Expand and Collapse tableview cells - ios

Question

I'm able to expand and collapse cells but i wanna call functions (expand and collapse) inside UITableViewCell to change button title.
import UIKit
class MyTicketsTableViewController: UITableViewController {
var selectedIndexPath: NSIndexPath?
var extraHeight: CGFloat = 100
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 5
}
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("cell", forIndexPath: indexPath) as! MyTicketsTableViewCell
return cell
}
override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
if(selectedIndexPath != nil && indexPath.compare(selectedIndexPath!) == NSComparisonResult.OrderedSame) {
return 230 + extraHeight
}
return 230.0
}
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
if(selectedIndexPath == indexPath) {
selectedIndexPath = nil
} else {
selectedIndexPath = indexPath
}
tableView.beginUpdates()
tableView.endUpdates()
}
}
import UIKit
class MyTicketsTableViewCell: UITableViewCell {
#IBOutlet weak var expandButton: ExpandButton!
#IBOutlet weak var detailsHeightConstraint: NSLayoutConstraint!
var defaultHeight: CGFloat!
override func awakeFromNib() {
super.awakeFromNib()
defaultHeight = detailsHeightConstraint.constant
expandButton.button.setTitle("TAP FOR DETAILS", forState: .Normal)
detailsHeightConstraint.constant = 30
}
func expand() {
UIView.animateWithDuration(0.3, delay: 0.0, options: .CurveLinear, animations: {
self.expandButton.arrowImage.transform = CGAffineTransformMakeRotation(CGFloat(M_PI * 0.99))
self.detailsHeightConstraint.constant = self.defaultHeight
self.layoutIfNeeded()
}, completion: { finished in
self.expandButton.button.setTitle("CLOSE", forState: .Normal)
})
}
func collapse() {
UIView.animateWithDuration(0.3, delay: 0.0, options: .CurveLinear, animations: {
self.expandButton.arrowImage.transform = CGAffineTransformMakeRotation(CGFloat(M_PI * 0.0))
self.detailsHeightConstraint.constant = CGFloat(30.0)
self.layoutIfNeeded()
}, completion: { finished in
self.expandButton.button.setTitle("TAP FOR DETAILS", forState: .Normal)
})
}
}

Answer 1

If you want the cell to get physically bigger, then where you have your store IndexPath, in heightForRow: use:
override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
if selectedIndexPath == indexPath {
return 230 + extraHeight
}
return 230.0
}
Then when you want to expand one in the didSelectRow:
selectedIndexPath = indexPath
tableView.beginUpdates
tableView.endUpdates
Edit
This will make the cells animate themselves getting bigger, you dont need the extra animation blocks in the cell.
Edit 2
override func tableView(tableView: UITableView, didSelectRowAtIndexPath indexPath: NSIndexPath) {
if(selectedIndexPath == indexPath) {
selectedIndexPath = nil
if let cell = tableView.cellForRowAtIndexPath(indexPath) as? MyTicketsTableViewCell {
cell.collapse()
}
if let cell = tableView.cellForRowAtIndexPath(NSIndexPath(forRow:indexPath.row+1, section: indexPath.section) as? MyTicketsTableViewCell {
cell.collapse()
}
} else {
selectedIndexPath = indexPath
if let cell = tableView.cellForRowAtIndexPath(indexPath) as? MyTicketsTableViewCell {
cell.expand()
}
if let cell = tableView.cellForRowAtIndexPath(NSIndexPath(forRow:indexPath.row+1, section: indexPath.section) as? MyTicketsTableViewCell {
cell.expand()
}
}
tableView.beginUpdates()
tableView.endUpdates()
}

Answer 2

All you need is implement UITableView Delegate this way:
override func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return UITableViewAutomaticDimension
}
override func tableView(tableView: UITableView, estimatedHeightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return UITableViewAutomaticDimension
}
By default, estimatedHeight is CGRectZero, when you set some value for it, it enables autoresizing (the same situation with UICollectionView), you can do even also so:
tableView?.estimatedRowHeight = CGSizeMake(50.f, 50.f);
Then you need to setup you constraints inside your cell.
Check this post: https://www.hackingwithswift.com/read/32/2/automatically-resizing-uitableviewcells-with-dynamic-type-and-ns
Hope it helps)

Answer 3

In MyTicketsTableViewController class, inside cellForRowAtIndexPath datasource method add target for the button.
cell.expandButton.addTarget(self, action: "expandorcollapsed:", forControlEvents: UIControlEvents.TouchUpInside)

Answer 4

I tried to implement lots of the given examples on this and other pages with similar questions, but none worked for me since I had to perform some logic in my custom cell (eg. hide unneeded UILables in CustomCell.swift when the cell is collapsed).
Here is the implementation that worked for me:
Create a dictionary:
private var _expandedCells: [IndexPath:Bool] = [:]
Implement the heightForRowAt method:
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return _expandedCells[indexPath] == nil ? 70 : _expandedCells[indexPath]! ? 150 : 70
}
Implement the didSelectRowAt method:
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
_expandedCells[indexPath] = _expandedCells[indexPath] == nil ? true : !_expandedCells[indexPath]!
tableView.reloadRows(at: [indexPath], with: .fade)
}
Adjust your customCell:
func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath) {
guard let cell = cell as? YourCustomTableViewCell, let isExpanded = _expandedCells[indexPath] else { return }
cell.set(expanded: isExpanded)
}