Overview

SNStarRating is an iOS UI control that lets users choose a rating visually by tapping on the appropriate number of stars. This implementation is contained in a UIView and uses no subviews; instead, drawRect is overridden and draws the images directly into the context. (It was designed with performance in mind)

There are only four files: a header and implementation for SNStarRating and two images that represent the on/off states for each star. (Also included is the Photoshop PSD file used to create the images)

Usage

1. Copy SNStarRating.h and SNStarRating.m into your project.

2. Copy dot.png and star.png into your application's resources folder.

3. Allocate the object and initialize it with initWithNumberOfStars:

    SNStarRating *starRating = [[SNStarRating alloc] initWithNumberOfStars:5];
    [starRating setCenter:CGPointMake(320.0/2, 100.0)];
    [[self view] addSubview:starRating];
    [starRating release];
   

4. If you wish to specify an initial rating, you can do so by initializing with initialRating:

    SNStarRating *starRating2 = [[SNStarRating alloc] initWithNumberOfStars:5 initialRating:3];
    [starRating2 setCenter:CGPointMake(320.0/2, 200.0)];
    [[self view] addSubview:starRating2];
    [starRating2 release];
   

5. SNStarRating is similar to UIButton in that you don't initWithFrame, so you have to either manually set the frame to change the X/Y or (preferred) set the center to a CGPoint.

6. You can get the value of the control by using the rating property.

Customization

You can create any number of stars you wish by changing the argument value for the initWithNumberOfStars: selector. See the example project for this.

The BTN_HEIGHT and BTN_WIDTH constants must be set to the width of your images; the touchesBegan and touchesMoved methods use the width to determine the ratings

initWithNumberOfStars: automatically creates a frame based on the number of stars you are initializing with. The frame size is automatically calculated; you shouldn't have to mess with it.

Feedback

If you have any suggestions or feedback, feel free to drop me a note.