UITableView tableHeaderView using autolayout height too small - ios

I'm trying to create a UITableView with a header view using autolayout using storyboards. It looks fine in Xcode, but when I run the app, it does not look the same.
In Xcode:
In the app:
The image has a constraint for 150x150, and there are 8-high constraints between the top-image, image-middle label, middle description-label and description label-bottom.
Both labels have numberOfRows set to 0 and lineBreakMode set to ByWordWrapping.
I have tried settings the frame via:
if let headerView = self.tableView.tableHeaderView {
headerView.setNeedsLayout()
headerView.layoutIfNeeded()
let height = headerView.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize).height
println("Setting height to \(height)")
var headerFrame = headerView.frame
headerFrame.size.height = height
headerView.frame = headerFrame
self.tableView.tableHeaderView = headerView
}
One of the original issues was that I had some erroneous constraints (that for some reason Xcode only started complaining about today), so I have removed those and set a contentHuggingPriority of 252 (higher than all others) on the app name label. When I resize the header view manually in the storyboard the image and app name label stay the same height, and the description label grows. It would appear that the apps uses the size of the header in the storyboard at run time, and doesn't get the height from its children.

Answering my own question here:
There are 2 steps that seem to get this to work. The first is in ViewDidLoad, and the second is in viewDidLayoutSubviews:
var headerView: UIView!
override func viewDidLoad() {
super.viewDidLoad()
if let currentTableHeaderView = self.tableView.tableHeaderView {
currentTableHeaderView.removeFromSuperview()
}
// Setting the table header view with a height of 0.01 fixes a bug that adds a gap between the
// tableHeaderView (once added) and the top row. See: http://stackoverflow.com/a/18938763/657676
self.tableView.tableHeaderView = UIView(frame: CGRectMake(0, 0, CGRectGetWidth(self.tableView.frame), 0.01))
self.headerView = AboutTableViewHeaderView(frame: CGRectZero)
}
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
if let tableHeaderView = self.headerView {
var frame = CGRectZero
frame.size.width = self.tableView.bounds.size.width
frame.size.height = tableHeaderView.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize).height
if self.tableView.tableHeaderView == nil || !CGRectEqualToRect(frame, tableHeaderView.frame) {
tableHeaderView.frame = frame
tableHeaderView.layoutIfNeeded()
self.tableView.tableHeaderView = tableHeaderView
}
}
}
Hopefully that all makes sense. The viewDidLayoutSubview code is via http://osdir.com/ml/general/2014-06/msg19399.html

Related

Dynamic height for UITableView header view - Problem with huge margins

In my application I have a UITableViewController that allows preview of a photo and description to that photo, which are both contained in the UITableView's header. The description label needs to be multiline-compatible, so the lines amount is set to 0, obviously the next problem is to make the UITableView header dynamically resizable to adjust it's size to the amount of text in the description label.
The description label is set to fit it's content with self.descriptionLabel.sizeToFit()
The UITableView header view is also set to dynamically resize to fit it's contents via the widely accepted answer from this post:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
if let headerView = tableView.tableHeaderView {
let height = headerView.systemLayoutSizeFitting(UIView.layoutFittingCompressedSize).height
var headerFrame = headerView.frame
//Comparison necessary to avoid infinite loop
if height != headerFrame.size.height {
headerFrame.size.height = height
headerView.frame = headerFrame
tableView.tableHeaderView = headerView
}
}
}
This solution resizes the UITableView header view, but for some reason gives my description label absolutely huge margins stretching up and down from the text. I highlighted my description label with self.descriptionLabel.backgroundColor = .red to be sure it's the description label that stretches and that indeed seems to be the case. I tried a multitude of other solutions, but this is the only one that actually at least resizes the UITableView header view, so I'm stuck with this at the moment.
The margins, however, are absolutely enormous and I can't find a solution to make them fit the description label text size. Any help will be greatly appreciated, because I can't get my head around it.
I added screenshots displaying the problem at the end of this post.
This is the top of the UITableView header, with the red displaying the UILabel beginning to stretch down
This is the actual text of the UILabel
And finally this is where the UILabel stretching finishes with the UIButton at the bottom. I am at a complete loss of how to fix this.
This is my header view UI in Interface Builder
And these are the detailed constraints of my description label in Interface Builder
I believe since the translatesAutoresizingMaskIntoConstraints ARE set to false for the headerView the layout is not auto adjusted once it's calculated in layoutSubviews method.
Try setting the translatesAutoresizingMaskIntoConstraints to true to set the headerView height properly as below:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
if let headerView = tableView.tableHeaderView {
let height = headerView.systemLayoutSizeFitting(UIView.layoutFittingCompressedSize).height
var headerFrame = headerView.frame
//Comparison necessary to avoid infinite loop
if height != headerFrame.size.height {
headerFrame.size.height = height
headerView.frame = headerFrame
tableView.tableHeaderView = headerView
}
}
translatesAutoresizingMaskIntoConstraints = true
}

Autolayout working wrong

I'm working on profile screen, there is a UITableView inside the ViewController and I placed all user info inside the UITableView Header. To make screen more accurate due to different sizes of "About" label I use Autolayout with this code:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
sizeHeaderToFit()
}
func sizeHeaderToFit() {
let headerView = tableView.tableHeaderView!
headerView.setNeedsLayout()
headerView.layoutIfNeeded()
let height = headerView.systemLayoutSizeFitting(UILayoutFittingCompressedSize).height
var frame = headerView.frame
frame.size.height = height
headerView.frame = frame
tableView.tableHeaderView = headerView
}
Everything works fine, but the last string of About label is not showing, text interrupts (I set word wrap):
Add a height constraint on tableview header and try to change height constraint where you are changing frame. As you are using autolayout so you should play with the constraints rather than playing directly with the frames
you can follow this tutorial
https://useyourloaf.com/blog/variable-height-table-view-header/
Hope it will help you.

How to dynamically resize xib according to UITextView

I am using auto layout.
I am loading UIView from xib.
All elements have static size except UITextView.
I've disabled scroll on UITextView
UITextView is filled with the text of different size on ViewDidLoad(). So it can be 1 line or 7 lines there for example.
I am loading this UIView with the following method:
fileprivate func setTableHeaderView() {
guard let _headerView = UINib(nibName: "TableHeaderView",
bundle: nil).instantiate(withOwner: self, options: nil)[0] as? UIView else { return }
tableView.tableHeaderView = UIView(frame:
CGRect(x: 0, y: 0, width: tableView.frame.width, height: _headerView.frame.size.height))
configureViewController() // here I set the text for UITextView
tableView.tableHeaderView?.addSubview(_headerView)
}
When I load this UIView the height is always the same both before and after layoutSubviews. Actually the size always is equal to the initial size of the xib that is set in the Size Inspector of XCode.
I want to UITextView to fit the text size and to have different xib UIView size that will depend on the size of UITextView + all other elements + constraints.
I've tried different ways to implement this but but none did not help. What I've tried:
to set constraints in different ways
to call layoutSubviews() forcibly and check the size of the resulted UIView
to check size of UIView after viewDidLayoutSubviews
translatesAutoresizingMaskIntoConstraints = true with autoresizingMask = .flexibleHeight
Is it possible to implement this idea in such way?
Try to override viewDidLayoutSubviewsMethod
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
// Dynamic sizing for the header view
if let headerView = tableView.tableHeaderView {
let height = headerView.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize).height
var headerFrame = headerView.frame
// If we don't have this check, viewDidLayoutSubviews() will get
// repeatedly, causing the app to hang.
if height != headerFrame.size.height {
headerFrame.size.height = height
headerView.frame = headerFrame
tableView.tableHeaderView = headerView
}
}
}

Swift - How dynamically fixed UITableViewHeaderFooterView height size?

I have just tried below lines of code, but I doesn't work correctly. I wonder that how can I provide this case for header or footer programmatically, may be using autolayout I don't know exactly which one solved my problem. I'm using xib file both of UITableViewHeaderFooterView.
If someone explain I would be great.
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
// Dynamic sizing for the footer view
if let footerView = tableView.tableFooterView {
let height = footerView.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize).height
var footerFrame = footerView.frame
if height != footerFrame.size.height {
footerFrame.size.height = height
footerView.frame = footerFrame
tableView.tableFooterView = footerView
}
}
}
The UITableView calculates the HeaderFooter before they displayed, you can't update that height without calling reloadData() again.
Have you tried to use AutoLayout on those HeaderFooterViews?
I would set up the view from xib with the right constraint, and then:
self.tableView.estimatedSectionHeaderHeight = 100
self.tableView.sectionHeaderHeight = UITableViewAutomaticDimension

How do I set the height of tableHeaderView (UITableView) with autolayout?

I'm been smashing my head against the wall with this for last 3 or 4 hours and I can't seem to figure it out. I have a UIViewController with a full screen UITableView inside of it (there's some other stuff on the screen, which is why I can't use a UITableViewController) and I want to get my tableHeaderView to resize with autolayout. Needless to say, it's not cooperating.
See screenshot below.
Because the overviewLabel (e.g. the "List overview information here." text) has dynamic content, I'm using autolayout to resize it and it's superview. I've got everything resizing nicely, except for the tableHeaderView, which is right below Paralax Table View in the hiearchy.
The only way I've found to resize that header view is programatically, with the following code:
CGRect headerFrame = self.headerView.frame;
headerFrame.size.height = headerFrameHeight;
self.headerView.frame = headerFrame;
[self.listTableView setTableHeaderView:self.headerView];
In this case, headerFrameHeight is a manual calculation of the tableViewHeader height as follows (innerHeaderView is the white area, or the second "View", headerView is tableHeaderView):
CGFloat startingY = self.innerHeaderView.frame.origin.y + self.overviewLabel.frame.origin.y;
CGRect overviewSize = [self.overviewLabel.text
boundingRectWithSize:CGSizeMake(290.f, CGFLOAT_MAX)
options:NSStringDrawingUsesLineFragmentOrigin
attributes:#{NSFontAttributeName: self.overviewLabel.font}
context:nil];
CGFloat overviewHeight = overviewSize.size.height;
CGFloat overviewPadding = ([self.overviewLabel.text length] > 0) ? 10 : 0; // If there's no overviewText, eliminate the padding in the overall height.
CGFloat headerFrameHeight = ceilf(startingY + overviewHeight + overviewPadding + 21.f + 10.f);
The manual calculation works, but it's clunky and prone to error if things change in the future. What I want to be able to do is have the tableHeaderView auto-resize based on the provided constraints, like you can anywhere else. But for the life of me, I can't figure it out.
There's several posts on SO about this, but none are clear and ended up confusing me more. Here's a few:
Auto layout on UITableViewHeader
Auto Layout for tableHeaderView
Is it possible to use AutoLayout with UITableView's tableHeaderView?
table header view height is wrong when using auto layout, IB, and font sizes
It doesn't really make sense to change the translatesAutoresizingMaskIntoConstraints property to NO, since that just causes errors for me and doesn't make sense conceptually anyway.
Any help would really be appreciated!
EDIT 1:
Thanks to TomSwift's suggestion, I was able to figure it out. Instead of manually calculating the height of the overview, I can have it calculated for me as follows and then re-set the tableHeaderView as before.
[self.headerView setNeedsLayout];
[self.headerView layoutIfNeeded];
CGFloat height = [self.innerHeaderView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize].height + self.innerHeaderView.frame.origin.y; // adding the origin because innerHeaderView starts partway down headerView.
CGRect headerFrame = self.headerView.frame;
headerFrame.size.height = height;
self.headerView.frame = headerFrame;
[self.listTableView setTableHeaderView:self.headerView];
Edit 2: As others have noted, the solution posted in Edit 1 doesn't seem to work in viewDidLoad. It does, however, seem to work in viewWillLayoutSubviews. Example code below:
// Note 1: The variable names below don't match the variables above - this is intended to be a simplified "final" answer.
// Note 2: _headerView was previously assigned to tableViewHeader (in loadView in my case since I now do everything programatically).
// Note 3: autoLayout code can be setup programatically in updateViewConstraints.
- (void)viewWillLayoutSubviews {
[super viewWillLayoutSubviews];
[_headerWrapper setNeedsLayout];
[_headerWrapper layoutIfNeeded];
CGFloat height = [_headerWrapper systemLayoutSizeFittingSize:UILayoutFittingCompressedSize].height;
CGRect headerFrame = _headerWrapper.frame;
headerFrame.size.height = height;
_headerWrapper.frame = headerFrame;
_tableView.tableHeaderView = _headerWrapper;
}
You need to use the UIView systemLayoutSizeFittingSize: method to obtain the minimum bounding size of your header view.
I provide further discussion on using this API in this Q/A:
How to resize superview to fit all subviews with autolayout?
I've found an elegant way to way to use auto layout to resize table headers, with and without animation.
Simply add this to your View Controller.
func sizeHeaderToFit(tableView: UITableView) {
if let headerView = tableView.tableHeaderView {
let height = headerView.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize).height
var frame = headerView.frame
frame.size.height = height
headerView.frame = frame
tableView.tableHeaderView = headerView
headerView.setNeedsLayout()
headerView.layoutIfNeeded()
}
}
To resize according to a dynamically changing label:
#IBAction func addMoreText(sender: AnyObject) {
self.label.text = self.label.text! + "\nThis header can dynamically resize according to its contents."
}
override func viewDidLayoutSubviews() {
// viewDidLayoutSubviews is called when labels change.
super.viewDidLayoutSubviews()
sizeHeaderToFit(tableView)
}
To animate a resize according to a changes in a constraint:
#IBOutlet weak var makeThisTallerHeight: NSLayoutConstraint!
#IBAction func makeThisTaller(sender: AnyObject) {
UIView.animateWithDuration(0.3) {
self.tableView.beginUpdates()
self.makeThisTallerHeight.constant += 20
self.sizeHeaderToFit(self.tableView)
self.tableView.endUpdates()
}
}
See the AutoResizingHeader project to see this in action.
https://github.com/p-sun/Swift2-iOS9-UI
I really battled with this one and plonking the setup into viewDidLoad didn't work for me since the frame is not set in viewDidLoad, I also ended up with tons of messy warnings where the encapsulated auto layout height of the header was being reduced to 0. I only noticed the issue on iPad when presenting a tableView in a Form presentation.
What solved the issue for me was setting the tableViewHeader in viewWillLayoutSubviews rather than in viewDidLoad.
func viewWillLayoutSubviews() {
super.viewWillLayoutSubviews()
if tableView.tableViewHeaderView == nil {
let header: MyHeaderView = MyHeaderView.createHeaderView()
header.setNeedsUpdateConstraints()
header.updateConstraintsIfNeeded()
header.frame = CGRectMake(0, 0, CGRectGetWidth(tableView.bounds), CGFloat.max)
var newFrame = header.frame
header.setNeedsLayout()
header.layoutIfNeeded()
let newSize = header.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize)
newFrame.size.height = newSize.height
header.frame = newFrame
self.tableView.tableHeaderView = header
}
}
This solution resizes the tableHeaderView and avoids infinite loop in the viewDidLayoutSubviews() method I was having with some of the other answers here:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
if let headerView = tableView.tableHeaderView {
let height = headerView.systemLayoutSizeFitting(UILayoutFittingCompressedSize).height
var headerFrame = headerView.frame
// comparison necessary to avoid infinite loop
if height != headerFrame.size.height {
headerFrame.size.height = height
headerView.frame = headerFrame
tableView.tableHeaderView = headerView
}
}
}
See also this post: https://stackoverflow.com/a/34689293/1245231
Your solution using systemLayoutSizeFittingSize: works if the header view is just updated once on each view appearance. In my case, the header view updated multiple times to reflect status changes. But systemLayoutSizeFittingSize: always reported the same size. That is, the size corresponding to the first update.
To get systemLayoutSizeFittingSize: to return the correct size after each update I had to first remove the table header view before updating it and re-adding it:
self.listTableView.tableHeaderView = nil;
[self.headerView removeFromSuperview];
This worked for me on ios10 and Xcode 8
func layoutTableHeaderView() {
guard let headerView = tableView.tableHeaderView else { return }
headerView.translatesAutoresizingMaskIntoConstraints = false
let headerWidth = headerView.bounds.size.width;
let temporaryWidthConstraints = NSLayoutConstraint.constraintsWithVisualFormat("[headerView(width)]", options: NSLayoutFormatOptions(rawValue: UInt(0)), metrics: ["width": headerWidth], views: ["headerView": headerView])
headerView.addConstraints(temporaryWidthConstraints)
headerView.setNeedsLayout()
headerView.layoutIfNeeded()
let headerSize = headerView.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize)
let height = headerSize.height
var frame = headerView.frame
frame.size.height = height
headerView.frame = frame
self.tableView.tableHeaderView = headerView
headerView.removeConstraints(temporaryWidthConstraints)
headerView.translatesAutoresizingMaskIntoConstraints = true
}
It works for both header view and footer just replace the header with footer
func sizeHeaderToFit() {
if let headerView = tableView.tableHeaderView {
headerView.setNeedsLayout()
headerView.layoutIfNeeded()
let height = headerView.systemLayoutSizeFitting(UILayoutFittingCompressedSize).height
var frame = headerView.frame
frame.size.height = height
headerView.frame = frame
tableView.tableHeaderView = headerView
}
}
For iOS 12 and above, the following steps will ensure autolayout works properly in both your table and the header.
Create your tableView first, then the header.
At the end of your header creation code, call:
[headerV setNeedsLayout];
[headerV layoutIfNeeded];
Upon orientation change, mark the header for layout again and reload the table, this needs to happen slightly after the orientation change is reported:
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 0.1 *NSEC_PER_SEC), dispatch_get_main_queue(), ^{
[tableV.tableHeaderView setNeedsLayout];
[tableV.tableHeaderView layoutIfNeeded];
[tableV reloadData];});
In my case viewDidLayoutSubviews worked better. viewWillLayoutSubviews causes white lines of a tableView to appear. Also I added checking if my headerView object already exists.
- (void)viewDidLayoutSubviews
{
[super viewDidLayoutSubviews];
if ( ! self.userHeaderView ) {
// Setup HeaderView
self.userHeaderView = [[[NSBundle mainBundle] loadNibNamed:#"SSUserHeaderView" owner:self options:nil] objectAtIndex:0];
[self.userHeaderView setNeedsLayout];
[self.userHeaderView layoutIfNeeded];
CGFloat height = [self.userHeaderView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize].height;
CGRect headerFrame = self.userHeaderView.frame;
headerFrame.size.height = height;
self.userHeaderView.frame = headerFrame;
self.tableView.tableHeaderView = self.userHeaderView;
// Update HeaderView with data
[self.userHeaderView updateWithProfileData];
}
}
It is quite possible to use generic AutoLayout-based UIView with any AL inner subview structure as a tableHeaderView.
The only thing one needs is to set a simple tableFooterView before!
Let self.headerView is some constraint-based UIView.
- (void)viewDidLoad {
........................
self.tableView.tableFooterView = [UIView new];
[self.headerView layoutIfNeeded]; // to set initial size
self.tableView.tableHeaderView = self.headerView;
[self.tableView.leadingAnchor constraintEqualToAnchor:self.headerView.leadingAnchor].active = YES;
[self.tableView.trailingAnchor constraintEqualToAnchor:self.headerView.trailingAnchor].active = YES;
[self.tableView.topAnchor constraintEqualToAnchor:self.headerView.topAnchor].active = YES;
// and the key constraint
[self.tableFooterView.trailingAnchor constraintEqualToAnchor:self.headerView.trailingAnchor].active = YES;
}
If self.headerView changes height under UI rotation one have to implement
- (void)viewWillTransitionToSize:(CGSize)size withTransitionCoordinator:(id<UIViewControllerTransitionCoordinator>)coordinator {
[super viewWillTransitionToSize:size withTransitionCoordinator:coordinator];
[coordinator animateAlongsideTransition: ^(id<UIViewControllerTransitionCoordinatorContext> context) {
// needed to resize header height
self.tableView.tableHeaderView = self.headerView;
} completion: NULL];
}
One can use ObjC category for this purpose
#interface UITableView (AMHeaderView)
- (void)am_insertHeaderView:(UIView *)headerView;
#end
#implementation UITableView (AMHeaderView)
- (void)am_insertHeaderView:(UIView *)headerView {
NSAssert(self.tableFooterView, #"Need to define tableFooterView first!");
[headerView layoutIfNeeded];
self.tableHeaderView = headerView;
[self.leadingAnchor constraintEqualToAnchor:headerView.leadingAnchor].active = YES;
[self.trailingAnchor constraintEqualToAnchor:headerView.trailingAnchor].active = YES;
[self.topAnchor constraintEqualToAnchor:headerView.topAnchor].active = YES;
[self.tableFooterView.trailingAnchor constraintEqualToAnchor:headerView.trailingAnchor].active = YES;
}
#end
And also Swift extension
extension UITableView {
func am_insertHeaderView2(_ headerView: UIView) {
assert(tableFooterView != nil, "Need to define tableFooterView first!")
headerView.layoutIfNeeded()
tableHeaderView = headerView
leadingAnchor.constraint(equalTo: headerView.leadingAnchor).isActive = true
trailingAnchor.constraint(equalTo: headerView.trailingAnchor).isActive = true
topAnchor.constraint(equalTo: headerView.topAnchor).isActive = true
tableFooterView?.trailingAnchor.constraint(equalTo: headerView.trailingAnchor).isActive = true
}
}
This solution works perfectly for me:
https://spin.atomicobject.com/2017/08/11/swift-extending-uitableviewcontroller/
It extends the UITableViewController. But if you are just using a UITableView, it will still work, just extend the UITableView instead of the UITableViewController.
Call the methods sizeHeaderToFit() or sizeFooterToFit() whenever there is an event that changes the tableViewHeader height.
Copied from this post
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
if let headerView = tableView.tableHeaderView {
let height = headerView.systemLayoutSizeFitting(UIView.layoutFittingCompressedSize).height
var headerFrame = headerView.frame
//Comparison necessary to avoid infinite loop
if height != headerFrame.size.height {
headerFrame.size.height = height
headerView.frame = headerFrame
tableView.tableHeaderView = headerView
}
}
}

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