i want to stretch collectionView height in tableView.
as the gitHub App's Label (below picture),
when the collectionViewCell's width excess collectionView's width,
I want to set collectionViewCell in a new line
To set cell in the new line, i tried to use flowlayout.
but it did not be increased height. just can scroll in collectionView. ðŸ˜.
unfortunately, tableView's height did not be increased
what's the best way to do this ?😂
This approach from SRP-Achiever should work.
override func systemLayoutSizeFitting(_ targetSize: CGSize, withHorizontalFittingPriority horizontalFittingPriority: UILayoutPriority, verticalFittingPriority: UILayoutPriority) -> CGSize {
collectionView.layoutIfNeeded()
collectionView.frame = CGRect(x: 0, y: 0, width: targetSize.width , height: 1)
return collectionView.collectionViewLayout.collectionViewContentSize
}
Related
As this video, (you can download source code from here, I've tried my best to remove all the unnecessary code)
I need to manually scroll through tableview to make it reset to the right height of each cell and if I expand and unexpand multiple cells, it will show the wrong height again.
I'm trying to use "systemLayoutSizeFittingSize" instead of "heightForRowAt". (CustomCell.swift)
override func systemLayoutSizeFitting(_ targetSize: CGSize, withHorizontalFittingPriority horizontalFittingPriority: UILayoutPriority, verticalFittingPriority: UILayoutPriority) -> CGSize {
setNeedsLayout()
layoutIfNeeded()
let defaultHeight: CGFloat = 90
return CGSize(width: 0, height: !isExpanded ? defaultHeight : tableView.contentSize.height + defaultHeight)
}
I want to use autolayout instead of giving the exact height for tableview. what do I do wrong?
I did what this answer said but it did not work why?
How to adjust height of UICollectionView to be the height of the content size of the UICollectionView?
but there is a problem its not resizing what am i missing out
I have also faced same issue so I did another approach. You need to add width constraint and you need to set it constant in systemLayoutSizeFitting function.
The main thing you should be careful about that is add all subviews to contentView of cell and also the last subview must has a constraint to bottom of contentView like the autoResizing TableViewCell
class ABCCell: UICollectionViewCell {
lazy var width: NSLayoutConstraint = {
let width = contentView.widthAnchor.constraint(equalToConstant: bounds.size.width)
width.isActive = true
return width
}()
override func systemLayoutSizeFitting(_ targetSize: CGSize, withHorizontalFittingPriority horizontalFittingPriority: UILayoutPriority, verticalFittingPriority: UILayoutPriority) -> CGSize {
width.constant = bounds.size.width
return contentView.systemLayoutSizeFitting(CGSize(width: targetSize.width, height: 1))
}
}
I am using a UICollectionView for chat and using scroll to bottom on load. It's all working good except the first time I scroll manually it bounces up about 50-100 pt. If I continue scrolling it's fine and goes into the safe area and below the screen.
What is causing the initial bounce? It seems that it bounces off the top of the bottom safe area first, and then goes below the safe area fine if you continue scrolling.
What I'm trying to get is a nice smooth scroll initially without the weird bounce.
It seems to be caused by the fact that I am dynamically sizing image heights after they load with invalidateLayout.
I was able to solve this by luck with the following
AutoSizing cells: cell width equal to the CollectionView
// UICollectionViewController
if let layout = collectionView?.collectionViewLayout as? UICollectionViewFlowLayout {
layout.estimatedItemSize = CGSize(width: view.frame.width, height: 100)
}
// UICollectionViewCell
override func preferredLayoutAttributesFitting(_ layoutAttributes: UICollectionViewLayoutAttributes) -> UICollectionViewLayoutAttributes {
let autoLayoutAttributes = super.preferredLayoutAttributesFitting(layoutAttributes)
// Specify you want _full width_
let targetSize = CGSize(width: layoutAttributes.frame.width, height: 200)
// Calculate the size (height) using Auto Layout
let autoLayoutSize = contentView.systemLayoutSizeFitting(targetSize, withHorizontalFittingPriority: UILayoutPriority.required, verticalFittingPriority: UILayoutPriority.defaultLow)
let autoLayoutFrame = CGRect(origin: autoLayoutAttributes.frame.origin, size: autoLayoutSize)
// Assign the new size to the layout attributes
autoLayoutAttributes.frame = autoLayoutFrame
return autoLayoutAttributes
}
I have collection view cells with equal width and height in a flow layout. They contain a single UILabel, which numberOfLines property is set to 0. The constraints of the label are:
The cell is made circular:
cell.layer.cornerRadius = cell.frame.width / 2
cell.clipsToBounds = true
I increase the size of each cell based on the label's text size. However, it's width and height can't be greater than 150. Here is how I determine the size of each cell:
private func estimatedFrameForText(text: String) -> CGRect {
let size = CGSize(width: 100, height: 1000)
let options = NSStringDrawingOptions.usesFontLeading.union(.usesLineFragmentOrigin)
return NSString(string: text).boundingRect(with: size, options: options, attributes: [NSAttributedStringKey.font: UIFont.systemFont(ofSize: 17)], context: nil)
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let hashLabelText = textArray[indexPath.item]
let textSize = estimatedFrameForText(text: hashLabelText)
let width = min(150, textSize.width + 20)
let height = width
return CGSize(width: width, height: height)
}
With this I get the following result (I'm showing the part where the cells' width and height are equal to 150).:
As you can see, when the cell hits its maximum possible size and the text of the labels continues to increase, at some point, the text gets off the visible part of the cells. I understand why this happens (the layout debugger shows this clearly), however I can't find a solution to the problem, yet.
What I want is that the edges of the label remain visible no matter what is the size of the cell. The text's tail can be truncated if the cell reaches its maximum size, but the text continues to increase.
I've tried to increase the space between the label and the bounds of the cells but that affects how the text looks in the smallest cells. I've also tried to change the minimum font scale of the label, but again, without a success.
You have to use UIEdgeInsets for this, Create a class for UILabel:
import UIKit
class UILabelDraw: UILabel {
override func drawText(in rect: CGRect) {
let insets: UIEdgeInsets = UIEdgeInsets(top: 10.0, left: 10.0, bottom: 10.0, right: 10.0)
super.drawText(in: UIEdgeInsetsInsetRect(rect, insets))
}
}
Use this class as a Label class like below:
Output of UIEdgeInsets is below:
I'm currently have the following extension on UITextField to calculate the bounding rect for a given string.
func widthHeight(font: UIFont) -> CGRect {
let constraintRect = CGSize(width: 200, height: 1000)
let boundingBox = self.boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, attributes: [NSFontAttributeName: font], context: nil)
return boundingBox
}
The width for constraintRect is the maximum width I want to allow for the box.
I set the values and the cells like this:
func collectionView(_ collectionView: UICollectionView, cellForItemAt indexPath: IndexPath) -> UICollectionViewCell {
if let cell = collectionView.dequeueReusableCell(withReuseIdentifier: reuse, for: indexPath) as? ChatCollectionViewCell {
let text = self.chatLog[indexPath.row].text
cell.chatTextView.text = text
cell.chatViewWidth = (text?.widthHeight(font: UIFont.systemFont(ofSize: 16)).width)!
return cell
}
return UICollectionViewCell()
}
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
if let text = self.chatLog[indexPath.row].text {
let box = text.widthHeight(font: UIFont.systemFont(ofSize: 16))
return CGSize(width: view.frame.width, height: box.height + 10)
}
return CGSize(width: self.view.frame.width, height: 60)
}
When this code runs, I get massively miscalculated cell sizes:
As you can see, the view's frames are very messed up.
The first line is "Heya", the second line is "How's life going so far", and the third line is "I'm a stapler, you're a textbook." Some cells are too narrow, some cells are too wide.
Here's some additional code for my custom collectionViewCell:
override init(frame: CGRect) {
super.init(frame: frame)
setupViews()
}
override func layoutSubviews() {
chatView.frame = CGRect(x: 0, y: 0, width: chatViewWidth, height: frame.height)
chatTextView.frame = CGRect(x: chatView.frame.origin.x + 10, y: 0, width: chatView.frame.width - 20, height: chatView.frame.height)
}
func setupViews() {
if isTextFromCurrentUser {
chatTextView.frame = CGRect(x: 10, y: 0, width: frame.width - 140, height: frame.height)
chatTextView.backgroundColor = .white
} else {
chatTextView.frame = CGRect(x: frame.width - 150, y: 0, width: frame.width - 140, height: frame.height)
chatTextView.backgroundColor = .blue
}
chatTextView.font = UIFont.systemFont(ofSize: 16)
chatTextView.layer.cornerRadius = 9
chatTextView.clipsToBounds = true
chatTextView.autoresizingMask = UIViewAutoresizing.flexibleHeight
chatTextView.isScrollEnabled = false
contentView.addSubview(chatView)
contentView.addSubview(chatTextView)
}
Chemo,
As I believe its a chat bubble to which you are trying to set the hight for and chat bubble cant have any scroll inside it make sure your textView's scroll is disabled.
Second as Chat bubble should increase its height based on content and there is no height limit use CGFloat.greatestFiniteMagnitude as possible height that you can accommodate while calculating boundingRect
func widthHeight(font: UIFont) -> CGRect {
let constraintRect = CGSize(width: 200, height: CGFloat.greatestFiniteMagnitude)
let boundingBox = self.boundingRect(with: constraintRect, options: .usesLineFragmentOrigin, attributes: [NSFontAttributeName: font], context: nil)
return boundingBox
}
Finally make sure there is no contentInset set to the textView. If contentInset set as left 5 and right 5 make sure to subtract 10 (5 + 5) from max width you can accommodate.
As height is the only variable here in equation setting width exactly is the key to get correct height. Make sure you set the line options correct matching ur textViews property.
Suggestion:
UITableView can make use of automatic height for cell and setting scroll disable on textView makes textView to calculate its size based on the text set. I mean textView will respect the implicit size.
As I believe you are creating a chat app where each bubble is a cell, consider more sane option of using UITableView and leverage the benefit of automatic cell height then messing up with collectionView which expects you to provide the size for each item manually.
Pinch of Advice :D
I have personally used bounding rect and managed to calculate the exact height for text after loads of trial and error method. I personally suggest creating a textView instance, setting its property exactly matching the property of textView you have in your storyboard and then set the text you wanna show and use sizeThatFits to get the actual size of textView which is much easier.
func collectionView(_ collectionView: UICollectionView, layout collectionViewLayout: UICollectionViewLayout, sizeForItemAt indexPath: IndexPath) -> CGSize {
let textView = UITextView(frame: CGRect.zero)
//set textView property here
textView.text = self.chatLog[indexPath.row].text
let size = textView.sizeThatFits(CGSize(width: textView.bounds.width, height: CGFloat.greatestFiniteMagnitude))
return size;
}