How to show a UISearchBar from top of screen for table view controller

Question

I'm looking to duplicate how the Facebook Messenger app shows the UISearchBar. When you tap the leftBarButtonItem in the navigationBar, the UISearchBar appears/animates from the top of the screen down, and when you cancel, it simply disappears upwards where it originated from.

I used to have my UISearchBar as the default setup in my table view's header (in storyboard), but now I'm wanting to do what I stated above but I am not sure where to begin. My search displayer controller is still in my storyboard, but I have deleted the searchBar from the tableView controller in the storyboard.

I appreciate any help offered!

Answer 1

Omitting detail of my own project where I make the same thing it looks as follows:

static CGFloat searchBarHeight = 64.0;

@implementation
{
    NSArray *_tableData; // active list of data to show in table at the moment
    NSMutableArray *_filteredContacts; // filtered list while search is active
    NSArray *_allContacts; // initial list of all data without search
    UIView* _searchBarWrapper;
    UIView *_shadowView;
    UISearchBar *_searchBar;
}

- (void)loadView
{
    [super loadView];

    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemSearch target:self action:@selector(showSearchBar:)];

    _searchBarWrapper = [[UIView alloc] initWithFrame:CGRectMake(0, -searchBarHeight, self.navigationController.view.bounds.size.width, searchBarHeight)];
    _searchBar = [[UISearchBar alloc] initWithFrame:CGRectMake(0, 20.0, _searchBarContainer.bounds.size.width, searchBarHeight - 20.0)];
    [_searchBarContainer addSubview:_searchBar];
    [self.navigationController.view addSubview:_searchBarContainer];

    _shadowView = [[UIView alloc] initWithFrame:self.navigationController.view.bounds];
    _shadowView.backgroundColor = [UIColor blackColor];
    _shadowView.alpha = 0;
    [self.navigationController.view addSubview:_shadowView];
    UITapGestureRecognizer *tapGesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(hideSearchBar:)];
    UISwipeGestureRecognizer *swipeGesture = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(hideSearchBar:)];
    [_shadowView addGestureRecognizer:tapGesture];
    [_shadowView addGestureRecognizer:swipeGesture];

    //_searchController = [[UISearchDisplayController alloc] initWithSearchBar:_searchBar contentsController:self];
    //_searchController.delegate = self;
    //_searchController.searchResultsDataSource = self;
    //_searchController.searchResultsDelegate = self;
}

- (void)showSearchBar:(id)sender
{
    [_searchBar becomeFirstResponder];
    [UIView animateWithDuration:0.25 animations:^{
        _searchBarWrapper.center = CGPointMake(_searchBar.center.x, searchBarHeight/2.0);
        _shadowView.alpha = 0.5;
    }];
}

- (void)hideSearchBar:(id)sender
{
    _searchBar.text = nil;
    [_tableView reloadData];

    [UIView animateWithDuration:0.25 animations:^{
        _searchBarWrapper.center = CGPointMake(_searchBar.center.x, -searchBarHeight/2.0);
        _shadowView.alpha = 0.0;
    }];
    [_searchBar resignFirstResponder];
    [_tableView reloadData];
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    _tableData = _searchBar.isFirstResponder ? _filteredContacts : _allContacts;

    ....................
}


- (void)searchBar:(UISearchBar *)searchBar textDidChange:(NSString *)searchText
{
    if (searchText.length) {

        _filteredContacts = ....;

        _shadowView.alpha = 0.0;
        [_tableView reloadData];
    }
    else {
        _shadowView.alpha = 0.5;
    }
}

- (void)searchBarCancelButtonClicked:(UISearchBar*)searchBar
{
    [self hideSearchBar:searchBar];
}

Note: The general behavior of this construction is analogous to UISearchDisplayController, the only difference is that we use the same table to show all results and filtered result. Also we need artificial shadow view.

It was my initial code and its behavior coincides with FB People view controller. After your comment I wrote standard UISearchDisplayController embedding but after commented it out because it breaks desired UI. It is impossible to change its animation behavior.

Answer 2

Check out Apple's UICatalog sample code. Basically just present your UISearchController modally and you get the dropdown animation for free.