I have an extension for UITextView which centers the text on a UITextView vertically that I found in the following SO answer: https://stackoverflow.com/a/38855122/4660602
My UITextView lives within a UITableViewCell, and the problem is that the function doesn't seem to work on the initial load. It only works when I reload the tableView or when I scroll.
I am calling the method within cellForRowAtIndexPath but I have tried adding it to my custom cell class in awakeFromNib and prepareForReuse but have and no luck. Wondering if anyone has any other advice / solutions.
EDIT:
Also forgot to mention, my VC with the tableView is embedded in a navigationBar and tabBar. When I switch to a new VC in the tabBar and then back, the UITextView text realigns to the top incorrectly, even if it was centered already.
Thanks!
The correct place for sizing code in a view is UIView.layoutSubviews. Since your centering function depends on the bounds, you have to call it in layoutSubviews, otherwise the bounds may not be correct (ie they match whats in the nib and not the current device). You can call setNeedsLayout in your cellforRowAtIndexPath to tell the view to update its layout after you ahve set the text.
In iOS 10, a bound of view hasn't initialized in viewDidLoad or awakeFromNib as before, so functions based on the view's bound don't work in viewDidLoad or awakeFromNib.
You should use it in viewDidAppear or when view's bound has certainly been initialized.
Works for me (Swift 5):
class VerticallyCenteredTextView: UITextView {
override var contentSize: CGSize {
didSet {
var topCorrection = (bounds.size.height - contentSize.height * zoomScale) / 2.0
topCorrection = max(0, topCorrection)
contentInset = UIEdgeInsets(top: topCorrection, left: 0, bottom: 0, right: 0)
}
}
}
The source - https://geek-is-stupid.github.io/2017-05-15-how-to-center-text-vertically-in-a-uitextview/
Related
I have a scenario where I need to change UIEdgeInsets for UIButton which is added to the UITableViewCell, I set it in layoutSubviews but that's called a number of times, it also work's with init too but I am not sure that's really a place because that will called only once.
override func layoutSubviews() {
super.layoutSubviews()
if imageView != nil {
titleEdgeInsets = UIEdgeInsets(top: 52, left: -10, bottom: 0, right:-10)
}
}
Can someone tell me which one is the ideal place and why?
awakeFromNib will be called when a new cell is loaded from a xib or storyboard
, but not when a cell is re-used.
But during awakeFromNib the frame layouts do not appear . UIEdgeInsets will not effected by frame so i prefer to call it at awakeFromNib not in
layoutSubviews
layoutSubviews you will get correct frame so used only with stylish that need correct frame like corner radius
Use awakeFromNib() if you use xib.
It call one time and this from documentation to awakeFromNib():
Typically, you implement awakeFromNib for objects that require additional set up that cannot be done at design time. For example, you might use this method to customize the default configuration of any controls to match user preferences or the values in other controls. You might also use it to restore individual controls to some previous state of your application.
Or if you don't use xib just use init because it called once.
I have a TableView footerView with two labels that can hold multiple lines.
I'm using this code in viewDidLayoutSubviews:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
label1.preferredMaxLayoutWidth = tableView.frame.size.width - Constant.footerMarginSpace
label2.preferredMaxLayoutWidth = tableView.frame.size.width - Constant.footerMarginSpace
footerView.setNeedsLayout()
footerView.layoutIfNeeded()
footerView.frame.size.height = footerView.systemLayoutSizeFitting(UILayoutFittingCompressedSize).height
tableView.tableFooterView = footerView
}
This is working fine (the labels will eventually spread over multiples lines and the size of the view is adjusting) when the labels value are set before the view is shown, but If I update their content after, the view won't update its layout, even when using tableView.reloadData().
If I push another view on top of my view, and dismiss it, the layout will be correct.
What is the proper way to update the layout and size of my TableView footer ?
I think it might be easier to calculate how many lines you need based on your data and return the correct height using
tableView(_:heightForFooterInSection:)
This method will be called to layout your tableview when the reloadData is called.
I designed a custom view as my UITableView's header view. just like this
(I just put image link here instead of image since I don't have 10 reputations.)
http://i.stack.imgur.com/KhNbE.png
Then in my UITableViewController I use this view as tableHeaderView
override func viewDidLoad() {
tableView.tableHeaderView = headerView!
//...other things
}
I got text from a JSON to fulfill the ContentLabel. If the text is long, the headerView will overlap cells just like below image.(short text is OK)
http://i.stack.imgur.com/gtO2g.png
Section is visible but two lines of cell have been overlapped by the headerView.I'm not sure if I did wrong constraints or code on ContentLabel. Below is the code I configured the contentLabel in TopicHeaderView.swift
var content: String? {
didSet {
self.contentLabel.text = content!
self.setNeedsUpdateConstraints()
self.updateConstraintsIfNeeded()
self.setNeedsLayout()
self.layoutIfNeeded()
}
}
func setFrameHeight(height: CGFloat) {
var frame = self.frame
frame.size.height = height
self.frame = frame
}
override func layoutSubviews() {
super.layoutSubviews()
self.contentLabel.preferredMaxLayoutWidth = self.contentLabel.alignmentRectForFrame(contentLabel.frame).width
self.titleLabel.preferredMaxLayoutWidth = self.titleLabel.bounds.size.width
self.authorLabel.preferredMaxLayoutWidth = self.authorLabel.bounds.size.width
self.setFrameHeight(CGRectGetMaxY(contentLabel.frame) + 8)
}
I browsed similar questions in SO but seems I can't find a solution to fix my problem. Can anyone help on this?
EDITED:
I logged the origin CGPoint of my first tableView cell and headerView's height. It shows the right number which means the first cell is right next to the header view vertically. There is a 22 points gap because of the height of section of course.
headerheight:600.0
first cell's y: 622.0
So maybe it's the label problem that its height is too big to exceed the bounds of TableView headerView? I'm not sure.
EDITED:
Strange things happen. I logged the y value of headerView's bottom,contentLabel's bottom and first UITableViewCell's origin. Please see the image from the link in the question comment below(still need 10 reputation)
As you can see, from the value in console, the view sequence from top should be "contentLabel's bottom(value:224) - headerView's bottom bounds(value: 232) - first cell's origin(value:254)". But in simulator, the sequence is totally messed up.It turns "headerView's bottom bounds - first cell's origin - contentLabel's bottom"
I really appreciate if anyone can help on this.
Problem is, that UITableView does not automatically change positions of cells when its headerView's height changes. Thus you need to reload UITableView every time TopicHeaderView.content changes.
Select that header view, or imageView what you have there, and check Clip Subviews in Attributes Inspector tab.
This worked for me.
My UICollectionView cells don't get displayed on iOS6, because my delegate method cellForItemAtIndexPath doesn't get called. I suspect because of this warning:
the behavior of the UICollectionViewFlowLayout is not defined because:
the item height must be less that the height of the `UICollectionView`
minus the section inset's top and bottom values.
I don't get the warning on iOS7, and all the cells display correctly there too.
I've set my collectionView frame to height 270 in the .xib and there are no insets defined.
I've set my cell height to 270 in the .xib.
I can print out my collectionView frame at runtime and it's 271.
Also, my collectionview is actually inside a custom tableview cell.
Any ideas?
Thanks!
Try to set self.automaticallyAdjustsScrollViewInsets = NO
This was introduced in ios7 so you might want to wrap that with an ios version check, if you are supporting ios6 and below.
This fixed my problem! In my .xib, setting my Collection View Size Cell Size to a smaller value.
My setup is that I have this collectionview inside a custom tableview cell and
I do return the height of my tableview cell programatically (depending on the content). So it could be that my warnings had to do with my collectionview not fitting inside the tableview cell. So setting the initial collectionview to a smaller value fixed it.
I was on the wrong path thinking that the problem was with my collectionview and its colletionview cell.
Maybe?
self.automaticallyAdjustsScrollViewInsets = NO
actually did the trick. it also resolved my issue in swift, where the cells of a horizontal flow layout had a frame top of -32 (???) and did not fit into the collection view properly.
I found that I had to manually set self.collectionView.collectionViewLayout.itemSize in viewWillLayoutSubviews.
- (void)viewWillLayoutSubviews {
self.collectionView.collectionViewLayout.itemSize = CGRectMake(...);
}
Another possibility to generate the same trick would be to implement the method
collectionView:layout:sizeForItemAtIndexPath:
I have the same issue, in my case the size of collectionCell in storyboard is 96x96 and also under -(CGSize)collectionView:layout:sizeForItemAtIndexPath:
the solution was removing this delegate:
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section
{
UIEdgeInsets insets = {.left = 10, .right = 10, .top = 5, .bottom = 5};
return insets;
}
And by the way this is under ios7, it's late but hope this will help some.. Cheers..
Set:
self.itemSize = CGSizeMake(1, 1);
I need to add some blank space to the top of my UITableView that does not affect the size of the content area. Shifting the content down or adding a blank cell is NOT what I want to do. Instead I just want an offset.
How?
I'm not sure if I'm following you but I think I'm having the same predicament. In my case I must give some space to the ADBannerView at the top of the screen so what I did was in the viewDidLoad method I added:
[self.tableView setContentInset:UIEdgeInsetsMake(50,0,0,0)];
the values it takes are UIEdgeInsetsMake(top,left,bottom,right).
Alternatively the same with Swift:
self.tableView.contentInset = UIEdgeInsetsMake(50, 0, 0, 0)
Swift 4.2:
self.tableView.contentInset = UIEdgeInsets(top: 50, left: 0, bottom: 0, right: 0)
Swift 5.1
add the following in viewDidLoad
tableView.contentInset.top = 100
Really that's all there is to it.
override func viewDidLoad() {
super.viewDidLoad()
tableView.contentInset.top = 100
}
You can add an "empty" header view to the table... this would give the initial appearance of the table to have an offset, but once you started scrolling the offset would be gone. NOt sure that's what you want.
If you need a permanent offset and are not already using section headers, then you could create the offset similarly to above by making custom views for the section headers, especially if you just have one section, this could give you the look of a permanent offset.
I can post sample code if it sounds like either of those are what you are looking for.
I combined Jigzat's answer with:
[self.tableView scrollRectToVisible:CGRectMake(0, 0, 320, 1) animated:NO];
in
- (void)viewDidLoad
so the first cell isn't at the top.
Sounds like you want to wrap a 'View' around your UITableView. If you have a UITableViewController in IB the UITableView will automatically be set to the view of UITableViewController. You change view property to a normal UIView and add your UITableView in there and give it a offset.
---Edit---
I just read my post and thought it made little sense :) When you create a UITableViewController you get this (in pseudo code):
UITableViewController.view = UITableView
This means that the actual table will take up the whole space and you cannot even add other views. So you need to change the
UITableViewController.view = UIView
and add your table to that UIView
I combined this answer with this one:
https://stackoverflow.com/a/9450345/1993937
To make the tableView appear at the top of the content inset, so the space at the top isn't cut off by having the tableView scrolled down slightly when the view initially appears. (18 is my top gap)
[self.tableView setContentInset:UIEdgeInsetsMake(18,0,0,0)];
[self.tableView setContentOffset:
CGPointMake(0, -self.songListTable.contentInset.top) animated:YES];