Accordion table cell - How to dynamically expand/contract uitableviewcell?

Question

I am trying create an accordion type of uitableviewcell that, when the user selects the cell, it expands to display a detailed info view inline similar to how the digg app works. I initially tried replacing the current tablecell with a customcell in cellForRowAtIndex, however the animation looks a bit choppy as you can see the cell being replaced and overall the effect doesn't work too well.

If you look at the digg app and others who have done this it seems that they aren't replacing the current cell but instead perhaps adding a subview to the cell? The original cell however doesn't seem to animate at all and only the new view accordions into the table.

Does anyone have any ideas how to accomplish a similar effect?

I have made some progress using neha's method below and while the cell is animating the correct way it is wreaking havoc with the other cells in the table. What I have done is subclassed UITableViewCell with a custom class which contains an instance of a UIView which actually draws the view which I then add to the table cell's contentview.

- (void)setSelected:(BOOL)selected animated:(BOOL)animated {

if (selected) { 
    [self expandCell];
}
}

-(void)expandCell { 
    self.contentView.frame = CGRectMake(0.0, 0.0, self.contentView.bounds.size.width, 110);
}

Here are all the table delegate methods I am using:

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    
if (isSearching && indexPath.row == selectedIndex) {
    
    static NSString *CellIdentifier = @"SearchCell";
    CustomTableCell *cell = (CustomTableCell*)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[CustomTableCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
    }
    
    [cell setCustomTitle:[timeZoneNames objectAtIndex:indexPath.row] detail:[timeZoneNames objectAtIndex:indexPath.row]];

    UILabel *theText = [[UILabel alloc] initWithFrame:CGRectMake(10.0, 10.0, cell.contentView.bounds.size.width -20, 22.0)];
    theText.text = @"Title Text";
    [cell.contentView addSubview:theText];


    UITextField *textField = [[UITextField alloc] initWithFrame:CGRectMake(10.0, 10 + 46.0, cell.contentView.bounds.size.width - 20, 40.0)];
    textField.borderStyle = UITextBorderStyleLine;
    [cell.contentView addSubview:textField];        

    UILabel *testLabel = [[UILabel alloc] initWithFrame:CGRectMake(5.0, 88.0, cell.contentView.bounds.size.width - 20, 22.0)];
    testLabel.text = [NSString stringWithFormat:@"Some text here"];
    [cell.contentView addSubview:testLabel];

    [theText release];
    [textField release];
    [testLabel release];

    return cell;        
} else {
    
    static NSString *CellIdentifier = @"Cell";
    CustomTableCell *cell = (CustomTableCell*)[tableView dequeueReusableCellWithIdentifier:CellIdentifier];
    if (cell == nil) {
        cell = [[[CustomTableCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];
    }

    [cell setCustomTitle:[timeZoneNames objectAtIndex:indexPath.row] detail:[timeZoneNames objectAtIndex:indexPath.row]];
    return cell; 
}


- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

[tableView deselectRowAtIndexPath:indexPath animated:NO];   

selectedIndex = indexPath.row;
isSearching = YES;


[tableView beginUpdates];
[tableView endUpdates];

}


- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {        
if (isSearching && indexPath.row == selectedIndex) {
    return 110;
}
return rowHeight;           
} 

It seems now that the cell is expanding but not actually being refreshed so the labels, and textfield aren't being shown. They do however show up when I scroll the cell off and on the screen.

Any ideas?

Answer 1

The Apple way to do is quite simple.

First, you'll need to save the selected indexPath row:

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {
   self.selectedRowIndex = [indexPath retain];
   [tableView beginUpdates];
   [tableView endUpdates];
}

I'll explain the begin/end updated part later.

Then, when you have the currently selected index, you can tell the tableView that it should give that row more space.

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
   //check if the index actually exists
   if(selectedRowIndex && indexPath.row == selectedRowIndex.row) {
        return 100;
   }
   return 44;
}

This will return height 100 for the selected cell.

Now we can go back to the begin/end updates. That block triggers the reload of all tableView geometry. Moreover, that block is animated, which eventually gives the impressions of the row expanding.

Answer 2

Pawel's beginUpdates/endUpdates trick is good, and I often use it. But in this case you simply need to reload the rows that are changing state, ensuring that you correctly reload them with the desired cell type, and that you return the correct new cell height.

Here is a complete working implementation of what I think you're trying to accomplish:

.h:

#import <UIKit/UIKit.h>

@interface ExpandingTableViewController : UITableViewController 
{

}

@property (retain) NSIndexPath* selectedIndexPath;

@end

.m:

@implementation ExpandingTableViewController
@synthesize selectedIndexPath;

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView {
    // Return the number of sections.
    return 1;
}


- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section {
    // Return the number of rows in the section.
    return 10;
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {

    static NSString *CellIdentifier1 = @"Cell1";
    static NSString *CellIdentifier2 = @"Cell2";

    UITableViewCell *cell;

    NSIndexPath* indexPathSelected = self.selectedIndexPath;

    if ( nil == indexPathSelected || [indexPathSelected compare: indexPath] != NSOrderedSame )
    {
        cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier1];
        if (cell == nil) {
            cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier1] autorelease];
        }

        cell.textLabel.text = [NSString stringWithFormat: @"cell %d", indexPath.row];
    }
    else
    {
        cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier2];
        if (cell == nil) {
            cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:CellIdentifier2] autorelease];
        }

        cell.textLabel.text = [NSString stringWithFormat: @"cell %d", indexPath.row];
        cell.detailTextLabel.text = [NSString stringWithFormat: @"(expanded!)", indexPath.row];
    }

    return cell;
}

#pragma mark -
#pragma mark Table view delegate

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    if ( self.selectedIndexPath != nil && [self.selectedIndexPath compare: indexPath] == NSOrderedSame )
    {
        return tableView.rowHeight * 2;
    }

    return tableView.rowHeight;
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath 
{
    NSArray* toReload = [NSArray arrayWithObjects: indexPath, self.selectedIndexPath, nil];
    self.selectedIndexPath = indexPath;

    [tableView reloadRowsAtIndexPaths: toReload withRowAnimation: UITableViewRowAnimationMiddle];
}


#pragma mark -
#pragma mark Memory management

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
}

- (void)viewDidUnload {
}

- (void)dealloc {
    [super dealloc];
}

@end

If you don't want to reload the cell (you want to keep your existing cell and just change the size, and likely add/remove some subviews), then simply do the beginUpdates/endUpdates trick in didSelectRowAtIndexPath:, and call some method on your cell to incite the layout change. beginUpdates/endUpdates will prompt the tableView to re-query the heights for each cell - so be sure to return the correct value.

Answer 3

Create a class that subclasses UITableviewcell in your project. Create this class' nib and set its parent to be the class in your project with tableview and override its -

(void)setSelected:(BOOL)selected animated:(BOOL)animated 

Write methods contractCell() and expandCell() in this class, and provide the height of the cells you want in expandCell method. Call this methods appropriately based on some flags set to identify wheather the cell is in expanded state or contracted state. Use your tableview's

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {

method to handle selection of cells.

Answer 4

Replace your cellForRowAtIndexPath function with this one.

    - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath
*)indexPath {

    if (isSearching && indexPath.row == selectedIndex) {

        static NSString *CellIdentifier = @"SearchCell";
       CustomTableCell *cell = [[[CustomTableCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];

        [cell setCustomTitle:[timeZoneNames objectAtIndex:indexPath.row] detail:[timeZoneNames objectAtIndex:indexPath.row]];

        UILabel *theText = [[UILabel alloc] initWithFrame:CGRectMake(10.0,
10.0, cell.contentView.bounds.size.width
-20, 22.0)];
        theText.text = @"Title Text";
        [cell.contentView addSubview:theText];


        UITextField *textField = [[UITextField alloc] initWithFrame:CGRectMake(10.0, 10 +
46.0, cell.contentView.bounds.size.width - 20, 40.0)];
        textField.borderStyle = UITextBorderStyleLine;
        [cell.contentView addSubview:textField];        

        UILabel *testLabel = [[UILabel alloc] initWithFrame:CGRectMake(5.0,
88.0, cell.contentView.bounds.size.width - 20, 22.0)];
        testLabel.text = [NSString stringWithFormat:@"Some text here"];
        [cell.contentView addSubview:testLabel];

        [theText release];
        [textField release];
        [testLabel release];

        return cell;        
    } else {

        static NSString *CellIdentifier = @"Cell";
        CustomTableCell *cell = [[[CustomTableCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease];

        [cell setCustomTitle:[timeZoneNames objectAtIndex:indexPath.row] detail:[timeZoneNames objectAtIndex:indexPath.row]];
        return cell; 
    }
    }

Answer 5

create array wof dictionary which have a key Select_sts which is 0 in start when click its change 1 accourding u change table

- (UIView *)tableView:(UITableView *)tableView viewForHeaderInSection:(NSInteger)section{

    customView = [[UIView alloc] initWithFrame:CGRectMake(0.0, 0.0, 320.0, 40.0)];
    UILabel * headerLabel = [[UILabel alloc] initWithFrame:CGRectZero];
    headerLabel.backgroundColor = [UIColor clearColor];
    headerLabel.opaque = NO;
    headerLabel.textColor = [UIColor blackColor];
    headerLabel.highlightedTextColor = [UIColor whiteColor];
    headerLabel.font = [UIFont boldSystemFontOfSize:16];
    headerLabel.frame = CGRectMake(5.0, 10.0, 300.0, 20.0);
    headerLabel.text=[NSString stringWithFormat: @"PNR %@",[[record objectAtIndex:section] objectForKey:@"number"]];
    customView.backgroundColor=[UIColor whiteColor];

btn_openClose.tag=section+10000;
    btn_openClose.backgroundColor=[UIColor clearColor];
    //  [btn_openClose setImage:[UIImage imageNamed:@"down_arrow.png"] forState:UIControlStateNormal];
    [btn_openClose addTarget:self action:@selector(collapseExpandButtonTap:) forControlEvents:UIControlEventTouchUpInside];
    [customView addSubview:btn_openClose];

}


- (void) collapseExpandButtonTap:(id) sender{
    int indexNo=[sender tag]-10000;
//    NSLog(@"total_record    %@",[total_record objectAtIndex:indexNo]);
    NSMutableDictionary *mutDictionary = [[total_record objectAtIndex:indexNo] mutableCopy];
   if([[mutDictionary objectForKey:@"Select_sts"] integerValue]==0)
       [mutDictionary setObject:[NSNumber numberWithInt:1] forKey:@"√"];
    else
       [mutDictionary setObject:[NSNumber numberWithInt:0] forKey:@"Select_sts"];

    [total_record replaceObjectAtIndex:indexNo withObject:mutDictionary];

//    [table_view beginUpdates];
//    [table_view reloadData];
//    [table_view endUpdates];

    NSMutableIndexSet *indetsetToUpdate = [[NSMutableIndexSet alloc]init];
    [indetsetToUpdate addIndex:indexNo]; // [indetsetToUpdate addIndex:<#(NSUInteger)#>]
    // You can add multiple indexes(sections) here.
    [table_view reloadSections:indetsetToUpdate withRowAnimation:UITableViewRowAnimationFade];

}