thepowerofswift / drawsana

An open source library that lets your users draw on things - mark up images with text, shapes, etc.

Drawsana 0.11.0

Drawsana is a generalized framework for making freehand drawing views on iOS. You can let users scribble over images, add shapes and text, and even make your own tools.

Do you want to let your users mark up images? Are you writing a simple painting app? Drawsana might work for you!

Demo source code

Docs

Like what you see? Come work with us!

Features

• Built-in tools
  • Pen with line smoothing
  • Eraser
  • Ellipse, rect, line, arrow
  • Selection
  • Text
• Undo/redo
• Drawings are Codable, so you can save and load them
• Extensible—make your own shapes and tools without forking the library

Installation

Add Asana/Drawsana to your Cartfile and update your project like you would for any other Carthage framework, or clone the source code and add the project to your workspace.

github "Asana/Drawsana" == 0.11.0

Usage

import Drawsana

class MyViewController: UIViewController {
  let drawsanaView = DrawsanaView()
  let penTool = PenTool()
  
  func viewDidLoad() {
    /* ... */
    drawsanaView.set(tool: penTool)
    drawsanaView.userSettings.strokeWidth = 5
    drawsanaView.userSettings.strokeColor = .blue
    drawsanaView.userSettings.fillColor = .yellow
    drawsanaView.userSettings.fontSize = 24
    drawsanaView.userSettings.fontName = "Marker Felt"
  }
  
  func save() {
    let jsonEncoder = JSONEncoder()
    jsonEncoder.outputFormatting = [.prettyPrinted, .sortedKeys]
    let jsonData = try! jsonEncoder.encode(drawingView.drawing)
    // store jsonData somewhere
  }
  
  func load() {
    let data = // load data from somewhere
    let jsonDecoder = JSONDecoder()
    let drawing = try! jsonDecoder.decode(Drawing.self, from: jsonData)
    drawsanaView.drawing = drawing
  }
  
  func showFinalImage() {
    imageView.image = drawsanaView.render() 
  }
}

Background images

Drawsana does not currently have a way to automatically show an image under your drawing. We recommend that, like in the example class, you add a UIImageView underneath your DrawsanaView and make sure your DrawsanaView's frame matches the image frame. When it's time to get the final image, use DrawsanaView.render(over: myImage).

Building docs

sudo gem install jazzy
make docs
open .docs/index.html

pip install ghp-import
make publish-docs
open https://asana.github.io/Drawsana

Changelog

0.11.0

• DrawingOperationStack.clearRedoStack() clears all redo operations from the redo stack.
• DrawingToolForShapeWithThreePoints and DrawingToolForShapeWithTwoPoints are declared open instead of public so they can be subclassed.
• PenShape now works with the selection tool.
• DrawsanaView.selectionIndicatorAnchorPointOffset allows Drawsana to keep working when you change the anchorPoint.
• Shape.id is now settable.
• Fix bug that prevented character input of some languages, including Chinese.
• Fix bugs in gesture recognizer.

0.10.0

• Convert to Swift 5
• Fix NgonShape and TextShape serialization bugs. Old data can't be fixed, but new data will be correct.
• Deserialization error reporting is more detailed. Shapes that find a JSON object with the correct type will now throw errors instead of causing the whole operation to silently fail, as long as you enable Drawing.debugSerialization.
• Replacing DrawingView.drawing now behaves correctly instead of being unusably buggy.
• PenLineSegment's members are now public.
• ShapeTransform and PenLineSegment are now Equatable.

0.9.4

• Star, triangle, pentagon, and angle tools
• DrawsanaView.render() accepts a scale parameter instead of always using zero

0.9.2

• Convert to Swift 4.2
• CocoaPods support

0.9.1

• DrawsanaView.selectionIndicatorViewShapeLayer is exposed, allowing you to more easily customize the appearance of the selection indicator
• Changes to DrawsanaView.selectionIndicatorView's style are animated in fewer cases, which more closely matches user intent
• Improved text tool use in the demo app

0.9.0

Initial release