CDVViewController.m

/*
 Licensed to the Apache Software Foundation (ASF) under one
 or more contributor license agreements.  See the NOTICE file
 distributed with this work for additional information
 regarding copyright ownership.  The ASF licenses this file
 to you under the Apache License, Version 2.0 (the
 "License"); you may not use this file except in compliance
 with the License.  You may obtain a copy of the License at

 http://www.apache.org/licenses/LICENSE-2.0

 Unless required by applicable law or agreed to in writing,
 software distributed under the License is distributed on an
 "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 KIND, either express or implied.  See the License for the
 specific language governing permissions and limitations
 under the License.
 */

#import <TargetConditionals.h>
#import <AVFoundation/AVFoundation.h>
#import <Foundation/Foundation.h>
#import <WebKit/WebKit.h>

#import <Cordova/CDVAppDelegate.h>
#import <Cordova/CDVPlugin.h>
#import "CDVPlugin+Private.h"
#import <Cordova/CDVConfigParser.h>
#import <Cordova/CDVSettingsDictionary.h>
#import <Cordova/CDVTimer.h>
#import "CDVCommandDelegateImpl.h"

static UIColor* defaultBackgroundColor(void) {
    return UIColor.systemBackgroundColor;
}

@interface CDVViewController () <CDVWebViewEngineConfigurationDelegate> {
    id <CDVWebViewEngineProtocol> _webViewEngine;
    id <CDVCommandDelegate> _commandDelegate;
    NSMutableDictionary<NSString *, CDVPlugin *> *_pluginObjects;
    NSMutableDictionary<NSString *, NSString *> *_pluginsMap;
    CDVCommandQueue* _commandQueue;
    UIColor* _backgroundColor;
    UIColor* _splashBackgroundColor;
    CDVSettingsDictionary* _settings;
}

@property (nonatomic, readwrite, strong) NSMutableArray* startupPluginNames;
@property (nonatomic, readwrite, strong) UIView* launchView;
@property (readwrite, assign) BOOL initialized;

@end

@implementation CDVViewController

@synthesize pluginObjects = _pluginObjects;
@synthesize pluginsMap = _pluginsMap;
@synthesize commandDelegate = _commandDelegate;
@synthesize commandQueue = _commandQueue;
@synthesize webViewEngine = _webViewEngine;
@synthesize backgroundColor = _backgroundColor;
@synthesize splashBackgroundColor = _splashBackgroundColor;
@synthesize settings = _settings;
@dynamic webView;
@dynamic enumerablePlugins;

#pragma mark - Initializers

- (instancetype)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self != nil) {
        [self _cdv_init];
    }
    return self;
}

- (instancetype)initWithCoder:(NSCoder *)aDecoder
{
    self = [super initWithCoder:aDecoder];
    if (self != nil) {
        [self _cdv_init];
    }
    return self;
}

- (instancetype)init
{
    self = [super init];
    if (self != nil) {
        [self _cdv_init];
    }
    return self;
}

- (void)_cdv_init
{
    if (!self.initialized) {
        _commandQueue = [[CDVCommandQueue alloc] initWithViewController:self];
        _commandDelegate = [[CDVCommandDelegateImpl alloc] initWithViewController:self];
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(onAppWillTerminate:)
                                                     name:UIApplicationWillTerminateNotification object:nil];
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(onAppWillResignActive:)
                                                     name:UIApplicationWillResignActiveNotification object:nil];
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(onAppDidBecomeActive:)
                                                     name:UIApplicationDidBecomeActiveNotification object:nil];

        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(onAppWillEnterForeground:)
                                                     name:UIApplicationWillEnterForegroundNotification object:nil];
        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(onAppDidEnterBackground:)
                                                     name:UIApplicationDidEnterBackgroundNotification object:nil];

        [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(onWebViewPageDidLoad:)
                                                     name:CDVPageDidLoadNotification object:nil];

        // Default property values
        self.configFile = @"config.xml";
        self.webContentFolderName = @"www";
        self.showInitialSplashScreen = YES;

        // Initialize the plugin objects dict.
        _pluginObjects = [[NSMutableDictionary alloc] initWithCapacity:20];

        // Prevent reinitializing
        self.initialized = YES;
    }
}

#pragma mark -

- (void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
    [_commandQueue dispose];

    [self.webViewEngine loadHTMLString:@"about:blank" baseURL:nil];

    @synchronized(_pluginObjects) {
        [[_pluginObjects allValues] makeObjectsPerformSelector:@selector(dispose)];
        [_pluginObjects removeAllObjects];
    }

    [self.webView removeFromSuperview];
    [self.launchView removeFromSuperview];

    _webViewEngine = nil;
}

#pragma mark - Getters & Setters

- (NSArray <CDVPlugin *> *)enumerablePlugins
{
    @synchronized(_pluginObjects) {
        return [_pluginObjects allValues];
    }
}

- (NSString *)wwwFolderName
{
    return self.webContentFolderName;
}

- (void)setWwwFolderName:(NSString *)name
{
    self.webContentFolderName = name;
}

- (void)setBackgroundColor:(UIColor *)color
{
    _backgroundColor = color ?: defaultBackgroundColor();
}

- (void)setSplashBackgroundColor:(UIColor *)color
{
    _splashBackgroundColor = color ?: self.backgroundColor;
}

// Only for testing
- (void)setSettings:(CDVSettingsDictionary *)settings
{
    _settings = settings;
}

- (nullable NSURL *)configFilePath
{
    NSString* path = self.configFile;

    // if path is relative, resolve it against the main bundle
    if (![path isAbsolutePath]) {
        NSString* absolutePath = [[NSBundle mainBundle] pathForResource:path ofType:nil];
        if(!absolutePath){
            NSAssert(NO, @"ERROR: %@ not found in the main bundle!", path);
        }
        path = absolutePath;
    }

    // Assert file exists
    if (![[NSFileManager defaultManager] fileExistsAtPath:path]) {
        NSAssert(NO, @"ERROR: %@ does not exist.", path);
        return nil;
    }

    return [NSURL fileURLWithPath:path];
}

- (NSURL *)appUrl
{
    NSURL* appURL = nil;

    if ([self.startPage rangeOfString:@"://"].location != NSNotFound) {
        appURL = [NSURL URLWithString:self.startPage];
    } else if ([self.webContentFolderName rangeOfString:@"://"].location != NSNotFound) {
        appURL = [NSURL URLWithString:[NSString stringWithFormat:@"%@/%@", self.webContentFolderName, self.startPage]];
    } else if([self.webContentFolderName rangeOfString:@".bundle"].location != NSNotFound){
        // www folder is actually a bundle
        NSBundle* bundle = [NSBundle bundleWithPath:self.webContentFolderName];
        appURL = [bundle URLForResource:self.startPage withExtension:nil];
    } else if([self.webContentFolderName rangeOfString:@".framework"].location != NSNotFound){
        // www folder is actually a framework
        NSBundle* bundle = [NSBundle bundleWithPath:self.webContentFolderName];
        appURL = [bundle URLForResource:self.startPage withExtension:nil];
    } else {
        // CB-3005 strip parameters from start page to check if page exists in resources
        NSURL* startURL = [NSURL URLWithString:self.startPage];
        NSString* startFilePath = [self.commandDelegate pathForResource:[startURL path]];

        if (startFilePath == nil) {
            appURL = nil;
        } else {
            appURL = [NSURL fileURLWithPath:startFilePath];
            // CB-3005 Add on the query params or fragment.
            NSString* startPageNoParentDirs = self.startPage;
            NSRange r = [startPageNoParentDirs rangeOfCharacterFromSet:[NSCharacterSet characterSetWithCharactersInString:@"?#"] options:0];
            if (r.location != NSNotFound) {
                NSString* queryAndOrFragment = [self.startPage substringFromIndex:r.location];
                appURL = [NSURL URLWithString:queryAndOrFragment relativeToURL:appURL];
            }
        }
    }

    return appURL;
}

- (nullable NSURL *)errorURL
{
    NSString *setting = [self.settings cordovaSettingForKey:@"ErrorUrl"];
    if (setting == nil) {
        return nil;
    }

    if ([setting rangeOfString:@"://"].location != NSNotFound) {
        return [NSURL URLWithString:setting];
    } else {
        NSURL *url = [NSURL URLWithString:setting];
        NSString *errorFilePath = [self.commandDelegate pathForResource:[url path]];
        if (errorFilePath) {
            return [NSURL fileURLWithPath:errorFilePath];
        }
    }

    return nil;
}

- (nullable UIView *)webView
{
    if (_webViewEngine != nil) {
        return _webViewEngine.engineWebView;
    }

    return nil;
}

- (nullable NSString *)appURLScheme
{
    NSString* URLScheme = nil;

    NSArray* URLTypes = [[[NSBundle mainBundle] infoDictionary] objectForKey:@"CFBundleURLTypes"];

    if (URLTypes != nil) {
        NSDictionary* dict = [URLTypes objectAtIndex:0];
        if (dict != nil) {
            NSArray* URLSchemes = [dict objectForKey:@"CFBundleURLSchemes"];
            if (URLSchemes != nil) {
                URLScheme = [URLSchemes objectAtIndex:0];
            }
        }
    }

    return URLScheme;
}

#pragma mark - UIViewController & App Lifecycle

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

    // TODO: Remove in Cordova iOS 9
    if ([UIApplication.sharedApplication.delegate isKindOfClass:[CDVAppDelegate class]]) {
        CDVAppDelegate *appDelegate = (CDVAppDelegate *)UIApplication.sharedApplication.delegate;
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wdeprecated-declarations"
        if (appDelegate.viewController == nil) {
            appDelegate.viewController = self;
        }
#pragma clang diagnostic pop
    }

    // Load settings
    [self loadSettings];

    // Instantiate the Launch screen
    if (!self.launchView) {
        [self createLaunchView];
    }

    // Instantiate the WebView
    if (!self.webView) {
        [self createGapView];
    }

    // /////////////////

    if ([self.startupPluginNames count] > 0) {
        [CDVTimer start:@"TotalPluginStartup"];

        for (NSString* pluginName in self.startupPluginNames) {
            [CDVTimer start:pluginName];
            [self getCommandInstance:pluginName];
            [CDVTimer stop:pluginName];
        }

        [CDVTimer stop:@"TotalPluginStartup"];
    }

    // /////////////////
    NSURL* appURL = [self appUrl];

    if (appURL) {
        NSURLRequest* appReq = [NSURLRequest requestWithURL:appURL cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:20.0];
        [_webViewEngine loadRequest:appReq];
    } else {
        NSString* loadErr = [NSString stringWithFormat:@"ERROR: Start Page at '%@/%@' was not found.", self.webContentFolderName, self.startPage];
        NSLog(@"%@", loadErr);

        NSURL* errorUrl = [self errorURL];
        if (errorUrl) {
            errorUrl = [NSURL URLWithString:[NSString stringWithFormat:@"?error=%@", [loadErr stringByAddingPercentEncodingWithAllowedCharacters:NSCharacterSet.URLPathAllowedCharacterSet]] relativeToURL:errorUrl];
            NSLog(@"%@", [errorUrl absoluteString]);
            [_webViewEngine loadRequest:[NSURLRequest requestWithURL:errorUrl]];
        } else {
            NSString* html = [NSString stringWithFormat:@"<html><body> %@ </body></html>", loadErr];
            [_webViewEngine loadHTMLString:html baseURL:nil];
        }
    }
    // /////////////////

    [self.webView setBackgroundColor:self.backgroundColor];
    [self.launchView setBackgroundColor:self.splashBackgroundColor];

    if (self.showInitialSplashScreen) {
        [self.launchView setAlpha:1];
    }
}

-(void)viewWillAppear:(BOOL)animated
{
    [super viewWillAppear:animated];
    [[NSNotificationCenter defaultCenter] postNotification:[NSNotification notificationWithName:CDVViewWillAppearNotification object:nil]];
}

-(void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];

#if TARGET_OS_MACCATALYST
    BOOL hideTitlebar = [self.settings cordovaBoolSettingForKey:@"HideDesktopTitlebar" defaultValue:NO];
    if (hideTitlebar) {
        UIWindowScene *scene = self.view.window.windowScene;
        if (scene) {
            scene.titlebar.titleVisibility = UITitlebarTitleVisibilityHidden;
            scene.titlebar.toolbar = nil;
        }
    } else {
        // We need to fix the web content going behind the title bar
        self.webView.translatesAutoresizingMaskIntoConstraints = NO;
        [self.webView.topAnchor constraintEqualToAnchor:self.view.safeAreaLayoutGuide.topAnchor].active = YES;
        [self.webView.leadingAnchor constraintEqualToAnchor:self.view.leadingAnchor].active = YES;
        [self.webView.trailingAnchor constraintEqualToAnchor:self.view.trailingAnchor].active = YES;
        [self.webView.bottomAnchor constraintEqualToAnchor:self.view.bottomAnchor].active = YES;

        if ([self.webView respondsToSelector:@selector(scrollView)]) {
            UIScrollView *scrollView = [self.webView performSelector:@selector(scrollView)];
            scrollView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
        }
    }
#endif

    [[NSNotificationCenter defaultCenter] postNotification:[NSNotification notificationWithName:CDVViewDidAppearNotification object:nil]];
}

-(void)viewWillDisappear:(BOOL)animated
{
    [super viewWillDisappear:animated];
    [[NSNotificationCenter defaultCenter] postNotification:[NSNotification notificationWithName:CDVViewWillDisappearNotification object:nil]];
}

-(void)viewDidDisappear:(BOOL)animated
{
    [super viewDidDisappear:animated];
    [[NSNotificationCenter defaultCenter] postNotification:[NSNotification notificationWithName:CDVViewDidDisappearNotification object:nil]];
}

-(void)viewWillLayoutSubviews
{
    [super viewWillLayoutSubviews];
    [[NSNotificationCenter defaultCenter] postNotification:[NSNotification notificationWithName:CDVViewWillLayoutSubviewsNotification object:nil]];
}

-(void)viewDidLayoutSubviews
{
    [super viewDidLayoutSubviews];
    [[NSNotificationCenter defaultCenter] postNotification:[NSNotification notificationWithName:CDVViewDidLayoutSubviewsNotification object:nil]];
}

-(void)viewWillTransitionToSize:(CGSize)size withTransitionCoordinator:(id <UIViewControllerTransitionCoordinator>)coordinator
{
    [super viewWillTransitionToSize:size withTransitionCoordinator:coordinator];
    [[NSNotificationCenter defaultCenter] postNotification:[NSNotification notificationWithName:CDVViewWillTransitionToSizeNotification object:[NSValue valueWithCGSize:size]]];
}

/*
 This method lets your application know that it is about to be terminated and purged from memory entirely
 */
- (void)onAppWillTerminate:(NSNotification *)notification
{
    // empty the tmp directory
    NSFileManager* fileMgr = [[NSFileManager alloc] init];
    NSError* __autoreleasing err = nil;

    // clear contents of NSTemporaryDirectory
    NSString* tempDirectoryPath = NSTemporaryDirectory();
    NSDirectoryEnumerator* directoryEnumerator = [fileMgr enumeratorAtPath:tempDirectoryPath];
    NSString* fileName = nil;
    BOOL result;

    while ((fileName = [directoryEnumerator nextObject])) {
        NSString* filePath = [tempDirectoryPath stringByAppendingPathComponent:fileName];
        result = [fileMgr removeItemAtPath:filePath error:&err];
        if (!result && err) {
            NSLog(@"Failed to delete: %@ (error: %@)", filePath, err);
        }
    }
}

/*
 This method is called to let your application know that it is about to move from the active to inactive state.
 You should use this method to pause ongoing tasks, disable timer, ...
 */
- (void)onAppWillResignActive:(NSNotification *)notification
{
    [self checkAndReinitViewUrl];
    // NSLog(@"%@",@"applicationWillResignActive");
    [self.commandDelegate evalJs:@"cordova.fireDocumentEvent('resign');" scheduledOnRunLoop:NO];
}

/*
 In iOS 4.0 and later, this method is called instead of the applicationWillTerminate: method
 when the user quits an application that supports background execution.
 */
- (void)onAppDidEnterBackground:(NSNotification *)notification
{
    [self checkAndReinitViewUrl];
    // NSLog(@"%@",@"applicationDidEnterBackground");
    [self.commandDelegate evalJs:@"cordova.fireDocumentEvent('pause', null, true);" scheduledOnRunLoop:NO];
}

/*
 In iOS 4.0 and later, this method is called as part of the transition from the background to the inactive state.
 You can use this method to undo many of the changes you made to your application upon entering the background.
 invariably followed by applicationDidBecomeActive
 */
- (void)onAppWillEnterForeground:(NSNotification *)notification
{
    [self checkAndReinitViewUrl];
    // NSLog(@"%@",@"applicationWillEnterForeground");
    [self.commandDelegate evalJs:@"cordova.fireDocumentEvent('resume');"];
}

// This method is called to let your application know that it moved from the inactive to active state.
- (void)onAppDidBecomeActive:(NSNotification *)notification
{
    [self checkAndReinitViewUrl];
    // NSLog(@"%@",@"applicationDidBecomeActive");
    [self.commandDelegate evalJs:@"cordova.fireDocumentEvent('active');"];
}

- (void)didReceiveMemoryWarning
{
    BOOL doPurge = YES;

    // iterate through all the plugin objects, and call hasPendingOperation
    // if at least one has a pending operation, we don't call [super didReceiveMemoryWarning]
    for (CDVPlugin *plugin in self.enumerablePlugins) {
        if (plugin.hasPendingOperation) {
            NSLog(@"Plugin '%@' has a pending operation, memory purge is delayed for didReceiveMemoryWarning.", NSStringFromClass([plugin class]));
            doPurge = NO;
        }
    }

    if (doPurge) {
        // Releases the view if it doesn't have a superview.
        [super didReceiveMemoryWarning];
    }

    // Release any cached data, images, etc. that aren't in use.
}

/**
 Show the webview and fade out the intermediary view
 This is to prevent the flashing of the mainViewController
 */
- (void)onWebViewPageDidLoad:(NSNotification*)notification
{
    self.webView.hidden = NO;

    if ([self.settings cordovaBoolSettingForKey:@"AutoHideSplashScreen" defaultValue:YES]) {
        CGFloat splashScreenDelaySetting = [self.settings cordovaFloatSettingForKey:@"SplashScreenDelay" defaultValue:0];

        if (splashScreenDelaySetting == 0) {
            [self showSplashScreen:NO];
        } else {
            // Divide by 1000 because config returns milliseconds and NSTimer takes seconds
            CGFloat splashScreenDelay = splashScreenDelaySetting / 1000;

            [NSTimer scheduledTimerWithTimeInterval:splashScreenDelay repeats:NO block:^(NSTimer * _Nonnull timer) {
                [self showSplashScreen:NO];
            }];
        }
    }
}

#pragma mark - View Setup

- (void)loadSettings
{
    CDVConfigParser *parser = [CDVConfigParser parseConfigFile:self.configFilePath];

    // Get the plugin dictionary, allowList and settings from the delegate.
    _pluginsMap = parser.pluginsDict;
    self.startupPluginNames = parser.startupPluginNames;
    self.settings = [[CDVSettingsDictionary alloc] initWithDictionary:parser.settings];

    // And the start page
    if(parser.startPage && self.startPage == nil){
        self.startPage = parser.startPage;
    }
    if (self.startPage == nil) {
        self.startPage = @"index.html";
    }

    self.appScheme = [self.settings cordovaSettingForKey:@"Scheme"] ?: @"app";
}

/// Retrieves the view from a newwly initialized webViewEngine
/// @param bounds The bounds with which the webViewEngine will be initialized
- (nonnull UIView*)newCordovaViewWithFrame:(CGRect)bounds
{
    NSString* defaultWebViewEngineClassName = [self.settings cordovaSettingForKey:@"CordovaDefaultWebViewEngine"];
    NSString* webViewEngineClassName = [self.settings cordovaSettingForKey:@"CordovaWebViewEngine"];

    if (!defaultWebViewEngineClassName) {
        defaultWebViewEngineClassName = @"CDVWebViewEngine";
    }
    if (!webViewEngineClassName) {
        webViewEngineClassName = defaultWebViewEngineClassName;
    }

    // Determine if a provided custom web view engine is sufficient
    id <CDVWebViewEngineProtocol> engine;
    Class customWebViewEngineClass = NSClassFromString(webViewEngineClassName);
    if (customWebViewEngineClass) {
        id customWebViewEngine = [self initWebViewEngine:customWebViewEngineClass bounds:bounds];
        BOOL customConformsToProtocol = [customWebViewEngine conformsToProtocol:@protocol(CDVWebViewEngineProtocol)];
        BOOL customCanLoad = [customWebViewEngine canLoadRequest:[NSURLRequest requestWithURL:self.appUrl]];
        if (customConformsToProtocol && customCanLoad) {
            engine = customWebViewEngine;
        }
    }
    
    // Otherwise use the default web view engine
    if (!engine) {
        Class defaultWebViewEngineClass = NSClassFromString(defaultWebViewEngineClassName);
        id defaultWebViewEngine = [self initWebViewEngine:defaultWebViewEngineClass bounds:bounds];
        NSAssert([defaultWebViewEngine conformsToProtocol:@protocol(CDVWebViewEngineProtocol)],
                 @"we expected the default web view engine to conform to the CDVWebViewEngineProtocol");
        engine = defaultWebViewEngine;
    }
    
    if ([engine isKindOfClass:[CDVPlugin class]]) {
        [self registerPlugin:(CDVPlugin*)engine withClassName:webViewEngineClassName];
    }

    _webViewEngine = engine;
    return _webViewEngine.engineWebView;
}

/// Initialiizes the webViewEngine, with config, if supported and provided
/// @param engineClass A class that must conform to the `CDVWebViewEngineProtocol`
/// @param bounds with which the webview will be initialized
- (id _Nullable) initWebViewEngine:(nonnull Class)engineClass bounds:(CGRect)bounds {
    WKWebViewConfiguration *config = [self respondsToSelector:@selector(configuration)] ? [self configuration] : nil;
    if (config && [engineClass instancesRespondToSelector:@selector(initWithFrame:configuration:)]) {
        return [[engineClass alloc] initWithFrame:bounds configuration:config];
    } else {
        return [[engineClass alloc] initWithFrame:bounds];
    }
}

- (void)createLaunchView
{
    CGRect webViewBounds = self.view.bounds;
    webViewBounds.origin = self.view.bounds.origin;

    UIView* view = [[UIView alloc] initWithFrame:webViewBounds];
    view.translatesAutoresizingMaskIntoConstraints = NO;
    [view setAlpha:0];

    NSString* launchStoryboardName = [[NSBundle mainBundle] objectForInfoDictionaryKey:@"UILaunchStoryboardName"];
    if (launchStoryboardName != nil) {
        UIStoryboard* storyboard = [UIStoryboard storyboardWithName:launchStoryboardName bundle:[NSBundle mainBundle]];
        UIViewController* vc = [storyboard instantiateInitialViewController];
        [self addChildViewController:vc];

        UIView* imgView = vc.view;
        imgView.translatesAutoresizingMaskIntoConstraints = NO;
        [view addSubview:imgView];

        [NSLayoutConstraint activateConstraints:@[
                [NSLayoutConstraint constraintWithItem:imgView attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:view attribute:NSLayoutAttributeWidth multiplier:1 constant:0],
                [NSLayoutConstraint constraintWithItem:imgView attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:view attribute:NSLayoutAttributeHeight multiplier:1 constant:0],
                [NSLayoutConstraint constraintWithItem:imgView attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:view attribute:NSLayoutAttributeCenterY multiplier:1 constant:0],
                [NSLayoutConstraint constraintWithItem:imgView attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:view attribute:NSLayoutAttributeCenterX multiplier:1 constant:0]
            ]];
    }

    self.launchView = view;
    [self.view addSubview:view];

    [NSLayoutConstraint activateConstraints:@[
            [NSLayoutConstraint constraintWithItem:view attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeWidth multiplier:1 constant:0],
            [NSLayoutConstraint constraintWithItem:view attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeHeight multiplier:1 constant:0],
            [NSLayoutConstraint constraintWithItem:view attribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeCenterY multiplier:1 constant:0],
            [NSLayoutConstraint constraintWithItem:view attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeCenterX multiplier:1 constant:0]
        ]];
}

- (void)createGapView
{
    CGRect webViewBounds = self.view.bounds;
    webViewBounds.origin = self.view.bounds.origin;

    UIView* view = [self newCordovaViewWithFrame:webViewBounds];
    view.hidden = YES;
    view.autoresizingMask = (UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight);

    [self.view addSubview:view];
    [self.view sendSubviewToBack:view];
}

#pragma mark CordovaCommands

- (void)registerPlugin:(CDVPlugin*)plugin withClassName:(NSString*)className
{
    plugin.viewController = self;
    plugin.commandDelegate = _commandDelegate;

    @synchronized(_pluginObjects) {
        [_pluginObjects setObject:plugin forKey:className];
    }
    [plugin pluginInitialize];
}

- (void)registerPlugin:(CDVPlugin*)plugin withPluginName:(NSString*)pluginName
{
    plugin.viewController = self;
    plugin.commandDelegate = _commandDelegate;

    NSString* className = NSStringFromClass([plugin class]);

    @synchronized(_pluginObjects) {
        [_pluginObjects setObject:plugin forKey:className];
    }
    [_pluginsMap setValue:className forKey:[pluginName lowercaseString]];
    [plugin pluginInitialize];
}

/**
 Returns an instance of a CordovaCommand object, based on its name.  If one exists already, it is returned.
 */
- (nullable CDVPlugin *)getCommandInstance:(NSString *)pluginName
{
    // first, we try to find the pluginName in the pluginsMap
    // (acts as a allowList as well) if it does not exist, we return nil
    // NOTE: plugin names are matched as lowercase to avoid problems - however, a
    // possible issue is there can be duplicates possible if you had:
    // "org.apache.cordova.Foo" and "org.apache.cordova.foo" - only the lower-cased entry will match
    NSString* className = [_pluginsMap objectForKey:[pluginName lowercaseString]];

    if (className == nil) {
        return nil;
    }

    id obj = nil;
    @synchronized(_pluginObjects) {
        obj = [_pluginObjects objectForKey:className];
    }

    if (!obj) {
        obj = [[NSClassFromString(className) alloc] initWithWebViewEngine:_webViewEngine];
        if (!obj) {
            NSString* fullClassName = [NSString stringWithFormat:@"%@.%@",
                                       NSBundle.mainBundle.infoDictionary[@"CFBundleExecutable"],
                                       className];
            obj = [[NSClassFromString(fullClassName)alloc] initWithWebViewEngine:_webViewEngine];
        }

        if (obj != nil) {
            [self registerPlugin:obj withClassName:className];
        } else {
            NSLog(@"CDVPlugin class %@ (pluginName: %@) does not exist.", className, pluginName);
        }
    }
    return obj;
}

#pragma mark -

- (bool)isUrlEmpty:(NSURL *)url
{
    if (!url || (url == (id) [NSNull null])) {
        return true;
    }
    NSString *urlAsString = [url absoluteString];
    return (urlAsString == (id) [NSNull null] || [urlAsString length]==0 || [urlAsString isEqualToString:@"about:blank"]);
}

- (bool)checkAndReinitViewUrl
{
    NSURL* appURL = [self appUrl];
    if ([self isUrlEmpty: [_webViewEngine URL]] && ![self isUrlEmpty: appURL]) {
        NSURLRequest* appReq = [NSURLRequest requestWithURL:appURL cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:20.0];
        [_webViewEngine loadRequest:appReq];
        return true;
    }
    return false;
}

#pragma mark - API Methods for Plugins

- (void)showLaunchScreen:(BOOL)visible
{
    [self showSplashScreen:visible];
}

- (void)showSplashScreen:(BOOL)visible
{
    CGFloat fadeSplashScreenDuration = [self.settings cordovaFloatSettingForKey:@"FadeSplashScreenDuration" defaultValue:250.f];

    // Setting minimum value for fade to 0.25 seconds
    fadeSplashScreenDuration = fadeSplashScreenDuration < 250 ? 250 : fadeSplashScreenDuration;

    // AnimateWithDuration takes seconds but cordova documentation specifies milliseconds
    CGFloat fadeDuration = fadeSplashScreenDuration/1000;

    [UIView animateWithDuration:fadeDuration animations:^{
        [self.launchView setAlpha:(visible ? 1 : 0)];

        if (!visible) {
            [self.webView becomeFirstResponder];
        }
    }];
}

- (void)parseSettingsWithParser:(id <NSXMLParserDelegate>)delegate
{
    [CDVConfigParser parseConfigFile:self.configFilePath withDelegate:delegate];
}

@end