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()
Related
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.
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)
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.
I have a UITableViewCell and I am adding xib in cellForRowIndexPath method. It works fine until I update the model and call reloadData on UITableView. The cell is showing new data on top of the old data, I can see the label on the old label text.
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
let customView:CustomView = UIView.fromNib()
userView.frame = CGRect(x: 10, y: y, width: Int(self.tableView.bounds.size.width-50), height: 50)
userView.label.text = data[indexPath.row]
cell.addSubview(customView:)
Any guesses why this could happen?
The quick answer is this: since cells are reused when dequeued, you are adding a new CustomView to a cell that already had a CustomView added when dequeued previously.
One way you could handle this is to remove any existing CustomView from the hierarchy before creating a new one and adding it. To do this you could add a recognizable tag to the view each time, and then look for a view with that same tag to remove during your dequeue process, like this:
//Remove existing view, if it exists
if let existingView = cell.viewWithTag(999) {
//A view was found - so remove it.
existingView.removeFromSuperview()
}
let customView: CustomView = UIView.fromNib()
//Set a tag so it can be removed in the future
customView.tag = 999
customView.frame = CGRect(x: 10, y: y, width: Int(self.tableView.bounds.size.width-50), height: 50)
customView.label.text = data[indexPath.row]
cell.addSubview(customView)
To me this feels like overkill, as it seems you should just add your customView to a custom UICollectionViewCell so you aren't essentially creating a custom cell on the fly, but that is just me. If you did this you could simply dequeue your custom cell and set the text on the label without having to add more views to the hierarchy all the time.
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