iOS: Xcode - How to reveal content from under a cell?

Question 1

OK. I figured it out.

Here's my updated code if anyone needs it:

    #import "ViewController.h"
    #import "Data.h"

    @interface ViewController ()

    @end

    @implementation ViewController {
        NSArray *data;
        NSInteger selectedIndex;
    }

    - (void)viewDidLoad
    {
        [super viewDidLoad];
        // Do any additional setup after loading the view, typically from a nib.

        selectedIndex = -1;

        self.navigationItem.title = @"Test App";

        UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithTitle:@"Back" style:UIBarButtonItemStyleBordered target:nil action:nil];
        [[self navigationItem] setBackBarButtonItem:backButton];

        // Create Data array
        Data *data1 = [Data new];
        data1.text = @"Abhijit ipsum dolor sit amet, consectetur adipiscing elit.";
        data1.translation = @"AbhijitDE ipsum dolor sit amet, consectetur adipiscing elit.";

        Data *data2 = [Data new];
        data2.text = @"Anurag ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit.";
        data2.translation = @"AnuragDE ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit.";

        Data *data3 = [Data new];
        data3.text = @"Chetan ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit.";
        data3.translation = @"ChetanDE ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit.";

        Data *data4 = [Data new];
        data4.text = @"Eric ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit.";
        data4.translation = @"EricDE ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit.";

        Data *data5 = [Data new];
        data5.text = @"Neha ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsumiraj dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit.";
        data5.translation = @"NehaDE ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit.";

        Data *data6 = [Data new];
        data6.text = @"Nilesh ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit.";
        data6.translation = @"NileshDE ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit.";

        Data *data7 = [Data new];
        data7.text = @"Niraj ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsumiraj dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit.";
        data7.translation = @"NirajDE ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Lorem ipsum dolor sit amet, consectetur adipiscing elit.";

        data = [NSArray arrayWithObjects:data1, data2, data3, data4, data5, data6, data7, nil];
    }

    - (void)didReceiveMemoryWarning
    {
        [super didReceiveMemoryWarning];
        // Dispose of any resources that can be recreated.
    }

    -(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
    {
        return 1;
    }

    -(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
    {
        return data.count;
    }

    -(CGFloat)getLabelHeightForIndex:(NSString *)string
    {
        CGSize maximumSize = CGSizeMake(320, 10000);
        CGSize labelHeightSize = [string sizeWithFont:[UIFont fontWithName:@"Helvetica" size:14.0f] constrainedToSize:maximumSize lineBreakMode:NSLineBreakByWordWrapping];

        return labelHeightSize.height + 10;
    }

    -(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
    {
        static NSString *CellIdentifier = @"Cell";
        static const int mainLabelTag = 1, secondLabelTag = 2;
        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier];

        if (!cell) {
            cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier];

            // First label
            UILabel *mainLabel = [[UILabel alloc] initWithFrame:CGRectMake(0.0, 0.0, 320.0, 36.00)];
            mainLabel.tag = mainLabelTag;
            mainLabel.font = [UIFont fontWithName:@"Helvetica" size:14.0f];
            mainLabel.textColor = [UIColor blackColor];
            mainLabel.backgroundColor = [UIColor clearColor];
            mainLabel.numberOfLines = 0;
            mainLabel.lineBreakMode = NSLineBreakByWordWrapping;
            mainLabel.autoresizingMask = UIViewAutoresizingFlexibleWidth;
            // mainLabel.clipsToBounds = YES;
            [cell.contentView addSubview:mainLabel];

            // Second label
            UILabel *secondLabel = [[UILabel alloc] initWithFrame:CGRectMake(0.0, 10.0, 320.0, 36.00)];
            secondLabel.tag = secondLabelTag;
            secondLabel.font = [UIFont fontWithName:@"Helvetica" size:14.0f];
            secondLabel.textColor = [UIColor whiteColor];
            secondLabel.backgroundColor = [UIColor grayColor];
            secondLabel.numberOfLines = 0;
            secondLabel.lineBreakMode = NSLineBreakByWordWrapping;
            secondLabel.autoresizingMask = UIViewAutoresizingFlexibleWidth;
            // secondLabel.clipsToBounds = YES;
            [cell.contentView addSubview:secondLabel];
        }

        // Get data for the current row
        Data *dataContent = [data objectAtIndex:indexPath.row];

        CGFloat dataTextHeight = [self getLabelHeightForIndex:dataContent.text];

        UILabel *mainLabel = [cell.contentView viewWithTag:mainLabelTag];
        CGRect mainLabelFrame = mainLabel.frame;
        mainLabel.frame = CGRectMake(0.0, 0.0, mainLabelFrame.size.width, dataTextHeight);
        mainLabel.text = dataContent.text;

        CGFloat dataTranslationHeight = [self getLabelHeightForIndex:dataContent.translation];

        UILabel *secondLabel = [cell.contentView viewWithTag:secondLabelTag];
        CGRect secondLabelFrame = mainLabel.frame;
        secondLabel.frame = CGRectMake(0.0, dataTextHeight + 10.00, secondLabelFrame.size.width, dataTranslationHeight);
        secondLabel.text = dataContent.translation;

        if(selectedIndex == indexPath.row)
        {
            secondLabel.hidden = NO;
        }
        else
        {
            secondLabel.hidden = YES;
        }

        return cell;
    }

    - (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
        // Get data for the current row
        Data *dataContent = [data objectAtIndex:indexPath.row];
        CGFloat dataTextHeight = [self getLabelHeightForIndex:dataContent.text];
        CGFloat dataTranslationHeight = [self getLabelHeightForIndex:dataContent.translation];

        if(selectedIndex == indexPath.row)
        {
            return (dataTextHeight + dataTranslationHeight) + 10;
        }
        else
        {
            return dataTextHeight;
        }
    }

    - (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath {    
        // An expanded cell is clicked, minimize it
        if(selectedIndex == indexPath.row)
        {
            selectedIndex = -1;
            [tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationAutomatic];
            return;
        }

        // If any previous cell is expanded, minimize it
        if(selectedIndex > -1)
        {
            NSIndexPath *previousPath = [NSIndexPath indexPathForRow:selectedIndex inSection:0];
            selectedIndex = -1;
            [tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:previousPath] withRowAnimation:UITableViewRowAnimationAutomatic];
        }

        // Expand the currently expanded cell
        selectedIndex = indexPath.row;
        NSIndexPath *currentPath = [NSIndexPath indexPathForRow:selectedIndex inSection:0];
        [tableView reloadRowsAtIndexPaths:[NSArray arrayWithObject:currentPath] withRowAnimation:UITableViewRowAnimationAutomatic];
    }

    @end

Question 2

Dynamically sized cells are a pain in the butt and then some. Look it up because there's a bunch of questions on it on StackOverflow with some interesting solutions.

As far as an underside view is concerned, there's a great open source project called HHPanningTableViewCell that you should look into. We've used for a couple of our projects and it does the trick. Unfortunately there's some performance issues (see my open issue on the project) so make sure that you test it on a device.

Question 3

In the table view delegate tableView:didSelectRowAtIndexPath: method, use the insertRowsAtIndexPaths:withRowAnimation: and deleteRowsAtIndexPaths:withRowAnimation: methods to insert a new cell when the 'source language' cell is tapped, with the inserted cell being the 'destination language'. When the user taps again, delete the 'destination language' cell. In both methods, the reveal animation you wish can be specified.

Question 4

maybe try something like

cell.clipsToBounds = YES;
cell.autoresizingMask = UIViewAutoresizingFlexibleHeight;

?