two options.
Since you know the size of the scroll view and the main view, you are unable to tell whether the scroll view hit the bottom or not.
if (scrollView.contentOffset.y >= (scrollView.contentSize.height - scrollView.frame.size.height)) {
// reach bottom
}
So when it hit; you basically set
[contentScrollView setScrollEnabled:NO];
and other way around for your tableView.
The other thing, which is more precise I think, is to add Gesture to your views.
UITapGestureRecognizer *tapRecognizer = [[UITapGestureRecognizer alloc]
initWithTarget:self action:#selector(respondToTapGesture:)];
// Specify that the gesture must be a single tap
tapRecognizer.numberOfTapsRequired = 1;
// Add the tap gesture recognizer to the view
[self.view addGestureRecognizer:tapRecognizer];
// Do any additional setup after loading the view, typically from a nib
So when you add Gesture, you can simply control the active view by changing setScrollEnabled in the respondToTapGesture.
I found an awesome library
MXParallaxHeader
In Storyboard just set UIScrollView class to MXScrollView then magic happens.
I used this class to handle my UIScrollView when I embed a UIPageViewController container view. even you can insert a parallax header view for more detail.
Also, this library provides Cocoapods and Carthage
I attached an image below which represent UIViewHierarchy.
MXScrollView Hierarchy
SWIFT 5
I had some trouble using Vineet's answer for when I could not guarantee the scrollView content offset (Y) due to various different screen sizes. To resolve this, I changed the first trigger event of when the tableView's scroll gets enabled.
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if scrollView.bounds.contains(button.frame) {
tableView.isScrollEnabled = true
}
if scrollView == tableView {
self.tableView.isScrollEnabled = (tableView.contentOffset.y > 0)
}
}
The scrollView.bounds.contains will check if a given element's frame is FULLY within the scrollView's visible content. I set this to a button that I have below the tableView. You could set this to your tableVIew's frame instead if your only condition is that your tableView is fully visible.
I left the original implementation of when to disable the tableView's scroll and it works very well.
I tried the solution marked as the correct answer, but it was not working properly. The user need to click two times on the table view for scroll and after that I was not able to scroll the entire screen again. So I just applied the following code in viewDidLoad():
tableView.addGestureRecognizer(UISwipeGestureRecognizer(target: self, action: #selector(tableViewSwiped)))
scrollView.addGestureRecognizer(UISwipeGestureRecognizer(target: self, action: #selector(scrollViewSwiped)))
And the code below is the implementation of the actions:
func tableViewSwiped(){
scrollView.isScrollEnabled = false
tableView.isScrollEnabled = true
}
func scrollViewSwiped(){
scrollView.isScrollEnabled = true
tableView.isScrollEnabled = false
}
One easy trick, if you want to achieve it is replacing parent scrollview with normal container view.
Adding a pan gesture on container view, you can play with top constraint of first view to assign negative values. You can keep a check of page View's origin if it achieves to top you can start assigning that value on content offset of the pageView's child view. Until user achieves the table view in a state of top most view in container view, you can keep page tableView's scrolling disabled and allow scrolling manually by setting content offset.
So initially the page view height will be collapsed (or say out of screen) or less at bottom. Later on scrolling down it will expand to take more space.
Gesture will automatically stop responding if out of frames say on nav bar or other view outside container view.
Gestures are a key to user interactive transitions used in many apps. You can mimic scroll for a certain time with it.
In my case I'm using constraint for height like that:
self.heightTableViewConstraint.constant = self.tableView.contentSize.height
self.scrollView.contentInset.bottom = self.tableView.contentSize.height
Below code works great for me
As I wanted to show some header after some scroll and table view supposed to scroll
And in ViewDidLoad add
override func viewDidLoad() {
super.viewDidLoad()
mainScrollView.delegate = self
}
Change 265 to whatever number you want to stop upper scroll
extension AccountViewController: UIScrollViewDelegate {
func scrollViewDidScroll(_ scrollView: UIScrollView) {
print(notebookTableView.contentOffset.y)
if notebookTableView.contentOffset.y < 265 {
if notebookTableView.contentOffset.y > 0 {
mainScrollView.setContentOffset(notebookTableView.contentOffset, animated: false)
} else {
mainScrollView.setContentOffset(CGPoint(x: 0.0, y: 0.0), animated: false)
}
} else {
mainScrollView.setContentOffset(CGPoint(x: 0.0, y: 265), animated: false)
}
}
}
CGFloat tableHeight = 0.0f;
YourArray =[response valueForKey:#"result"];
tableHeight = 0.0f;
for (int i = 0; i < [YourArray count]; i ++) {
tableHeight += [self tableView:self.aTableviewDoc heightForRowAtIndexPath:[NSIndexPath indexPathForRow:i inSection:0]];
}
self.aTableviewDoc.frame = CGRectMake(self.aTableviewDoc.frame.origin.x, self.aTableviewDoc.frame.origin.y, self.aTableviewDoc.frame.size.width, tableHeight);
Maybe brute-force, but working perfectly if cell heights are the same: by the way, I use auto layout.
for the tableView (or collectionView or whatever), set an arbitrary height in storyboard, and make an outlet to class. Wherever appropriate, (viewDidLoad() or...) set the tableView's height big enough so that tableView doesn't need to scroll. (need to know the number of rows in advance) Then only the outer scrollView will scroll nicely.

Limit the scroll for UITableView

I have a TableViewController:
As you see I have my own custom bar at the top.
The UITable View is just a static one, and I add a view at the top of UITableView.
The thing is when I scroll the TableView to top-side it become like bellow image, and I don't want it. is there any easy code that I can limit the scroll for the tableView?
since UITableView is a subclass of UIScrollView you can use this UIScrollViewDelegate method to forbid scrolling above the top border
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
if (scrollView == self.tableView) {
if (scrollView.contentOffset.y < 0) {
scrollView.contentOffset = CGPointZero;
}
}
}
Yo will need to set the bounce property of the uitableview to NO
UITableView *tableView;
tableView.bounces = NO;
Edit: Note also you can uncheck the bounces from interface builder too
Please check this answer for further details Disable UITableView vertical bounces when scrolling
I had the same problem and asked our UX-Designer, how it would be better to do. He said, that both strict solutions (prevent bouncing or allow it as it is) are bad. It's better to allow bouncing but only for some space
My solution was:
override func scrollViewDidScroll(_ scrollView: UIScrollView) {
if scrollView == self.tableView {
if scrollView.contentOffset.y < -64 {
scrollView.scrollRectToVisible(CGRect(origin: CGPoint(x: 0, y: -64), size: scrollView.frame.size), animated: false)
scrollView.scrollRectToVisible(CGRect(origin: CGPoint.zero, size: scrollView.frame.size), animated: true)
}
}
}
Where 64 was that "some space" for me. Code stops tableView at -64 from the top and brings it up with an animation.
Good luck!
If i understand correctly you have set-up your custom bar as part of your tableview. Put your custom bar in a separate view not in the tableview and put your tableview below custom bar when you are setting up your views. You need to create your custom view controller that will have your custom bar and your static table view.
You need to create your view controller object as type UIViewController and not UITableViewController. Then add the custom bar as a subview to self.view. Create a separate UITableView and add it below the custom bar. That should make custom bar static and table view scrollable.
Update:
In order to make the tableview static you need to set it as
tableView.scrollEnabled = NO:
Let me know if this works for you.
Swift version of Mattias's answer:
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if (scrollView == self.ordersTable) {
if (scrollView.contentOffset.y < 0) {
scrollView.contentOffset = CGPoint.zero;
}
}
}

In iOS - When touching a text field in a scroll view the view can not scroll

When trying to scroll a view by touching and dragging on a text field, similarly to how you would scroll around on the edit contacts view on the iPhone, the view will not move, touching and dragging in between the text fields or off to the side of the text fields in the scroll view works but not when touching a textfield.
Any insights would be greatly appreciated. Thanks!
Try setting the delaysContentTouches property to YES for the UIScrollView to which you have added to text field. This should allow you to scroll if you touch and then drag within a text field.
Setting delaysContentTouches to true didn't work for me either. What did was iterating through the scrollview's gesture recognizers and setting each of their delaysTouchesBegan and cancelsTouchesInView to true and false, respectively:
scrollView.gestureRecognizers?.forEach {
$0.delaysTouchesBegan = true; $0.cancelsTouchesInView = false
}
I think it solution in this situation
extension UITableView {
override public func touchesShouldCancelInContentView(view: UIView) -> Bool {
if view is UITextField || view is UITextView {
return true
}
return super.touchesShouldCancelInContentView(view)
}
}
try with below approach. Just replace your UIScrollView with ScrollView and adds the code to your project.
SWIFT 4.1
class ScrollView: UIScrollView {
override func touchesShouldCancel(in view: UIView) -> Bool {
if type(of: view) == TextField.self || type(of: view) == UITextView.self {
return true
}
return super.touchesShouldCancel(in: view)
}
}

check if UIView is in UIScrollView visible state

What is the easiest and most elegant way to check if a UIView is visible on the current UIScrollView's contentView? There are two ways to do this, one is involving the contentOffset.y position of the UIScrollView and the other way is to convert the rect area?
If you're trying to work out if a view has been scrolled on screen, try this:
CGRect thePosition = myView.frame;
CGRect container = CGRectMake(scrollView.contentOffset.x, scrollView.contentOffset.y, scrollView.frame.size.width, scrollView.frame.size.height);
if(CGRectIntersectsRect(thePosition, container))
{
// This view has been scrolled on screen
}
Swift 5: in case that you want to trigger an event that checks that the entire UIView is visible in the scroll view:
extension ViewController: UIScrollViewDelegate {
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if scrollView.bounds.contains(targetView.frame) {
// entire UIView is visible in scroll view
}
}
}
Implement scrollViewDidScroll: in your scroll view delegate and calculate manually which views are visible (e.g. by checking if CGRectIntersectsRect(scrollView.bounds, subview.frame) returns true.
updated for swift 3
var rect1: CGRect!
// initialize rect1 to the relevant subview
if rect1.frame.intersects(CGRect(origin: scrollView.contentOffset, size: scrollView.frame.size)) {
// the view is visible
}
I think your ideas are correct. if it was me i would do it as following:
//scrollView is the main scroll view
//mainview is scrollview.superview
//view is the view inside the scroll view
CGRect viewRect = view.frame;
CGRect mainRect = mainView.frame;
if(CGRectIntersectsRect(mainRect, viewRect))
{
//view is visible
}
José's solution didn't quite work for me, it was detecting my view before it came on screen. The following intersects code works perfect in my tableview if José's simpler solution doesn't work for you.
func scrollViewDidScroll(_ scrollView: UIScrollView) {
let viewFrame = scrollView.convert(targetView.bounds, from: targetView)
if viewFrame.intersects(scrollView.bounds) {
// targetView is visible
}
else {
// targetView is not visible
}
}
Solution that takes into account insets
public extension UIScrollView {
/// Returns `adjustedContentInset` on iOS >= 11 and `contentInset` on iOS < 11.
var fullContentInsets: UIEdgeInsets {
if #available(iOS 11.0, *) {
return adjustedContentInset
} else {
return contentInset
}
}
/// Visible content frame. Equal to bounds without insets.
var visibleContentFrame: CGRect {
bounds.inset(by: fullContentInsets)
}
}
if scrollView.visibleContentFrame.contains(view) {
// View is fully visible even if there are overlaying views
}