/*

 Copyright (C) 2016 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 The root view controller. Demonstrates detailed steps on how to show content on an external display.

 */

#import "MainViewController.h"

#import "GLViewController.h"

@interface MainViewController ()

@property (nonatomic, strong) UIWindow *extWindow;

@property (nonatomic, strong) UIScreen *extScreen;

@end

@implementation MainViewController

- (void)screenDidChange:(NSNotification *)notification

{

    // To display content on an external display, do the following:

    // 1. Use the screens class method of the UIScreen class to determine if an external display is available.

    NSArray *screens = [UIScreen screens];

    NSUInteger screenCount = [screens count];

    if (screenCount > 1)

    {

        // 2. If an external screen is available, get the screen object and look at the values in its availableModes

        // property. This property contains the configurations supported by the screen.

        // Select first external screen

        self.extScreen = [screens objectAtIndex:1]; //index 0 is your iPhone/iPad

        NSArray *availableModes = [self.extScreen availableModes];

        // 3. Select the UIScreenMode object corresponding to the desired resolution and assign it to the currentMode

        // property of the screen object.

        // Select the highest resolution in this sample

        NSInteger selectedRow = [availableModes count] - 1;

        self.extScreen.currentMode = [availableModes objectAtIndex:selectedRow];

        // Set a proper overscanCompensation mode

        self.extScreen.overscanCompensation = UIScreenOverscanCompensationInsetApplicationFrame;

        if (self.extWindow == nil) {

            // 4. Create a new window object (UIWindow) to display your content.

            UIWindow *extWindow = [[UIWindow alloc] initWithFrame:[self.extScreen bounds]];

            self.extWindow = extWindow;

            self.extWindow.rootViewController = self.glController;

        }

        // 5. Assign the screen object to the screen property of your new window.

        self.extWindow.screen = self.extScreen;

        // 6. Configure the window (by adding views or setting up your OpenGL ES rendering context).

        // Resize the GL view to fit the external screen

        self.glController.view.frame = self.extWindow.frame;

        // Set the target screen to the external screen

        // This will let the GL view create a CADisplayLink that fires at the native fps of the target display.

        [(GLViewController *)self.glController setTargetScreen:self.extScreen];

        // Configure user interface

        // In this sample, we use the same UI layout when an external display is connected or not.

        // In your real application, you probably want to provide distinct UI layouts for best user experience.

        [(GLViewController *)self.glController screenDidConnect:self.userInterfaceController];

        // Add the GL view

        [self.extWindow addSubview:self.glController.view];

        // 7. Show the window.

        [self.extWindow makeKeyAndVisible];

        // On the iPhone/iPad screen

        // Remove the GL view (it is displayed on the external screen)

        for (UIView* v in [self.view subviews])

            [v removeFromSuperview];

        // Display the fullscreen UI on the iPhone/iPad screen

        [self.view addSubview:self.userInterfaceController.view];

    }

    else //handles disconnection of the external display

    {

        // Release external screen and window

        self.extScreen = nil;

        self.extWindow = nil;

        // On the iPhone/iPad screen

        // Remove the fullscreen UI (a window version will be displayed atop the GL view)

        for (UIView* v in [self.view subviews])

            [v removeFromSuperview];

        // Resize the GL view to fit the iPhone/iPad screen

        self.glController.view.frame = self.view.frame;

        // Set the target screen to the main screen

        // This will let the GL view create a CADisplayLink that fires at the native fps of the target display.

        [(GLViewController *)self.glController setTargetScreen:[UIScreen mainScreen]];

        // Configure user interface

        // In this sample, we use the same UI layout when an external display is connected or not.

        // In your real application, you probably want to provide distinct UI layouts for best user experience.

        [(GLViewController *)self.glController screenDidDisconnect:self.userInterfaceController];

        // Display the GL view on the iPhone/iPad screen

        [self.view addSubview:self.glController.view];

    }

}

- (void)dealloc

{

    [[NSNotificationCenter defaultCenter] removeObserver:self

                                                    name:UIScreenDidConnectNotification

                                                  object:nil];

    [[NSNotificationCenter defaultCenter] removeObserver:self

                                                    name:UIScreenDidDisconnectNotification

                                                  object:nil];

}

- (void)viewDidLoad

{

    [super viewDidLoad];

    UIViewController *userInterfaceController = [[UIStoryboard storyboardWithName:@"MainStoryboard" bundle:NULL] instantiateViewControllerWithIdentifier:@"UserInterfaceViewController"];

    self.userInterfaceController = userInterfaceController;

    UIViewController *glController = [[UIStoryboard storyboardWithName:@"MainStoryboard" bundle:NULL] instantiateViewControllerWithIdentifier:@"GLViewController"];

    self.glController = glController;

    // No notifications are sent for screens that are present when the app is launched.

    [self screenDidChange:nil];

    // Register for screen connect and disconnect notifications.

    [[NSNotificationCenter defaultCenter] addObserver:self

                                             selector:@selector(screenDidChange:)

                                                 name:UIScreenDidConnectNotification

                                               object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self

                                             selector:@selector(screenDidChange:)

                                                 name:UIScreenDidDisconnectNotification

                                               object:nil];

}

- (BOOL)shouldAutorotate {

    return YES;

}

@end