Tldraw/packages/core/README.md

@tldraw/core

This package contains the core of the tldraw library. It includes:

• Renderer - a React component
• TLShapeUtility - an abstract class for custom shape utilities
• the library's TypeScript types
• several utility classes:
  • Utils
  • Vec
  • Svg
  • brushUpdater
  • Intersect

Installation

yarn add @tldraw/core --peer

Usage

Import the Renderer React component and pass it the required props.

• Example
• Guide: Create a Custom Shape

Documentation

Renderer

Prop	Type	Description
page	TLPage	The current page object.
pageState	TLPageState	The current page's state.
shapeUtils	TLShapeUtils{}	The shape utilities used to render the shapes.
theme	object	(optional) an object with overrides for the Renderer's default colors.

The theme object accepts valid CSS colors for the following properties:

Property	Description
foreground	(optional) The primary (usually "text") color
background	(optional) The default page's background color
brushFill	(optional) The fill color of the brush selection box
brushStroke	(optional) The stroke color of the brush selection box
selectFill	(optional) The fill color of the selection bounds
selectStroke	(optional) The stroke color of the selection bounds and handles

Tip: If providing an object for the theme prop, either define the object outside of the parent component or memoize it with React.useMemo.

The renderer also accepts many (optional) event callbacks.

Prop	Description
onPan	The user panned with the mouse wheel
onZoom	The user zoomed with the mouse wheel
onPinch	The user moved their pointers during a pinch
onPinchEnd	The user stopped a two-pointer pinch
onPinchStart	The user began a two-pointer pinch
onPointerMove	The user moved their pointer
onPointerUp	The user ended a point
onPointShape	The user pointed a shape
onDoubleClickShape	The user double-pointed a shape
onRightPointShape	The user right-pointed a shape
onMoveOverShape	The user moved their pointer a shape
onHoverShape	The user moved their pointer onto a shape
onUnhoverShape	The user moved their pointer off of a shape
onPointHandle	The user pointed a shape handle
onDoubleClickHandle	The user double-pointed a shape handle
onRightPointHandle-	he user right-pointed a shape handle
onMoveOverHandle	The user moved their pointer over a shape handle
onHoverHandle	The user moved their pointer onto a shape handle
onUnhoverHandle	The user moved their pointer off of a shape handle
onPointCanvas	The user pointed the canvas
onDoubleClickCanvas	The user double-pointed the canvas
onRightPointCanvas	The user right-pointed the canvas
onPointBounds	The user pointed the selection bounds
onDoubleClickBounds	The user double-pointed the selection bounds
onRightPointBounds	The user right-pointed the selection bounds
onPointBoundsHandle	The user pointed a selection bounds edge or corner
onDoubleClickBoundsHandle	The user double-pointed a selection bounds edge or corner
onBlurEditingShape	The user blurred an editing (text) shape
onError	The renderer encountered an error

Tip: If providing callbacks, either define the functions outside of the parent component or memoize them first with React.useMemo.

TLPage

An object describing the current page. It contains:

Property	Type	Description
id	string	A unique id for the page.
shapes	TLShape{}	A table of shapes.
bindings	TLBinding{}	A table of bindings.
backgroundColor	string	(optional) The page's background fill color. Will also overwrite the theme.

TLPageState

An object describing the current page. It contains:

Property	Type	Description
id	string	The corresponding page's id
selectedIds	string[]	An array of selected shape ids
camera	object	An object describing the camera state
camera.point	number[]	The camera's [x, y] coordinates
camera.zoom	number	The camera's zoom level
currentParentId	string	(optional) The current parent id for selection
brush	TLBounds	(optional) A Bounds for the current selection box
pointedId	string	(optional) The currently pointed shape id
hoveredId	string	(optional) The currently hovered shape id
editingId	string	(optional) The currently editing shape id
editingBindingId	string	(optional) The currently editing binding id

TLShape

An object that describes a shape on the page. The shapes in your document should extend this interface with other properties. See Guide: Create a Custom Shape.

Property	Type	Description
id	string	The shape's id.
type	string	The type of the shape, corresponding to the type of a TLShapeUtil.
parentId	string	The id of the shape's parent (either the current page or another shape).
childIndex	number	the order of the shape among its parent's children
name	string	the name of the shape
point	number[]	the shape's current [x, y] coordinates on the page
rotation	number	(optiona) The shape's current rotation in radians
children	string[]	(optional) An array containing the ids of this shape's children
handles	TLHandle{}	(optional) A table of TLHandle objects
isLocked	boolean	(optional) True if the shape is locked
isHidden	boolean	(optional) True if the shape is hidden
isEditing	boolean	(optional) True if the shape is currently editing
isGenerated	boolean	optional) True if the shape is generated programatically
isAspectRatioLocked	boolean	(optional) True if the shape's aspect ratio is locked

TLHandle

An object that describes a relationship between two shapes on the page.

Property	Type	Description
id	string	An id for the handle.
index	number	The handle's order within the shape's handles.
point	number[]	The handle's [x, y] coordinates.

TLBinding

An object that describes a relationship between two shapes on the page.

Property	Type	Description
id	string	A unique id for the binding.
type	string	The binding's type.
fromId	string	The id of the shape where the binding begins.
toId	string	The id of the shape where the binding begins.

TLShapeUtil

The TLShapeUtil is an abstract class that you can extend to create utilities for your custom shapes. See Guide: Create a Custom Shape.

brushUpdater

The brushUpdater is a special class instance that allows you to quickly update the selection brush rectangle.

Method	Description
set	a method that accepts either a TLBounds object or undefined
clear	a method to hide the brush

Normally, the renderer's brush will update in response to changes to pageState.brush; however, calling brushUpdater.set will produce a faster change in the brush rectangle. Calling brushUpdater.set will prevent the brush from any future updates from pageState.brush.

inputs

A class instance that stores the current pointer position and pressed keys.

Utils

A general purpose utility class.

Vec

A utility class for vector math and related methods.

Svg

A utility class for creating SVG path data through imperative commands.

Intersect

A utility class for finding intersections between various geometric shapes.

Guides

Create a Custom Shape

...

Example

import * as React from "react"
import { Renderer, TLShape, TLShapeUtil, Vec } from '@tldraw/core'

interface RectangleShape extends TLShape {
  type: "rectangle",
  size: number[]
}

class Rectangle extends TLShapeUtil<RectangleShape> {
  // See the "Create a Custom Shape" guide
}

const myShapes = { rectangle: new Rectangle() }

function App() {
  const [page, setPage] = React.useState({
    id: "page1"
    shapes: {
      "rect1": {
        id: 'rect1',
        parentId: 'page1',
        name: 'Rectangle',
        childIndex: 0,
        type: 'rectangle',
        point: [0, 0],
        rotation: 0,
        size: [100, 100],
      }
    },
    bindings: {}
  })

  const [pageState, setPageState] = React.useState({
    id: "page1",
    selectedIds: [],
    camera: {
      point: [0,0],
      zoom: 1
    }
  })

  const handlePan = React.useCallback((delta: number[]) => {
    setPageState(pageState => {
      ...pageState,
      camera: {
        zoom,
        point: Vec.sub(pageState.point, Vec.div(delta, pageState.zoom)),
      },
    })
  }, [])

  return (<Renderer
    shapes={myShapes}
    page={page}
    pageState={pageState}
    onPan={handlePan}
  />)
}

Development

Run yarn to install dependencies.

Run yarn start to begin the monorepo's development server (@tldraw/site).

Run nx test core to execute unit tests via Jest.

Contribution

To contribute, visit the Discord channel.