Understanding Facebook-Style Bar Button Items in iOS

Introduction

In recent years, social media platforms like Facebook have become ubiquitous, providing users with seamless ways to interact with friends, share updates, and receive messages. One distinctive feature of these platforms is the presence of bar button items at the bottom of the screen, which serve as navigation buttons for various actions such as sending messages, posting updates, or viewing sent content. In this article, we’ll delve into the technical details of creating these bar button items in iOS using UIKit.

What are Bar Button Items?

Bar button items are UI elements that appear at the bottom of a screen, typically used for navigation or as indicators of actions. They can be customized to display various labels, icons, and badges. In this context, we’re interested in creating Facebook-style bar button items with specific labels and badges.

The Solution: UISegmentedControl

The Stack Overflow post hints at using UISegmentedControl, which is a built-in iOS control for displaying multiple segments or options. However, as the questioner pointed out, there isn’t built-in support for badges in UISegmentedControl. To overcome this limitation, we’ll explore an alternative solution.

Creating Facebook-Style Bar Button Items using Three20

Facebook’s official documentation recommends using the three20 library, which is a custom-built framework designed to provide a consistent user experience across Apple devices. The three20 library offers a range of UI components, including bar button items, that can be customized to match Facebook’s distinctive style.

To create Facebook-style bar button items using three20, we’ll need to import the necessary libraries and use the BBButton class from the three20.UI BB framework. Here’s an example code snippet:

#import <UIKit/UIKit.h>
#import "three20/UI/BB.h"

@interface ViewController ()
@property (nonatomic, strong) BBNavigation *navigation;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    // Create a BBNavigation instance with three bar button items
    self.navigation = [[BBNavigation alloc] initWithBarItems:@[
        [[BBButton alloc] setTitle:@"Messages" badge:[BBBadge badgeColor:[UIColor redColor] textSize:12.0]],
        [[BBButton alloc] setTitle:@"Updates" badge:nil],
        [[BBButton alloc] setTitle:@"Sent" badge:[BBBadge badgeColor:[UIColor redColor] textSize:10.0]]
    ]]];
    
    // Add the navigation bar to the view controller's view
    [self.view addSubview:self.navigation];
}

@end

Customizing Bar Button Items

To create Facebook-style bar button items, we need to customize their appearance by adding badges or modifying their fonts and colors. The BBBadge class provides a range of options for customizing badge appearances.

// Create a BBBadge instance with red color and font size 12
BBBadge *badge = [[BBBadge alloc] initWithBadgeColor:[UIColor redColor] textSize:12.0];

// Add the badge to the "Messages" button
[[BBButton alloc] setTitle:@"Messages" badge:badge];

Conclusion

Creating Facebook-style bar button items in iOS requires some understanding of UIKit and custom UI components like BBNavigation and BBBadge. By using the three20 library, we can create a consistent user experience that mirrors Facebook’s distinctive style. With this knowledge, you should be able to customize your own bar button items to match your app’s branding and visual identity.

Additional Tips

• For more information on customizing UI components in iOS, check out Apple’s official documentation on UISegmentedControl and the three20 library.
• Experiment with different badge designs and colors to create a unique look for your app.
• Consider using a theme or style sheet to define consistent visual elements throughout your app.

Last modified on 2023-06-15