SwiftyKnob

SwiftyKnob allows you to easily add knobs in your iOS apps. If you are unfamiliar with knobs, they are basically curved progress bars. You can use them to show profile completion, stats or just about anything else!

Here's what it looks like:

Installation

Via Cocoapods

pod "SwiftyKnob"

Manually

Just drag the Knob.swift in SwiftyKnob/Classes/ to your project tree and you're ready to go.

Usage

In code

import SwiftyKnob

let knob = Knob(frame: CGRect(x: 8, y: 20, width: 120, height: 120),
          borderWidth: 18,
          borderColor: UIColor.red,
          value: 0.78, 
          text: "78%",
          description: "open rate"
)

view.addSubview(knob)

Simply initialize the Knob class with the wanted parameters and add it to the view. The knob will animate automatically when needed.

For a detailed description of the Knob initializer see the following table:

Parameter	Description
frame	The rectangle defining the size and position of the knob
borderWidth	The width of the knob's border
borderColor	The color of the above border
value	The value of the knob. Should be between 0.0 and 1.0
text	The main text, displayed at the center of the knob
description	A smaller description, displayed below the text above

Controlling animations

By default, the knob animates as soon as it's drawn. If you want to control that, you can use the follwing code:

let knob = Knob(frame: CGRect(x: 8, y: 20, width: 120, height: 120),
          borderWidth: 18,
          borderColor: UIColor.red,
          value: 0.78, 
          text: "78%",
          description: "open rate",
          autoAnimate: false
)

The last parameter tells SwiftyKnob not to animate the knob when it's drawn. You can then use the following line to fire the animation.

knob.animate()

Note: Calling animate inside viewDidLoad will not work. Instead you should call it in viewDidAppear.

In storyboards

1. Add a UIView to your scene

2. Make Knob the custom class of your view

3. Customize your knob using the exposed attributes

Contributing

1. Fork it!
2. Create your feature branch: git checkout -b my-new-feature
3. Commit your changes: git commit -am 'Add some feature'
4. Push to the branch: git push origin my-new-feature
5. Submit a pull request

Credits

Thanks to @mikedev for his awesome answer on StackOverflow about CAShapeLayer and CABasicAnimation!

License

SwiftyKnob is available under the MIT License. See the LICENSE file for more info.

If you like what I do, you should follow me on Twitter: @jevinsew ✌️