Flutter iOS Pencil Kit

Flutter plugin for using iOS Pencil Kit

Changelog

Note 📒

• This package only provides iOS implementation. If you try use widget of this package other than iOS, you see a Red warning box.
• iOS Pencil Kit is available from iOS 13.0

Supported Platforms 📱

• iOS

Highlights 🌟

• Drawing
• Show/Hide palette
• Undo/Redo
• Clear
• UI properties(background color, scrollability, isOpaque, etc...)
• Import/Export drawing data
• Get drawing png/jpeg image data as base64
• Manage drawing tools programmatically

Requirements ✅

• iOS: Deployment target >= 9.0

Setup & Usage 🎉

flutter pub add pencil_kit

Available Methods

Methods available for PencilKitController.

Method	Description	Throws	Etc
clear()	Clear canvas	X
show()	Show Palette	X
hide()	Hide Palette	X
redo()	Redo last drawing action	X
undo()	Undo last drawing action	X
save(): Future<String?>	Save drawing data into file system, can return base 64 data if withBase64Data is true	O
load(): Future<String?>	Load drawing data from file system, can return base 64 data if withBase64Data is true	O
getBase64Data(): Future	Get current drawing data as base64 string form	O
loadBase64Data(String base64Data): Future	Load base64 drawing data into canvas	O
getBase64PngData(): Future	Get current drawing data as png base64 string form	O	scale = 0 means use default UIScreen.main.scale
getBase64JpegData(): Future	Get current drawing data as jpeg base64 string form	O	scale = 0 means use default UIScreen.main.scale. default compression is 0.93
setPKTool({required ToolType toolType, double? width, Color? color}): Future	Set PKTool type with width and color	X

Caution for setPKTool

setPKTool can fail if tool type is not supported by device iOS version In eraser tools, the width parameter will work only from iOS 16.4 or above iOS version

You should check whether feature is available in user's iOS version with [ToolType.isAvailableFromIos16_4] and [ToolType.isAvailableFromIos17]

Read more about ToolType type definition.

Type definition

/// PKTool type enum for [PencilKitController.setPKTool]
enum ToolType {
  /// pen tool
  pen(false, false),

  /// pencil tool
  pencil(false, false),

  /// marker tool
  marker(false, false),

  /// monoline tool, available from iOS 17.0
  monoline(false, true),

  /// fountainPen tool, available from iOS 17.0
  fountainPen(false, true),

  /// watercolor tool, available from iOS 17.0
  watercolor(false, true),

  /// crayon tool, available from iOS 17.0
  crayon(false, true),

  /// vector eraser tool
  eraserVector(false, false),

  /// bitmap eraser tool
  eraserBitmap(false, false),

  /// fixed width bitmap eraser tool, available from iOS 16.4
  eraserFixedWidthBitmap(true, false),
  ;

  const ToolType(this.isAvailableFromIos16_4, this.isAvailableFromIos17);

  final bool isAvailableFromIos16_4;
  final bool isAvailableFromIos17;
}

PencilKit Widget Parameters

All the available parameters.

Parameter	Description
onPencilKitViewCreated	A callback for platform view created. You can store PencilKitController from argument of this callback.
hitTestBehavior	iOS UIKitView hitTestBehavior
unAvailableFallback	A widget for render UnAvailable state. The default is A red box
alwaysBounceVertical	A Boolean value that determines whether bouncing always occurs when vertical scrolling reaches the end of the content.
alwaysBounceHorizontal	A Boolean value that determines whether bouncing always occurs when horizontal scrolling reaches the end of the content view.
isRulerActive	A Boolean value that indicates whether a ruler view is visible on the canvas.
drawingPolicy	The policy that controls the types of touches allowed when drawing on the canvas. This properties can be applied from iOS 14.0
toolPickerVisibilityDidChange	Tells the delegate that the tool picker UI changed visibility.
toolPickerIsRulerActiveDidChange	Tells the delegate that the ruler active state was changed by the user.
toolPickerFramesObscuredDidChange	Tells the delegate that the frames the tool picker obscures changed.
toolPickerSelectedToolDidChange	Tells the delegate that the selected tool was changed by the user.
canvasViewDidBeginUsingTool	Called when the user starts using a tool, eg. selecting, drawing, or erasing.
canvasViewDidEndUsingTool	Called when the user stops using a tool, eg. selecting, drawing, or erasing.
canvasViewDrawingDidChange	Called after the drawing on the canvas did change.
canvasViewDidFinishRendering	Called after setting drawing when the entire drawing is rendered and visible.

Contribution

Please read CONTRIBUTING.md and contribute your works! Thank you :)

Example

Check example on pub.dev page or example project repo

Troubleshooting

• I get a Pencil Kit XXX+ ms and it freezes.
  • Turn off Graphics HUD menu in iOS Developer Settings. #22