Expand/collapse section in UITableView in iOS

Question

Could somebody tell me the way to perform UITableView expandable/collapsible animations in sections of UITableView as below?

or

Answer 1

To implement the collapsible table section in iOS, the magic is how to control the number of rows for each section, or we can manage the height of rows for each section.

Also, we need to customize the section header so that we can listen to the tap event from the header area (whether it's a button or the whole header).

How to deal with the header? It's very simple, we extend the UITableViewCell class and make a custom header cell like so:

import UIKit

class CollapsibleTableViewHeader: UITableViewCell {

    @IBOutlet var titleLabel: UILabel!
    @IBOutlet var toggleButton: UIButton!

}

then use the viewForHeaderInSection to hook up the header cell:

override func tableView(tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
  let header = tableView.dequeueReusableCellWithIdentifier("header") as! CollapsibleTableViewHeader

  header.titleLabel.text = sections[section].name
  header.toggleButton.tag = section
  header.toggleButton.addTarget(self, action: #selector(CollapsibleTableViewController.toggleCollapse), forControlEvents: .TouchUpInside)

  header.toggleButton.rotate(sections[section].collapsed! ? 0.0 : CGFloat(M_PI_2))

  return header.contentView
}

remember we have to return the contentView because this function expects a UIView to be returned.

Now let's deal with the collapsible part, here is the toggle function that toggle the collapsible prop of each section:

func toggleCollapse(sender: UIButton) {
  let section = sender.tag
  let collapsed = sections[section].collapsed

  // Toggle collapse
  sections[section].collapsed = !collapsed

  // Reload section
  tableView.reloadSections(NSIndexSet(index: section), withRowAnimation: .Automatic)
}

depends on how you manage the section data, in this case, I have the section data something like this:

struct Section {
  var name: String!
  var items: [String]!
  var collapsed: Bool!

  init(name: String, items: [String]) {
    self.name = name
    self.items = items
    self.collapsed = false
  }
}

var sections = [Section]()

sections = [
  Section(name: "Mac", items: ["MacBook", "MacBook Air", "MacBook Pro", "iMac", "Mac Pro", "Mac mini", "Accessories", "OS X El Capitan"]),
  Section(name: "iPad", items: ["iPad Pro", "iPad Air 2", "iPad mini 4", "Accessories"]),
  Section(name: "iPhone", items: ["iPhone 6s", "iPhone 6", "iPhone SE", "Accessories"])
]

at last, what we need to do is based on the collapsible prop of each section, control the number of rows of that section:

override func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
  return (sections[section].collapsed!) ? 0 : sections[section].items.count
}

I have a fully working demo on my Github: https://github.com/jeantimex/ios-swift-collapsible-table-section

If you want to implement the collapsible sections in a grouped-style table, I have another demo with source code here: https://github.com/jeantimex/ios-swift-collapsible-table-section-in-grouped-section

Hope that helps.

Answer 2

This is the best way i found to create expandable table view cells

.h file

  NSMutableIndexSet *expandedSections;

.m file

if (!expandedSections)
    {
        expandedSections = [[NSMutableIndexSet alloc] init];
    }
   UITableView *masterTable = [[UITableView alloc] initWithFrame:CGRectMake(0,100,1024,648) style:UITableViewStyleGrouped];
    masterTable.delegate = self;
    masterTable.dataSource = self;
    [self.view addSubview:masterTable];

Table view delegate methods

- (BOOL)tableView:(UITableView *)tableView canCollapseSection:(NSInteger)section
{
    // if (section>0) return YES;

    return YES;
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    // Return the number of sections.
    return 4;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    if ([self tableView:tableView canCollapseSection:section])
    {
        if ([expandedSections containsIndex:section])
        {
            return 5; // return rows when expanded
        }

        return 1; // only top row showing
    }

    // Return the number of rows in the section.
    return 1;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *CellIdentifier = @"Cell";

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] ;
    }

    // Configure the cell...

    if ([self tableView:tableView canCollapseSection:indexPath.section])
    {
        if (!indexPath.row)
        {
            // first row
            cell.textLabel.text = @"Expandable"; // only top row showing

            if ([expandedSections containsIndex:indexPath.section])
            {

                UIImageView *imView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"UITableContract"]];
                cell.accessoryView = imView;
            }
            else
            {

                UIImageView *imView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"UITableExpand"]];
                cell.accessoryView = imView;
            }
        }
        else
        {
            // all other rows
            if (indexPath.section == 0) {
                cell.textLabel.text = @"section one";
            }else if (indexPath.section == 1) {
                cell.textLabel.text = @"section 2";
            }else if (indexPath.section == 2) {
                cell.textLabel.text = @"3";
            }else {
                cell.textLabel.text = @"some other sections";
            }

            cell.accessoryView = nil;
            cell.accessoryType = UITableViewCellAccessoryDisclosureIndicator;
        }
    }
    else
    {
        cell.accessoryView = nil;
        cell.textLabel.text = @"Normal Cell";

    }

    return cell;
}
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    if ([self tableView:tableView canCollapseSection:indexPath.section])
    {
        if (!indexPath.row)
        {
            // only first row toggles exapand/collapse
            [tableView deselectRowAtIndexPath:indexPath animated:YES];

            NSInteger section = indexPath.section;
            BOOL currentlyExpanded = [expandedSections containsIndex:section];
            NSInteger rows;


            NSMutableArray *tmpArray = [NSMutableArray array];

            if (currentlyExpanded)
            {
                rows = [self tableView:tableView numberOfRowsInSection:section];
                [expandedSections removeIndex:section];

            }
            else
            {
                [expandedSections addIndex:section];
                rows = [self tableView:tableView numberOfRowsInSection:section];
            }


            for (int i=1; i<rows; i++)
            {
                NSIndexPath *tmpIndexPath = [NSIndexPath indexPathForRow:i 
                                                               inSection:section];
                [tmpArray addObject:tmpIndexPath];
            }

            UITableViewCell *cell = [tableView cellForRowAtIndexPath:indexPath];

            if (currentlyExpanded)
            {
                [tableView deleteRowsAtIndexPaths:tmpArray 
                                 withRowAnimation:UITableViewRowAnimationTop];

                UIImageView *imView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"UITableExpand"]];
                cell.accessoryView = imView;
            }
            else
            {
                [tableView insertRowsAtIndexPaths:tmpArray 
                                 withRowAnimation:UITableViewRowAnimationTop];

                UIImageView *imView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"UITableContract"]];
                cell.accessoryView = imView;
            }
        }
    }

    NSLog(@"section :%d,row:%d",indexPath.section,indexPath.row);

}

Answer 3

I found another relatively simple way to solve that problem. By using this method we will not required to alter our cell which is almost always related to data array index, potentially causing mess in our view controller.

First, we add this following properties to our controller class:

@property (strong, nonatomic) NSMutableArray* collapsedSections;
@property (strong, nonatomic) NSMutableArray* sectionViews;

collapsedSections will save collapsed section numbers. sectionViews will store our custom section view.

Synthesize it:

@synthesize collapsedSections;
@synthesize sectionViews;

Initialize it:

- (void) viewDidLoad
{
    [super viewDidLoad];

    self.collapsedSections = [NSMutableArray array];
    self.sectionViews      = [NSMutableArray array];
}

After that, we must connect our UITableView so it can be accessed from within our view controller class:

@property (strong, nonatomic) IBOutlet UITableView *tblMain;

Connect it from XIB to view controller using ctrl + drag like usually.

Then we create view as custom section header for our table view by implementing this UITableView delegate:

- (UIView*) tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
    // Create View
    CGRect frame = CGRectZero;

    frame.origin = CGPointZero;

    frame.size.height = 30.f;
    frame.size.width  = tableView.bounds.size.width;

    UIView* view = [[UIView alloc] initWithFrame:frame];

    [view setBackgroundColor:[UIColor blueColor]];

    // Add label for title
    NSArray* titles = @[@"Title 1", @"Title 2", @"Title 3"];

    NSString* selectedTitle = [titles objectAtIndex:section];

    CGRect labelFrame = frame;

    labelFrame.size.height = 30.f;
    labelFrame.size.width -= 20.f;
    labelFrame.origin.x += 10.f;

    UILabel* titleLabel = [[UILabel alloc] initWithFrame:labelFrame];

    [titleLabel setText:selectedTitle];
    [titleLabel setTextColor:[UIColor whiteColor]];

    [view addSubview:titleLabel];

    // Add touch gesture
    [self attachTapGestureToView:view];

    // Save created view to our class property array
    [self saveSectionView:view inSection:section];

    return view;
}

Next, we implement method to save our previously created custom section header in class property:

- (void) saveSectionView:(UIView*) view inSection:(NSInteger) section
{
    NSInteger sectionCount = [self numberOfSectionsInTableView:[self tblMain]];

    if(section < sectionCount)
    {
        if([[self sectionViews] indexOfObject:view] == NSNotFound)
        {
            [[self sectionViews] addObject:view];
        }
    }
}

Add UIGestureRecognizerDelegate to our view controller .h file:

@interface MyViewController : UIViewController<UITableViewDelegate, UITableViewDataSource, UIGestureRecognizerDelegate>

Then we create method attachTapGestureToView:

- (void) attachTapGestureToView:(UIView*) view
{
    UITapGestureRecognizer* tapAction = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(onTap:)];

    [tapAction setDelegate:self];

    [view addGestureRecognizer:tapAction];
}

Above method will add tap gesture recognizer to all of section view we created before. Next we should implement onTap: selector

- (void) onTap:(UITapGestureRecognizer*) gestureRecognizer
{
    // Take view who attach current recognizer
    UIView* sectionView = [gestureRecognizer view]; 

    // [self sectionViews] is Array containing our custom section views
    NSInteger section = [self sectionNumberOfView:sectionView];

    // [self tblMain] is our connected IBOutlet table view
    NSInteger sectionCount = [self numberOfSectionsInTableView:[self tblMain]];

    // If section more than section count minus one set at last
    section = section > (sectionCount - 1) ? 2 : section;

    [self toggleCollapseSection:section];
}

Above method will invoked when user tap any of our table view section. This method search correct section number based on our sectionViews array we created before.

Also, we implement method to get wihch section of header view belongs to.

- (NSInteger) sectionNumberOfView:(UIView*) view
{
    UILabel* label = [[view subviews] objectAtIndex:0];

    NSInteger sectionNum = 0;

    for(UIView* sectionView in [self sectionViews])
    {
        UILabel* sectionLabel = [[sectionView subviews] objectAtIndex:0];

        //NSLog(@"Section: %d -> %@ vs %@", sectionNum, [label text], [sectionLabel text]);

        if([[label text] isEqualToString:[sectionLabel text]])
        {
            return sectionNum;
        }

        sectionNum++;
    }

    return NSNotFound;
}

Next, we must implement method toggleCollapseSection:

- (void) toggleCollapseSection:(NSInteger) section
{
    if([self isCollapsedSection:section])
    {
        [self removeCollapsedSection:section];
    }
    else
    {
        [self addCollapsedSection:section];
    }

    [[self tblMain] reloadSections:[NSIndexSet indexSetWithIndex:section] withRowAnimation:UITableViewRowAnimationFade];
}

This method will insert/remove section number to our collapsedSections array we created before. When a section number inserted to that array, it means that the section should be collapsed and expanded if otherwise.

Next we implement removeCollapsedSection:, addCollapsedSection:section and isCollapsedSection:section

- (BOOL)isCollapsedSection:(NSInteger) section
{
    for(NSNumber* existing in [self collapsedSections])
    {
        NSInteger current = [existing integerValue];

        if(current == section)
        {
            return YES;
        }
    }

    return NO;
}

- (void)removeCollapsedSection:(NSInteger) section
{
    [[self collapsedSections] removeObjectIdenticalTo:[NSNumber numberWithInteger:section]];
}

- (void)addCollapsedSection:(NSInteger) section
{
    [[self collapsedSections] addObject:[NSNumber numberWithInteger:section]];
}

This three method is just helpers to make us easier in accessing collapsedSections array.

Finally, implement this table view delegate so our custom section views looks nice.

- (CGFloat) tableView:(UITableView *)tableView heightForHeaderInSection:(NSInteger)section
{
    return 30.f; // Same as each custom section view height
}

Hope it helps.

Answer 4

I have done the same thing using multiple sections .

class SCTierBenefitsViewController: UIViewController {
    @IBOutlet private weak var tblTierBenefits: UITableView!
    private var selectedIndexPath: IndexPath?
    private var isSelected:Bool = false

    override func viewDidLoad() {
        super.viewDidLoad()

        tblTierBenefits.register(UINib(nibName:"TierBenefitsTableViewCell", bundle: nil), forCellReuseIdentifier:"TierBenefitsTableViewCell")
        tblTierBenefits.register(UINib(nibName:"TierBenefitsDetailsCell", bundle: nil), forCellReuseIdentifier:"TierBenefitsDetailsCell")

        tblTierBenefits.rowHeight = UITableViewAutomaticDimension;
        tblTierBenefits.estimatedRowHeight = 44.0;
        tblTierBenefits.tableFooterView = UIView()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

}

extension SCTierBenefitsViewController : UITableViewDataSource{

    func numberOfSections(in tableView: UITableView) -> Int {
        return 7
    }
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return (isSelected && section == selectedIndexPath?.section) ? 2 : 1 
    }

    func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {
        return  0.01
    }

    func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
        return nil
    }

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        switch indexPath.row {
        case 0:
            let cell:TierBenefitsTableViewCell = tableView.dequeueReusableCell(withIdentifier: "TierBenefitsTableViewCell")! as! TierBenefitsTableViewCell
            cell.selectionStyle = .none
            cell.contentView.setNeedsLayout()
            cell.contentView.layoutIfNeeded()
            return cell

        case 1:
            let cell:TierBenefitsDetailsCell = tableView.dequeueReusableCell(withIdentifier: "TierBenefitsDetailsCell")! as! TierBenefitsDetailsCell
            cell.selectionStyle = .none
            return cell

        default:
            break
        }

        return UITableViewCell()
    }
}

extension SCTierBenefitsViewController : UITableViewDelegate{

    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
        if indexPath.row == 0 {

            if let _selectedIndexPath = selectedIndexPath ,selectedIndexPath?.section == indexPath.section {
                tblTierBenefits.beginUpdates()
                expandCollapse(indexPath: _selectedIndexPath, isExpand: false)
                selectedIndexPath = nil
            }
            else{
                tblTierBenefits.beginUpdates()
                if selectedIndexPath != nil {
                    tblTierBenefits.reloadSections([(selectedIndexPath?.section)!], with: .none)
                }
                expandCollapse(indexPath: indexPath, isExpand: true)
            }
        }
    }

    private func  expandCollapse(indexPath: IndexPath?,isExpand: Bool){
        isSelected = isExpand
        selectedIndexPath = indexPath
        tblTierBenefits.reloadSections([(indexPath?.section)!], with: .none)
        tblTierBenefits.endUpdates()
    }

}

Answer 5

I ended up just creating a headerView that contained a button ( i saw Son Nguyen's solution above after the fact, but heres my code.. it looks like a lot but it's pretty simple):

declare a couple bools for you sections

bool customerIsCollapsed = NO;
bool siteIsCollapsed = NO;

...code

now in your tableview delegate methods...

- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section
{
    UIView *headerView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, _tblSearchResults.frame.size.width, 35)];

    UILabel *lblSection = [UILabel new];
    [lblSection setFrame:CGRectMake(0, 0, 300, 30)];
    [lblSection setFont:[UIFont fontWithName:@"Helvetica-Bold" size:17]];
    [lblSection setBackgroundColor:[UIColor clearColor]];
    lblSection.alpha = 0.5;
    if(section == 0)
    {
        if(!customerIsCollapsed)
            [lblSection setText:@"Customers    --touch to show--"];
        else
            [lblSection setText:@"Customers    --touch to hide--"];
    }
    else
    {
        if(!siteIsCollapsed)
            [lblSection setText:@"Sites    --touch to show--"];
        else
            [lblSection setText:@"Sites    --touch to hide--"];    }

    UIButton *btnCollapse = [UIButton buttonWithType:UIButtonTypeCustom];
    [btnCollapse setFrame:CGRectMake(0, 0, _tblSearchResults.frame.size.width, 35)];
    [btnCollapse setBackgroundColor:[UIColor clearColor]];
    [btnCollapse addTarget:self action:@selector(touchedSection:) forControlEvents:UIControlEventTouchUpInside];
    btnCollapse.tag = section;


    [headerView addSubview:lblSection];
    [headerView addSubview:btnCollapse];

    return headerView;
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    // Return the number of rows in the section.
    if(section == 0)
    {
        if(customerIsCollapsed)
            return 0;
        else
            return _customerArray.count;
    }
    else if (section == 1)
    {
        if(siteIsCollapsed)
            return 0;
        else
        return _siteArray.count;

    }
    return 0;
}

and finally the function that gets called when you touch one of the section header buttons:

- (IBAction)touchedSection:(id)sender
{
    UIButton *btnSection = (UIButton *)sender;

    if(btnSection.tag == 0)
    {
        NSLog(@"Touched Customers header");
        if(!customerIsCollapsed)
            customerIsCollapsed = YES;
        else
            customerIsCollapsed = NO;

    }
    else if(btnSection.tag == 1)
    {
        NSLog(@"Touched Site header");
        if(!siteIsCollapsed)
            siteIsCollapsed = YES;
        else
            siteIsCollapsed = NO;

    }
    [_tblSearchResults reloadData];
}

Answer 6

Some sample code for animating an expand/collapse action using a table view section header is provided by Apple here: Table View Animations and Gestures

The key to this approach is to implement - (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section and return a custom UIView which includes a button (typically the same size as the header view itself). By subclassing UIView and using that for the header view (as this sample does), you can easily store additional data such as the section number.