CropperCanvas

The CropperCanvas interface provides properties and methods for manipulating the layout and presentation of <cropper-canvas> elements.

Examples

Basic

TIP

The default minimum width and minimum height of this element are 200px and 100px.

Background

Interactive

Disabled

All pointer events are disabled.

Properties

Inherits properties from its parent, CropperElement, and implements the following properties:

NameTypeDefaultOptionsDescription
backgroundbooleanfalse-Indicates whether this element has a grid background.
disabledbooleanfalse-Indicates whether this element is disabled.
scaleStepnumber0.1-Indicates the stepping interval of the scaling factor when zooming in/out by wheeling, must a positive number.
themeColorstring"#39f"-Indicates the primary color of this element and its children.

Methods

$setAction

  • Syntax: $setAction(action)
  • Arguments:
    • action:
      • Type: string
      • The new action.
  • Returns:
    • Type: CropperCanvas
    • The element instance for chaining.

Changes the current action to a new one.

$toCanvas

  • Syntax:
    • $toCanvas()
    • $toCanvas(options)
  • Arguments:
    • options:
      • Type: Object
      • The available options.
      • Properties:
        • width:
          • Type: number
          • The width of the canvas.
        • height:
          • Type: number
          • The height of the canvas.
        • beforeDraw:
          • Type: Function
          • The function called before drawing the image onto the canvas.
          • Syntax: beforeDraw(context, canvas)
          • Arguments:
            • context:
              • Type: CanvasRenderingContext2D
              • The 2D rendering context of the canvas.
            • canvas:
              • Type: HTMLCanvasElement
              • The canvas element itself.
          • Example: function (context) { context.filter = 'grayscale(100%)'; }
  • Returns:
    • Type: Promise
    • A promise that resolves to the generated canvas element.
  • Example:

Generates a real canvas element, with the image drawn into if there is one.

Events

action

The event is fired when a pointer changes on the canvas.

  • Event:
    • event.bubbles: true
    • event.cancelable: false
    • event.composed: true
    • event.detail:
      • Type: Object
      • The related data of the action.
    • event.detail.action:
      • Type: string
      • Options: "select", "move", "scale", "rotate", "transform", "n-resize", "e-resize", "s-resize", "w-resize", "ne-resize", "nw-resize", "se-resize", and "sw-resize".
      • The action type.
    • event.detail.relatedEvent:
      • Type: PointerEvent | TouchEvent | MouseEvent | WheelEvent
      • The related native event that triggered this event.
    • event.detail.scale:
      • Type: number
      • The scaling factor, only available when the action is "scale" or "transform".
    • event.detail.rotate:
      • Type: number
      • The scaling factor, only available when the action is "rotate"or "transform".
    • event.detail.startX:
      • Type: number
      • The starting pageX value, only available when the relatedEvent is PointerEvent, TouchEvent, or MouseEvent.
    • event.detail.startY:
      • Type: number
      • The starting pageY value, only available when the relatedEvent is PointerEvent, TouchEvent, or MouseEvent.
    • event.detail.endX:
      • Type: number
      • The ending pageX value, only available when the relatedEvent is PointerEvent, TouchEvent, or MouseEvent.
    • event.detail.endY:
      • Type: number
      • The ending pageY value, only available when the relatedEvent is PointerEvent, TouchEvent, or MouseEvent.
  • Example:
<cropper-canvas id="canvas"></cropper-canvas>

<script>
document.querySelector('#canvas').addEventListener('action', function (event) {
  console.log(event);
});
</script>

actionstart

The event is fired when a pointer becomes active.

  • Event:
    • event.bubbles: true
    • event.cancelable: true
    • event.composed: true
    • event.detail:
      • Type: Object
      • The related data of the action.
    • event.detail.action:
      • Type: string
      • Options: same as the action event.
      • The action type.
    • event.detail.relatedEvent:
      • Type: PointerEvent | TouchEvent | MouseEvent
      • The related native event that triggered this event.

actionmove

This event is fired when a pointer changes coordinates.

  • Event:
    • event.bubbles: true
    • event.cancelable: true
    • event.composed: true
    • event.detail:
      • Type: Object
      • The related data of the action.
    • event.detail.action:
      • Type: string
      • Options: same as the action event.
      • The action type.
    • event.detail.relatedEvent:
      • Type: PointerEvent | TouchEvent | MouseEvent
      • The related native event that triggered this event.

actionend

This event is fired when a pointer is no longer active.

  • Event:
    • event.bubbles: true
    • event.cancelable: true
    • event.composed: true
    • event.detail:
      • Type: Object
      • The related data of the action.
    • event.detail.action:
      • Type: string
      • Options: same as the action event.
      • The action type.
    • event.detail.relatedEvent:
      • Type: PointerEvent | TouchEvent | MouseEvent
      • The related native event that triggered this event.

Slots

There is only one default slot in this element.

You can disable it by setting the slottable property to false:

<cropper-canvas slottable="false"></cropper-canvas>