GDIIndexBar - A custom index bar for iOS

GDIIndexBar is a component for navigating sections of a UITableView. It reproduces the index bar seen in the Contacts app on iOS and styled to match both iOS6 and iOS7 by default. GDIIndexBar can also be customized through the appearance protocol or by subclassing.

GDIIndexBar behaves by automatically sizing and positioning itself on the right side of the provided UITableView. Subclasses can alter this by overriding the layoutSubviews method of the GDIIndexBar. GDIIndexBar provides automatic vertical adjustments for the index bar by setting a GDIIndexBarAlignment value.

GDIIndexBar is supports being added directly to a UITableView as a child subview, or can exist in a different view than the table while still positioning automatically. NOTE: In order to correctly receive touch events as a subview of a UITableView, the delaysContentTouches property is automatically set to NO.

Usage

To run the example project; clone the repo, and run pod install from the Project directory first.

The example project contains two example view controllers. One demonstrates a UITableViewController subclass, and the other is a UIViewController that manages a UITableView and GDIIndexBar as subviews of the main view.

Instantiation

GDIIndexBar can be instantiated through code or by setting outlets with Interface Builder. See the example project for an IB-only implementation. Below is an example of of instantiating an index bar from a view controller's viewDidLoad method:

GDIIndexBar *indexBar = [[GDIIndexBar alloc] initWithTableView:tableView];
indexBar.delegate = self;
[self.view addSubview:indexBar];

Providing Data

To correctly display an index bar its delegate must implement the numberOfIndexesForIndexBar: and stringForIndex: methods of the <GDIIndexBarDelegate> protocol.

- (NSUInteger)numberOfIndexesForIndexBar:(GDIIndexBar *)indexBar
{
    return self.dataModel.sectionNames.count;
}

- (NSString *)stringForIndex:(NSUInteger)index
{
    return [self.dataModel.sectionNames objectAtIndex:index];
}

To respond to index bar touches, the delegate should implement the following delegate method and tell the table view to scroll sections:

- (void)indexBar:(GDIIndexBar *)indexBar didSelectIndex:(NSUInteger)index
{
    [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:0 inSection:index]
                          atScrollPosition:UITableViewScrollPositionTop
                                  animated:NO];
}

Styling

GDIIndexBar can be customized by setting properties for the text font, text color, text shadow color, and the bar background color and width. A custom bar background view can also be provided using the barBackgroundView property. Offsets can also be provided for the text and bar background by setting the textOffset and barBackgroundOffset values, respectively.

Below are examples of styling the index bar through the appearance protocol.

[[GDIIndexBar appearance] setTextColor:[UIColor redColor]];
[[GDIIndexBar appearance] setTextShadowColor:[UIColor purpleColor]];
[[GDIIndexBar appearance] setTextFont:[UIFont italicSystemFontOfSize:11.5];

For further customization, subclasses can override the drawRect: method of the GDIIndexBar to perform completely custom drawing.

Requirements

• iOS 6.0+

Installation

GDIIndexBar is available through CocoaPods, to install it simply add the following line to your Podfile:

pod "GDIIndexBar"

Author

Grant Davis, [email protected]

License

GDIIndexBar is available under the MIT license. See the LICENSE file for more info.