In swift how can I set the width of the scroll view to be the width of the screen size?
I tried setting right leading and trailing bounds, but my aspectscalefill image keeps stretching the entire frame.
I am trying to force the view to be the width of the screen and allow vertical scrolling only.
If you want to make a scroll view with auto layout try this. No code at all so you will have to drag things out of the library to the right of Xcode.
In your view controller drag and place the scroll view size it to whatever you want but it looks like you want to make it the size of the screen. Pin all edges to the edges of the view controller. Pin trailing, leading, top, and bottom.
Now, instead of placing your items in the scroll view, place another view in the scroll view. With this new view you will place all of your items. You will most likely have to move the view up or down to place them all and resize the view. You can then place whatever constraints you want on your items. When all items are in their place, set the frame of the new view back to x = 0 and y = 0.
You will then place constraints as follows. Select the new view and pin to top, bottom, trailing, and leading and then center in container. This will make a constraint that is vertical with some negative number. In the storyboard outline select this constraint and set it to zero.
You will now be able to scroll vertically. Let me know if you have any questions.
I created a single view application, and added a UIScrollView in the storyboard with four constraints (top, left, right, bottom). And I add the following code in the viewDidLoad(). Everything works just fine. My image is only scrolling vertically, but not horizontally. No additional settings are needed.
#IBOutlet weak var scrollView: UIScrollView!
override func viewDidLoad() {
super.viewDidLoad()
// Just as an example, I make a size with same with of the view
// and twice the height of the view.
let size = CGSizeMake(
self.view.frame.size.width,
self.view.frame.size.height * 2);
// Load an image and make a image view
let image = UIImage(named: "im.jpg")!
let imageView = UIImageView(image: image)
imageView.frame = CGRect(
origin: CGPoint(x: 0, y: 0),
size: size);
imageView.contentMode = UIViewContentMode.ScaleToFill;
// Add the image view to scroll view
scrollView.addSubview(imageView)
scrollView.contentSize = size;
}
Your problem i caused by the fact that you add your elements to the scrollView from the storyBoard.
In the storyBoard you need:
1) Add the scrollView, if you need to be in the width of the screen then set it's trailing and leading spaces to superView to 0
2) uncheck the "allow horizontal scrolling" in the attribute inspector
In your code
1) set the scrollView's contentSize to what ever size you want it to be.
1.1) in your code you need to set the size of the contentView like so
scroller.contentSize = CGSizeMake(your width, your height);
This is a very important step, the scrollView will not be able to scroll if you don't set the size. Think about the scrollView as the window and the contentView as the view. If the contentView if the same size as the scrollView then the scrollView can't scroll anywhere (all of the contentView fits into the scrollView) in order to create the scrolling you need to make the contentView bigger then the scrollView itself
2) start adding your elements to the scrollView's contentView by calling
[scroller addSubView:<your view>];
this will add your views to the scrollView's contentView and will be
I have a UIScrollView sitting inside a popover. It is pinned to the edges of the popover using constraints, and it's full content is able to be displayed in the popover without scrolling (so the scroll view is not scrollable). When I tap a UITextField (located inside this scroll view), the keyboard slides up and the popover resizes. When the popover resizes, the UIScrollView becomes smaller and the content is now scrollable.
So my question is, how can I detect when my scroll view becomes scrollable?
P.S. I want to detect this so that I can set the delaysContentTouches property to YES when it is scrollable and to NO when the content is not scrollable.
You can check to see if the contentSize is larger than the scrollView's bounds.
CGSize contentSize = scrollView.contentSize;
CGSize boundsSize = scrollView.bounds.size;
if (contentSize.width > boundsSize.width && contentSize.height > boundsSize.height) {
// scrollable both vertically and horizontally
}
else if (contentSize.width > boundsSize.width) {
// scrollable horizontally
}
else if (contentSize.height > boundsSize.height) {
// scrollable vertically
}
else {
// same size or smaller, not scrollable
}
I put a UIScrollView in my nib's view, and linked it to a an IBOutlet property.
Now, when I do this in my viewDidLoad method, it seems to have no effect on the contentSize:
self.sv.backgroundColor = [UIColor yellowColor]; // this works
CGSize size = CGSizeMake(1000.0, 1000.0);
[self.sv setContentSize:size]; // this does not
It behaves as if the contentSize was the same as the frame. What's going on?
This started working when I turned off AutoLayout. Why?
I had the same problem. Auto Layout for UIScrollView is messed up.
Work around: Put everything in the UIScrollView into another UIView, and put that UIView as the only child of the UIScrollView. Then you can use Auto Layout.
If things near the end is messed up (the end of whichever direction your UIScrollView scrolls), change the constraint at the end to have the lowest possible priority.
I tried viewWillLayoutSubviews to update scrollView's contentSize, it worked for me.
- (void)viewDidLayoutSubviews
{
[self.bgScrollView setContentSize:CGSizeMake(320, self.view.frame.size.height* 1.5)];
}
Apple Doc
-(void)viewDidLayoutSubviews
Called to notify the view controller that its view has just laid out its subviews.
Discussion
When the bounds change for a view controller’s view, the view adjusts the positions of its subviews and then the system calls this method. However, this method being called does not indicate that the individual layouts of the view’s subviews have been adjusted. Each subview is responsible for adjusting its own layout.
Your view controller can override this method to make changes after the view lays out its subviews. The default implementation of this method does nothing.
The easiest/cleanest way is to set contentSize at viewDidAppear so you negate the effects of autolayout. This doesn't involve adding random views. However relying on load order for an implementation to work may not be the best idea.
Use this code. ScrollView setContentSize should be called async in main thread.
Swift:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
DispatchQueue.main.async {
var contentRect = CGRect.zero
for view in self.scrollView.subviews {
contentRect = contentRect.union(view.frame)
}
self.scrollView.contentSize = contentRect.size
}
}
Objective C:
- (void)viewDidLayoutSubviews {
[super viewDidLayoutSubviews];
dispatch_async(dispatch_get_main_queue(), ^ {
CGRect contentRect = CGRectZero;
for(UIView *view in scrollView.subviews)
contentRect = CGRectUnion(contentRect,view.frame);
scrollView.contentSize = contentRect.size;
});
}
There are two problems here. (1) viewDidLoad is too soon; you have to wait until after layout has taken place. (2) If you want to use autolayout with a scrollview that comes from a nib, then either you must use constraints to completely describe the size of the contentSize (and then you don't set the contentSize in code at all), or, if you want to set it in code, you must prevent the constraints on the scrollview's subviews from dictating the contentSize. It sounds like you would like to do the latter. To do so, you need a UIView that acts as the sole top-level subview of the scrollview, and in code you must set it to not use autolayout, enabling its autoresizingMask and removing its other external constraints. I show an example of how to do that, here:
https://github.com/mattneub/Programming-iOS-Book-Examples/blob/master/ch20p573scrollViewAutoLayout/ch20p573scrollViewAutoLayout/ViewController.m
But notice also the next example, which shows how to use constraints completely, instead of contentSize.
A SUPER easy way to use AutoLayout with UIScrollViews inside Interface Builder:
Step 1: Create a UIScrollView
Step 2: Create a UIView that is a child of your scroll view like so:
-UIScrollView
---UIView
-----Your other content
(We'll call this one contentView).
Step 3: In the size inspector, give this view a height and width (say, 320x700).
Step 4 (using AutoLayout): Create unambiguous constraints from your contentView to its superview (the UIScrollView): connect the 4 edges (top, leading, trailing, bottom), then give it a defined width and height that you want it to scroll too.
For example: If your scroll view spans the entire screen, you could give your content view a width of [device width] and a height of 600; it will then set the content size of the UIScrollView to match.
OR:
Step 4 (not using AutoLayout): Connect both of these new controls to your view controller using IB (ctrl+drag from each control to your view controller's .h #implementation). Let's assume each is called scrollView and contentView, respectively. It should look like this:
#interface YourViewController : UIViewController
#property (strong, nonatomic) IBOutlet UIScrollView *scrollView;
#property (strong, nonatomic) IBOutlet UIView *contentView;
#end
Step 5 (not using AutoLayout): In the view controller's .h file add (actually, override) the following method:
-(void)viewDidLayoutSubviews
{
[super viewDidLayoutSubviews];
self.scrollView.contentSize = self.contentView.frame.size;
}
You can use this lines of code into your *.m file's
- (void)viewDidLoad{
[scroll setContentSize:CGSizeMake(320, 800)] ;
[scroll setScrollEnabled:TRUE];
[scroll setShowsVerticalScrollIndicator:NO];
[scroll setShowsHorizontalScrollIndicator:YES];
}
for this you need to take an IBOutlet property of UIScrollView into your *.h file this way:
IBOutlet UIScrollView *scroll;
And connect this from Storyboard.
Or,
You can use this method into your *.m file:
-(void)viewDidLayoutSubviews
{
[scroll setContentSize:CGSizeMake(320, self.view.frame.size.height* 1.5)];
// this will pick height automatically from device's height and multiply it with 1.5
}
This both solution works for me in xcode-5, xcode-6, xcode-6.1, xcode-6.2
Setting the contentSize in viewDidAppear is critical.
But I also had a variation of what worked in the 3.5 inch screen, and the 4 inch screen. The 4 inch screen worked, the older one does not. Both iOS 7. Bizarre is an understatement!
I could never get auto layout based on constraints to work. Since my view was already a subclass UIScrollView I solved it by overriding setContentView: and ignoring auto layouts zero height setContentSize: message.
#interface MyView : UIScrollView {}
#end
#implementation MyView
- (void)setContentSize:(CGSize)aSize {
if (aSize.height > 0)
[super setContentSize:aSize];
}
#end
I used to do set up the uiscrollview programmatically UNTIL I watched the following wonderful tutorial, step by step how to get uiscrollview and uiview to work: https://www.youtube.com/watch?v=PgeNPRBrB18
After watching the video you will start liking Interface Builder I am sure.
Vote up
Still not scrolling when dynamic height of labels exceeds view height.
I did what yuf's answer marked as correct above said to do (I added a content view to my scrollview and set the constraints leading, trailing, top bottom, and equal widths from the content view to the scroll view.) but still my view was not scrolling when the internal controls height exceeded the height of the scrollview.
Inside my content view I have an image and 3 labels below it. Each label adjusts their own height dependant on how much text is in them (they are set to word-wrap and numberoflines = 0 to achieve this).
The problem I had was my content view's height was not adjusting with the dynamic height of the labels when they exceeded the height of the scroll view/main view.
To fix this I worded out I needed to set the Bottom Space to Container constraint between my bottom label and the contentview and gave it a value of 40 (chosen arbitrarily to give it a nice margin at the bottom). This now means that my contentview adjusts its height so that there is a space between the bottom of the last label and itself and it scrolls perfectly!
Yay!
Try this out...
add all constraints like you do for UIView (See screenShot of my ViewControler in Storyboard)
Now trick begins. select your last object and select its bottom constraint. (See above screenShot, Instagram button's Bottom Constraint(Yellow line)) and Change the Constant in Size Inspector like in bellow screenshot.
i require Constant=8 but you can change as per your requirements.
this Constant is the Space between That Orange Button's Bottom and the scrollView.
EDIT
Make Sure about your view's hierarchy .
0) ViewController.view (optional)
1) UIScrollView
2) UIView (Rename as "contentView")
3) UIView (this view is your content that will make scrollView scroll)
I finally worked out my own solution to this problem because in my case I couldn't use the view controller's life cycle. Create your own scroll view subclass and use it instead of UIScrollView. This even worked for a scroll view inside a collection view cell.
class MyScrollView:UIScrollView {
var myContentSize:CGSize = CGSize.zero // you must set this yourself
override func layoutSubviews() {
super.layoutSubviews()
contentSize = myContentSize
}
}
My MyScrollView was defined in the nib with a tag of 90. If so this is a good way to set content size in the code in the parent view.
let scrollView = viewWithTag(90) as! MyScrollView
scrollView.myContentSize = ...
If you are using AutoLayout a really easy way to set the contentSize of a UIScrollView is just to add something like this:
CGFloat contentWidth = YOUR_CONTENT_WIDTH;
NSLayoutConstraint *constraintWidth =
[NSLayoutConstraint constraintWithItem:self.scrollView
attribute:NSLayoutAttributeTrailing
relatedBy:NSLayoutRelationEqual
toItem:self.scrollView
attribute:NSLayoutAttributeLeading
multiplier:1
constant:contentWidth];
[self.scrollView addConstraint:constraintWidth];
I got Autolayout to work for paginated scroll views whose pages occupy the full-width of the screen. The pages automatically resize according to the scroll view's size. I haven't tested this for lesser-width scroll views but do comment away if it works--I beleieve it should. Targeted for iOS 9, wrote code in Swift 2, used a mix of IB's and custom code in awakeFromNib.
Steps:
Define a full-screen scroll view.
Inside the scroll view, add a UIView (I called mine contentView) whose top, trailing, bottom, and leading edges to the scroll view are all zero; the height is equal to the scroll view's; but the width is the scroll view's width times the number of pages. If you're doing this visually, you will see your content view extend beyond your scroll view in Inteface Builder.
For every "page" inside the contentView, add Autolayout rules to put them side-by-side each other, but most importantly, give them each a constraint so that their widths are equal to the scroll view's, not the content view's.
Sample code below. embedChildViewController is just my convenience method for adding child VCs--do look at setupLayoutRulesForPages. I have exactly two pages so the function is too simple, but you can expand it to your needs.
In my view controller:
override func loadView() {
self.view = self.customView
}
override func viewDidLoad() {
super.viewDidLoad()
self.embedChildViewController(self.addExpenseVC, toView: self.customView.contentView, fillSuperview: false)
self.embedChildViewController(self.addCategoryVC, toView: self.customView.contentView, fillSuperview: false)
self.customView.setupLayoutRulesForPages(self.addExpenseVC.view, secondPage: self.addCategoryVC.view)
}
My custom view:
class __AMVCView: UIView {
#IBOutlet weak var scrollView: UIScrollView!
#IBOutlet weak var contentView: UIView!
#IBOutlet weak var pageControl: UIPageControl!
override func awakeFromNib() {
super.awakeFromNib()
self.scrollView.pagingEnabled = true
self.scrollView.bounces = true
self.scrollView.showsHorizontalScrollIndicator = false
self.scrollView.showsVerticalScrollIndicator = false
self.pageControl.numberOfPages = 2
self.contentView.backgroundColor = UIColor.blueColor()
self.scrollView.backgroundColor = UIColor.clearColor()
self.backgroundColor = UIColor.blackColor()
}
func setupLayoutRulesForPages(firstPage: UIView, secondPage: UIView) {
guard self.contentView.subviews.contains(firstPage) && self.contentView.subviews.contains(secondPage)
else {
return
}
let rules = [
"H:|-0-[firstPage]-0-[secondPage]-0-|",
"V:|-0-[firstPage]-0-|",
"V:|-0-[secondPage]-0-|"
]
let views = [
"firstPage" : firstPage,
"secondPage" : secondPage
]
let constraints = NSLayoutConstraint.constraintsWithVisualFormatArray(rules, metrics: nil, views: views)
UIView.disableAutoresizingMasksInViews(firstPage, secondPage)
self.addConstraints(constraints)
// Add the width Autolayout rules to the pages.
let widthConstraint = NSLayoutConstraint(item: firstPage, attribute: .Width, relatedBy: .Equal, toItem: self.scrollView, attribute: .Width, multiplier: 1, constant: 0)
self.addConstraint(widthConstraint)
}
}
I have five UIView on a UIScrollView. All of them with the same width. Each view has other subviews that resize its height according to the content assigned, thus making the parent UIView and the UIScrollView resizable as well. I am trying to keep the 5 UIView separated from each other at a certain "Padding" distance even after resizing. What I do right now is set the position of the origin.y and the height of each UIView when layoutSubviews is called. Is there an easier way to do this?
I have tried to set their position on creation like: CGRectMake(0, aboveView.frame.origin.y + aboveView.frame.size.height + Padding, width, 0) and setting its autoresizingMask to UIViewAutoresizingMaskTopMargin. Hoping that when I call sizeToFit on the main UIView, all the UView will set their positions relative to the view above them.
Overriding layoutSubviews is the right way to do this. UIKit doesn't have any built-in layout management that can do it for you.
However, you might not realize that UIScrollView sends itself layoutSubviews each time it scrolls - on every frame of the scrolling. That may be a lot more often than you need! You don't want to do a lot of work in a UIScrollView's layoutSubviews if you can avoid it.
To avoid doing extra layout, I suggest you set up your view hierarchy like this:
UIScrollView
ContainerView with layoutSubviews method
content view 1
content view 2
content view 3
content view 4
content view 5
Use a standard UIScrollView. Give it one subview, which is a custom UIView subclass (I called it ContainerView in my example). The ContainerView has your five content views as its subviews.
When you assign new content to one of your five content views, send sizeToFit to that content view. If the view's size changes, UIKit should automatically send layoutSubviews to its superview - the ContainerView. The ContainerView's layoutSubviews method adjusts the position of its subviews to maintain the padding between them, and then sets the contentSize of its parent - the UIScrollView.
- (void)layoutSubviews {
CGRect myFrame = CGRectZero;
for (UIView *subview in self.subviews) {
CGRect frame = subview.frame;
if (myFrame.size.height > 0) {
frame.origin.y = myBounds.size.height + Padding;
subview.frame = frame;
}
myFrame = CGRectUnion(myFrame, frame);
}
self.frame = myFrame;
UIScrollView *scrollView = self.superview;
scrollView.contentSize = myFrame.size;
}
This way, you don't do any extra work just because the scroll view scrolled. You only lay out your content views when the content actually changes.
My application uses a UINavigationController and the final view (detail view) lets you view an external website within the application using a UIWebView.
I'd like to free up some additional screen real estate when the user is viewing a webpage and wanted to emulate how Safari on iPhone works where their URL bar at the top scrolls up and off the screen when you're viewing content in the UIWebView that's below the fold.
Anyone have ideas on how to achieve this? If I set the navigationBarHidden property and roll my own custom bar at the top and set it and a UIWebView within a UIScrollView then there are scrolling issues in the UIWebView as it doesn't play nicely with other scrollable views.
Based on #Brian suggestion I made this code:
- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
CGFloat height = navigationBar.frame.size.height;
CGFloat y = scrollView.bounds.origin.y;
if (y <= 0) {
CGRect frame = navigationBar.frame;
frame.origin.y = 0;
navigationBar.frame = frame;
} else if (tableView.contentSize.height > tableView.frame.size.height) {
CGFloat diff = height - y;
CGRect frame = navigationBar.frame;
frame.origin.y = -y;
navigationBar.frame = frame;
CGFloat origin = 0;
CGFloat h = height; // height of the tableHeaderView
if (diff > 0) {
origin = diff;
h = y;
}
frame = tableView.frame;
frame.origin.y = origin;
frame.size.height = tableView.superview.frame.size.height - origin;
tableView.frame = frame;
CGRect f = CGRectMake(0, 0, tableView.frame.size.width, h);
UILabel* label = [[UILabel alloc] initWithFrame:f];
tableView.tableHeaderView = label;
[label release];
}
}
My code has a UITableView but should work with any scrollable component. If you have other components than the navigationBar and the UIScrollView subclass, you should change the way the height of the scrollable component is calculated. Something like this:
frame.size.height = tableView.superview.frame.size.height - origin - otherComponentsHeight;
I needed to add a dumb tableHeaderView to have the desired behaviour. The problem was that when scrollViewDidScroll: is called the content has an offset, but the apparience in Mobile Safari is that the content is not scrolled until the navigationBar fully disappears. I tried first changing the contentOffset.y to 0, but obviously it didn't work since all the code relies on the scrolling mechanism. So I just added a tableHeaderView whose height is exactly the scrolled offset, so the header is never really seen, and the content appears to not scroll until the navigationBar fully disappears.
If you don't add the dumb tableHeaderView, then the scrollable component appears to scroll behind the navigationBar.
With the tableHeaderView, the scrollable component is actually scrolling (as seen in the scrollbar), but since there is a tableHeaderView whose height is exactly the same than the scrolled offset, the scrollable content appears to not be scrolling until the navigationBar fully disappears:
Have a delegate for the scrolling events in the UIWebView and when you initially start scrolling the UIWebView, have the UIWebView increase in height and have it's Y position decrease at the same time while simultaneously shifting the nav bar up in the Y direction. Once the nav bar has been completely shifted out of view, stop increasing the size of the UIWebView and just allow normal scrolling to occur.
This will give the illusion of the nav bar being part of the UIWebView as it scrolls off the screen.
Also, you'll need to do the reverse when you are scrolling in the opposite direction and are reaching the top of the content of the UIWebView.
Can't give you a straight answer, but have a look at iWebKit. Maybe that provides a solution. The demo, at least, contains a "full screen" item.