Challenge Complete

ChangingBackground.xcodeproj/project.pbxproj

@@ -24,6 +24,7 @@
 		001809EC171C6764002D3E93 /* blue@2x.png in Resources */ = {isa = PBXBuildFile; fileRef = 001809E8171C6764002D3E93 /* blue@2x.png */; };
 		001809ED171C6764002D3E93 /* green.png in Resources */ = {isa = PBXBuildFile; fileRef = 001809E9171C6764002D3E93 /* green.png */; };
 		001809EE171C6764002D3E93 /* green@2x.png in Resources */ = {isa = PBXBuildFile; fileRef = 001809EA171C6764002D3E93 /* green@2x.png */; };
+		AD8A1488191B0508000F8002 /* MyNavigationController.m in Sources */ = {isa = PBXBuildFile; fileRef = AD8A1487191B0508000F8002 /* MyNavigationController.m */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXFileReference section */
@@ -50,6 +51,8 @@
 		001809E8171C6764002D3E93 /* blue@2x.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = "blue@2x.png"; sourceTree = "<group>"; };
 		001809E9171C6764002D3E93 /* green.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = green.png; sourceTree = "<group>"; };
 		001809EA171C6764002D3E93 /* green@2x.png */ = {isa = PBXFileReference; lastKnownFileType = image.png; path = "green@2x.png"; sourceTree = "<group>"; };
+		AD8A1486191B0508000F8002 /* MyNavigationController.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MyNavigationController.h; sourceTree = "<group>"; };
+		AD8A1487191B0508000F8002 /* MyNavigationController.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MyNavigationController.m; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -98,6 +101,7 @@
 			children = (
 				001809EF171C6768002D3E93 /* BackgroundImages */,
 				001809D5171C63FC002D3E93 /* AppDelegate */,
+				AD8A1489191B0512000F8002 /* NavigationController */,
 				001809DC171C6453002D3E93 /* ViewControllers */,
 				001809BF171C637E002D3E93 /* Supporting Files */,
 			);
@@ -167,6 +171,15 @@
 			name = BackgroundImages;
 			sourceTree = "<group>";
 		};
+		AD8A1489191B0512000F8002 /* NavigationController */ = {
+			isa = PBXGroup;
+			children = (
+				AD8A1486191B0508000F8002 /* MyNavigationController.h */,
+				AD8A1487191B0508000F8002 /* MyNavigationController.m */,
+			);
+			name = NavigationController;
+			sourceTree = "<group>";
+		};
 /* End PBXGroup section */
 
 /* Begin PBXNativeTarget section */
@@ -242,6 +255,7 @@
 				001809C9171C637E002D3E93 /* AppDelegate.m in Sources */,
 				001809D9171C6448002D3E93 /* FirstViewController.m in Sources */,
 				001809E0171C64E4002D3E93 /* SecondViewController.m in Sources */,
+				AD8A1488191B0508000F8002 /* MyNavigationController.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -356,6 +370,7 @@
 				001809D4171C637E002D3E93 /* Release */,
 			);
 			defaultConfigurationIsVisible = 0;
+			defaultConfigurationName = Release;
 		};
 /* End XCConfigurationList section */
 	};

ChangingBackground/AppDelegate.m

@@ -8,26 +8,53 @@
 
 #import "AppDelegate.h"
 #import "FirstViewController.h"
+#import "MyNavigationController.h"
 
-@interface AppDelegate () {
+@interface AppDelegate ()<UINavigationControllerDelegate>
+{
     UIWindow *window;
+    MyNavigationController *navController;
 }
 @end
 
 
 @implementation AppDelegate
 
-- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
+- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
+{
     window = [UIWindow.alloc initWithFrame:UIScreen.mainScreen.bounds];
     [window makeKeyAndVisible];
 
     FirstViewController *firstViewController = FirstViewController.new;
-    UINavigationController *navigationController = [UINavigationController.alloc initWithRootViewController:firstViewController];
-    [navigationController setNavigationBarHidden:YES];
-
-    window.rootViewController = navigationController;
+    navController = [MyNavigationController.alloc initWithRootViewController:firstViewController];
+    [navController setNavigationBarHidden:YES];
+    window.rootViewController = navController;
+    navController.delegate = self;
+    navController.imageView = [UIImageView.alloc initWithFrame:UIScreen.mainScreen.bounds];
+    navController.imageView.image = [UIImage imageNamed:@"blue.png"];
+    [navController.view insertSubview:navController.imageView atIndex:0];
 
     return YES;
 }
 
+-(void)navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated
+{
+    [navController backgroundCheck];
+}
+
+-(id<UIViewControllerAnimatedTransitioning>)navigationController:(UINavigationController *)navigationController animationControllerForOperation:(UINavigationControllerOperation)operation fromViewController:(UIViewController *)fromVC toViewController:(UIViewController *)toVC
+{
+    if (operation == UINavigationControllerOperationPush)
+    {
+        [UIView animateWithDuration:.25 animations:^{
+            fromVC.view.frame = CGRectMake(-320, 0, fromVC.view.frame.size.width, fromVC.view.frame.size.height);
+        }];
+    }
+    return nil;
+}
+
+
+
+
+
 @end

ChangingBackground/FirstViewController.m

@@ -10,12 +10,22 @@
 #import "SecondViewController.h"
 
 @interface FirstViewController ()
+{
+    UIImageView *imageView;
+}
 
 @end
 
 @implementation FirstViewController
 
-- (IBAction)goForwardButtonPressed {
+-(void)viewWillAppear:(BOOL)animated
+{
+    [super viewWillAppear:animated];
+    self.view.backgroundColor = [UIColor clearColor];
+}
+
+- (IBAction)goForwardButtonPressed
+{
     SecondViewController *secondViewController = SecondViewController.new;
     [self.navigationController pushViewController:secondViewController animated:YES];
 }

ChangingBackground/MyNavigationController.h

@@ -0,0 +1,16 @@
+//
+//  MyNavigationController.h
+//  ChangingBackground
+//
+//  Created by Calvin Hildreth on 5/7/14.
+//  Copyright (c) 2014 Ora Interactive. All rights reserved.
+//
+
+#import <UIKit/UIKit.h>
+
+@interface MyNavigationController : UINavigationController
+@property (strong, nonatomic) UIImageView *imageView;
+
+-(void)backgroundCheck;
+-(void)changeBackgroundWithImageNamed:(NSString *)imageName;
+@end

ChangingBackground/MyNavigationController.m

@@ -0,0 +1,48 @@
+//
+//  MyNavigationController.m
+//  ChangingBackground
+//
+//  Created by Calvin Hildreth on 5/7/14.
+//  Copyright (c) 2014 Ora Interactive. All rights reserved.
+//
+
+#import "MyNavigationController.h"
+
+@interface MyNavigationController ()
+
+@end
+
+@implementation MyNavigationController
+
+-(void)backgroundCheck
+{
+    NSString *imageName;
+    switch (self.viewControllers.count)
+    {
+        case 1:
+            imageName = @"blue.png";
+            [self changeBackgroundWithImageNamed:imageName];
+            break;
+
+        case 2:
+            imageName = @"green.png";
+            [self changeBackgroundWithImageNamed:imageName];
+            break;
+
+        default:
+            break;
+    }
+}
+
+-(void)changeBackgroundWithImageNamed:(NSString *)imageName
+{
+    [UIView transitionWithView:self.view
+                      duration:2
+                       options:UIViewAnimationOptionTransitionCrossDissolve
+                    animations:^{
+                        self.imageView.image = [UIImage imageNamed:imageName];
+                    }
+                    completion:NULL];
+}
+
+@end

ChangingBackground/SecondViewController.m

@@ -8,10 +8,16 @@
 
 #import "SecondViewController.h"
 
-
 @implementation SecondViewController
 
-- (IBAction)goBackButtonPressed {
+-(void)viewWillAppear:(BOOL)animated
+{
+    [super viewWillAppear:animated];
+    self.view.backgroundColor = [UIColor clearColor];
+}
+
+- (IBAction)goBackButtonPressed
+{
     [self.navigationController popViewControllerAnimated:YES];
 }