I'm trying to code a short intros for my first app.
Here is my code:
import UIKit
class ViewController: UIViewController, UIScrollViewDelegate {
var MainscrollView = UIScrollView()
override func viewDidLoad() {
super.viewDidLoad()
MainscrollView.delegate = self
//Frames
var singleFrame : CGRect = self.view.frame;
var scrollFrame : CGRect = singleFrame
scrollFrame.size.width *= 3.0 //num. frames
//Views
//ScrollView
MainscrollView = UIScrollView(frame: singleFrame)
view.addSubview(MainscrollView)
MainscrollView.isPagingEnabled = true
MainscrollView.contentSize = scrollFrame.size
//1 frame
let firstView : UIView = UIView(frame: singleFrame)
firstView.backgroundColor = UIColor.red
MainscrollView.addSubview(firstView)
//2 frame
singleFrame.origin.x = firstView.frame.size.width
let secondView : UIView = UIView(frame: singleFrame)
secondView.backgroundColor = UIColor.yellow
MainscrollView.addSubview(secondView)
//3 frame
singleFrame.origin.x = firstView.frame.size.width * 2
let thirdView : UIView = UIView(frame: singleFrame)
thirdView.backgroundColor = UIColor.green
MainscrollView.addSubview(thirdView)
}
func scrollViewDidEndDecelerating(_ MainscrollView : UIScrollView) {
print("in here")
}
}
Unfortunatelly the scrollViewDidEndDecelerating function is never triggered.
I have a couple of needs:
How can I use correctly the scrollViewDidEndDecelerating? (I need it to trigger the event "page changed" for a pageController element).
Can you put me on the right direction to implement some additional graphical effects above the scrollView as objects that enter and exit in the view with a different speed than the scrollView (as Google Calendar Intro, or Evernote Intro, etc.)?
Also, you've created UIScrollView twice:
var MainscrollView = UIScrollView()
and
MainscrollView = UIScrollView(frame: singleFrame)
So, after setting of delegate your MainscrollView created again. You can change your code to set correct frame like that:
MainscrollView.frame = singleFrame
view.addSubview(MainscrollView)
MainscrollView.isPagingEnabled = true
MainscrollView.contentSize = scrollFrame.size
And you must named your property in camel case - mainScrollView
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
I have a "off-screen" UIView hierarchy which I want render in different locations of my screen. In addition it should be possible to show only parts of this view hierarchy and should reflect all changes made to this hierarchy.
The difficulties:
The UIView method drawHierarchy(in:afterScreenUpdates:) always calls draw(_ rect:) and is therefore very inefficient for large hierarchies if you want to incorporate all changes to the view hierarchy. You would have to redraw it every screen update or observe all changing properties of all views. Draw view hierarchy documentation
The UIView method snapshotView(afterScreenUpdates:) also does not help much since I have not found a way to get a correct view hierarchy drawing if this hierarchy is "off-screen". Snapshot view documentation
"Off-Screen": The root view of this view hierarchy is not part of the UI of the app. It has no superview.
Below you can see a visual representation of my idea:
Here's how I would go about doing it. First, I would duplicate the view you are trying to duplicate. I wrote a little extension for this:
extension UIView {
func duplicate<T: UIView>() -> T {
return NSKeyedUnarchiver.unarchiveObject(with: NSKeyedArchiver.archivedData(withRootObject: self)) as! T
}
func copyProperties(fromView: UIView, recursive: Bool = true) {
contentMode = fromView.contentMode
tag = fromView.tag
backgroundColor = fromView.backgroundColor
tintColor = fromView.tintColor
layer.cornerRadius = fromView.layer.cornerRadius
layer.maskedCorners = fromView.layer.maskedCorners
layer.borderColor = fromView.layer.borderColor
layer.borderWidth = fromView.layer.borderWidth
layer.shadowOpacity = fromView.layer.shadowOpacity
layer.shadowRadius = fromView.layer.shadowRadius
layer.shadowPath = fromView.layer.shadowPath
layer.shadowColor = fromView.layer.shadowColor
layer.shadowOffset = fromView.layer.shadowOffset
clipsToBounds = fromView.clipsToBounds
layer.masksToBounds = fromView.layer.masksToBounds
mask = fromView.mask
layer.mask = fromView.layer.mask
alpha = fromView.alpha
isHidden = fromView.isHidden
if let gradientLayer = layer as? CAGradientLayer, let fromGradientLayer = fromView.layer as? CAGradientLayer {
gradientLayer.colors = fromGradientLayer.colors
gradientLayer.startPoint = fromGradientLayer.startPoint
gradientLayer.endPoint = fromGradientLayer.endPoint
gradientLayer.locations = fromGradientLayer.locations
gradientLayer.type = fromGradientLayer.type
}
if let imgView = self as? UIImageView, let fromImgView = fromView as? UIImageView {
imgView.tintColor = .clear
imgView.image = fromImgView.image?.withRenderingMode(fromImgView.image?.renderingMode ?? .automatic)
imgView.tintColor = fromImgView.tintColor
}
if let btn = self as? UIButton, let fromBtn = fromView as? UIButton {
btn.setImage(fromBtn.image(for: fromBtn.state), for: fromBtn.state)
}
if let textField = self as? UITextField, let fromTextField = fromView as? UITextField {
if let leftView = fromTextField.leftView {
textField.leftView = leftView.duplicate()
textField.leftView?.copyProperties(fromView: leftView)
}
if let rightView = fromTextField.rightView {
textField.rightView = rightView.duplicate()
textField.rightView?.copyProperties(fromView: rightView)
}
textField.attributedText = fromTextField.attributedText
textField.attributedPlaceholder = fromTextField.attributedPlaceholder
}
if let lbl = self as? UILabel, let fromLbl = fromView as? UILabel {
lbl.attributedText = fromLbl.attributedText
lbl.textAlignment = fromLbl.textAlignment
lbl.font = fromLbl.font
lbl.bounds = fromLbl.bounds
}
if recursive {
for (i, view) in subviews.enumerated() {
if i >= fromView.subviews.count {
break
}
view.copyProperties(fromView: fromView.subviews[i])
}
}
}
}
to use this extension, simply do
let duplicateView = originalView.duplicate()
duplicateView.copyProperties(fromView: originalView)
parentView.addSubview(duplicateView)
Then I would mask the duplicate view to only get the particular section that you want
let mask = UIView(frame: CGRect(x: 0, y: 0, width: yourNewWidth, height: yourNewHeight))
mask.backgroundColor = .black
duplicateView.mask = mask
finally, I would scale it to whatever size you want using CGAffineTransform
duplicateView.transform = CGAffineTransform(scaleX: xScale, y: yScale)
the copyProperties function should work well but you can change it if necessary to copy even more things from one view to another.
Good luck, let me know how it goes :)
I'd duplicate the content I wish to display and crop it as I want.
Let's say I have a ContentViewController which carries the view hierarchy I wish to replicate. I would encapsule all the changes that can be made to the hierarchy inside a ContentViewModel. Something like:
struct ContentViewModel {
let actionTitle: String?
let contentMessage: String?
// ...
}
class ContentViewController: UIViewController {
func display(_ viewModel: ContentViewModel) { /* ... */ }
}
With a ClippingView (or a simple UIScrollView) :
class ClippingView: UIView {
var contentOffset: CGPoint = .zero // a way to specify the part of the view you wish to display
var contentFrame: CGRect = .zero // the actual size of the clipped view
var clippedView: UIView?
override init(frame: CGRect) {
super.init(frame: frame)
clipsToBounds = true
}
override func layoutSubviews() {
super.layoutSubviews()
clippedView?.frame = contentFrame
clippedView?.frame.origin = contentOffset
}
}
And a view controller container, I would crop each instance of my content and update all of them each time something happens :
class ContainerViewController: UIViewController {
let contentViewControllers: [ContentViewController] = // 3 in your case
override func viewDidLoad() {
super.viewDidLoad()
contentViewControllers.forEach { viewController in
addChil(viewController)
let clippingView = ClippingView()
clippingView.clippedView = viewController.view
clippingView.contentOffset = // ...
viewController.didMove(to: self)
}
}
func somethingChange() {
let newViewModel = ContentViewModel(...)
contentViewControllers.forEach { $0.display(newViewModel) }
}
}
Could this scenario work in your case ?
I had created an extension to the UIView and created an ActivityIndicatorView and added it as the subview to UIApplication Window. Now when the device rotates the UIViewController also rotates and not this ActivityIndicatorView.
internal extension UIView{
func showActivityViewWithText(text: String?) -> UIView{
let window = UIApplication.sharedApplication().delegate?.window!!
let baseLineView = window!.viewForBaselineLayout()
let locView = UIView(frame:window!.frame)
locView.backgroundColor = UIColor.clearColor()
locView.center = window!.center
baseLineView.addSubview(locView)
baseLineView.bringSubviewToFront(locView)
let overlay = UIView(frame: locView.frame)
overlay.backgroundColor = UIColor.blackColor()
overlay.alpha = 0.35
locView.addSubview(overlay)
locView.bringSubviewToFront(overlay)
let hud = UIActivityIndicatorView(activityIndicatorStyle: .WhiteLarge)
hud.hidesWhenStopped = true
hud.center = CGPoint(x: locView.frame.size.width/2,
y: locView.frame.size.height/2)
hud.transform = CGAffineTransformMakeScale(1, 1)
hud.color = UIColor.redColor()
hud.startAnimating()
locView.addSubview(hud)
locView.bringSubviewToFront(hud)
}
May be problem is in missed autoresizing mask? Try to add:
hud.autoresizingMask = [ .flexibleTopMargin, .flexibleBottomMargin, .flexibleLeftMargin, .flexibleRightMargin ]
In a reason your hud is subview of a locView autoresizingMask is required for locView too I suppose.
I would like to achieve the design you see in dating apps. Where you can vertically scroll images of a profile and also horizontally scroll to view the next or previous person in the list.
Currently I have my views laid out as such.
Previous-UIView - current UIView - next UIView
UIScrollView. UIScrollView. UIScrollView
Images. Images. Images
UIView. UIView. UIView
Profile info. Profile info. Profile info
UIPageControl. UIPageControl UIPageControl.
Only one of the Views occupies the main view with next and previous off screen. Ideally when the user moves the view left I would programmatically remove the previous view, make current the previous, the next current and add a new view for next. Visa versa for moving right.
What is the best way to scroll the views horizontally?
Should I wrap them all in a UIScrollView? And would that interfere with the UIScrollView sub Views?
Or should I program touch controls to move the views?
Or is there a better way?
I'm still a newbie at iOS development so any help would be greatly appreciated.
So I've tried some experimenting with a test app and I'm pleased to say you can have UIScrollviews inside UIScrollviews.
I was able to get it running perfectly. Here is my code below.
override func viewDidLoad() {
super.viewDidLoad()
self.superView.delegate = self
// Do any additional setup after loading the view, typically from a nib.
var subImages1 = ["IMG_0004.JPG","IMG_0005.JPG","IMG_0008.JPG"]
var subImages2 = ["IMG_0009.JPG","IMG_0010.JPG","IMG_0011.JPG"]
var subImages3 = ["IMG_0013.JPG","IMG_0017.JPG","IMG_0018.JPG"]
self.images.append(subImages1)
self.images.append(subImages2)
self.images.append(subImages3)
self.superView.frame = self.view.frame
self.superView.contentSize = CGSizeMake(self.view.frame.width*3, self.view.frame.height)
self.superView.contentOffset = CGPoint(x:self.view.frame.width,y:0)
self.superView.pagingEnabled = true
self.view.addSubview(self.superView)
//layout the UIVeiws into the master ScrollView
for i in 0...2{
var offset = self.view.frame.width * CGFloat(i)
var pView = UIView()
pView.frame = CGRectMake(offset, 0, self.view.frame.width, self.view.frame.height)
pView.backgroundColor = colours[i]
self.superView.addSubview(pView)
self.profileViews.append(pView)
}
// Add sub Scroll views and images to the Views.
for (index, view) in enumerate(self.profileViews){
var scrollView = UIScrollView()
scrollView.delegate = self
scrollView.frame = CGRectMake(10, 10, self.view.frame.width-20, self.view.frame.height-20)
scrollView.pagingEnabled = true
scrollView.contentSize = CGSizeMake(scrollView.frame.width, scrollView.frame.height * CGFloat(images[index].count))
for (index2, image) in enumerate(images[index]){
var subImage = UIImageView()
subImage.frame = CGRectMake(0, scrollView.frame.height * CGFloat(index2), scrollView.frame.width, scrollView.frame.height)
subImage.contentMode = UIViewContentMode.ScaleAspectFit
subImage.image = UIImage(named: image as! String)
scrollView.addSubview(subImage)
}
view.addSubview(scrollView)
self.scrollViews.append(scrollView)
}
}
//Use the did end decelerating as it executes the code once the scoll has finished moving.
func scrollViewDidEndDecelerating(scrollView: UIScrollView) {
if(scrollView == self.superView){
var contentOffset = scrollView.contentOffset
var pageWidth = self.superView.frame.width
var fractionalPage:Double = Double(self.superView.contentOffset.x / pageWidth)
var page = lround(fractionalPage)
// In this example I take the last UIView from the stack and move it to the first.
// I would do the same in the real app but update the contents of the view after
if(page == 0){
var tempView = self.profileViews[2]
self.profileViews[2].removeFromSuperview()
self.profileViews.removeAtIndex(2)
for view in self.profileViews{
view.frame = CGRectMake(view.frame.minX + self.view.frame.width, 0, view.frame.width, view.frame.height)
println(view.frame)
}
tempView.frame = CGRectMake(0, 0, tempView.frame.width, tempView.frame.height)
self.profileViews.insert(tempView, atIndex: 0)
self.superView.addSubview(tempView)
var newOffset = contentOffset.x + pageWidth
self.superView.contentOffset = CGPoint(x: newOffset, y: 0)
}
// Take the first view and move it to the last.
if(page == 2){
var tempView = self.profileViews[0]
self.profileViews[0].removeFromSuperview()
self.profileViews.removeAtIndex(0)
for view in self.profileViews{
view.frame = CGRectMake(view.frame.minX - self.view.frame.width, 0, view.frame.width, view.frame.height)
println(view.frame)
}
tempView.frame = CGRectMake(tempView.frame.width*2, 0, tempView.frame.width, tempView.frame.height)
self.profileViews.append(tempView)
self.superView.addSubview(tempView)
var newOffset = contentOffset.x - pageWidth
self.superView.contentOffset = CGPoint(x: newOffset, y: 0)
}
}
}
I'm trying to build a very simple UIScrollView with several images where paging is enabled.
However, I can't seen to get the images to correctly be resized to the bounds of my UIScrollView. The images are always bigger than the bounds, thus messing with my paging.
I have a UIScollView and a UIPageControl in Interface Builder and link it in my ViewController swift file.
Here is my viewDidLoad method (pageImages is defined as var pageImages: [UIImage] = [] and pageViews as var pageViews: [UIImageView?] = []:
override func viewDidLoad() {
scrollView.delegate = self
scrollView.pagingEnabled = true
scrollView.scrollEnabled = true
scrollView.showsHorizontalScrollIndicator = false
scrollView.showsVerticalScrollIndicator = false
scrollView.bounces = true
scrollView.scrollsToTop = false
pageImages = [UIImage(named: "image1")!,
UIImage(named: "image2")!,
UIImage(named: "image3")!,
UIImage(named: "image4")!,
UIImage(named: "image5")!]
let pageCount = pageImages.count
pageControl.currentPage = 0
pageControl.numberOfPages = pageCount
for (var i=0; i<pageCount; i++) {
var xOrigin: CGFloat = CGFloat(i) * scrollView.bounds.size.width
let imageView: UIImageView = UIImageView(frame: CGRectMake(xOrigin, 0, scrollView.bounds.size.width, scrollView.bounds.size.height))
imageView.image = pageImages[i]
imageView.contentMode = UIViewContentMode.ScaleAspectFill
imageView.clipsToBounds = true
scrollView.addSubview(imageView)
}
let pagesScrollViewSize = scrollView.frame.size
scrollView.contentSize = CGSize(width: pagesScrollViewSize.width * CGFloat(pageImages.count),
height: pagesScrollViewSize.height)
}
My scrollViewDidScroll method is as follows:
func scrollViewDidScroll(scrollView: UIScrollView) {
let pageWidth = self.scrollView.frame.size.width
let page = Int(floor((self.scrollView.contentOffset.x - pageWidth/2)/pageWidth) + 1)
self.pageControl.currentPage = page
}
Can anyone spot my mistake? Do I have to set the contentMode maybe in viewWillAppear or viewDidAppear?
Try setting up your imageViews sizes under:
(void)viewDidLayoutSubviews
At this point, autolayout had finished resizing your views/subviews according to the layout system you defined on interface builder so if your calculations are correct (according your requirements) this should work out fine.