PushViewController Not working

Question

Hi, I am trying to learn Objective-C and have run into a problem with pushing a new View controller when a Button is clicked. I have a switch View Controller that is responsible for pushing the settings.nib file when I press the settings toolbar button. Here is the code of the ViewController:

//
//  ViewController.h
//  iReader
//
//  Created by Vivek Manjunath on 22/08/10.
//  Copyright (c) 2010 __MyCompanyName__. All rights reserved.
//

#import <UIKit/UIKit.h>
@class ReaderMain;
@class Settings;
@class GoogleClientLogin;

@interface ViewController : UIViewController {

    ReaderMain *readerMain;
    Settings *settings;
    GoogleClientLogin *gClientLogin;
    UIBarButtonItem *mSignInOutButton;
    UIBarButtonItem *mRefresh;

}

@property (nonatomic, retain) ReaderMain *readerMain;
@property (nonatomic, retain) Settings *settings;
@property (nonatomic, retain) GoogleClientLogin *gClientLogin;
@property (nonatomic, retain) IBOutlet UIBarButtonItem *signInOutButton;
@property (nonatomic, retain) IBOutlet UIBarButtonItem *refreshButton;

-(IBAction) switchViews:(id)sender;
@end

ViewController.m file

//
//  ViewController.m
//  iReader
//
//  Created by Vivek Manjunath on 22/08/10.
//  Copyright (c) 2010 __MyCompanyName__. All rights reserved.
//

#import "ViewController.h"
#import "ReaderMain.h"
#import "Settings.h"


@implementation ViewController
@synthesize readerMain;
@synthesize settings;
@synthesize signInOutButton = mSignInOutButton;
@synthesize refreshButton =mRefresh;
@synthesize gClientLogin;

/*
 // The designated initializer.  Override if you create the controller programmatically and want to perform customization that is not appropriate for viewDidLoad.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    if ((self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil])) {
        // Custom initialization
    }
    return self;
}
*/


// Implement viewDidLoad to do additional setup after loading the view, typically from a nib.
- (void)viewDidLoad {
    ReaderMain *readerController= [[ReaderMain alloc] initWithNibName:@"ReaderMain" bundle:nil];
    self.readerMain = readerController;
    [self.view insertSubview:readerController.view atIndex:0];
    [readerController release];
    [super viewDidLoad];
}

-(IBAction)switchViews:(id)sender
{
    if(self.settings ==nil)
    {   
        //[mSignInOutButton setTitle:@"SignIn"];
        Settings *googleController = [[Settings alloc]initWithNibName:@"Settings" bundle:nil];
        self.settings = googleController;

        [googleController release];
    }
    [UIView beginAnimations:@"View Flip" context:nil];
    [UIView setAnimationDuration:1.00];
    [UIView setAnimationCurve:UIViewAnimationCurveEaseInOut];

    if(readerMain.view.superview ==nil)
    {   
        [mSignInOutButton setTitle:@"Settings"];
        [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromRight forView:self.view cache:NO];
        [readerMain viewWillAppear:YES];
        [settings viewWillDisappear:YES];
        [settings.view removeFromSuperview];
        [self.view insertSubview:readerMain.view atIndex:0];
        [settings viewDidDisappear:YES];
        [readerMain viewDidAppear:YES];
        //[mSignInOutButton setTitle:@"SignOut"];

    }

    else 
    {   
        [mSignInOutButton setTitle:@"Back"];
        [UIView setAnimationTransition:UIViewAnimationTransitionFlipFromLeft forView:self.view cache:NO];
        [settings viewWillAppear:YES];
        [readerMain viewWillDisappear:YES];

        [readerMain.view removeFromSuperview];
        [self.view insertSubview:settings.view atIndex:0];

        [readerMain viewDidDisappear:YES];

        [settings viewDidAppear:YES];

    }
    [UIView commitAnimations];
}
/*
// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    // Return YES for supported orientations
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
*/

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

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

- (void)viewDidUnload {
    [super viewDidUnload];
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}


- (void)dealloc {
    [readerMain release];
    [settings release];
    [mSignInOutButton release];
    [mRefresh release];
    [super dealloc];
}


@end

This works as expected. After loading the settings.nib file, I want to load another viewController for advanced settings. I tried to do this as below:

Settings.h file

//
//  Settings.h
//  iReader
//
//  Created by Vivek Manjunath on 22/08/10.
//  Copyright (c) 2010 __MyCompanyName__. All rights reserved.
//

#import <UIKit/UIKit.h>
#import "ViewController.h"


@interface Settings : UIViewController {

    IBOutlet UIButton *googleReaderSettings;

}

@property (nonatomic, retain) IBOutlet UIButton *googleReaderSettings;
-(IBAction) goToViewTwo;
@end

The settings.m file

//
//  Settings.m
//  iReader
//
//  Created by Vivek Manjunath on 22/08/10.
//  Copyright (c) 2010 __MyCompanyName__. All rights reserved.
//

#import "Settings.h"
#import "GoogleClientLogin.h"
#import "iReaderAppDelegate.h"


@implementation Settings
@synthesize googleReaderSettings;

-(IBAction)goToViewTwo{
    GoogleClientLogin *gClient=[[GoogleClientLogin alloc]initWithNibName:@"GoogleClientLogin" bundle:[NSBundle mainBundle]];
    [self.navigationController pushViewController:gClient animated:YES];
    [gClient release];
}
/*
 // The designated initializer.  Override if you create the controller programmatically and want to perform customization that is not appropriate for viewDidLoad.
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    if ((self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil])) {
        // Custom initialization
    }
    return self;
}
*/

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

/*
// Override to allow orientations other than the default portrait orientation.
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
    // Return YES for supported orientations
    return (interfaceOrientation == UIInterfaceOrientationPortrait);
}
*/

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

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

- (void)viewDidUnload {
    [super viewDidUnload];
    // Release any retained subviews of the main view.
    // e.g. self.myOutlet = nil;
}


- (void)dealloc {
    [googleReaderSettings release];
    [super dealloc];
}


@end

Finally my Delegate File:

//
//  iReaderAppDelegate.h
//  iReader
//
//  Created by Vivek Manjunath on 22/08/10.
//  Copyright (c) 2010 __MyCompanyName__. All rights reserved.
//


#import <UIKit/UIKit.h>
@class ViewController;
@class Settings;

@interface iReaderAppDelegate : NSObject <UIApplicationDelegate> {

    UIWindow *window;
    IBOutlet ViewController *switchViewController;
    IBOutlet ViewController *settings;

}

@property (nonatomic, retain) IBOutlet UIWindow *window;
@property (nonatomic, retain) IBOutlet ViewController *switchViewController;
@property (nonatomic, retain) IBOutlet ViewController *settings;

@end

And the Delegate.m file

//
//  iReaderAppDelegate.m
//  iReader
//
//  Created by Vivek Manjunath on 22/08/10.
//  Copyright (c) 2010 __MyCompanyName__. All rights reserved.
//


#import "iReaderAppDelegate.h"
#import "ViewController.h"

@implementation iReaderAppDelegate


@synthesize window;
@synthesize switchViewController, settings;

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    // Override point for customization after application launch.
    [window addSubview:switchViewController.view];
    [window addSubview:settings.view];
    [window makeKeyAndVisible];
    return YES;
}

- (void)applicationWillTerminate:(UIApplication *)application {

    // Save data if appropriate.
}

- (void)dealloc {

    [window release];
    [switchViewController release];
    [settings release];
    [super dealloc];
}

@end

But, when I press the button to load the GoogleClientLogin view, it does nothing. There is no console output either. Can someone help me with this issue? I fixed the memory leaks and NSLog shows that it is entering goToViewTwo.

Answer 1

Hey, On the go I see 2 things in your Code.

1) Did you connect the IBAction to the Button, which should trigger the change? (in InterfaceBuilder)

2) In your GoToViewTwo Methode, you allocate gClient but you never release it. So you produce a Memory Leak.

My Suggestion: Put a NSLog(@'Was in GoToViewTwo-Method') in your GoToViewTwo-Method to test if it's executed while using your program. So you can see if the viewcontroller is the Problem or showing it is the problem. ;-)

Sorry for my English. I know it's not the best, but I tried writing as good as I can. ;-)

Answer 2

Did you setup your navigationController in IB ?

otherwise I can't see a place where you use it in your code.