Understanding the Issue with DDMenuController and UIButton on iOS

When it comes to implementing custom UI elements in iOS, such as a dropdown menu (DDMenuController) that can be triggered from a button click, understanding how the underlying navigation stack works is crucial. In this blog post, we will delve into the details of why pushing a DDMenuController from a UIButton might result in a double Navigation Bar effect and explore ways to resolve this issue.

Background: Understanding the Navigation Stack

The navigation stack in iOS is designed to manage the flow of views within an application. The main components of the navigation stack are:

1. UINavigationController: Manages the presentation and dismissal of view controllers, as well as the push and pop of new view controllers onto the stack.
2. UIViewController: A generic view controller class that can be customized with different views and behaviors.

When a user interacts with a UIButton, the app’s delegate (usually the AppDelegate) receives the event and decides what action to take. In this case, we want to push a DDMenuController onto the navigation stack when the button is clicked.

The Problem: Double Navigation Bar Effect

The issue arises because pushing a new view controller onto the navigation stack automatically adds it as a child of the current topmost view controller in the stack. This means that if you have already pushed another view controller (in this case, the main app’s view controller) onto the stack, and then push another view controller again (the DDMenuController), both view controllers will be displayed on top of each other with their own Navigation Bars.

This results in a double Navigation Bar effect, which is often undesirable.

Resolving the Issue: Pushing a View Controller from a UIButton

To resolve this issue, we need to understand that the DDMenuController should not be pushed onto the navigation stack directly. Instead, we can use the present method to display the DDMenuController modally (independent of the app’s view controller).

However, if you want to push a view controller from a UIButton and still avoid the double Navigation Bar effect, there are two approaches:

Approach 1: Using Present Modally

One approach is to present the DDMenuController modally, rather than pushing it onto the navigation stack. Here’s an example of how you can do this:

DDMenuController *ddMenu = (DDMenuController *)[[self storyboard] instantiateViewControllerWithIdentifier:@"DDMenuVC"];
[self presentViewController:ddMenu animated:YES completion:nil];

By presenting the DDMenuController modally, we avoid adding it to the navigation stack and thus avoid the double Navigation Bar effect.

Approach 2: Using SetRootViewController

Another approach is to use the setRootViewController method on the app’s main window to push a new view controller onto the navigation stack. Here’s an example of how you can do this:

[self.window setRootViewController:[self navigationController]];

By using this method, we can push a new view controller onto the navigation stack without adding it as a child of the current topmost view controller.

Approach 3: Using a Navigation Controller for the DDMenuController

If you still want to use a navigation controller for your app’s main content and want to push the DDMenuController onto the navigation stack, there is an alternative approach. You can create a separate navigation controller for the DDMenuController and then present it modally.

Here’s an example of how you can do this:

DDMenuController *ddMenu = (DDMenuController *)[[self storyboard] instantiateViewControllerWithIdentifier:@"DDMenuVC"];

UINavigationController *ddMenuNavigationController = [[UINavigationController alloc] initWithRootViewController:ddMenu];
[self presentViewController:ddMenuNavigationController animated:YES completion:nil];

By using this approach, we can push the DDMenuController onto a separate navigation controller and then present it modally.

Conclusion

Pushing a view controller from a UIButton can be a straightforward process in iOS. However, when dealing with custom UI elements like the DDMenuController, understanding how the underlying navigation stack works is crucial to avoiding unwanted effects such as double Navigation Bars.

By using one of the approaches outlined above (presenting modally, using setRootViewController, or creating a separate navigation controller for the DDMenuController), you can push your custom view controller onto the navigation stack without adding it as a child of the current topmost view controller. This will help ensure that your app presents its main content in an intuitive and user-friendly way.

Example Use Cases

Here are some example use cases where you might want to push a view controller from a UIButton:

• A dropdown menu for selecting a language or region.
• A modal window for displaying additional information about an item.
• A navigation panel for accessing frequently used items or settings.

By using the approaches outlined above, you can create custom UI elements that seamlessly integrate with your app’s main content and provide a consistent user experience across all platforms.

Last modified on 2023-10-01