swift tableview cell change width frame not work - swift

This is my code but not work!
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! MyChatCell
var frame = cell.frame
if(indexPath%2 == 0){
frame.size.width = CGFloat(200)
} else {
frame.size.width = CGFloat(100)
}
cell.frame = frame
return cell
}
I want change cell width to 100 or 200 per cell
But frame.size.width not work

You can't change that, because all cells in a table view must have the same width, but can have different heights if needed.
However, you can try to make the table view's .backgroundColor transparent, and maybe the content view of the cell, than add another "wrapper view" on the cell's content view and make it have different widths. It will create the "visual impression" that cells indeed have different widths.

Related

Setting up different layouts for one cell, depending on its content

In an UITableViewCell, I have an UIView container, which contains a UIImageView on top and an UILabel on the bottom. When the UILabel does not contain text, I want to remove the UILabel and resize the UImageView to the bottom of my UIView container.
In my TableViewCell, I have this:
let x = imageViewPostPreview.bottomAnchor.constraint(equalTo: viewPreviewOverlay.topAnchor, constant: 0)
if postText == "" {
x.isActive = true
imageViewPostPreview.layer.maskedCorners = [.layerMaxXMinYCorner, .layerMinXMinYCorner, .layerMaxXMaxYCorner, .layerMinXMaxYCorner]
self.layoutSubviews()
self.layoutIfNeeded()
} else if postText != "" {
x.isActive = false
imageViewPostPreview.layer.maskedCorners = [.layerMaxXMinYCorner, .layerMinXMinYCorner]
self.layoutSubviews()
self.layoutIfNeeded()
}
}
This piece of code works on when the initial UITableViewCell is loaded, but when I scroll my UITableView, the cell loses the initial layout.
How do I setup the layout correctly, so the layout is kept on scroll?
Edit:
Initial cell, which is correct:
After scrolling, incorrect layout:
Add this to prepareToReuse method
override func prepareForReuse() {
super.prepareForReuse()
let x = imageViewPostPreview.bottomAnchor.constraint(equalTo: viewPreviewOverlay.topAnchor, constant: 0)
if postText.isEmpty {
x.isActive = true
imageViewPostPreview.layer.maskedCorners = [.layerMaxXMinYCorner, .layerMinXMinYCorner, .layerMaxXMaxYCorner, .layerMinXMaxYCorner]
} else {
x.isActive = false
imageViewPostPreview.layer.maskedCorners = [.layerMaxXMinYCorner, .layerMinXMinYCorner]
}
self.layoutIfNeeded()
}
Note: Dont call layoutSubview directly ... always try to call layoutifNeeded or setNeeedsLayout
A way you can have the cell calculate its size automatically, is to have constraints set inside the cell view for all directions on vertical axis. So, in your case the image view will have top, leading and trailing set to superview, and bottom to the label. The label will have leading and bottom to superview, and the top will be to the image view you set. It's important to set for vertical axis, since for table view we need it to calculate the height. This way the table view will know what to expect and can set height automatically.
After that you set tableView.rowHeight = UITableView.automaticDimension. Or you can also set in the delegate method.
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return UITableView.automaticDimension
}
After all this is in place, you will only need to give the right values to the cell subviews(in this case set image and text). You can do this inside cell for row function. A sample code will look something like this.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "identifier", for: indexPath)
let model = self.models[indexPath.row]
cell.imageViewPostPreview.image = model.image ?? nil
cell.postText.text = model.text ?? nil
return cell
}
This should work without any further need to calculate constraints and calling layouts to update. Hope this helps! You can also check this question.

UITableViewCell style goes away after scrolling down

I am trying to figure out why my custom styling for table cells disappears after scrolling down in a table view and them back up. What do I need to do to have the style persist?
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell : CustomTrendingCell = trendingTableView.dequeueReusableCell(withIdentifier: "cell") as! CustomTrendingCell
cell.selectionStyle = .none
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(searchForTrendingTerm(sender:)))
cell.iconView_search.isUserInteractionEnabled = true
cell.iconView_search.tag = indexPath.row
cell.iconView_search.addGestureRecognizer(tapGesture)
cell.trendingLabel.text = trendingSearchTerms[indexPath.row]
cell.elevate(elevation: 4.0) //where my style is being set
return cell
}
extension UIView {
func elevate(elevation: Double) {
self.layer.masksToBounds = false
self.layer.shadowColor = UIColor.black.cgColor
self.layer.shadowOffset = CGSize(width: 0, height: elevation)
self.layer.shadowRadius = abs(CGFloat(elevation))
self.layer.shadowOpacity = 0.4
}
}
The top 2 items in the screenshot below have been scrolled down and up. The drop shadow styling has been removed. The bottom 2 have the correct styling and have not been scrolled down.
Screenshot example
One possible solution here is to explicitly specify the zPosition of each cell's layer.
You would want to ensure that the upper cell has the higher position so that it's content (shadow) lies over the lower cell.
In your cell for row at function add:
cell.layer.zPosition = CGFloat(numberOfRows - indexPath.row)

NSTableView start cells from bottom

I have a osX project with NSTableview
[Screen]
[a]
[b]
[c]
[d]
no cell
no cell
[Screen]
is is posible to change direction of this tableview to look like this?
[Screen]
no cell
no cell
[d]
[c]
[b]
[a]
[Screen]
i have tried transform like in iOS but it throwing errors
tableView.transform = CGAffineTransform(scaleX: 1, y: -1)
same goes for cell
cell.contentView.transform = CGAffineTransform(scaleX: 1, y: -1)
what must be done to access transform property in OSX like in iOS?
From what I think you want, you don't need to use CGAffineTransform .
You just need to organise your data set as you wish and populate the cells accordingly.
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
guard let cell = tableView.dequeueReusableCell(withIdentifier: cellReuseIdentifier, for: indexPath) as? CustomTableViewCell else {
return UITableViewCell()
}
cell.updateTitle(customCellTitles[indexPath.row])
return cell
}
instead of having your data set as:
customCellTitles = ["a","b","c","d"]
make it:
customCellTitles = ["d","c","b","a"]
In addition to this, I would go for the following setup of your layout:
Notice there is no top constraint.
Next, create an outlet from your table view height constraint and update it when you have your data set ready.
In the simple scenario where your cell size is the same (or independent from the content you display) update your height constraint based on the cell size:
tableViewHeightConstraint.constant = cellSize * numberOfCells
view.setNeedsLayout()

iOS8 Swift - Problems dynamically resizing tableview cells

Here's what my application looks like currently.
You'll see that when the subtitle text label is only one line is resizes correctly, but when there's multiple lines it gets all messed up. I think this has to do with the constraints possibly? Right now I'm using the auto-layout constraints. You can see them in the screenshot. Here's the code that creates my cells.
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> DealCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Deal Cell", forIndexPath: indexPath) as DealCell
let currentBar = bars[indexPath.row] as BarAnnotation
cell.barName.text = currentBar.name
cell.deal.text = currentBar.deal
cell.distanceToBar.text = String(format: "%.3f mi", currentBar.distance)
// Set the height of the table view cells
self.tableView.rowHeight = UITableViewAutomaticDimension;
self.tableView.estimatedRowHeight = 44.0;
return cell
}
Any ideas?
Use tableView:heightForRowAtIndexPath: function in the UITableViewDelegate.
Using this you can individually set the height of each row separately.
For more information : https://developer.apple.com/library/ios/documentation/UIKit/Reference/UITableViewDelegate_Protocol/index.html#//apple_ref/occ/intfm/UITableViewDelegate/tableView:heightForRowAtIndexPath:
Or you can use auto layout settings like in this article.
http://useyourloaf.com/blog/2014/02/14/table-view-cells-with-varying-row-heights.html

How to increase the UITableView separator height?

I want more space(10px) between each cell. How can I do this?
And I have added this code
tableView.separatorStyle = UITableViewCellSeparatorStyleNone;
The best way for me, just add this in cellForRowAtIndexPath or in willDisplayCell
CGRect sizeRect = [UIScreen mainScreen].applicationFrame;
NSInteger separatorHeight = 3;
UIView * additionalSeparator = [[UIView alloc] initWithFrame:CGRectMake(0,cell.frame.size.height-separatorHeight,sizeRect.size.width,separatorHeight)];
additionalSeparator.backgroundColor = [UIColor grayColor];
[cell addSubview:additionalSeparator];
For Swift 3.0:
let screenSize = UIScreen.main.bounds
let separatorHeight = CGFloat(3.0)
let additionalSeparator = UIView.init(frame: CGRect(x: 0, y: self.frame.size.height-separatorHeight, width: screenSize.width, height: separatorHeight))
additionalSeparator.backgroundColor = UIColor.gray
self.addSubview(additionalSeparator)
You should add this to cell's method awakeFromNib() to avoid re-creation.
I have seen many clunky solutions like subclassing UITableView with hidden cells, and other less optimal ones incl. in this thread.
When initializing the UITableView, Set the rowHeight property of UITableView to a height that equals = cell height + desired separator/space height.
Do not use standard UITableViewCell class though, instead, subclass the UITableViewCell class and override its layoutSubviews method. There, after calling super (don't forget that), set the height of the cell itself to desired height.
BONUS UPDATE 18/OCT/2015:
You can be a bit smart about this. The solution above basically puts the "separator" at the bottom of the cell. What really happens is, the row height is managed by the TableViewController but the cell is resized to be a bit lower. This results in the separator/empty space being at the bottom. But you can also centre all the subviews vertically so that you leave the same space at the top and the bottom. For example 1pt and 1pt.
You can also create isFirst, isLast convenience properties on your cell subclass. You would set these to yes in the cellForRowAtIndexPath.
This way you can handle the edge cases for top and bottom separators inside the layoutSubviews method as this would have access to these properties.
This way you can handle the edge cases for top or bottom - because sometimes the design department wants N+1 separators while the number of cells is only N. So you have to either deal with the top one or the boot one in a special way. But it's best do this inside cells instead tableViewHeader or TableViewFooter.
I don't think it's possible using standard API. I guess you would need to subclass the UITableViewCell and add a view that simulates a separator at the bottom of the cell.
You may want to check this question, it seems related and has some sample code:
iPhone + UITableView + place an image for separator
In Swift
The easiest and shortest way for me was to add the snippet below in cellForRowAtIndexPath or in willDisplayCell:
override func tableView(tableView: UITableView,
willDisplayCell cell: UITableViewCell,
forRowAtIndexPath indexPath: NSIndexPath)
{
let additionalSeparatorThickness = CGFloat(3)
let additionalSeparator = UIView(frame: CGRectMake(0,
cell.frame.size.height - additionalSeparatorThickness,
cell.frame.size.width,
additionalSeparatorThickness))
additionalSeparator.backgroundColor = UIColor.redColor()
cell.addSubview(additionalSeparator)
}
this is quite old. Nevertheless I will post my approach.
Simply increase your cell height a bit and assign a mask layer to the cell, like that:
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "...", for: indexPath)
// Configure the cell...
let maskLayer = CAShapeLayer()
let bounds = cell.bounds
maskLayer.path = UIBezierPath(roundedRect: CGRect(x: 2, y: 2, width: bounds.width-4, height: bounds.height-4), cornerRadius: 5).cgPath
cell.layer.mask = maskLayer
return cell
}
So in this example my seperator height will be 4.
Have fun!
You can do this entirely in the storyboard. Here is how:
go to the storyboard and select the tableview
Show the Size Inspector and from there set row height to say 140.
then show the Attributes Inspector and from there set your separator to Single Line and Style Plain and choose a color
then in the storyboard (or in Document Outline) select the cell
and again in the Size Inspector, under the Table View Cell, set custom Row Height to say 120.
That’s all. Your separator will be 20 units tall.
Kinda old thread, but since I only found hacky solutions in this thread,
here the solution that worked best for me (without additional UIView in every cell)
Swift 3:
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
//configure your cell...
cell.layer.shadowColor = UIColor.red.cgColor
cell.layer.shadowOffset = CGSize(width: 0, height: 1)
cell.layer.shadowOpacity = 1
cell.layer.shadowRadius = 0
cell.layer.masksToBounds = false
return cell
}
EDIT: Unfortunately this does not work if you scroll up in a table. I leave the answer here anyway, since it might be a solution if your table has limited content.
See Shadow on a UITableViewCell disappears when scrolling for more info.
For a table cell with height of 50 and a space of 5 pix between the rows. Width is 320.
Define the background of the cells to be clear:
- (void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath {
cell.backgroundColor = [UIColor clearColor];
}
Set the height of the cells, this is the size of the row PLUS the delimiter:
-(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath{
return 55;
}
And define in cellForRowAtIndexPath a box, with the size of the row (MINUS delimiter) to draw in the background color:
UILabel *headerBackgroundLabel = [[UILabel alloc] initWithFrame:CGRectMake(0,0,320,50)];
backgroundBox.backgroundColor = [UIColor grayColor];
[cell addSubview:backgroundBox];
I do it a much simpler and more flexible way. Some may call it a hack. I call it pragmatic.
I hide the standard UITableViewSeparator. I then add a subview to my cell, using auto layout pin it to the top. Fix the height to what I desire. Pin it to the edges with a margin either side. Change it's background colour. I have a plain separator with the height i desire.
You may question how efficient this is having another UIView in the cell hierarchy. Is it really going to make a noticeable difference? Probably not - you've just taken the standard separator out of the table hierarchy anyway.
Swift 4
It's not possible to make the default separator higher. Instead you need to add a subview that will look as a separator to each cell (and optionally make the cell higher). You can do it for example in cellForRowAtIndexPath or in a UITableViewCell subclass.
In case you allow to select the cell, you need to add the subview for selected state as well, otherwise the separator would disappear when the cell is selected. That's why selectedBackgroundView is also configured.
Add this into your UITableViewController subclass:
override func viewDidLoad() {
super.viewDidLoad()
tableView.separatorStyle = .none
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
cell.backgroundView = UIView(backgroundColor: .white)
cell.backgroundView?.addSeparator()
cell.selectedBackgroundView = UIView(backgroundColor: .blue)
cell.selectedBackgroundView?.addSeparator()
// configure the cell
return cell
}
Add this extensions into the same file at the bottom:
private extension UIView {
convenience init(backgroundColor: UIColor) {
self.init()
self.backgroundColor = backgroundColor
}
func addSeparator() {
let separatorHeight: CGFloat = 2
let frame = CGRect(x: 0, y: bounds.height - separatorHeight, width: bounds.width, height: separatorHeight)
let separator = UIView(frame: frame)
separator.backgroundColor = .gray
separator.autoresizingMask = [.flexibleTopMargin, .flexibleWidth]
addSubview(separator)
}
}
Here's an option that might work for some people
cell.layer.borderColor = UIColor.white.cgColor
cell.layer.borderWidth = 4.0
cell.layer.masksToBounds = true
The easier and safest solution to this problem is to turn off the table separator and use a UITableViewCell as a separator of variable height. Sure, you'll have to do some index math to figure out where items are, but really it's odd / even.
It won't break and you get the benefit of recyclable cells (no extraneous views to clean up).
First make tableview separator none from the storyboard. Then add UILabel/UIView at bottom of cell of height(you needed) using storyboard or Xib
For Swift 4
Implemented King-Wizard's solution to Swift 4:
public func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
let additionalSeparatorThickness = CGFloat(4)
let additionalSeparator = UIView(frame: CGRect(x: 0,
y: cell.frame.size.height - additionalSeparatorThickness, width: cell.frame.size.width, height: additionalSeparatorThickness))
additionalSeparator.backgroundColor = UIColor.groupTableViewBackground
cell.addSubview(additionalSeparator)
}
This is the easiest solution I've found:
override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
" "
}
then just set the height to whatever you want:
tableView.sectionHeaderHeight = 30.0
I came across a way that has allowed me to effectively change the gap between cells.
In Interface builder I set the row height to be 46.
In the cellForRowAtIndexPath method of my TableView delegate I set the frame of the cell to be a smaller value.
cell.frame=CGRectMake(44,0,tableView.bounds.size.width,44)
This gives me a cell with a height of 44 that fits the width of the tableView but the space provided for the row will be 46 as defined in IB.
I was filling the cell programmatically anyway so this suited me fine.
You should implement
- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
delegate method. and return 100.0 there.