I have a scrollView with paging enables. I have a UIView as a subview of the scrollView. When the scrollView reaches the buttom of it's content, I'm turning scrolling off:
scrollView.scrollEnabled = false
because I'm doing other things that require dragging in a part of the scrollView (Yellow part). So the scrollViews offset locks at the buttom of the page. I want to be able to drag in the UIView (red), to enable scrolling of the scrollView, and thereby change the scrollviews content offset.
So I've added a UIPanGestureRecognizer to the UIView, which action enables scrolling of the scrollview.
The problem is that, when I start panning on the UIView, I have to lift the finger and put it down again, before I can drag the scrollView.
Here's some code:
var scrollView: UIScrollView!
var someView: UIView!
var panAGes: UIGestureRecognizer!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
scrollView = UIScrollView(frame: CGRectMake(0, 0, view.frame.width, view.frame.height))
scrollView.contentSize = CGSizeMake(view.frame.width, view.frame.height * 2)
scrollView.pagingEnabled = true
scrollView.delegate = self
someView = UIView(frame: CGRectMake(0, view.frame.height, view.frame.width, 100))
someView.backgroundColor = UIColor.yellowColor()
panAGes = UIPanGestureRecognizer(target: self, action: "panning:")
someView.addGestureRecognizer(panAGes)
scrollView.addSubview(someView)
self.view.addSubview(scrollView)
}
func scrollViewDidScroll(scrollView: UIScrollView) {
// when page is locked
if scrollView.contentOffset.y >= view.frame.height {
scrollView.scrollEnabled = false
}
}
func panning(gesture: UIGestureRecognizer) {
scrollView.scrollEnabled = true
}
How can I make the scrollView scroll, when the panning method is called?
Thank You...
Related
I hv been trying to make a scrollview scroll, just to the extent that the scrollview is supposed to show. However, I am not able to. This is my code.
func setupMainView() {
// This is where the image view and other UIViews which are supposed to go in the contentview are set up
self.setupImagesView()
self.setupView1()
self.setupView2()
self.setupView3()
self.setupView4()
self.scrollView = UIScrollView()
self.scrollView.backgroundColor = UIColor.white
self.view.addSubview(self.scrollView)
self.automaticallyAdjustsScrollViewInsets = false
self.scrollView.contentInset = UIEdgeInsets.zero
self.scrollView.scrollIndicatorInsets = UIEdgeInsets.zero;
self.contentView = UIView()
self.scrollView.layer.masksToBounds = false
self.scrollView.backgroundColor = UIColor.white
self.scrollView.layer.borderWidth = 0
self.scrollView.layer.borderColor = UIColor.white.cgColor
self.view.addSubview(scrollView)
self.contentView.addSubview(imagesScrollView)
self.contentView.addSubview(view1)
self.contentView.addSubview(view2)
self.contentView.addSubview(view3)
self.contentView.addSubview(view4)
self.scrollView.addSubview(contentView)
self.scrollView.contentInset = UIEdgeInsets.zero
self.scrollView.scrollIndicatorInsets = UIEdgeInsets.zero;
var scrollViewHeight:CGFloat = 0.0;
for _ in self.scrollView.subviews {
scrollViewHeight += view.frame.size.height
}
var newHeight = scrollViewHeight * 1.1 + offset + 100
scrollView.contentSize = CGSize(width:screenWidth, height:newHeight)
scrollView.reloadInputViews()
}
The views are getting loaded etc, but I am not manage the scroll. It somehow either too little or too much.
Now, I tried setting the height of contentSize to scrollViewHeight and double of that etc. What I notice is that there is no predictability of how much it will scroll. Change from 1.1 to 1.6 .. there is too much whitescreen below the views, change it to 1.1 or 1.2 it does not even scroll to the bottom.
Note, everything has been set up programmatically, without storyboard etc.
Also note that I need to support all IOS devices with version > 10.
Am a little lost here. What am I doing wrong?
This is a very old way of configuring a scroll view - you should be using auto-layout.
And, you're doing a number of things wrong...
First, we'll assume you are setting frames of the various subviews in code you haven't shown.
However, the code you have shown creates a scrollView and adds it to self.view -- but you never set the frame of the scroll view.
Also, this part of your code:
for _ in self.scrollView.subviews {
scrollViewHeight += view.frame.size.height
}
you've added several views as subviews of contentView, then added contentView as the only subview of scrollView.
And... you are trying to increment scrollViewHeight by the height of your root view instead of the height of the scrollView's subviews.
So, scrollViewHeight will only be the height of self.view.
What you probably want to do is sum the heights of contentView.subviews:
var contentViewHeight: CGFloat = 0
for v in contentView.subviews {
contentViewHeight += v.frame.height
}
contentView.frame.size.height = contentViewHeight
then set the scrollView's contentSize.height to the height of contentView's frame.
Here is a very, very basic example, using explicitly set frame sizes -- again, though, you should start using auto-layout:
class SimpleScrollViewController: UIViewController {
var imagesScrollView: UIView!
var view1: UIView!
var view2: UIView!
var view3: UIView!
var view4: UIView!
var contentView: UIView!
var scrollView: UIScrollView!
override func viewDidLoad() {
super.viewDidLoad()
setupMainView()
}
func setupMainView() {
// This is where the image view and other UIViews which are supposed to go in the contentview are set up
self.setupImagesView()
self.setupView1()
self.setupView2()
self.setupView3()
self.setupView4()
self.scrollView = UIScrollView()
// let's use a color other than white so we can see the frame of the scrollView
self.scrollView.backgroundColor = UIColor.cyan
self.view.addSubview(self.scrollView)
self.automaticallyAdjustsScrollViewInsets = false
self.scrollView.contentInset = UIEdgeInsets.zero
self.scrollView.scrollIndicatorInsets = UIEdgeInsets.zero;
self.contentView = UIView()
self.contentView.backgroundColor = UIColor.lightGray
self.scrollView.layer.masksToBounds = false
self.scrollView.layer.borderWidth = 0
self.scrollView.layer.borderColor = UIColor.white.cgColor
self.view.addSubview(scrollView)
self.contentView.addSubview(imagesScrollView)
self.contentView.addSubview(view1)
self.contentView.addSubview(view2)
self.contentView.addSubview(view3)
self.contentView.addSubview(view4)
self.scrollView.addSubview(contentView)
self.scrollView.contentInset = UIEdgeInsets.zero
self.scrollView.scrollIndicatorInsets = UIEdgeInsets.zero;
var contentViewHeight: CGFloat = 0
for v in contentView.subviews {
contentViewHeight += v.frame.height
}
contentView.frame.size.height = contentViewHeight
// don't know what you're doing here....
//scrollView.reloadInputViews()
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
// here is where you know the frame of self.view
// so, make the scroll view cover the entire view
scrollView.frame = view.frame
// now, make contentView width equal to scrollView width
contentView.frame.size.width = scrollView.frame.size.width
// set the scrollView's content size
scrollView.contentSize = contentView.frame.size
}
func setupImagesView() -> Void {
imagesScrollView = UIView()
imagesScrollView.backgroundColor = .red
imagesScrollView.frame = CGRect(0, 0, 300, 100)
}
func setupView1() -> Void {
view1 = UIView()
view1.backgroundColor = .green
view1.frame = CGRect(20, imagesScrollView.frame.maxY, 300, 200)
}
func setupView2() -> Void {
view2 = UIView()
view2.backgroundColor = .blue
view2.frame = CGRect(40, view1.frame.maxY, 300, 250)
}
func setupView3() -> Void {
view3 = UIView()
view3.backgroundColor = .yellow
view3.frame = CGRect(60, view2.frame.maxY, 200, 275)
}
func setupView4() -> Void {
view4 = UIView()
view4.backgroundColor = .orange
view4.frame = CGRect(80, view3.frame.maxY, 200, 100)
}
}
If I remember correctly you need to in order for scroll view to work you need to implement a couple of delegate methods. You also need a couple of properties set.
contentSize is one
and I think min and max size
see: https://developer.apple.com/documentation/uikit/uiscrollviewdelegate
also see Stanford University's
Paul Hagarty Developing IOS 11 apps with swift episode 9 for loads of information on UIScrollView
https://www.youtube.com/watch?v=B281mrPUGjg
seek to about 31mins for the scroll view information.
This may help in the setup of UIScrollView programatically:
https://sheikhamais.medium.com/how-to-use-the-new-uiscrollview-programmatically-baf270ee9b4
How can I make a certain element on my screen scroll with the screen (e.i. have a fixed position relative to the screen) when my navbar scrolls past it?
In other words, I have an element that isn't at the top of my screen and you need to scroll down to its position before it starts scrolling with the screen. Then, when you scroll back up to the top of the screen, the item goes back to its original position and stays there.
I am currently using a UIScrollView to scroll across my screen. My original plan was to get certain dimensions and basically do something like this when a isScrolling() method is called (pseudocode):
if scrolledPositionOnScreen > positionOfUIView {
scrollUIViewWithRestOfScreen()
} else {
putUIViewInOriginalPosition()
}
However, this doesn't work well when I use different size screens even though I am getting these variables dynamically with respect to screen size.
Is there a delegate or something that will do what I am trying to do/is there an easier, more consistent way?
Thanks!
Yes, there is the UIScrollViewDelegate delegate from which you can use the scrollViewDidScroll method:
class ViewController : UIViewController, UIScrollViewDelegate {
let scrollView = UIScrollView()
let frame = CGRect(origin: .init(x: 0, y: 100), size: .init(width: 200, height: 200))
lazy var v = UIView(frame: frame)
override func viewDidLoad() {
super.viewDidLoad()
self.scrollView.delegate = self
self.view.addSubview(scrollView)
self.scrollView.contentSize = CGSize(width: self.view.bounds.width, height: UIScreen.main.bounds.height + 1000)
self.scrollView.translatesAutoresizingMaskIntoConstraints = false
self.scrollView.addSubview(v)
self.v.backgroundColor = .red
NSLayoutConstraint.activate([
self.scrollView.topAnchor.constraint(equalTo: self.view.topAnchor),
self.scrollView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor),
self.scrollView.leadingAnchor.constraint(equalTo: self.view.leadingAnchor),
self.scrollView.trailingAnchor.constraint(equalTo: self.view.trailingAnchor),
])
}
func scrollViewDidScroll(_ scrollView: UIScrollView) {
if scrollView.contentOffset.y > frame.origin.y {
v.center.y = scrollView.contentOffset.y + (v.bounds.height/2)
}
}
}
I am playing around with scroll views, and I've run into an issue I'be stuck with. I have a view controller create in Storyboard. The view controller contains a scroll view which fills the entire superview.
I then added the images programmatically to the scroll view. The images do show within the scroll view and paging works just fine. Only problem is the scroll view is set ti fill superview but the image view that hold the images seems like it stops above where the navigation bar would be. How can I have the image view fill the whole view within the scroll view?
#IBOutlet weak var scrollView: UIScrollView!
#IBOutlet weak var pagingView: UIPageControl!
var images = [UIImage]()
var frame = CGRect(x: 0, y: 0,width: 0,height: 0)
override func viewDidLoad() {
super.viewDidLoad()
scrollView.delegate = self
scrollView.isPagingEnabled = true
images = [UIImage(named: "Slide1")!, UIImage(named: "Slide2")!, UIImage(named: "Slide3")!, UIImage(named: "Slide4")!]
pagingView.numberOfPages = images.count
// This is where I think I'm having the height problem.
for i in 0..<images.count {
let imageView = UIImageView()
let x = self.view.frame.size.width * CGFloat(i)
imageView.frame = CGRect(x: x, y: 0, width: self.view.frame.width, height: self.view.frame.height)
imageView.contentMode = .scaleAspectFill
imageView.image = images[i]
scrollView.contentSize.width = scrollView.frame.size.width * CGFloat(i + 1)
scrollView.addSubview(imageView)
}
}
func scrollViewDidEndDecelerating(_ scrollView: UIScrollView) {
let pageNumber = scrollView.contentOffset.x / scrollView.frame.size.width
pagingView.currentPage = Int(pageNumber)
}
After setting nav bar to hidden, here is the output
Scroll view background color is red
In this case you need to enable the parent view clipsToBounds. Set UIScrollview clipsToBounds property to True.
Programmatically scrollView.clipsToBounds = true
In UIStoryBoard - Click the view->Attributes Inspector
If you would like to see the whole screen, make sure to add the topConstraint of scrollView assigned superView and hide the navigationBar in viewWillAppear,
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
navigationController?.setNavigationBarHidden(true, animated: animated)
}
Make sure to remove the status bar by
override var prefersStatusBarHidden: Bool {
return true
}
Update the Y position of Image.
imageView.frame = CGRect(x: x, y: **self.scrollView.frame.minY**, width: self.view.frame.width, height: self.view.frame.height)
Update the scrollView topConstraint by -20.
I try to add button overlay on UITableViewController with static cells. But i get this result, button is working, but i not see result of search:
I'm trying to get this result:
I want to button was always at the bottom regardless of scrolling up or down.
In my code i use framework InstantSearch:
import UIKit
import InstantSearch
import WARangeSlider
class SearchTableViewController: UITableViewController {
#IBOutlet weak var resultButton: StatsButtonWidget!
override func viewDidLoad() {
super.viewDidLoad()
resultButton.frame = CGRect(x: 0, y: 0, width: 150, height: 60)
navigationController?.view.addSubview(resultButton)
InstantSearch.shared.registerAllWidgets(in: self.view)
LayoutHelpers.setupResultButton(button: resultButton)
resultButton.addTarget(self, action: #selector(resultButtonClicked), for: .touchUpInside)
}
}
How can i add button overlay on bottom in UITableViewController? Me need use only UITableViewController, not UIViewController with TableView.
You could directly add the button to the UITableView without AutoLayout, and make sure TableView's delegate is the controller, like:
override func viewDidLoad() {
super.viewDidLoad()
self.button.frame = CGRect(x: 0, y: self.tableView.frame.size.height - 50, width: self.tableView.frame.width, height: 50)
self.tableView.addSubview(self.button)
self.tableView.delegate = self
}
Then you are able to fix the button's position by UIScrollView delegate (UITableViewDelegate inherited from this) while TableView is scrolling:
public func scrollViewDidScroll(_ scrollView: UIScrollView) {
if (scrollView == self.tableView) {
let originY = scrollView.frame.size.height - self.button.frame.size.height + scrollView.contentOffset.y
self.button.frame = CGRect(x: 0, y: originY, width: scrollView.frame.width, height: self.button.frame.size.height)
}
}
Alternatively, if you want to position the button by AutoLayout, just define a NSLayoutConstraint property, and bind it to button's bottom space constraint to its super view. Then adjust the constraint's constant value by same mechanism in scrollViewDidScroll function.
You can just add an view at the bottom of your tableview.
override func viewDidLoad() {
super.viewDidLoad()
addResultButtonView()
}
private func addResultButtonView() {
let resultButton = UIButton()
resultButton.backgroundColor = .red
resultButton.setTitle("Hello", for: .normal)
tableView.addSubview(resultButton)
// set position
resultButton.translatesAutoresizingMaskIntoConstraints = false
resultButton.leftAnchor.constraint(equalTo: tableView.safeAreaLayoutGuide.leftAnchor).isActive = true
resultButton.rightAnchor.constraint(equalTo: tableView.safeAreaLayoutGuide.rightAnchor).isActive = true
resultButton.bottomAnchor.constraint(equalTo: tableView.safeAreaLayoutGuide.bottomAnchor).isActive = true
resultButton.widthAnchor.constraint(equalTo: tableView.safeAreaLayoutGuide.widthAnchor).isActive = true
resultButton.heightAnchor.constraint(equalToConstant: 50).isActive = true // specify the height of the view
}
My problem is that my Button and other all controls are not working when i have adding scrollview programmatically to my subView.
override func viewDidLoad() {
super.viewDidLoad()
if(self.appDelegate.screenWidth < 568){
self.scrollView = UIScrollView(frame: view.bounds)
self.scrollView.delegate = self
self.scrollView.contentSize = CGSizeMake(self.appDelegate.screenWidth, 568)
scrollView.delaysContentTouches = false
scrollView.canCancelContentTouches = true
scrollView.scrollEnabled = true
// mainView consists all other controls like UIButton and other
scrollView.addSubview(mainView)
view.addSubview(scrollView)
}
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
if(self.appDelegate.screenWidth < 568){
scrollView.frame = view.bounds
mainView.frame = CGRectMake(0, 0, scrollView.contentSize.width, scrollView.contentSize.height)
}
}
Any suggestions for solving this query???
Thanks in advance
I truly believe its the issue with your view hierarchy. You are adding your scroll view on top of all other UI controls UIButton etc. All the UI controls should be sub-view of scroll view for scroll and controls to function well.