Konva Class: Transformer

new Transformer(config)

Transformer constructor. Transformer is a special type of group that allow you transform Konva
primitives and shapes. Transforming tool is not changing width and height properties of nodes
when you resize them. Instead it changes scaleX and scaleY properties.

Parameters:

Name Type Description

config

Object

Properties

Name	Type	Argument	Description
`resizeEnabled`	Boolean	<optional>	Default is true
`rotateEnabled`	Boolean	<optional>	Default is true
`rotationSnaps`	Array	<optional>	Array of angles for rotation snaps. Default is []
`rotationSnapTolerance`	Number	<optional>	Snapping tolerance. If closer than this it will snap. Default is 5
`rotateAnchorOffset`	Number	<optional>	Default is 50
`padding`	Number	<optional>	Default is 0
`borderEnabled`	Boolean	<optional>	Should we draw border? Default is true
`borderStroke`	String	<optional>	Border stroke color
`borderStrokeWidth`	Number	<optional>	Border stroke size
`borderDash`	Array	<optional>	Array for border dash.
`anchorFill`	String	<optional>	Anchor fill color
`anchorStroke`	String	<optional>	Anchor stroke color
`anchorCornerRadius`	String	<optional>	Anchor corner radius
`anchorStrokeWidth`	Number	<optional>	Anchor stroke size
`anchorSize`	Number	<optional>	Default is 10
`keepRatio`	Boolean	<optional>	Should we keep ratio when we are moving edges? Default is true
`centeredScaling`	Boolean	<optional>	Should we resize relative to node's center? Default is false
`enabledAnchors`	Array	<optional>	Array of names of enabled handles
`boundBoxFunc`	function	<optional>	Bounding box function
`ignoreStroke`	function	<optional>	Should we ignore stroke size? Default is false

Source:: konva.js

Example

var transformer = new Konva.Transformer({
  nodes: [rectangle],
  rotateAnchorOffset: 60,
  enabledAnchors: ['top-left', 'top-right', 'bottom-left', 'bottom-right']
});
layer.add(transformer);

Methods

anchorCornerRadius(enabled)

get/set anchor corner radius

Parameters:

Name	Type	Description
`enabled`	Number

Source:: konva.js

Returns:

Type: Number

Example

// get
var anchorCornerRadius = transformer.anchorCornerRadius();

// set
transformer.anchorCornerRadius(3);

anchorFill(enabled)

get/set anchor fill color

Parameters:

Name	Type	Description
`enabled`	Boolean

Source:: konva.js

Returns:

Type: Boolean

Example

// get
var anchorFill = transformer.anchorFill();

// set
transformer.anchorFill('red');

anchorStroke(enabled)

get/set anchor stroke color

Parameters:

Name	Type	Description
`enabled`	Boolean

Source:: konva.js

Returns:

Type: Boolean

Example

// get
var anchorStroke = transformer.anchorStroke();

// set
transformer.anchorStroke('red');

anchorStrokeWidth(enabled)

get/set anchor stroke width

Parameters:

Name	Type	Description
`enabled`	Boolean

Source:: konva.js

Returns:

Type: Boolean

Example

// get
var anchorStrokeWidth = transformer.anchorStrokeWidth();

// set
transformer.anchorStrokeWidth(3);

attachTo()

alias to tr.nodes([shape])/ This method is deprecated and will be removed soon.

Source:: konva.js

Returns:

Type: Konva.Transformer

Example

transformer.attachTo(shape);

borderDash(enabled)

get/set border dash array

Parameters:

Name	Type	Description
`enabled`	Boolean

Source:: konva.js

Returns:

Type: Boolean

Example

// get
var borderDash = transformer.borderDash();

// set
transformer.borderDash([2, 2]);

borderEnabled(enabled)

get/set visibility of border

Parameters:

Name	Type	Description
`enabled`	Boolean

Source:: konva.js

Returns:

Type: Boolean

Example

// get
var borderEnabled = transformer.borderEnabled();

// set
transformer.borderEnabled(false);

borderStroke(enabled)

get/set border stroke color

Parameters:

Name	Type	Description
`enabled`	Boolean

Source:: konva.js

Returns:

Type: Boolean

Example

// get
var borderStroke = transformer.borderStroke();

// set
transformer.borderStroke('red');

borderStrokeWidth(enabled)

get/set border stroke width

Parameters:

Name	Type	Description
`enabled`	Boolean

Source:: konva.js

Returns:

Type: Boolean

Example

// get
var borderStrokeWidth = transformer.borderStrokeWidth();

// set
transformer.borderStrokeWidth(3);

boundBoxFunc(func)

get/set bounding box function. IMPORTANT! boundBondFunc operates in absolute coordinates.

Parameters:

Name	Type	Description
`func`	function

Source:: konva.js

Returns:

Type: function

Example

// get
var boundBoxFunc = transformer.boundBoxFunc();

// set
transformer.boundBoxFunc(function(oldBox, newBox) {
  // width and height of the boxes are corresponding to total absolute width and height of all nodes combined
  // so it includes scale of the node.
  if (newBox.width > 200) {
    return oldBox;
  }
  return newBox;
});

centeredScaling(centeredScaling)

get/set should we resize relative to node's center?

Parameters:

Name	Type	Description
`centeredScaling`	Boolean

Source:: konva.js

Returns:

Type: Boolean

Example

// get
var centeredScaling = transformer.centeredScaling();

// set
transformer.centeredScaling(true);

detach()

detach transformer from an attached node

Source:: konva.js

Returns:

Type: Konva.Transformer

Example

transformer.detach();

enabledAnchors(array)

get/set enabled handlers

Parameters:

Name	Type	Description
`array`	Array

Source:: konva.js

Returns:

Type: Array

Example

// get list of handlers
var enabledAnchors = transformer.enabledAnchors();

// set handlers
transformer.enabledAnchors(['top-left', 'top-center', 'top-right', 'middle-right', 'middle-left', 'bottom-left', 'bottom-center', 'bottom-right']);

forceUpdate()

force update of Konva.Transformer.
Use it when you updated attached Konva.Group and now you need to reset transformer size

Source:: konva.js

getActiveAnchor()

return the name of current active anchor

Source:: konva.js

Returns:

Type: String | Null

Example

transformer.getActiveAnchor();

ignoreStroke(ignoreStroke)

get/set should we think about stroke while resize? Good to use when a shape has strokeScaleEnabled = false
default is false

Parameters:

Name	Type	Description
`ignoreStroke`	Boolean

Source:: konva.js

Returns:

Type: Boolean

Example

// get
var ignoreStroke = transformer.ignoreStroke();

// set
transformer.ignoreStroke(true);

isTransforming()

determine if transformer is in active transform

Source:: konva.js

Returns:

Type: Boolean

keepRatio(keepRatio)

get/set should we keep ratio while resize anchors at corners

Parameters:

Name	Type	Description
`keepRatio`	Boolean

Source:: konva.js

Returns:

Type: Boolean

Example

// get
var keepRatio = transformer.keepRatio();

// set
transformer.keepRatio(false);

nodes()

get/set attached nodes of the Transformer. Transformer will adapt to their size and listen to their events

Source:: konva.js

Returns:

Type: Konva.Node

Example

// get
const nodes = transformer.nodes();

// set
transformer.nodes([rect, circle]);

// push new item:
const oldNodes = transformer.nodes();
const newNodes = oldNodes.concat([newShape]);
// it is important to set new array instance (and concat method above will create it)
transformer.nodes(newNodes);

padding(padding)

get/set padding

Parameters:

Name	Type	Description
`padding`	Number

Source:: konva.js

Returns:

Type: Number

Example

// get
var padding = transformer.padding();

// set
transformer.padding(10);

resizeEnabled(array)

get/set resize ability. If false it will automatically hide resizing handlers

Parameters:

Name	Type	Description
`array`	Array

Source:: konva.js

Returns:

Type: Array

Example

// get
var resizeEnabled = transformer.resizeEnabled();

// set
transformer.resizeEnabled(false);

rotateAnchorOffset(offset)

get/set distance for rotation handler

Parameters:

Name	Type	Description
`offset`	Number

Source:: konva.js

Returns:

Type: Number

Example

// get
var rotateAnchorOffset = transformer.rotateAnchorOffset();

// set
transformer.rotateAnchorOffset(100);

rotateEnabled(enabled)

get/set ability to rotate.

Parameters:

Name	Type	Description
`enabled`	Boolean

Source:: konva.js

Returns:

Type: Boolean

Example

// get
var rotateEnabled = transformer.rotateEnabled();

// set
transformer.rotateEnabled(false);

rotationSnaps(array)

get/set rotation snaps angles.

Parameters:

Name	Type	Description
`array`	Array

Source:: konva.js

Returns:

Type: Array

Example

// get
var rotationSnaps = transformer.rotationSnaps();

// set
transformer.rotationSnaps([0, 90, 180, 270]);

rotationSnapTolerance(tolerance)

get/set distance for rotation tolerance

Parameters:

Name	Type	Description
`tolerance`	Number

Source:: konva.js

Returns:

Type: Number

Example

// get
var rotationSnapTolerance = transformer.rotationSnapTolerance();

// set
transformer.rotationSnapTolerance(100);

stopTransform()

Stop active transform action

Source:: konva.js

Returns:

Type: Boolean

validateAnchors(10)

get/set anchor size. Default is 10

Parameters:

Name	Type	Description
`10`	Number

Source:: konva.js

Returns:

Type: Number

Example

// get
var anchorSize = transformer.anchorSize();

// set
transformer.anchorSize(20)