/*

     File: PickerViewController.m

 Abstract: Displays a table of services that the user can pick.

  Version: 2.1

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 */

#import "PickerViewController.h"

@import QuartzCore;

@interface PickerViewController () <NSNetServiceBrowserDelegate>

@property (nonatomic, strong, readwrite) IBOutlet UILabel *     localServiceNameLabel;

@property (nonatomic, strong, readwrite) UIFont *               localServiceNameLabelFont;      // latched from localServiceNameLabel

@property (nonatomic, strong, readwrite) IBOutlet UIView *      connectView;

@property (nonatomic, strong, readwrite) IBOutlet UILabel *     connectLabel;

@property (nonatomic, copy,   readwrite) NSString *             connectLabelTemplate;           // latched from connectLabel

@property (nonatomic, strong, readonly ) NSMutableArray *       services;                       // of NSNetService, sorted by name

@property (nonatomic, strong, readwrite) NSNetServiceBrowser *  browser;

@end

@implementation PickerViewController

- (instancetype)init

{

    self = [super init];

    if (self != nil) {

        [self commonInit];

    }

    return self;

}

- (instancetype)initWithCoder:(NSCoder *)coder

{

    self = [super initWithCoder:coder];

    if (self) {

        [self commonInit];

    }

    return self;

}

- (void)commonInit

{

    self->_services = [[NSMutableArray alloc] init];

    // We observe localService so that we can react to the client changing it.

    [self addObserver:self forKeyPath:@"localService" options:0 context:&self->_localService];

}

- (void)dealloc

{

    [self removeObserver:self forKeyPath:@"localService" context:&self->_localService];

}

- (void)setupLocalServiceNameLabel

    // Called to set the local service name label in response to a change in the local service. 

    // It sets the label to either the actual name or "registering" if there's no local service.

{

    assert(self.localServiceNameLabel != nil);

    if (self.localService == nil) {

        self.localServiceNameLabel.font = [UIFont italicSystemFontOfSize:self.localServiceNameLabelFont.pointSize * 0.75f];

        self.localServiceNameLabel.text = @"registering…";

    } else {

        self.localServiceNameLabel.font = self.localServiceNameLabelFont;

        self.localServiceNameLabel.text = self.localService.name;

    }

}

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context

{

    if (context == &self->_localService) {

        assert([keyPath isEqual:@"localService"]);

        assert(object == self);

        // If there's a local service name label (that is, -viewDidLoad has been called), updated it.

        if (self.localServiceNameLabel != nil) {

            [self setupLocalServiceNameLabel];

        }

        // There's a chance that the browser saw our service before we heard about its successful 

        // registration, at which point we need to hide the service.  Doing that would be easy, 

        // but there are other edge cases to consider (for example, if the local service changes 

        // name, we would have to unhide the old name and hide the new name).  Rather than attempt 

        // to handle all of those edge cases we just stop and restart when the service name changes.

        if (self.browser != nil) {

            [self stop];

            [self start];

        }

    } else {

        [super observeValueForKeyPath:keyPath ofObject:object change:change context:context];

    }

}

- (void)viewDidLoad

{

    [super viewDidLoad];

    assert(self.localServiceNameLabel != nil);

    assert(self.connectView  != nil);

    assert(self.connectLabel != nil);

    // Stash the original font for use by -setupLocalServiceNameLabel then call 

    // -setupLocalServiceNameLabel to apply the local service to our header.

    self.localServiceNameLabelFont = self.localServiceNameLabel.font;       

    [self setupLocalServiceNameLabel];

    // Set up the connect view and stash the label text for use as a template.

    self.connectView.layer.cornerRadius = 10.0f;

    self.connectView.layer.shadowColor = [UIColor blackColor].CGColor;

    self.connectView.layer.shadowOffset = CGSizeMake(3.0f, 3.0f);

    self.connectView.layer.shadowOpacity = 0.7f;

    self.connectLabelTemplate = self.connectLabel.text;

}

- (void)start

    // See comment in header.

{

    assert([self.services count] == 0);

    assert(self.browser == nil);

    self.browser = [[NSNetServiceBrowser alloc] init];

    self.browser.includesPeerToPeer = YES;

    [self.browser setDelegate:self];

    [self.browser searchForServicesOfType:self.type inDomain:@"local"];

}

- (void)stop

    // See comment in header.

{

    [self.browser stop];

    self.browser = nil;

    [self.services removeAllObjects];

    if (self.isViewLoaded) {

        [self.tableView reloadData];

    }

}

- (void)cancelConnect

    // See comment in header.

{

    [self hideConnectViewAndNotify:NO];

}

#pragma mark * Connection-in-progress UI management

- (void)showConnectViewForService:(NSNetService *)service

    // Shows a view that indicates we're connecting to the specified service.

{

    CGRect  selfViewBounds;

    // Show the connection UI.

    assert(self.connectView  != nil);               // views should be loaded

    assert(self.connectLabel != nil);               // ditto

    assert(self.connectView.superview == nil);      // connection view must not be in the view hierarchy

    self.connectLabel.text = [NSString stringWithFormat:self.connectLabelTemplate, [service name]];

    selfViewBounds = self.tableView.bounds;

    self.connectView.center = CGPointMake( CGRectGetMidX(selfViewBounds), CGRectGetMidY(selfViewBounds) );

    [self.tableView addSubview:self.connectView];

    // Disable user interactions on the table view to prevent the user doing 

    // stuff 'behind' our connection-in-progress UI.

    self.tableView.scrollEnabled = NO;

    self.tableView.allowsSelection = NO;

    // Tell the delegate.

    [self.delegate pickerViewController:self connectToService:service];

}

- (void)hideConnectViewAndNotify:(BOOL)notify

    // Hide the view we showed in -showConnectViewForService:

{

    if (self.connectView.superview != nil) {

        [self.connectView removeFromSuperview];

        self.tableView.scrollEnabled = YES;

        self.tableView.allowsSelection = YES;

    }

    if (notify) {

        [self.delegate pickerViewControllerDidCancelConnect:self];

    }

}

- (IBAction)connectCancelAction:(id)sender

    // Called when the user taps the Cancel button in the connection UI.  This hides the 

    // connection UI and tells the delegate about the cancellation.

{

    #pragma unused(sender)

    [self hideConnectViewAndNotify:YES];

}

#pragma mark * Table view callbacks

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section

{

    #pragma unused(tableView)

    #pragma unused(section)

    return (NSInteger) [self.services count];

}

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

{

    UITableViewCell *   cell;

    NSNetService *      service;

    #pragma unused(tableView)

    service = [self.services objectAtIndex:(NSUInteger) indexPath.row];

    cell = [self.tableView dequeueReusableCellWithIdentifier:@"cell"];

    cell.textLabel.text = service.name;

    return cell;

}

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

{

    NSNetService *      service;

    #pragma unused(tableView)

    #pragma unused(indexPath)

    [self.tableView deselectRowAtIndexPath:indexPath animated:YES];

    // Find the service associated with the cell and start a connection to that.

    service = [self.services objectAtIndex:(NSUInteger) indexPath.row];

    [self showConnectViewForService:service];

}

#pragma mark * Browser view callbacks

- (void)sortAndReloadTable

{

    // Sort the services by name.

    [self.services sortUsingComparator:^NSComparisonResult(id obj1, id obj2) {

        return [[obj1 name] localizedCaseInsensitiveCompare:[obj2 name]];

    }];

    // Reload if the view is loaded.

    if (self.isViewLoaded) {

        [self.tableView reloadData];

    }

}

- (void)netServiceBrowser:(NSNetServiceBrowser *)browser didRemoveService:(NSNetService *)service moreComing:(BOOL)moreComing

{

    assert(browser == self.browser);

    #pragma unused(browser)

    assert(service != nil);

    // Remove the service from our array (assume it's there, of course).

    if ( (self.localService == nil) || ! [self.localService isEqual:service] ) {

        [self.services removeObject:service];

    }

    // Only update the UI once we get the no-more-coming indication.

    if ( ! moreComing ) {

        [self sortAndReloadTable];

    }

}   

- (void)netServiceBrowser:(NSNetServiceBrowser *)browser didFindService:(NSNetService *)service moreComing:(BOOL)moreComing

{

    assert(browser == self.browser);

    #pragma unused(browser)

    assert(service != nil);

    // Add the service to our array (unless its our own service).

    if ( (self.localService == nil) || ! [self.localService isEqual:service] ) {

        [self.services addObject:service];

    }

    // Only update the UI once we get the no-more-coming indication.

    if ( ! moreComing ) {

        [self sortAndReloadTable];

    }

}

- (void)netServiceBrowser:(NSNetServiceBrowser *)browser didNotSearch:(NSDictionary *)errorDict

{

    assert(browser == self.browser);

    #pragma unused(browser)

    assert(errorDict != nil);

    #pragma unused(errorDict)

    assert(NO);         // The usual reason for us not searching is a programming error.

}

@end