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trying to calculate height of a cell with specified width and cannot make it right. Here is a snippet. There are two columns specified by the custom layout which knows the column width.
let cell = TextNoteCell2.loadFromNib()
var frame = cell.frame
frame.size.width = columnWidth // 187.5
frame.size.height = 0 // it does not work either without this line.
cell.frame = frame
cell.update(text: note.text)
cell.contentView.layoutIfNeeded()
let size = cell.contentView.systemLayoutSizeFitting(CGSize(width: columnWidth, height: 0)) // 251.5 x 52.5
print(cell) // 187.5 x 0
return size.height
Both size and cell.frame are incorrect.
Cell has a text label inside with 16px margins on each label edge.
Thank you in advance.
To calculate the size for a UILabel to fully display the given text, i would add a helper as below,
extension UILabel {
public static func estimatedSize(_ text: String, targetSize: CGSize = .zero) -> CGSize {
let label = UILabel(frame: .zero)
label.numberOfLines = 0
label.text = text
return label.sizeThatFits(targetSize)
}
}
Now that you know how much size is required for your text, you can calculate the cell size by adding the margins you specified in the cell i.e 16.0 on each side so, the calculation should be as below,
let intrinsicMargin: CGFloat = 16.0 + 16.0
let targetWidth: CGFloat = 187.0 - intrinsicMargin
let labelSize = UILabel.estimatedSize(note.text, targetSize: CGSize(width: targetWidth, height: 0))
let cellSize = CGSize(width: labelSize.width + intrinsicMargin, height: labelSize.height + intrinsicMargin)
Hope you will get the required results. One more improvement would be to calculate the width based on the screen size and number of columns instead of hard coded 187.0
That cell you are loading from a nib has no view to be placed in, so it has an incorrect frame.
You need to either manually add it to a view, then measure it, or you'll need to dequeu it from the collectionView so it's already within a container view
For Swift 4.2 updated answer is to handle height and width of uicollectionview Cell on the basis of uilabel text
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize
{
let size = (self.FILTERTitles[indexPath.row] as NSString).size(withAttributes: [NSAttributedString.Key.font: UIFont.systemFont(ofSize: 14.0)])
return CGSize(width: size.width + 38.0, height: size.height + 25.0)
}
I have a UITextView in a custom UITableViewCell. The textview delegate is assigned in the tableviewcell custom class. Textview scrolling is disabled. Text loads into each textview and is multiline. But the text is always clipped because the cell height doesn't change.
I have the following in viewDidLoad of the tableview controller:
tableView.estimatedRowHeight = 56.0
tableView.rowHeight = UITableViewAutomaticDimension
Any idea why this isn't working?
Try my answer its work perfectly.
var record : NSArray = NSArray()
var hight: CGFloat = 0.0
Put this code in viewDidLoad()
record = ["I have a UITextView in a custom UITableViewCell. The textview delegate is assigned in the tableviewcell custom class." ,"Textview scrolling is disabled. Text loads into each textview and is multiline. But the text is always clipped because the cell height doesn't change.","I have the following in viewDidLoad of the tableview controller:"," have a UITextView in a custom UITableViewCell. The textview delegate is assigned in the tableviewcell custom class.","Textview scrolling is disabled. Text loads into each textview and is multiline. But the text is always clipped because the cell height doesn't change.","I have the following in viewDidLoad of the tableview controller:","i just give you one link at put place i use label and you can now use your textview and give same constrain that i give in that link and try it so your problem will be solve","I have the following in viewDidLoad of the tableview controller:"];
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return record.count
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Textviewcell", forIndexPath: indexPath)
let textview: UITextView = (cell.viewWithTag(5) as! UITextView)
textview.text = record.objectAtIndex(indexPath.row) as? String
return cell
}
func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
// 7.1>
hight = self.findHeightForText(self.record.objectAtIndex(indexPath.row) as! String, havingWidth: self.view.frame.size.width - 10, andFont: UIFont.systemFontOfSize(14.0)).height
return 44 + hight
}
func findHeightForText(text: String, havingWidth widthValue: CGFloat, andFont font: UIFont) -> CGSize {
var size = CGSizeZero
if text.isEmpty == false {
let frame = text.boundingRectWithSize(CGSizeMake(widthValue, CGFloat.max), options: .UsesLineFragmentOrigin, attributes: [NSFontAttributeName: font], context: nil)
size = CGSizeMake(frame.size.width, ceil(frame.size.height))
}
return size
}
In Swift 3.0
func findHeightForText(text: String, havingWidth widthValue: CGFloat, andFont font: UIFont) -> CGSize {
var size = CGSize.zero
if text.isEmpty == false {
let frame = text.boundingRect(with: CGSize(width: widthValue, height: CGFloat.greatestFiniteMagnitude), options: .usesLineFragmentOrigin, attributes: [NSFontAttributeName: font], context: nil)
size = CGSize(width: frame.size.width, height: ceil(frame.size.height))//CGSizeMake(frame.size.width, ceil(frame.size.height))
}
return size
}
Here are some screen shot .Storyboard
Runtime tableview with UITextView
You should use the delegate method
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
to set the height for the row. Then, inside that method, return the height that the cell should be by calculating the height of the textview which will occupy the space. You should use the function:
-(CGFloat)heightForTextViewRectWithWidth:(CGFloat)width andText:(NSString *)text withBuffer:(float)buffer
{
UIFont * font = [UIFont fontWithName:#"YourFontName" size:15.0f]; // Replace with your font name and size
NSDictionary *attributes = #{NSFontAttributeName: font};
// this returns us the size of the text for a rect but assumes 0, 0 origin, width is the width of that your text box will occupy.
// Ex. If you text box has padding of 12 both trailing and leading to the cell, then width should be the cell's width minus 24.
CGRect rect = [text boundingRectWithSize:CGSizeMake(width, MAXFLOAT)
options:(NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading)
attributes:attributes
context:nil];
// return height of rect
return rect.size.height;
}
This will determine the rect that your text view will occupy in the cell. The height that is returned is equal to the height of the text view, so if you want the cell to be taller than the text box, add that padding.
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
NSString * yourText = commentDict.text; // or however you are getting the text
float widthPadding = 24.0f;
float heightPadding = 16.0f;
float height = [self heightForTextViewRectWithWidth: (tableView.frame.size.width - widthPadding) andText:yourText];
return height + heightPadding;
}
Hope this helped!
How do I set cell spacing in a section of UICollectionView? I know there is a property minimumInteritemSpacing I have set it to 5.0 still the spacing is not appearing 5.0. I have implemented the flowout delegate method.
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section
{
return 5.0;
}
still I am not getting the desired result. I think its the minimum spacing . Isn't there any way by which I can set the maximum spacing?
Supporting the initial question. I tried to get the spacing to 5px on the UICollectionView but this does not work, as well with a UIEdgeInsetsMake(0,0,0,0)...
On a UITableView I can do this by directly specifying the x,y coordinates in a row...
Heres my UICollectionView code:
#pragma mark collection view cell layout / size
- (CGSize)collectionView:(UICollectionView*)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
return [self getCellSize:indexPath]; // will be w120xh100 or w190x100
// if the width is higher, only one image will be shown in a line
}
#pragma mark collection view cell paddings
- (UIEdgeInsets)collectionView:(UICollectionView*)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
return UIEdgeInsetsMake(0, 0, 0, 0); // top, left, bottom, right
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {
return 5.0;
}
Update: Solved my problem, with the following code.
ViewController.m
#import "ViewController.h"
#import "MagazineCell.h" // created just the default class.
static NSString * const cellID = #"cellID";
#interface ViewController ()
#end
#implementation ViewController
#pragma mark - Collection view
-(NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
return 1;
}
-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
return 30;
}
-(UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
MagazineCell *mCell = (MagazineCell *)[collectionView dequeueReusableCellWithReuseIdentifier:cellID forIndexPath:indexPath];
mCell.backgroundColor = [UIColor lightGrayColor];
return mCell;
}
#pragma mark Collection view layout things
// Layout: Set cell size
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
NSLog(#"SETTING SIZE FOR ITEM AT INDEX %d", indexPath.row);
CGSize mElementSize = CGSizeMake(104, 104);
return mElementSize;
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {
return 2.0;
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {
return 2.0;
}
// Layout: Set Edges
- (UIEdgeInsets)collectionView:
(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
// return UIEdgeInsetsMake(0,8,0,8); // top, left, bottom, right
return UIEdgeInsetsMake(0,0,0,0); // top, left, bottom, right
}
#end
I know that the topic is old, but in case anyone still needs correct answer here what you need:
Override standard flow layout.
Add implementation like that:
- (NSArray *) layoutAttributesForElementsInRect:(CGRect)rect {
NSArray *answer = [super layoutAttributesForElementsInRect:rect];
for(int i = 1; i < [answer count]; ++i) {
UICollectionViewLayoutAttributes *currentLayoutAttributes = answer[i];
UICollectionViewLayoutAttributes *prevLayoutAttributes = answer[i - 1];
NSInteger maximumSpacing = 4;
NSInteger origin = CGRectGetMaxX(prevLayoutAttributes.frame);
if(origin + maximumSpacing + currentLayoutAttributes.frame.size.width < self.collectionViewContentSize.width) {
CGRect frame = currentLayoutAttributes.frame;
frame.origin.x = origin + maximumSpacing;
currentLayoutAttributes.frame = frame;
}
}
return answer;
}
where maximumSpacing could be set to any value you prefer. This trick guarantees that the space between cells would be EXACTLY equal to maximumSpacing!!
Using a horizontal flow layout, I was also getting a 10 points spacing between cells. To remove the spacing I needed to set minimumLineSpacing as well as minimumInterItemSpacing to zero.
UICollectionViewFlowLayout *flow = [[UICollectionViewFlowLayout alloc] init];
flow.itemSize = CGSizeMake(cellWidth, cellHeight);
flow.scrollDirection = UICollectionViewScrollDirectionHorizontal;
flow.minimumInteritemSpacing = 0;
flow.minimumLineSpacing = 0;
Also, if all your cells are the same size, it's simpler and more efficient to set the property on the flow layout directly instead of using delegate methods.
Remember, it is minimum line space, not minimum inter item spacing or cell space. Because your collectionView's scroll direction is HORIZONTAL.
If it is vertical then you need to set cell space or inter item space for horizontal space between cells and line spacing for vertical space between cells.
Objective-C version
- (CGFloat)collectionView:(UICollectionView *)collectionView
layout:(UICollectionViewLayout*)collectionViewLayout
minimumLineSpacingForSectionAtIndex:(NSInteger)section
{
return 20;
}
Swift version:
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 20
}
Try this code to ensure you have a spacing of 5px between each item:
- (UIEdgeInsets)collectionView:(UICollectionView *) collectionView
layout:(UICollectionViewLayout *) collectionViewLayout
insetForSectionAtIndex:(NSInteger) section {
return UIEdgeInsetsMake(0, 0, 0, 5); // top, left, bottom, right
}
- (CGFloat)collectionView:(UICollectionView *) collectionView
layout:(UICollectionViewLayout *) collectionViewLayout
minimumInteritemSpacingForSectionAtIndex:(NSInteger) section {
return 5.0;
}
Swift version of the most popular answer. Space between the cells will be equal to cellSpacing.
class CustomViewFlowLayout : UICollectionViewFlowLayout {
let cellSpacing:CGFloat = 4
override func layoutAttributesForElementsInRect(rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
if let attributes = super.layoutAttributesForElementsInRect(rect) {
for (index, attribute) in attributes.enumerate() {
if index == 0 { continue }
let prevLayoutAttributes = attributes[index - 1]
let origin = CGRectGetMaxX(prevLayoutAttributes.frame)
if(origin + cellSpacing + attribute.frame.size.width < self.collectionViewContentSize().width) {
attribute.frame.origin.x = origin + cellSpacing
}
}
return attributes
}
return nil
}
}
I have found very easy way to configure spacing between cells or rows by using IB.
Just select UICollectionView from storyboard/Xib file and click in Size Inspector as specified in below image.
For configuring space programatically use following properties.
1) For setting space between rows.
[self.collectionView setMinimumLineSpacing:5];
2) For setting space between items/cells.
[self.collectionView setMinimumInteritemSpacing:5];
Please note the property name minimumInterItemSpacing . This will be the minimum spacing between the items not the exact spacing. If you set minimumInterItemSpacing to some value you can assure that spacing wont be a value less than that. But there is a chance get a higher value.
Actually the spacing between items depends on several factors itemSize and sectionInset. Collection view dynamically place the contents based on these values. So you cannot assure the exact spacing. You should do some trial and error with sectionInset and minimumInterItemSpacing.
Answer for Swift 3.0, Xcode 8
1.Make sure you set collection view delegate
class DashboardViewController: UIViewController {
#IBOutlet weak var dashboardCollectionView: UICollectionView!
override func viewDidLoad() {
super.viewDidLoad()
dashboardCollectionView.delegate = self
}
}
2.Implement UICollectionViewDelegateFlowLayout protocol, not UICollectionViewDelegate.
extension DashboardViewController: UICollectionViewDelegateFlowLayout {
fileprivate var sectionInsets: UIEdgeInsets {
return .zero
}
fileprivate var itemsPerRow: CGFloat {
return 2
}
fileprivate var interitemSpace: CGFloat {
return 5.0
}
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
sizeForItemAt indexPath: IndexPath) -> CGSize {
let sectionPadding = sectionInsets.left * (itemsPerRow + 1)
let interitemPadding = max(0.0, itemsPerRow - 1) * interitemSpace
let availableWidth = collectionView.bounds.width - sectionPadding - interitemPadding
let widthPerItem = availableWidth / itemsPerRow
return CGSize(width: widthPerItem, height: widthPerItem)
}
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
insetForSectionAt section: Int) -> UIEdgeInsets {
return sectionInsets
}
func collectionView(_ collectionView: UICollectionView,
layout collectionViewLayout: UICollectionViewLayout,
minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return 0.0
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return interitemSpace
}
}
Simple code for spacing
let layout = collectionView.collectionViewLayout as! UICollectionViewFlowLayout
layout.minimumInteritemSpacing = 10 // Some float value
The voted answer (and also the swift version) has a small issue: there will be a big spacing on the right.
This is because the flow layout is customised to make the cell spacing exact, with a float left behaviour.
My solution is to manipulate the section inset, so that the section is align center, yet the spacing is exactly as specified.
In screenshot below, the item/line spacing is exactly 8pt, while the section left & right inset will be bigger than 8pt (to make it center aligned):
Swift code as such:
private let minItemSpacing: CGFloat = 8
private let itemWidth: CGFloat = 100
private let headerHeight: CGFloat = 32
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
// Create our custom flow layout that evenly space out the items, and have them in the center
let layout = UICollectionViewFlowLayout()
layout.itemSize = CGSize(width: itemWidth, height: itemWidth)
layout.minimumInteritemSpacing = minItemSpacing
layout.minimumLineSpacing = minItemSpacing
layout.headerReferenceSize = CGSize(width: 0, height: headerHeight)
// Find n, where n is the number of item that can fit into the collection view
var n: CGFloat = 1
let containerWidth = collectionView.bounds.width
while true {
let nextN = n + 1
let totalWidth = (nextN*itemWidth) + (nextN-1)*minItemSpacing
if totalWidth > containerWidth {
break
} else {
n = nextN
}
}
// Calculate the section inset for left and right.
// Setting this section inset will manipulate the items such that they will all be aligned horizontally center.
let inset = max(minItemSpacing, floor( (containerWidth - (n*itemWidth) - (n-1)*minItemSpacing) / 2 ) )
layout.sectionInset = UIEdgeInsets(top: minItemSpacing, left: inset, bottom: minItemSpacing, right: inset)
collectionView.collectionViewLayout = layout
}
Storyboard Approach
Select CollectionView in your storyboard and go to size inspector and set min spacing for cells and lines as 5
Swift 5 Programmatically
lazy var collectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
layout.scrollDirection = .horizontal
//Provide Width and Height According to your need
let width = UIScreen.main.bounds.width / 4
let height = UIScreen.main.bounds.height / 10
layout.itemSize = CGSize(width: width, height: height)
//For Adjusting the cells spacing
layout.minimumInteritemSpacing = 5
layout.minimumLineSpacing = 5
return UICollectionView(frame: self.view.frame, collectionViewLayout: layout)
}()
Define UICollectionViewDelegateFlowLayout protocol in your header file.
Implement following method of UICollectionViewDelegateFlowLayout protocol like this:
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout insetForSectionAtIndex:(NSInteger)section
{
return UIEdgeInsetsMake(5, 5, 5, 5);
}
Click Here to see Apple Documentation of UIEdgeInsetMake method.
If u want to tweak the spacing without touching the actual cell size, this is the solution that worked best for me. #xcode 9 #tvOS11 #iOS11 #swift
So in UICollectionViewDelegateFlowLayout, change implement the next methods, the trick is u have to use both of them, and the documentation was not really pointing me to think in that direction. :D
open func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumInteritemSpacingForSectionAt section: Int) -> CGFloat {
return cellSpacing
}
public func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, minimumLineSpacingForSectionAt section: Int) -> CGFloat {
return cellSpacing
}
Well, if you're creating a horizontal collection view then to give space between the cells, you need to set the property minimumLineSpacing .
I'm using monotouch, so the names and code will be a bit different, but you can do this by making sure that the width of the collectionview equals (x * cell width) + (x-1) * MinimumSpacing with x = amount of cells per row.
Just do following steps based on your MinimumInteritemSpacing and the Width of the Cell
1) We calculate amount of items per row based on cell size + current insets + minimum spacing
float currentTotalWidth = CollectionView.Frame.Width - Layout.SectionInset.Left - Layout.SectionInset.Right (Layout = flowlayout)
int amountOfCellsPerRow = (currentTotalWidth + MinimumSpacing) / (cell width + MinimumSpacing)
2) Now you have all info to calculate the expected width for the collection view
float totalWidth =(amountOfCellsPerRow * cell width) + (amountOfCellsPerRow-1) * MinimumSpacing
3) So the difference between the current width and the expected width is
float difference = currentTotalWidth - totalWidth;
4) Now adjust the insets (in this example we add it to the right, so the left position of the collectionview stays the same
Layout.SectionInset.Right = Layout.SectionInset.Right + difference;
I have a horizontal UICollectionView and subclassed UICollectionViewFlowLayout. The collection view has large cells, and only shows one row of them at a time, and the collection view fits the width of the screen.
I tried iago849's answer and it worked, but then I found out I didn't even need his answer. For some reason, setting the minimumInterItemSpacing does nothing. The spacing between my items/cells can be entirely controlled by minimumLineSpacing.
Not sure why it works this way, but it works.
My solution in Swift 3 cell line spacing like in Instagram:
lazy var collectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
let cv = UICollectionView(frame: .zero, collectionViewLayout: layout)
cv.backgroundColor = UIColor.rgb(red: 227, green: 227, blue: 227)
cv.showsVerticalScrollIndicator = false
layout.scrollDirection = .vertical
layout.minimumLineSpacing = 1
layout.minimumInteritemSpacing = 1
return cv
}()
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
switch UIDevice.current.modelName {
case "iPhone 4":
return CGSize(width: 106, height: 106)
case "iPhone 5":
return CGSize(width: 106, height: 106)
case "iPhone 6,7":
return CGSize(width: 124, height: 124)
case "iPhone Plus":
return CGSize(width: 137, height: 137)
default:
return CGSize(width: frame.width / 3, height: frame.width / 3)
}
}
How to detect device programmaticlly:
https://stackoverflow.com/a/26962452/6013170
I stumbled upon a similar problem as OP. Unfortunately the accepted answer did not work for me since the content of the collectionView would not be centered properly. Therefore I came up with a different solution which only requires that all items in the collectionView are of the same width, which seems to be the case in the question:
#define cellSize 90
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout insetForSectionAtIndex:(NSInteger)section {
float width = collectionView.frame.size.width;
float spacing = [self collectionView:collectionView layout:collectionViewLayout minimumInteritemSpacingForSectionAtIndex:section];
int numberOfCells = (width + spacing) / (cellSize + spacing);
int inset = (width + spacing - numberOfCells * (cellSize + spacing) ) / 2;
return UIEdgeInsetsMake(0, inset, 0, inset);
}
That code will ensure that the value returned by ...minimumInteritemSpacing... will be the exact spacing between every collectionViewCell and furthermore guarantee that the cells all together will be centered in the collectionView
The above solution by vojtech-vrbka is correct but it triggers a warning:
warning:UICollectionViewFlowLayout has cached frame mismatch for index path - cached value: This is likely occurring because the flow layout subclass Layout is modify attributes returned by UICollectionViewFlowLayout without copying them
The following code should fix it:
class CustomViewFlowLayout : UICollectionViewFlowLayout {
let cellSpacing:CGFloat = 4
override func layoutAttributesForElementsInRect(rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
let original = super.layoutAttributesForElementsInRect(rect)
if let original = original {
let attributes = NSArray.init(array: original, copyItems: true) as! [UICollectionViewLayoutAttributes]
for (index, attribute) in attributes.enumerate() {
if index == 0 { continue }
let prevLayoutAttributes = attributes[index - 1]
let origin = CGRectGetMaxX(prevLayoutAttributes.frame)
if(origin + cellSpacing + attribute.frame.size.width < self.collectionViewContentSize().width) {
attribute.frame.origin.x = origin + cellSpacing
}
}
return attributes
}
return nil
}
}
I have problem with the accepted answer, so I updated it, this is working for me:
.h
#interface MaxSpacingCollectionViewFlowLayout : UICollectionViewFlowLayout
#property (nonatomic,assign) CGFloat maxCellSpacing;
#end
.m
#implementation MaxSpacingCollectionViewFlowLayout
- (NSArray *) layoutAttributesForElementsInRect:(CGRect)rect {
NSArray *attributes = [super layoutAttributesForElementsInRect:rect];
if (attributes.count <= 0) return attributes;
CGFloat firstCellOriginX = ((UICollectionViewLayoutAttributes *)attributes[0]).frame.origin.x;
for(int i = 1; i < attributes.count; i++) {
UICollectionViewLayoutAttributes *currentLayoutAttributes = attributes[i];
if (currentLayoutAttributes.frame.origin.x == firstCellOriginX) { // The first cell of a new row
continue;
}
UICollectionViewLayoutAttributes *prevLayoutAttributes = attributes[i - 1];
CGFloat prevOriginMaxX = CGRectGetMaxX(prevLayoutAttributes.frame);
if ((currentLayoutAttributes.frame.origin.x - prevOriginMaxX) > self.maxCellSpacing) {
CGRect frame = currentLayoutAttributes.frame;
frame.origin.x = prevOriginMaxX + self.maxCellSpacing;
currentLayoutAttributes.frame = frame;
}
}
return attributes;
}
#end
Swift 3 Version
Simply create a UICollectionViewFlowLayout subclass and paste this method.
override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
guard let answer = super.layoutAttributesForElements(in: rect) else { return nil }
for i in 1..<answer.count {
let currentAttributes = answer[i]
let previousAttributes = answer[i - 1]
let maximumSpacing: CGFloat = 8
let origin = previousAttributes.frame.maxX
if (origin + maximumSpacing + currentAttributes.frame.size.width < self.collectionViewContentSize.width && currentAttributes.frame.origin.x > previousAttributes.frame.origin.x) {
var frame = currentAttributes.frame
frame.origin.x = origin + maximumSpacing
currentAttributes.frame = frame
}
}
return answer
}
I have tried iago849's answer and it worked.
Swift 4
open override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
guard let answer = super.layoutAttributesForElements(in: rect) else {
return nil
}
let count = answer.count
for i in 1..<count {
let currentLayoutAttributes = answer[i]
let prevLayoutAttributes = answer[i-1]
let origin = prevLayoutAttributes.frame.maxX
if (origin + CGFloat(spacing) + currentLayoutAttributes.frame.size.width) < self.collectionViewContentSize.width && currentLayoutAttributes.frame.origin.x > prevLayoutAttributes.frame.origin.x {
var frame = currentLayoutAttributes.frame
frame.origin.x = origin + CGFloat(spacing)
currentLayoutAttributes.frame = frame
}
}
return answer
}
Here is the link for the github project.
https://github.com/vishalwaka/MultiTags
Previous versions did not really work with sections > 1. So my solution was found here https://codentrick.com/create-a-tag-flow-layout-with-uicollectionview/. For the lazy ones:
override func layoutAttributesForElements(in rect: CGRect) -> [UICollectionViewLayoutAttributes]? {
let attributesForElementsInRect = super.layoutAttributesForElements(in: rect)
var newAttributesForElementsInRect = [UICollectionViewLayoutAttributes]()
// use a value to keep track of left margin
var leftMargin: CGFloat = 0.0;
for attributes in attributesForElementsInRect! {
let refAttributes = attributes
// assign value if next row
if (refAttributes.frame.origin.x == self.sectionInset.left) {
leftMargin = self.sectionInset.left
} else {
// set x position of attributes to current margin
var newLeftAlignedFrame = refAttributes.frame
newLeftAlignedFrame.origin.x = leftMargin
refAttributes.frame = newLeftAlignedFrame
}
// calculate new value for current margin
leftMargin += refAttributes.frame.size.width + 10
newAttributesForElementsInRect.append(refAttributes)
}
return newAttributesForElementsInRect
}
Swift 5 UIKit Programmatically
//Create UICollectionView
lazy var collectionView: UICollectionView = {
let layout = UICollectionViewFlowLayout()
layout.scrollDirection = .horizontal
//CollectionCellView width autoSize
layout.estimatedItemSize = UICollectionViewFlowLayout.automaticSize
let collectionView = UICollectionView(frame: .zero, collectionViewLayout: layout)
collectionView.translatesAutoresizingMaskIntoConstraints = false
collectionView.register(CustomCollectionViewCell.self, forCellWithReuseIdentifier: cellId)
collectionView.backgroundColor = .clear
collectionView.delegate = self
collectionView.dataSource = self
collectionView.alwaysBounceHorizontal = true
//Add Spacing in each cell
layout.minimumInteritemSpacing = 15
layout.minimumLineSpacing = 15
return collectionView
}()
Try playing around with this method:
- (UIEdgeInsets)collectionView:(UICollectionView *)collectionView
layout:(UICollectionViewLayout*)collectionViewLayout
insetForSectionAtIndex:(NSInteger)section {
UIEdgeInsets insets = UIEdgeInsetsMake(?, ?, ?, ?);
return insets;
}
I am trying to adjust the cell height resize to fit the UILabel text, but it is not working..
var mySize = CGFloat()
func collectionView(collectionView: UICollectionView, cellForItemAtIndexPath indexPath: NSIndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCellWithReuseIdentifier("cell", forIndexPath: indexPath) as! cellView
cell.myLabel.text = self.items[indexPath.item]
cell.myLabel.bounds.size.height = self.mySize
cell.backgroundColor = UIColor.yellowColor()
return cell
}
func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
// handle tap events
print("You selected cell #\(indexPath.item)!")
}
func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
func heightForLabel(text:String, font:UIFont, width:CGFloat) -> CGFloat
{
let label:UILabel = UILabel(frame: CGRectMake(0, 0, width, CGFloat.max))
label.numberOfLines = 0
label.lineBreakMode = NSLineBreakMode.ByWordWrapping
label.font = font
label.text = items[indexPath.row]
label.sizeToFit()
return label.frame.height
}
let font = UIFont(name: "Helvetica Neue", size: 30)
let detailHeight = heightForLabel(items[indexPath.row], font: font!, width: UIScreen.mainScreen().bounds.size.width)
self.mySize = detailHeight
return CGSizeMake(UIScreen.mainScreen().bounds.size.width, 358 + detailHeight)
}
Any suggestions what to do here? Should i do it another way? Please, I need help.. The problem is that the UILabel text is set in the cellForItemAtIndexPath, and items is an array for strings.
This is my project file, if someone watch to take a look at it:
http://www.filedropper.com/test_37
Why not try this in ObjC
[text boundingRectWithSize:CGSizeMake(maxWidth, maxHeight)
options:NSStringDrawingUsesLineFragmentOrigin
attributes:nil context:nil]
This will give CGRect. Get the height from it. set font size etc in attributes parameter.
UPDATE
In place of this
let detailHeight = heightForLabel(items[indexPath.row], font: font!, width: UIScreen.mainScreen().bounds.size.width)
Use this
let height = items[indexPath.row].boundingRectWithSize(CGSizeMake(CGFloat.max,UIScreen.mainScreen().bounds.size.width), options: .UsesLineFragmentOrigin, attributes: [NSFontAttributeName: font!], context: nil).size.height
Hope this helps
You can do it like that but I have implemented it in different way. Here is the sample of code you can do it.
let desiredWidth: CGFloat = tableView.bounds.size.width
let label: UILabel = UILabel()
let desiredString = "Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged."
label.text = desiredString
label.numberOfLines = 0;
label.lineBreakMode = NSLineBreakMode.ByWordWrapping
let size: CGSize = label.sizeThatFits(CGSizeMake(desiredWidth, CGFloat.max))
print("Label height you can set to your cell: \(size.height)")
Crate an String extension
extension String {
func heightOfString(usingFont font: UIFont) -> CGFloat {
let fontAttributes = [NSFontAttributeName: font]
let size = self.size(attributes: fontAttributes)
return size.height
}
}
get the height of the string as follows
let str = "Hello world"
let strHgt = str.heightOfString(usingFont: UIFont.systemFont(ofSize: 12))
I create this method for getting height of a label. You need to provide label's static Width and label's font
func dynamicHeight(font: UIFont, width: CGFloat) -> CGFloat{
let calString = NSString(string: self)
let textSize = calString.boundingRectWithSize(CGSizeMake(width, CGFloat.max), options: NSStringDrawingOptions.UsesLineFragmentOrigin|NSStringDrawingOptions.UsesFontLeading, attributes: [NSFontAttributeName: font], context: nil)
return textSize.height
}
Try this...
NSString *yourText = #"Your string";
CGSize lableWidth = CGSizeMake(300, CGFLOAT_MAX);
CGSize requiredSize = [yourText sizeWithFont:[UIFont fontWithName:#"CALIBRI" size:17] constrainedToSize:lableWidth lineBreakMode:NSLineBreakByWordWrapping];
int calculatedHeight = requiredSize.height;
return (float)calculatedHeight;
I took a look at your code, and I was able to solve it.
Firstly, on line 71 in your ViewController class:
let height = items[indexPath.row].boundingRectWithSize(CGSizeMake(CGFloat.max, UIScreen.mainScreen().bounds.size.width), options: .UsesLineFragmentOrigin, attributes: [NSFontAttributeName: font!], context: nil).size.height
You accidentally set CGFloat.max as width and the width as height. It should be:
CGSizeMake(UIScreen.mainScreen().bounds.size.width, CGFloat.max)
I'd say it's better practice to use the width of the view that the cell is directly contained in (the collectionView), but that's just my personal opinion.
Secondly, you need to enable AutoLayout. Go to your Main.storyboard file and make sure Use Auto Layout is selected.
Now you need to add constraints. (You can read more about AutoLayout and constraints here)
There are different ways to add constraints. The easiest way is to control click a UI element and drag the mouse to the element you want to set a constraint to.
You need to add the following constraints for your cell:
ImageView.top = cell.top
ImageView.leading = cell.leading
ImageView.trailing = cell.trailing
ImageView.bottom = MyLabel.top + 8 (your padding)
MyLabel.leading = cell.leading
MyLabel.trailing = cell.trailing
MyLabel.bottom = cell.bottom
And these for your CollectionView
CollectionView.top = view.top
CollectionView.leading = view.leading
CollectionView.trailing = view.trailing
CollectionView.bottom = view.bottom
I've attached the project, modified with AutoLayout here below.
Modified project
Edit:
Approach 2 - without AutoLayout.
This could also be achieved without using AutoLayout by manually updating the cell's label height in collectionView:willDisplayCell:. I'm sure there are better alternatives, I'd personally try AutoResizingMasks before this approach.
Project without AutoLayout
extension String{
func height(withConstrainedWidth width: CGFloat, font: UIFont) -> CGFloat {
let constraintRect = CGSize(width: width, height: .greatestFiniteMagnitude)
let boundingBox = self.boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, attributes: [NSFontAttributeName: font], context: nil)
return ceil(boundingBox.height)
}}
This question already has answers here:
UICollectionView, full width cells, allow autolayout dynamic height?
(21 answers)
Closed 3 years ago.
I need to display a bunch of collectionViewCells that have different heights. the views are too complex and I don't want to manually calculate the expected height. I want to enforce auto-layout to calculate cell height
Calling dequeueReusableCellWithReuseIdentifier outside of cellForItemAtIndexPath breaks collectionView and causes it to crash
Another problem is the cell is not in a separate xib, so I can't manually instantiate a temporary one and use it for height calculation.
Any solutions for this?
public func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
var cell = collectionView.dequeueReusableCellWithReuseIdentifier(cellIdentifier, forIndexPath: indexPath) as UICollectionViewCell
configureCell(cell, item: items[indexPath.row])
cell.contentView.setNeedsLayout()
cell.contentView.layoutIfNeeded()
return cell.contentView.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize)
}
EDIT:
Crash happens as soon as dequeueReusableCellWithReuseIdentifier is called. If I don't call that method and instead return a size everything works great and cells show up without the calculated size
negative or zero sizes are not supported in the flow layout
2015-01-26 18:24:34.231 [13383:9752256] *** Terminating app due to uncaught exception 'NSRangeException', reason: '*** -[__NSArrayM objectAtIndex:]: index 1 beyond bounds [0 .. 0]'
*** First throw call stack:
(
0 CoreFoundation 0x00000001095aef35 __exceptionPreprocess + 165
1 libobjc.A.dylib 0x0000000109243bb7 objc_exception_throw + 45
2 CoreFoundation 0x0000000109499f33 -[__NSArrayM objectAtIndex:] + 227
3 UIKit 0x0000000107419d9c -[UICollectionViewFlowLayout _getSizingInfos] + 842
4 UIKit 0x000000010741aca9 -[UICollectionViewFlowLayout _fetchItemsInfoForRect:] + 526
5 UIKit 0x000000010741651f -[UICollectionViewFlowLayout prepareLayout] + 257
6 UIKit 0x000000010742da10 -[UICollectionViewData _prepareToLoadData] + 67
7 UIKit 0x00000001074301c6 -[UICollectionViewData layoutAttributesForItemAtIndexPath:] + 44
8 UIKit 0x00000001073fddb1 -[UICollectionView _dequeueReusableViewOfKind:withIdentifier:forIndexPath:viewCategory:] + 248
9 0x00000001042b824c _TFC1228BasePaginatingViewController14collectionViewfS0_FTCSo16UICollectionView6layoutCSo22UICollectionViewLayout22sizeForItemAtIndexPathCSo11NSIndexPath_VSC6CGSize + 700
10 0x00000001042b83d4 _TToFC1228BasePaginatingViewController14collectionViewfS0_FTCSo16UICollectionView6layoutCSo22UICollectionViewLayout22sizeForItemAtIndexPathCSo11NSIndexPath_VSC6CGSize + 100
11 UIKit 0x0000000107419e2e -[UICollectionViewFlowLayout _getSizingInfos] + 988
12 UIKit 0x000000010741aca9 -[UICollectionViewFlowLayout _fetchItemsInfoForRect:] + 526
13 UIKit 0x000000010741651f -[UICollectionViewFlowLayout prepareLayout] + 257
14 UIKit 0x000000010742da10 -[UICollectionViewData _prepareToLoadData] + 67
15 UIKit 0x000000010742e0e9 -[UICollectionViewData validateLayoutInRect:] + 54
16 UIKit 0x00000001073f67b8 -[UICollectionView layoutSubviews] + 170
17 UIKit 0x0000000106e3c973 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 521
18 QuartzCore 0x0000000106b0fde8 -[CALayer layoutSublayers] + 150
19 QuartzCore 0x0000000106b04a0e _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 380
20 QuartzCore 0x0000000106b0487e _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 24
21 QuartzCore 0x0000000106a7263e _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 242
22 QuartzCore 0x0000000106a7374a _ZN2CA11Transaction6commitEv + 390
23 QuartzCore 0x0000000106a73db5 _ZN2CA11Transaction17observer_callbackEP19__CFRunLoopObservermPv + 89
24 CoreFoundation 0x00000001094e3dc7 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23
25 CoreFoundation 0x00000001094e3d20 __CFRunLoopDoObservers + 368
26 CoreFoundation 0x00000001094d9b53 __CFRunLoopRun + 1123
27 CoreFoundation 0x00000001094d9486 CFRunLoopRunSpecific + 470
28 GraphicsServices 0x000000010be869f0 GSEventRunModal + 161
29 UIKit 0x0000000106dc3420 UIApplicationMain + 1282
30 0x000000010435c709 main + 169
31 libdyld.dylib 0x000000010a0f2145 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
Here is a Ray Wenderlich tutorial that shows you how to use AutoLayout to dynamically size UITableViewCells. I would think it would be the same for UICollectionViewCell.
Basically, though, you end up dequeueing and configuring a prototype cell and grabbing its height. After reading this article, I decided to NOT implement this method and just write some clear, explicit sizing code.
Here's what I consider the "secret sauce" for the entire article:
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
return [self heightForBasicCellAtIndexPath:indexPath];
}
- (CGFloat)heightForBasicCellAtIndexPath:(NSIndexPath *)indexPath {
static RWBasicCell *sizingCell = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sizingCell = [self.tableView dequeueReusableCellWithIdentifier:RWBasicCellIdentifier];
});
[self configureBasicCell:sizingCell atIndexPath:indexPath];
return [self calculateHeightForConfiguredSizingCell:sizingCell];
}
- (CGFloat)calculateHeightForConfiguredSizingCell:(UITableViewCell *)sizingCell {
[sizingCell setNeedsLayout];
[sizingCell layoutIfNeeded];
CGSize size = [sizingCell.contentView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize];
return size.height + 1.0f; // Add 1.0f for the cell separator height
}
EDIT: I did some research into your crash and decided that there is no way to get this done without a custom XIB. While that is a bit frustrating, you should be able to cut and paste from your Storyboard to a custom, empty XIB.
Once you've done that, code like the following will get you going:
// ViewController.m
#import "ViewController.h"
#import "CollectionViewCell.h"
#interface ViewController () <UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout> {
}
#property (weak, nonatomic) IBOutlet CollectionViewCell *cell;
#property (weak, nonatomic) IBOutlet UICollectionView *collectionView;
#end
#implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor lightGrayColor];
[self.collectionView registerNib:[UINib nibWithNibName:#"CollectionViewCell" bundle:nil] forCellWithReuseIdentifier:#"cell"];
}
- (void)viewDidAppear:(BOOL)animated {
[super viewDidAppear:animated];
NSLog(#"viewDidAppear...");
}
- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
return 1;
}
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
return 50;
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumInteritemSpacingForSectionAtIndex:(NSInteger)section {
return 10.0f;
}
- (CGFloat)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout minimumLineSpacingForSectionAtIndex:(NSInteger)section {
return 10.0f;
}
- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
return [self sizingForRowAtIndexPath:indexPath];
}
- (CGSize)sizingForRowAtIndexPath:(NSIndexPath *)indexPath {
static NSString *title = #"This is a long title that will cause some wrapping to occur. This is a long title that will cause some wrapping to occur.";
static NSString *subtitle = #"This is a long subtitle that will cause some wrapping to occur. This is a long subtitle that will cause some wrapping to occur.";
static NSString *buttonTitle = #"This is a really long button title that will cause some wrapping to occur.";
static CollectionViewCell *sizingCell = nil;
static dispatch_once_t onceToken;
dispatch_once(&onceToken, ^{
sizingCell = [[NSBundle mainBundle] loadNibNamed:#"CollectionViewCell" owner:self options:nil][0];
});
[sizingCell configureWithTitle:title subtitle:[NSString stringWithFormat:#"%#: Number %d.", subtitle, (int)indexPath.row] buttonTitle:buttonTitle];
[sizingCell setNeedsLayout];
[sizingCell layoutIfNeeded];
CGSize cellSize = [sizingCell.contentView systemLayoutSizeFittingSize:UILayoutFittingCompressedSize];
NSLog(#"cellSize: %#", NSStringFromCGSize(cellSize));
return cellSize;
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
static NSString *title = #"This is a long title that will cause some wrapping to occur. This is a long title that will cause some wrapping to occur.";
static NSString *subtitle = #"This is a long subtitle that will cause some wrapping to occur. This is a long subtitle that will cause some wrapping to occur.";
static NSString *buttonTitle = #"This is a really long button title that will cause some wrapping to occur.";
CollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:#"cell" forIndexPath:indexPath];
[cell configureWithTitle:title subtitle:[NSString stringWithFormat:#"%#: Number %d.", subtitle, (int)indexPath.row] buttonTitle:buttonTitle];
return cell;
}
#end
The code above (along with a very basic UICollectionViewCell subclass and associated XIB) gives me this:
I just ran into this problem on a UICollectionView and the way that i solved it similar to the answer above but in a pure UICollectionView way.
Create a custom UICollectionViewCell that contains whatever you will be filling it with to make it dynamic. I created its own .xib for it as it seems like the easiest approach.
Add constraints in that .xib that allow for the cell to be calculated from top to bottom. The re-sizing won't work if you haven't accounted for all of the height. Say you have a view on top, then a label underneath it, and another label underneath that. You would need to connect constraints to the top of the cell to the top of that view, then the bottom of the view to the top of the first label, bottom of first label to the top of the second label, and bottom of second label to bottom of cell.
Load the .xib into the viewcontroller and register it with the collectionView on viewDidLoad
let nib = UINib(nibName: CustomCellName, bundle: nil)
self.collectionView!.registerNib(nib, forCellWithReuseIdentifier: "customCellID")`
Load a second copy of that xib into the class and store it as a property so you can use it to determine the size of what that cell should be
let sizingNibNew = NSBundle.mainBundle().loadNibNamed(CustomCellName, owner: CustomCellName.self, options: nil) as NSArray
self.sizingNibNew = (sizingNibNew.objectAtIndex(0) as? CustomViewCell)!
Implement the UICollectionViewFlowLayoutDelegate in your view controller. The method that matters is called sizeForItemAtIndexPath. Inside that method you will need to pull the data from the datasource that is associated with that cell from the indexPath. Then configure the sizingCell and call preferredLayoutSizeFittingSize. The method returns a CGSize which will consist of the width minus the content insets and the height that is returned from self.sizingCell.preferredLayoutSizeFittingSize(targetSize).
override func collectionView(collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAtIndexPath indexPath: NSIndexPath) -> CGSize {
guard let data = datasourceArray?[indexPath.item] else {
return CGSizeZero
}
let sectionInset = self.collectionView?.collectionViewLayout.sectionInset
let widthToSubtract = sectionInset!.left + sectionInset!.right
let requiredWidth = collectionView.bounds.size.width
let targetSize = CGSize(width: requiredWidth, height: 0)
sizingNibNew.configureCell(data as! CustomCellData, delegate: self)
let adequateSize = self.sizingNibNew.preferredLayoutSizeFittingSize(targetSize)
return CGSize(width: (self.collectionView?.bounds.width)! - widthToSubtract, height: adequateSize.height)
}
In the class of the custom cell itself you will need to override awakeFromNib and tell the contentView that its size needs to be flexible
override func awakeFromNib() {
super.awakeFromNib()
self.contentView.autoresizingMask = [UIViewAutoresizing.FlexibleHeight]
}
In the custom cell override layoutSubviews
override func layoutSubviews() {
self.layoutIfNeeded()
}
In the class of the custom cell implement preferredLayoutSizeFittingSize. This is where you will need to do any trickery on the items that are being laid out. If its a label you will need to tell it what its preferredMaxWidth should be.
func preferredLayoutSizeFittingSize(_ targetSize: CGSize)-> CGSize {
let originalFrame = self.frame
let originalPreferredMaxLayoutWidth = self.label.preferredMaxLayoutWidth
var frame = self.frame
frame.size = targetSize
self.frame = frame
self.setNeedsLayout()
self.layoutIfNeeded()
self.label.preferredMaxLayoutWidth = self.questionLabel.bounds.size.width
// calling this tells the cell to figure out a size for it based on the current items set
let computedSize = self.systemLayoutSizeFittingSize(UILayoutFittingCompressedSize)
let newSize = CGSize(width:targetSize.width, height:computedSize.height)
self.frame = originalFrame
self.questionLabel.preferredMaxLayoutWidth = originalPreferredMaxLayoutWidth
return newSize
}
All those steps should give you the correct sizes. If your getting 0 or other funky numbers than you haven't set up your constraints properly.
We can maintain dynamic height for collection view cell without xib(only using storyboard).
- (CGSize)collectionView:(UICollectionView *)collectionView
layout:(UICollectionViewLayout*)collectionViewLayout
sizeForItemAtIndexPath:(NSIndexPath *)indexPath {
NSAttributedString* labelString = [[NSAttributedString alloc] initWithString:#"Your long string goes here" attributes:#{NSFontAttributeName:[UIFont systemFontOfSize:17.0]}];
CGRect cellRect = [labelString boundingRectWithSize:CGSizeMake(cellWidth, MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin context:nil];
return CGSizeMake(cellWidth, cellRect.size.height);
}
Make sure that numberOfLines in IB should be 0.
Swift 4.*
I have created a Xib for UICollectionViewCell which seems to be the good approach.
extension ViewController: UICollectionViewDelegateFlowLayout {
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
return size(indexPath: indexPath)
}
private func size(for indexPath: IndexPath) -> CGSize {
// load cell from Xib
let cell = Bundle.main.loadNibNamed("ACollectionViewCell", owner: self, options: nil)?.first as! ACollectionViewCell
// configure cell with data in it
let data = self.data[indexPath.item]
cell.configure(withData: data)
cell.setNeedsLayout()
cell.layoutIfNeeded()
// width that you want
let width = collectionView.frame.width
let height: CGFloat = 0
let targetSize = CGSize(width: width, height: height)
// get size with width that you want and automatic height
let size = cell.contentView.systemLayoutSizeFitting(targetSize, withHorizontalFittingPriority: .defaultHigh, verticalFittingPriority: .fittingSizeLevel)
// if you want height and width both to be dynamic use below
// let size = cell.contentView.systemLayoutSizeFitting(UILayoutFittingCompressedSize)
return size
}
}
#note: I don't recommend setting image when configuring data in this size determining case. It gave me the distorted/unwanted result. Configuring texts only gave me below result.
TL;DR: Scan down to image, and then check out working project here.
Updating my answer for a simpler solution that I found..
In my case, I wanted to fix the width, and have variable height cells. I wanted a drop in, reusable solution that handled rotation and didn't require a lot of intervention.
What I arrived at, was override (just) systemLayoutFitting(...) in the collection cell (in this case a base class for me), and first defeat UICollectionView's effort to set the wrong dimension on contentView by adding a constraint for the known dimension, in this case, the width.
class EstimatedWidthCell: UICollectionViewCell {
override init(frame: CGRect) {
super.init(frame: frame)
contentView.translatesAutoresizingMaskIntoConstraints = false
}
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
contentView.translatesAutoresizingMaskIntoConstraints = false
}
override func systemLayoutSizeFitting(
_ targetSize: CGSize, withHorizontalFittingPriority
horizontalFittingPriority: UILayoutPriority,
verticalFittingPriority: UILayoutPriority) -> CGSize {
width.constant = targetSize.width
and then return the final size for the cell - used for (and this feels like a bug) the dimension of the cell itself, but not contentView - which is otherwise constrained to a conflicting size (hence the constraint above). To calculate the correct cell size, I use a lower priority for the dimension that I wanted to float, and I get back the height required to fit the content within the width to which I want to fix:
let size = contentView.systemLayoutSizeFitting(
CGSize(width: targetSize.width, height: 1),
withHorizontalFittingPriority: .required,
verticalFittingPriority: verticalFittingPriority)
print("\(#function) \(#line) \(targetSize) -> \(size)")
return size
}
lazy var width: NSLayoutConstraint = {
return contentView.widthAnchor
.constraint(equalToConstant: bounds.size.width)
.isActive(true)
}()
}
But where does this width come from? It is configured via the estimatedItemSize on the collection view's flow layout:
lazy var collectionView: UICollectionView = {
let view = UICollectionView(frame: CGRect(), collectionViewLayout: layout)
view.backgroundColor = .cyan
view.translatesAutoresizingMaskIntoConstraints = false
return view
}()
lazy var layout: UICollectionViewFlowLayout = {
let layout = UICollectionViewFlowLayout()
let width = view.bounds.size.width // should adjust for inset
layout.estimatedItemSize = CGSize(width: width, height: 10)
layout.scrollDirection = .vertical
return layout
}()
Finally, to handle rotation, I implement trailCollectionDidChange to invalidate the layout:
override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
layout.estimatedItemSize = CGSize(width: view.bounds.size.width, height: 10)
layout.invalidateLayout()
super.traitCollectionDidChange(previousTraitCollection)
}
The final result looks like this:
And I have published a working sample here.
Seems like it's quite a popular question, so I will try to make my humble contribution.
The code below is Swift 4 solution for no-storyboard setup. It utilizes some approaches from previous answers, therefore it prevents Auto Layout warning caused on device rotation.
I am sorry if code samples are a bit long. I want to provide an "easy-to-use" solution fully hosted by StackOverflow. If you have any suggestions to the post - please, share the idea and I will update it accordingly.
The setup:
Two classes: ViewController.swift and MultilineLabelCell.swift - Cell containing single UILabel.
MultilineLabelCell.swift
import UIKit
class MultilineLabelCell: UICollectionViewCell {
static let reuseId = "MultilineLabelCellReuseId"
private let label: UILabel = UILabel(frame: .zero)
override init(frame: CGRect) {
super.init(frame: frame)
layer.borderColor = UIColor.red.cgColor
layer.borderWidth = 1.0
label.numberOfLines = 0
label.lineBreakMode = .byWordWrapping
let labelInset = UIEdgeInsets(top: 10, left: 10, bottom: -10, right: -10)
contentView.addSubview(label)
label.translatesAutoresizingMaskIntoConstraints = false
label.topAnchor.constraint(equalTo: contentView.layoutMarginsGuide.topAnchor, constant: labelInset.top).isActive = true
label.leadingAnchor.constraint(equalTo: contentView.layoutMarginsGuide.leadingAnchor, constant: labelInset.left).isActive = true
label.trailingAnchor.constraint(equalTo: contentView.layoutMarginsGuide.trailingAnchor, constant: labelInset.right).isActive = true
label.bottomAnchor.constraint(equalTo: contentView.layoutMarginsGuide.bottomAnchor, constant: labelInset.bottom).isActive = true
label.layer.borderColor = UIColor.black.cgColor
label.layer.borderWidth = 1.0
}
required init?(coder aDecoder: NSCoder) {
fatalError("Storyboards are quicker, easier, more seductive. Not stronger then Code.")
}
func configure(text: String?) {
label.text = text
}
override func preferredLayoutAttributesFitting(_ layoutAttributes: UICollectionViewLayoutAttributes) -> UICollectionViewLayoutAttributes {
label.preferredMaxLayoutWidth = layoutAttributes.size.width - contentView.layoutMargins.left - contentView.layoutMargins.left
layoutAttributes.bounds.size.height = systemLayoutSizeFitting(UIView.layoutFittingCompressedSize).height
return layoutAttributes
}
}
ViewController.swift
import UIKit
let samuelQuotes = [
"Samuel says",
"Add different length strings here for better testing"
]
class ViewController: UIViewController, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout {
private(set) var collectionView: UICollectionView
// Initializers
init() {
// Create new `UICollectionView` and set `UICollectionViewFlowLayout` as its layout
collectionView = UICollectionView(frame: .zero, collectionViewLayout: UICollectionViewFlowLayout())
super.init(nibName: nil, bundle: nil)
}
required init?(coder aDecoder: NSCoder) {
// Create new `UICollectionView` and set `UICollectionViewFlowLayout` as its layout
collectionView = UICollectionView(frame: .zero, collectionViewLayout: UICollectionViewFlowLayout())
super.init(coder: aDecoder)
}
override func viewDidLoad() {
super.viewDidLoad()
title = "Dynamic size sample"
// Register Cells
collectionView.register(MultilineLabelCell.self, forCellWithReuseIdentifier: MultilineLabelCell.reuseId)
// Add `coolectionView` to display hierarchy and setup its appearance
view.addSubview(collectionView)
collectionView.backgroundColor = .white
collectionView.contentInsetAdjustmentBehavior = .always
collectionView.contentInset = UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)
// Setup Autolayout constraints
collectionView.translatesAutoresizingMaskIntoConstraints = false
collectionView.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: 0).isActive = true
collectionView.leftAnchor.constraint(equalTo: view.leftAnchor, constant: 0).isActive = true
collectionView.topAnchor.constraint(equalTo: view.topAnchor, constant: 0).isActive = true
collectionView.rightAnchor.constraint(equalTo: view.rightAnchor, constant: 0).isActive = true
// Setup `dataSource` and `delegate`
collectionView.dataSource = self
collectionView.delegate = self
(collectionView.collectionViewLayout as! UICollectionViewFlowLayout).estimatedItemSize = UICollectionViewFlowLayout.automaticSize
(collectionView.collectionViewLayout as! UICollectionViewFlowLayout).sectionInsetReference = .fromLayoutMargins
}
// MARK: - UICollectionViewDataSource -
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
let cell = collectionView.dequeueReusableCell(withReuseIdentifier: MultilineLabelCell.reuseId, for: indexPath) as! MultilineLabelCell
cell.configure(text: samuelQuotes[indexPath.row])
return cell
}
func collectionView(_ collectionView: UICollectionView, numberOfItemsInSection section: Int) -> Int {
return samuelQuotes.count
}
// MARK: - UICollectionViewDelegateFlowLayout -
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let sectionInset = (collectionViewLayout as! UICollectionViewFlowLayout).sectionInset
let referenceHeight: CGFloat = 100 // Approximate height of your cell
let referenceWidth = collectionView.safeAreaLayoutGuide.layoutFrame.width
- sectionInset.left
- sectionInset.right
- collectionView.contentInset.left
- collectionView.contentInset.right
return CGSize(width: referenceWidth, height: referenceHeight)
}
}
To run this sample create new Xcode project, create corresponding files and replace AppDelegate contents with the following code:
import UIKit
#UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {
var window: UIWindow?
var navigationController: UINavigationController?
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {
window = UIWindow(frame: UIScreen.main.bounds)
if let window = window {
let vc = ViewController()
navigationController = UINavigationController(rootViewController: vc)
window.rootViewController = navigationController
window.makeKeyAndVisible()
}
return true
}
}
Swift 4 answer based on helpful answer from #mbm29414.
Unfortunately, it requires the use of a XIB file. There doesn't appear to be an alternative.
The key parts are using a sizing cell (created only once) and registering the XIB when initializing the collection view.
Then you size each cell dynamically within the sizeForItemAt function.
// UICollectionView Vars and Constants
let CellXIBName = YouViewCell.XIBName
let CellReuseID = YouViewCell.ReuseID
var sizingCell = YouViewCell()
fileprivate func initCollectionView() {
// Connect to view controller
collectionView.dataSource = self
collectionView.delegate = self
// Register XIB
collectionView.register(UINib(nibName: CellXIBName, bundle: nil), forCellWithReuseIdentifier: CellReuseID)
// Create sizing cell for dynamically sizing cells
sizingCell = Bundle.main.loadNibNamed(CellXIBName, owner: self, options: nil)?.first as! YourViewCell
// Set scroll direction
let layout = UICollectionViewFlowLayout()
layout.scrollDirection = .vertical
collectionView.collectionViewLayout = layout
// Set properties
collectionView.alwaysBounceVertical = true
collectionView.alwaysBounceHorizontal = false
// Set top/bottom padding
collectionView.contentInset = UIEdgeInsets(top: collectionViewTopPadding, left: collectionViewSidePadding, bottom: collectionViewBottomPadding, right: collectionViewSidePadding)
// Hide scrollers
collectionView.showsVerticalScrollIndicator = false
collectionView.showsHorizontalScrollIndicator = false
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
// Get cell data and render post
let data = YourData[indexPath.row]
sizingCell.renderCell(data: data)
// Get cell size
sizingCell.setNeedsLayout()
sizingCell.layoutIfNeeded()
let cellSize = sizingCell.systemLayoutSizeFitting(UIView.layoutFittingCompressedSize)
// Return cell size
return cellSize
}
I followed the steps mentioned in this SO and everything is fine except when my Collection View has less data (text) to make it wide enough. Checking the documentation in systemLyaoutSizeFittingSize, I have this solution so my cell take up the width as I requested:
- (CGSize)calculateSizeForSizingCell:(UICollectionViewCell *)sizingCell width:(CGFloat)width {
CGRect frame = sizingCell.frame;
frame.size.width = width;
sizingCell.frame = frame;
[sizingCell setNeedsLayout];
[sizingCell layoutIfNeeded];
CGSize size = [sizingCell systemLayoutSizeFittingSize:UILayoutFittingCompressedSize
withHorizontalFittingPriority:UILayoutPriorityRequired
verticalFittingPriority:UILayoutPriorityFittingSizeLevel];
return size;
}
Hope this would help someone.
- (CGSize)systemLayoutSizeFittingSize:(CGSize)targetSize NS_AVAILABLE_IOS(6_0);
Apple doc:
Equivalent to sending -systemLayoutSizeFittingSize:withHorizontalFittingPriority:verticalFittingPriority: with UILayoutPriorityFittingSizeLevel for both priorities.
While the default value is "pretty low" according to Apple's doc:
When you send -[UIView systemLayoutSizeFittingSize:], the size fitting most closely to the target size (the argument) is computed. UILayoutPriorityFittingSizeLevel is the priority level with which the view wants to conform to the target size in that computation. It's quite low. It is generally not appropriate to make a constraint at exactly this priority. You want to be higher or lower.
So my change of default behavior is to enforce the width (horizontal fitting) with UILayoutPriorityRequired.
Follow bolnad answer up to Step 4.
Then make it simpler by replacing all the other steps with:
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
// Configure your cell
sizingNibNew.configureCell(data as! CustomCellData, delegate: self)
// We use the full width minus insets
let width = collectionView.frame.size.width - collectionView.sectionInset.left - collectionView.sectionInset.right
// Constrain our cell to this width
let height = sizingNibNew.systemLayoutSizeFitting(CGSize(width: width, height: .infinity), withHorizontalFittingPriority: UILayoutPriorityRequired, verticalFittingPriority: UILayoutPriorityFittingSizeLevel).height
return CGSize(width: width, height: height)
}
It worked for me, hope you too.
*Note: I have used auto layout in Nib, remember add top and bottom contraints for subviews in contentView
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let cell = YourCollectionViewCell.instantiateFromNib()
cell.frame.size.width = collectionView.frame.width
cell.data = viewModel.data[indexPath.item]
let resizing = cell.systemLayoutSizeFitting(UILayoutFittingCompressedSize, withHorizontalFittingPriority: UILayoutPriority.required, verticalFittingPriority: UILayoutPriority.fittingSizeLevel)
return resizing
}