DevTut

# UISplitViewController

# Interacting Between Master and Detail View using Delegates in Objective C

UISplitViewController needs to the root view controller of your app’s window

AppDelegate.m

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]
self.window.backgroundColor = [UIColor blackColor];
[self.window makeKeyAndVisible];
self.window.clipsToBounds = YES;
SplitViewController *spView = [[SplitViewController alloc]init];
self.window.rootViewController = spView;
[self.window makeKeyAndVisible];
return YES;
}

Just create an object for your UISplitVIewController and set it as the rootViewController for your application.

SplitViewController.h

#import <UIKit/UIKit.h>
#import "MasterViewController.h"
#import "DetailViewController.h"
@interface ViewController : UISplitViewController
{
DetailViewController *detailVC;
MasterViewController *masterVC;
NSMutableArray *array;
}
@end

MasterViewController is a UIViewController that is set on the left side of the device you can set the width in UISplitViewController using maximumPrimaryColumnWidth and DetailViewController is on the Right side

SplitViewController.m

#import "ViewController.h"
#define ANIMATION_LENGTH 0.3
@interface ViewController ()
@end

@implementation ViewController
- (void)viewDidLoad 
{
[super viewDidLoad];
masterVC = [[MasterViewController alloc]init];
detailVC = [[DetailViewController alloc]init];
[masterVC setDetailDelegate:(id)detailVC];
NSArray *vcArray = [NSArray arrayWithObjects:masterVC, detailVC, nil];
self.preferredDisplayMode = UISplitViewControllerDisplayModeAutomatic;
self.viewControllers = vcArray;
self.delegate = (id)self;
self.presentsWithGesture = YES;
}

The master and detail UIViewController's are added to an NSArray which is set to self.viewControllers. self.preferredDisplayMode is is the mode set for displaying of MasterViewController and DetailViewController . self.presentsWithGesture enables swipe gesture for displaying MasterViewController

MasterViewController.h

#import <UIKit/UIKit.h>

@protocol DetailViewDelegate <NSObject>
@required
- (void)sendSelectedNavController:(UIViewController *)viewController;
@end

@interface MasterViewController : UIViewController
{
    UITableView *mainTableView;
    NSMutableArray *viewControllerArray;
}
@property (nonatomic, retain) id<DetailViewDelegate> detailDelegate; 
@end

Create a DetailViewDelegate Delegate with sendSelectedNavController method for sending the UIViewControllers to the DetailViewController. Then in MasterViewController an UITableViewis created . The ViewControllerArray contains all the UIViewControllers that needs to be displayed in DetailViewController

MasterViewController.m

#import "MasterViewController.h"

@implementation MasterViewController
@synthesize detailDelegate;

-(void)viewDidLoad
{
[super viewDidLoad];

UIViewController *dashBoardVC = [[UIViewController alloc]init];
[dashBoardVC.view setBackgroundColor:[UIColor redColor]];
UIViewController *inventVC = [[UIViewController alloc]init];
[inventVC.view setBackgroundColor:[UIColor whiteColor]];
UIViewController *alarmVC = [[UIViewController alloc]init];
[alarmVC.view setBackgroundColor: [UIColor purpleColor]];
UIViewController *scanDeviceVC = [[UIViewController alloc]init];
[scanDeviceVC.view setBackgroundColor:[UIColor cyanColor]];
UIViewController *serverDetailVC = [[UIViewController alloc]init];
[serverDetailVC.view setBackgroundColor: [UIColor whiteColor]];
viewControllerArray = [[NSMutableArray alloc]initWithObjects:dashBoardVC,inventVC,alarmVC,scanDeviceVC,serverDetailVC,nil];
mainTableView = [[UITableView alloc]initWithFrame:CGRectMake(0, 50,self.view.frame.size.width, self.view.frame.size.height-50) style:UITableViewStylePlain];
[mainTableView setDelegate:(id)self];
[mainTableView setDataSource:(id)self];
[mainTableView setSeparatorStyle:UITableViewCellSeparatorStyleNone];
[mainTableView setScrollsToTop:NO];
[self.view addSubview:mainTableView];
}

- (CGFloat)tableView:(UITableView *)tableView
heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return 100;
}
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:    (NSInteger)section
{
    return [viewControllerArray count];
}

- (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return 1;    //count of section
}

- (UITableViewCell *)tableView:(UITableView *)tableView
     cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    NSString *cellId = [NSString stringWithFormat:@"Cell%li%ld",(long)indexPath.section,(long)indexPath.row];
UITableViewCell *cell =[tableView   dequeueReusableCellWithIdentifier:cellId];

if (cell == nil)
{
   cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:cellId];
}
[cell.contentView setBackgroundColor:[UIColor redColor]];
cell.textLabel.text =[NSString stringWithFormat:@"My VC at index %ld",(long)indexPath.row];
return cell;
}

- (void)tableView:(UITableView *)tableView
didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    [detailDelegate sendSelectedNavController:[viewControllerArray objectAtIndex:indexPath.row]];
}

@end

Created some UIViewController and added it to an NSMutableArray. The UITableView is initialized then on didselectrowatindexpath method I send a UIViewController to the DetailViewController using detailDelegate delegate with the corresponding UIViewController in the NSMutableArray as a parameter

DetailViewController.h

#import <UIKit/UIKit.h>

@interface DetailViewController : UIViewController<UICollectionViewDelegate>
{
    UIViewController *tempNav;
}
@end

DetailViewController.m

#import "DetailViewController.h"

@implementation DetailViewController
-(void)viewDidLoad
{
    [super viewDidLoad];
    [self.view setBackgroundColor:[UIColor whiteColor]];
}
-(void)sendSelectedNavController:(UIViewController *)navController
{
    NSArray *viewsToRemove = [self.view subviews];
    for (UIView *v in viewsToRemove) {
        [v removeFromSuperview];
    }
    tempNav = navController;
    [self.view addSubview:tempNav.view];
}
@end

The sendSelectedNavController is declared here with removing all the UIView's in the DetailViewController and adding the passed UIViewController from the MasterViewController.

# Remarks

In iOS 8 and later, you can use the UISplitViewController class on all iOS devices, in previous versions of iOS, the class is available only on iPad. UISplitViewController is a container class like UITabViewController, UINavigationController. It separates the main view into two UIViewControllers masterViewController(PrimaryViewController) and detailViewController(SecondaryViewController). we can send an NSArray with two UIViewControllers and Apple recommends UISplitViewController as a rootviewcontroller for your application. To interact between the UIViewControllers I use NSNotificationCenter.

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