I have a view that I want to change the size of with animation. Below that view are other views that I want to move accordingly.
I have created a new project just so simplify this for me to get this function to work properly. In this project I only have viewOne, viewTwo and a button to control this. There is also a boolean called "blue".
#IBAction func bttn() {
if blue {
blue = false
UIView.animate(withDuration: 1) {
self.viewOne.frame.size.height = 64
}
}else {
blue = true
self.viewOne.frame.size.height = 100
}
}
When I tap the button I expect viewOne to increase in size and viewTwo to be moved down since there is a constraint between the top and bottom of the views.
But the actual result is that viewOne increase but viewTwo does not move.
Only autolayout can do this as changing frames doesn't apply the constraints , You need to create a height outlet for view1 then
self.view1Height.constant = 64
UIView.animate(withDuration: 1) {
self.view.layoutIfNeeded()
}
The bottommost cell of my table view is a cell with a textField. When the user taps it, I want to scroll it so that the cell is right above the keyboard.
When I call the scrollRectToVisible(...) with animated false everything works as expected, but when animated is set to true the table scrolls the cell only so far, that the bottom of the textField is right above the keyboard (See left picture). Yet the bottonInsets should be correct, since I can scroll the cell the last bit manually and the cell sits right how it should (See right picture).
I think the table view scrolling the textField's bottom edge above the keyboard is the default behavior of a table view, but I'm afraid I don't know why it seems to override my own scrolling when I want it animated.
Left picture:
The textFields bottom edge right above the keyboard (I kept the border style so you can see it better).
Right picture:
How I want it. Cell's bottom edge right above the keyboard.
func repositionTextfieldCell(in tableView: UITableView) {
guard let textFieldCell = tableView.bottommostCell() else { return }
guard let keyboardRect = activeKeyboardRect else { return }
// - Adjust insets
var bottomInset = keyboardRect.size.height
tableView.contentInset.bottom = bottomInset
tableView.scrollIndicatorInsets.bottom = bottomInset
// - Make cell visible
let x = textFieldCell.frame.minX
let y = textFieldCell.frame.maxY
tableView.scrollRectToVisible(CGRect(origin: CGPoint(x: x, y: y),
size: CGSize(width: 1, height: 1)), animated: true)
}
add this in viewDidLoad() and create a NSlayout constraint for tableview bottom.
NotificationCenter.default.addObserver(
self,
selector: #selector(keyboardWillShow),
name: NSNotification.Name.UIKeyboardWillShow,
object: nil
)
create the function
#objc func keyboardWillShow(_ notification: Notification) {
if let keyboardFrame: NSValue = notification.userInfo?[UIKeyboardFrameEndUserInfoKey] as? NSValue {
let keyboardRectangle = keyboardFrame.cgRectValue
let keyboardHeight = keyboardRectangle.height
tableBottomConstraint.constant = self.view.frame.height - keyboardHeight
}
}
repeat the process to reset the tableBottomConstraint.constant = 0 in keyboardWillHide() method.
I could fix the problem.
The behavior seems to be depended on were scrollRectToVisible(...) is called. The behavior I described in the question occurs when scrollRectToVisible(...) is called in keyboardDidShow(...).
However when you call scrollRectToVisible(...) in keyboardWillShow(...) and set animated to false the cell / rect is pushed up by the keyboard sliding in. Which I think looks great.
I have a table view properly configured to have dynamic row heights based on Ray Wenderlich's guide found here:
I set up the constraints to have a clear line of constraints from the top to the bottom of the cell. I also set up content hugging and content compression resistance priorities and estimated row height.
This is the code I use to setup the table view:
func configureTableView() {
// its called on viewDidLoad()
tableView.rowHeight = UITableViewAutomaticDimension
tableView.estimatedRowHeight = 100.0
}
override func viewDidLoad() {
super.viewDidLoad()
configureTableView()
for i in 1...20 {
messages.append([
"title": "foo \(i)",
"message": "bla \(i)\nbla\nbla"
])
}
// this is because the actual row heights are not available until the next layout cycle or something like that
dispatch_async(dispatch_get_main_queue(), {self.scrollToBottom(false)})
}
func scrollToBottom(animated:Bool) {
let indexPath = NSIndexPath(forRow: self.messages.count-1, inSection: 0)
self.tableView.scrollToRowAtIndexPath(indexPath, atScrollPosition: UITableViewScrollPosition.Bottom, animated: animated)
}
And this is how I add new rows:
#IBAction func addMore(sender:UIBarButtonItem) {
let message = [
"title": "haiooo",
"message": "silver"]
messages.append(message)
let indexPath = NSIndexPath(forRow: messages.count-1, inSection: 0)
tableView.insertRowsAtIndexPaths([indexPath], withRowAnimation: UITableViewRowAnimation.Bottom)
scrollToBottom(true)
}
The setup with the default rows are fine. It add the rows and scrolls to the bottom as expected.
But when I add new rows after that, the scrolling seems to start above the last cell. As I add more cells, the offset seems to increase.
Here is a gif showing it happening: Imgur
It's certainly related to the scroll animation (not the insertRow animation) because it scrolls properly when the animation is turned off.
Changing the estimatedRowHeight makes difference on the scrolling offset, but I couldn't find a value that fixed it.
I also tried delaying up the scroll using dispatch_async but it didn't change anything.
Do you guys have any ideas?
Wow, that was a fun challenge. Thanks for posting the test project.
So it seems that after adding the new row there's something off with where the table view thinks it's scrolled to. Seems to me to be a bug in UIKit. So to work around that, I added some code to 'reset' the table view before applying the animation.
Here's what I ended up with:
#IBAction func addMore(sender:UIBarButtonItem) {
let message = [
"title": "haiooo",
"message": "silver"]
messages.append(message)
tableView.reloadData()
// To get the animation working as expected, we need to 'reset' the table
// view's current offset. Otherwise it gets confused when it starts the animation.
let oldLastCellIndexPath = NSIndexPath(forRow: messages.count-2, inSection: 0)
self.tableView.scrollToRowAtIndexPath(oldLastCellIndexPath, atScrollPosition: .Bottom, animated: false)
// Animate on the next pass through the runloop.
dispatch_async(dispatch_get_main_queue(), {
self.scrollToBottom(true)
})
}
I couldn't get it to work with insertRowsAtIndexPaths(_:withRowAnimation:), but reloadData() worked fine. Then you need the same delay again before animating to the new last row.
I have this table view whose table view cells have the width and the height of the screen. Each showing an image.
While you scroll through the table view you can have one table view cell occupying the whole screen. Or at the most you can see 2 table view cells on the screen of the app at the same time.
My question is: is there any way I can find out which of the 2 table view cells occupies more screen height than the other?
Here is the easy way to find out which cell is visible more than 60%.
func scrollViewDidScroll(scrollView: UIScrollView) {
checkWhichVideoToEnable()
}
func checkWhichVideoToEnable() {
for cell in tableView.visibleCells as [UITableViewCell] {
if cell.isKindOfClass(UITableViewCell) {
let indexPath = tableView.indexPathForCell(cell)
let cellRect = tableView.rectForRowAtIndexPath(indexPath!)
let superView = tableView.superview
let convertedRect = tableView.convertRect(cellRect, toView: superView)
let intersect = CGRectIntersection(tableView.frame, convertedRect)
let visibleHeight = CGRectGetHeight(intersect)
if visibleHeight > self.view.bounds.size.height * 0.6 { // only if 60% of the cell is visible.
//cell is visible more than 60%
print(indexPath?.row) //your visible cell.
}
}
}
}
Reference from HERE.
Look at the second visible cell (tableView.visibleCells[1]) and check its y position. If it's less than half the height of the tableView, it's taking up more of the screen, else less. Break ties any way you want.
edit
The y position for a given indexPath is fixed, so you need to take into account the tableView's contentOffset.
CGFloat yOrigin = [tableView.visibleCells[1] frame].origin.y - tableView.contentOffset.y;
you could maybe try to get the tableView's visibleCells and check the origin of those cells. Since you'll have 2 visibleCells at any time, comparing their respective frame's y value could tell you which is occupying more height
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.