/* eslint-disable no-unused-vars */
/* eslint-disable no-console */
/* globals debugCanvas */
import Interface from './interface.js'
import { Points, Polygon, Angle, Elements, LowPassFilter } from './utils.js'
import Events from './events.js'
import { InteractionMapper } from './interaction.js'
import { Capabilities } from './capabilities.js'

/** This interface allows scatters to delegate tap events to other objects. */
export class ITapDelegate extends Interface {
    /** This method must be defined by the delegate. It handles the tap event. */
    tap(event) {}

    /** Tells the delegate that it should handle standard click events. */
    handleClicks() {}
}

/**
 * A base class for scatter specific events.
 *
 * @constructor
 * @param {name} String - The name of the event
 * @param {target} Object - The target of the event
 */
export class BaseEvent {
    constructor(name, target) {
        this.name = name
        this.target = target
    }
}

// Event types
const START = 'onStart'
const UPDATE = 'onUpdate'
const END = 'onEnd'

/**
 * A scatter event that describes how the scatter has changed.
 *
 * @constructor
 * @param {target} Object - The target scatter of the event
 * @param {optional} Object - Optional parameter
 */
export class ScatterEvent extends BaseEvent {
    constructor(
        target,
        { translate = { x: 0, y: 0 }, scale = null, rotate = 0, about = null, fast = false, type = null } = {}
    ) {
        super('scatterTransformed', { target: target })
        this.translate = translate
        this.scale = scale
        this.rotate = rotate
        this.about = about
        this.fast = fast
        this.type = type
    }

    toString() {
        return (
            "Event('scatterTransformed', scale: " + this.scale + ' about: ' + this.about.x + ', ' + this.about.y + ')'
        )
    }
}

/**
 * A scatter resize event that describes how the scatter has changed.
 *
 * @constructor
 * @param {target} Object - The target scatter of the event
 * @param {optional} Object - Optional parameter
 */
export class ResizeEvent extends BaseEvent {
    constructor(target, { width = 0, height = 0 } = {}) {
        super('scatterResized', { width: width, height: height })
        this.width = width
        this.height = height
    }

    toString() {
        return 'Event(scatterResized width: ' + this.width + 'height: ' + this.height + ')'
    }
}

/**
 * A abstract base class that implements the throwable behavior of a scatter
 * object.
 *
 * @constructor
 */
class Throwable {
    constructor({
        movableX = true,
        movableY = true,
        throwVisibility = 44,
        throwDamping = 0.95,
        autoThrow = true,
        onThrowFinished = null
    } = {}) {
        this.movableX = movableX
        this.movableY = movableY
        this.throwVisibility = throwVisibility
        this.throwDamping = throwDamping
        this.autoThrow = autoThrow
        this.velocities = []
        this.velocity = null
        this.timestamp = null
        this.onThrowFinished = onThrowFinished
        //console.log("onThrowFinished", onThrowFinished)
    }

    observeVelocity() {
        this.lastframe = performance.now()
    }

    addVelocity(delta, buffer = 5) {
        let t = performance.now()
        let dt = t - this.lastframe
        this.lastframe = t
        if (dt > 0) {
            // Avoid division by zero errors later on
            // and consider the number of involved pointers sind addVelocity will be called by the
            // onMove events
            let velocity = {
                t: t,
                dt: dt,
                dx: delta.x / delta.number,
                dy: delta.y / delta.number
            }
            this.velocities.push(velocity)
            while (this.velocities.length > buffer) {
                this.velocities.shift()
            }
        }
    }

    meanVelocity(milliseconds = 30) {
        this.addVelocity({ x: 0, y: 0, number: 1 })
        let sum = { x: 0, y: 0 }
        let count = 0
        let t = 0
        for (let i = this.velocities.length - 1; i > 0; i--) {
            let v = this.velocities[i]
            t += v.dt
            let nv = { x: v.dx / v.dt, y: v.dy / v.dt }
            sum = Points.add(sum, nv)
            count += 1
            if (t > milliseconds) {
                break
            }
        }
        if (count === 0) return sum // empty vector
        return Points.multiplyScalar(sum, 1 / count)
    }

    killAnimation() {
        this.velocity = null
        this.velocities = []
    }

    startThrow() {
        this.velocity = this.meanVelocity()
        if (this.velocity != null) {
            // Call next velocity to ansure that specializations
            // that use keepOnStage are called
            this.velocity = this.nextVelocity(this.velocity)
            if (this.autoThrow) this.animateThrow(performance.now())
        } else {
            this.onDragComplete()
        }
    }

    _throwDeltaTime() {
        let t = performance.now()
        let dt = t - this.lastframe
        this.lastframe = t
        return dt
    }

    animateThrow(time) {
        if (this.velocity != null) {
            let dt = this._throwDeltaTime()
            // console.log("animateThrow", dt)
            let next = this.nextVelocity(this.velocity)
            let prevLength = Points.length(this.velocity)
            let nextLength = Points.length(next)
            if (nextLength > prevLength) {
                let factor = nextLength / prevLength
                next = Points.multiplyScalar(next, 1 / factor)
                console.log('Prevent acceleration', factor, this.velocity, next)
            }
            this.velocity = next
            let d = Points.multiplyScalar(this.velocity, dt)
            this._move(d)

            this.onDragUpdate(d)
            if (dt == 0 || this.needsAnimation()) {
                requestAnimationFrame(this.animateThrow.bind(this))
                return
            } else {
                if (this.isOutside()) {
                    requestAnimationFrame(this.animateThrow.bind(this))
                    return
                }
            }
        }
        this.onDragComplete()
        if (this.onThrowFinished != null) {
            this.onThrowFinished()
        }
    }

    needsAnimation() {
        if (this.velocity == null) {
            return false
        }
        return Points.length(this.velocity) > 0.01
    }

    nextVelocity(velocity) {
        // Must be overwritten: computes the changed velocity. Implement
        // damping, collison detection, etc. here
        let next = Points.multiplyScalar(velocity, this.throwDamping)
        return {
            x: this.movableX ? next.x : 0,
            y: this.movableY ? next.y : 0
        }
    }

    _move(delta) {
        // Overwrite if necessary
    }

    onDragComplete() {
        // Overwrite if necessary
    }

    onDragUpdate(delta) {
        // Overwrite if necessary
    }
}

export class AbstractScatter extends Throwable {
    constructor({
        minScale = 0.1,
        maxScale = 1.0,
        startScale = 1.0,
        autoBringToFront = true,
        autoThrow = true,
        translatable = true,
        scalable = true,
        rotatable = true,
        resizable = false,
        movableX = true,
        movableY = true,
        throwVisibility = 44,
        throwDamping = 0.95,
        overdoScaling = 1,
        mouseZoomFactor = 1.1,
        rotationDegrees = null,
        rotation = null,
        onTransform = null,
        interactive = true,
        onClose = null,
        onThrowFinished = null,
        scaleAutoClose = false,
        scaleCloseThreshold = 0.1,
        scaleCloseBuffer = 0.05,
        maxRotation = Angle.degree2radian(5),
        minInteractionDistance = 0,
        useLowPassFilter = false
    } = {}) {
        if (rotationDegrees != null && rotation != null) {
            throw new Error('Use rotationDegrees or rotation but not both')
        } else if (rotation != null) {
            rotationDegrees = Angle.radian2degree(rotation)
        } else if (rotationDegrees == null) {
            rotationDegrees = 0
        }
        super({
            movableX,
            movableY,
            throwVisibility,
            throwDamping,
            autoThrow,
            onThrowFinished
        })

        /**
         * Closes the card when the minScale is reached and the
         * card is released. Card can be saved by scaling it up again.
         */
        this.scaleAutoClose = scaleAutoClose
        this.scaleCloseThreshold = scaleCloseThreshold
        this.scaleCloseBuffer = scaleCloseBuffer
        this.scaleAutoCloseTimeout = null

        this.interactive = interactive
        this.startRotationDegrees = rotationDegrees
        this.startScale = startScale // Needed to reset object
        this.minScale = minScale
        this.maxScale = maxScale
        this.maxRotation = maxRotation
        this.overdoScaling = overdoScaling
        this.translatable = translatable
        if (!translatable) {
            this.movableX = false
            this.movableY = false
        }
        this.scalable = scalable
        this.rotatable = rotatable
        this.resizable = resizable
        this.mouseZoomFactor = mouseZoomFactor
        this.autoBringToFront = autoBringToFront
        this.useLowPassFilter = useLowPassFilter
        this.minInteractionDistance = minInteractionDistance
        if (useLowPassFilter) {
            this.rotateLPF = new LowPassFilter()
            this.zoomLPF = new LowPassFilter()
            this.zoomLPF.setup([1, 1, 1, 1, 1, 1, 1, 1, 1, 1])
        }
        this.dragging = false
        this.onTransform = onTransform != null ? [onTransform] : null
        this.onClose = onClose != null ? [onClose] : null
    }

    addCloseEventCallback(callback) {
        if (this.onClose == null) {
            this.onClose = []
        }
        this.onClose.push(callback)
    }

    addTransformEventCallback(callback) {
        if (this.onTransform == null) {
            this.onTransform = []
        }
        this.onTransform.push(callback)
    }

    startGesture(interaction) {
        this.bringToFront()
        this.killAnimation()
        this.observeVelocity()
        if (this.useLowPassFilter) {
            this.rotateLPF.clear()
            this.zoomLPF.clear()
            this.zoomLPF.setup([1, 1, 1, 1, 1, 1, 1, 1, 1, 1])
        }
        return true
    }

    close() {
        console.log('SCATTER WAS CLOSED!')
        this._callCloseCallbacks()
        this._removeCallbacks()
        this._removeSelfFromScatterContainer()
    }

    _callCloseCallbacks() {
        if (this.onClose) {
            this.onClose.forEach(callback => callback(this))
        }
    }

    _removeCallbacks() {
        this.onClose = []
        this.onTransform = []
    }

    _removeSelfFromScatterContainer() {
        // Removes self from container when it's closed.
        if (this.container) {
            this.container.remove(this)
        }
    }

    gesture(interaction) {
        let delta = interaction.delta()
        if (delta != null) {
            this.addVelocity(delta)
            let rotate = delta.rotate
            let zoom = delta.zoom
            if (this.maxRotation != null) {
                if (Math.abs(rotate) > this.maxRotation) {
                    rotate = 0
                }
            }
            if (this.useLowPassFilter) {
                rotate = this.rotateLPF.next(rotate)
                zoom = this.zoomLPF.next(zoom)
            }
            if (delta.distance < this.minInteractionDistance) {
                let ratio = delta.distance / this.minInteractionDistance
                rotate *= ratio
                let zoomDelta = zoom - 1
                zoomDelta *= ratio
                zoom = 1 + zoomDelta
            }

            this.transform(delta, zoom, rotate, delta.about)
            if (zoom != 1) this.interactionAnchor = delta.about
        }
    }

    get polygon() {
        let w2 = (this.width * this.scale) / 2
        let h2 = (this.height * this.scale) / 2
        let center = this.center
        let polygon = new Polygon(center)
        polygon.addPoint({ x: -w2, y: -h2 })
        polygon.addPoint({ x: w2, y: -h2 })
        polygon.addPoint({ x: w2, y: h2 })
        polygon.addPoint({ x: -w2, y: h2 })
        polygon.rotate(this.rotation)
        return polygon
    }

    isOutside() {
        let stagePolygon = this.containerPolygon
        if (stagePolygon == null) return false
        let polygon = this.polygon
        if (polygon == null) return false
        let result = stagePolygon.intersectsWith(polygon)
        return result === false || result.overlap < this.throwVisibility
    }

    recenter() {
        // Return a small vector that guarantees that the scatter is moving
        // towards the center of the stage
        let center = this.center
        let target = this.container.center
        let delta = Points.subtract(target, center)
        return Points.normalize(delta)
    }

    nextVelocity(velocity) {
        return this.keepOnStage(velocity)
    }

    bouncing() {
        // Implements the bouncing behavior of the scatter. Moves the scatter
        // to the center of the stage if the scatter is outside the stage or
        // not within the limits of the throwVisibility.

        let stagePolygon = this.containerPolygon
        let polygon = this.polygon
        let result = stagePolygon.intersectsWith(polygon)
        if (result === false || result.overlap < this.throwVisibility) {
            let cv = this.recenter()
            let recentered = false
            while (result === false || result.overlap < this.throwVisibility) {
                polygon.center.x += cv.x
                polygon.center.y += cv.y
                this._move(cv)
                result = stagePolygon.intersectsWith(polygon)
                recentered = true
            }
            return recentered
        }
        return false
    }

    keepOnStage(velocity, collision = 0.5) {
        let stagePolygon = this.containerPolygon
        // UO: since keepOnStage is called in nextVelocity we need to
        // ensure a return value
        if (!stagePolygon) return { x: 0, y: 0 }
        let polygon = this.polygon
        let bounced = this.bouncing()
        if (bounced) {
            let stage = this.containerBounds
            let x = this.center.x
            let y = this.center.y
            let dx = this.movableX ? velocity.x : 0
            let dy = this.movableY ? velocity.y : 0
            let factor = this.throwDamping
            // if (recentered) {
            if (x < 0) {
                dx = -dx
                factor = collision
            }
            if (x > stage.width) {
                dx = -dx
                factor = collision
            }
            if (y < 0) {
                dy = -dy
                factor = collision
            }
            if (y > stage.height) {
                dy = -dy
                factor = collision
            }
            // }
            return Points.multiplyScalar({ x: dx, y: dy }, factor)
        }
        return super.nextVelocity(velocity)
    }

    endGesture(interaction) {
        this.startThrow()
        this._checkAutoClose()
    }

    _checkAutoClose() {
        if (this.scaleAutoClose)
            if (this.scale < this.minScale + this.scaleCloseThreshold - this.scaleCloseBuffer) {
                this.zoom(this.minScale, {
                    animate: 0.2,
                    onComplete: this.close.bind(this)
                })
            } else if (this.scale < this.minScale + this.scaleCloseThreshold) {
                this.zoom(this.minScale + this.scaleCloseThreshold, {
                    animate: 0.4
                })
            }
    }

    rotateDegrees(degrees, anchor) {
        let rad = Angle.degree2radian(degrees)
        this.rotate(rad, anchor)
    }

    rotate(rad, anchor) {
        this.transform({ x: 0, y: 0 }, 1.0, rad, anchor)
    }

    move(d, { animate = 0 } = {}) {
        if (this.translatable) {
            if (animate > 0) {
                let startPos = this.position
                TweenLite.to(this, animate, {
                    x: '+=' + d.x,
                    y: '+=' + d.y,
                    /* scale: scale, uo: not defined, why was this here? */
                    onUpdate: e => {
                        let p = this.position
                        let dx = p.x - startPos.x
                        let dy = p.x - startPos.y
                        this.onMoved(dx, dy)
                    }
                })
            } else {
                this._move(d)
                this.onMoved(d.x, d.y)
            }
        }
    }

    moveTo(p, { animate = 0 } = {}) {
        let c = this.origin
        let delta = Points.subtract(p, c)
        this.move(delta, { animate: animate })
    }

    centerAt(p, { animate = 0 } = {}) {
        let c = this.center
        let delta = Points.subtract(p, c)
        this.move(delta, { animate: animate })
    }

    zoom(scale, { animate = 0, about = null, delay = 0, x = null, y = null, onComplete = null } = {}) {
        let anchor = about || this.center
        if (scale != this.scale) {
            if (animate > 0) {
                TweenLite.to(this, animate, {
                    scale: scale,
                    delay: delay,
                    onComplete: onComplete,
                    onUpdate: this.onZoomed.bind(this)
                })
            } else {
                this.scale = scale
                this.onZoomed(anchor)
            }
        }
    }

    _move(delta) {
        this.x += this.movableX ? delta.x : 0
        this.y += this.movableX ? delta.y : 0
    }

    transform(translate, zoom, rotate, anchor) {
        let delta = {
            x: this.movableX ? translate.x : 0,
            y: this.movableY ? translate.y : 0
        }
        if (this.resizable) var vzoom = zoom
        if (!this.translatable) delta = { x: 0, y: 0 }
        if (!this.rotatable) rotate = 0
        if (!this.scalable) zoom = 1.0
        if (zoom == 1.0 && rotate == 0) {
            this._move(delta)
            if (this.onTransform != null) {
                let event = new ScatterEvent(this, {
                    translate: delta,
                    scale: this.scale,
                    rotate: 0,
                    about: anchor,
                    fast: false,
                    type: UPDATE
                })
                this.onTransform.forEach(function(f) {
                    f(event)
                })
            }
            return
        }
        let origin = this.rotationOrigin
        let beta = Points.angle(origin, anchor)
        let distance = Points.distance(origin, anchor)
        let { scale: newScale, zoom: thresholdedZoom } = this.calculateScale(zoom)

        let newOrigin = Points.arc(anchor, beta + rotate, distance * thresholdedZoom)
        let extra = Points.subtract(newOrigin, origin)
        let offset = Points.subtract(anchor, origin)
        this._move(offset)
        this.scale = newScale
        this.rotation += rotate
        offset = Points.negate(offset)
        offset = Points.add(offset, extra)
        offset = Points.add(offset, translate)
        this._move(offset)

        delta.x += extra.x
        delta.y += extra.y
        if (this.onTransform != null) {
            let event = new ScatterEvent(this, {
                translate: delta,
                scale: newScale,
                rotate: rotate,
                about: anchor
            })
            this.onTransform.forEach(function(f) {
                f(event)
            })
        }
        if (this.resizable) {
            this.resizeAfterTransform(vzoom)
        }
    }

    /**
     * For a given zoom, a new scale is calculated, taking
     * min and max scale into account.
     *
     * @param {number} zoom - The zoom factor, to scale the object with.
     * @returns {object} - Returns an object containing the a value for a valid scale and the corrected zoom factor.
     */
    calculateScale(zoom) {
        let scale = this.scale * zoom

        let minScale = this.minScale / this.overdoScaling
        let maxScale = this.maxScale * this.overdoScaling
        if (scale < minScale) {
            scale = minScale
            zoom = scale / this.scale
        }
        if (scale > maxScale) {
            scale = maxScale
            zoom = scale / this.scale
        }

        if (this.scaleAutoClose) this._updateTransparency()

        return { zoom, scale }
    }

    _updateTransparency() {
        if (this.scale < this.minScale + this.scaleCloseThreshold) {
            let transparency = this.calculateScaleTransparency()
            this.element.style.opacity = transparency
        } else this.element.style.opacity = 1
    }

    calculateScaleTransparency() {
        let transparency = (this.scale - this.minScale) / this.scaleCloseThreshold
        transparency = transparency > 1 ? 1 : transparency < 0 ? 0 : transparency
        return transparency
    }

    resizeAfterTransform(zoom) {
        // Overwrite this in subclasses.
    }

    validScale(scale) {
        scale = Math.max(scale, this.minScale)
        scale = Math.min(scale, this.maxScale)
        return scale
    }

    animateZoomBounce(dt = 1) {
        if (this.zoomAnchor != null) {
            let zoom = 1
            let amount = Math.min(0.01, (0.3 * dt) / 100000.0)
            if (this.scale < this.minScale) zoom = 1 + amount
            if (this.scale > this.maxScale) zoom = 1 - amount
            if (zoom != 1) {
                this.transform({ x: 0, y: 0 }, zoom, 0, this.zoomAnchor)
                requestAnimationFrame(dt => {
                    this.animateZoomBounce(dt)
                })
                return
            }
            this.zoomAnchor = null
        }
    }

    checkScaling(about, delay = 0) {
        this.zoomAnchor = about
        clearTimeout(this.animateZoomBounce.bind(this))
        setTimeout(this.animateZoomBounce.bind(this), delay)
    }

    onMouseWheel(event) {
        if (event.claimedByScatter) {
            if (event.claimedByScatter != this) return
        }
        this.killAnimation()
        this.targetScale = null
        let direction = event.detail < 0 || event.wheelDelta > 0
        let globalPoint = { x: event.clientX, y: event.clientY }
        let centerPoint = this.mapPositionToContainerPoint(globalPoint)
        if (event.shiftKey) {
            let degrees = direction ? 5 : -5
            let rad = Angle.degree2radian(degrees)
            return this.transform({ x: 0, y: 0 }, 1.0, rad, centerPoint)
        }
        const zoomFactor = this.mouseZoomFactor
        let zoom = direction ? zoomFactor : 1 / zoomFactor
        this.transform({ x: 0, y: 0 }, zoom, 0, centerPoint)
        this.checkScaling(centerPoint, 200)

        if (this.scaleAutoClose) {
            if (this.scale <= this.minScale + this.scaleCloseThreshold) {
                if (this.scaleAutoCloseTimeout) clearTimeout(this.scaleAutoCloseTimeout)
                this.scaleAutoCloseTimeout = setTimeout(() => {
                    this._checkAutoClose()
                }, 600)
            }
            this._updateTransparency()
        }
    }

    onStart(event, interaction) {
        if (this.startGesture(interaction)) {
            this.dragging = true
            this.interactionAnchor = null
        }
        if (this.onTransform != null) {
            let event = new ScatterEvent(this, {
                translate: { x: 0, y: 0 },
                scale: this.scale,
                rotate: 0,
                about: null,
                fast: false,
                type: START
            })
            this.onTransform.forEach(function(f) {
                f(event)
            })
        }
    }

    onMove(event, interaction) {
        /** As long as mouseout && mouseleave interrupt we cannot be sure that
         * dragging remains correct.
         */
        if (this.dragging) {
            this.gesture(interaction)
        }
    }

    onEnd(event, interaction) {
        console.log("Scatter.onEnd", this.dragging)
        if (interaction.isFinished()) {
            this.endGesture(interaction)
            this.dragging = false
            for (let key of interaction.ended.keys()) {
                if (interaction.isTap(key)) {
                    console.log("Scatter.isTap")
                    let point = interaction.ended.get(key)
                    this.onTap(event, interaction, point)
                }
            }
            if (this.onTransform != null) {
                let event = new ScatterEvent(this, {
                    translate: { x: 0, y: 0 },
                    scale: this.scale,
                    rotate: 0,
                    about: null,
                    fast: false,
                    type: END
                })
                this.onTransform.forEach(function(f) {
                    f(event)
                })
            }
        }
        let about = this.interactionAnchor
        if (about != null) {
            this.checkScaling(about, 100)
        }
    }

    //onTap(event, interaction, point) {}

    onTap(event, interaction, point) {
        console.log("AbstractScatter.onTap", this.tapDelegate, interaction)
        if (this.tapDelegate) {
            Events.stop(event)
            this.tapDelegate.tap(event, 'scatter')
        }
    }


    onDragUpdate(delta) {
        if (this.onTransform != null) {
            let event = new ScatterEvent(this, {
                fast: true,
                translate: delta,
                scale: this.scale,
                about: this.currentAbout,
                type: null
            })
            this.onTransform.forEach(function(f) {
                f(event)
            })
        }
    }

    onDragComplete() {
        if (this.onTransform) {
            let event = new ScatterEvent(this, {
                scale: this.scale,
                about: this.currentAbout,
                fast: false,
                type: null
            })
            this.onTransform.forEach(function(f) {
                f(event)
            })
        }
    }

    onMoved(dx, dy, about) {
        if (this.onTransform != null) {
            let event = new ScatterEvent(this, {
                translate: { x: dx, y: dy },
                about: about,
                fast: true,
                type: null
            })
            this.onTransform.forEach(function(f) {
                f(event)
            })
        }
    }

    onResizing() {
        if (this.onTransform != null) {
            let event = new ScatterEvent(this, {
                scale: this.scale,
                fast: false,
                type: null
            })
            this.onTransform.forEach(function(f) {
                f(event)
            })
        }
    }

    onZoomed(about) {
        if (this.scaleAutoClose) this._updateTransparency()

        if (this.onTransform != null) {
            let event = new ScatterEvent(this, {
                scale: this.scale,
                about: about,
                fast: false,
                type: null
            })
            this.onTransform.forEach(function(f) {
                f(event)
            })
        }
    }
}

/** A container for scatter objects, which uses a single InteractionMapper
 * for all children. This reduces the number of registered event handlers
 * and covers the common use case that multiple objects are scattered
 * on the same level.
 */
export class DOMScatterContainer {
    /**
     * @constructor
     * @param {DOM node} element - DOM element that receives events
     * @param {Bool} stopEvents -  Whether events should be stopped or propagated
     * @param {Bool} claimEvents - Whether events should be marked as claimed
     *                             if findTarget return as non-null value.
     * @param {String} [touchAction=none] - CSS to set touch action style, needed to prevent
     *                              pointer cancel events. Use null if the
     *                              the touch action should not be set.
     * @param {DOM node} debugCanvas - Shows debug infos about touches if not null
     */
    constructor(
        element,
        {
            stopEvents = 'auto',
            claimEvents = true,
            useCapture = true,
            capturePointerEvents = true,
            touchAction = 'none',
            debugCanvas = null
        } = {}
    ) {
        this.onCapture = null
        this.element = element
        if (stopEvents === 'auto') {
            /*
            The events have to be stopped in Safari, otherwise the whole page will be zoomed with
            a pinch gesture (preventDefault in method preventPinch). In order to enable the
            movement of scatter objects, the touchmove event has to be bound again.
            */
            if (Capabilities.isSafari) {
                document.addEventListener('touchmove', event => this.preventPinch(event), false)
                stopEvents = false
            } else {
                stopEvents = true
            }
        }
        this.stopEvents = stopEvents
        this.claimEvents = claimEvents
        if (touchAction !== null) {
            Elements.setStyle(element, { touchAction })
        }
        this.scatter = new Map()
        this.delegate = new InteractionMapper(element, this, {
            useCapture,
            capturePointerEvents,
            mouseWheelElement: window
        })

        if (debugCanvas !== null) {
            requestAnimationFrame(dt => {
                this.showTouches(dt, debugCanvas)
            })
        }
    }

    showTouches(dt, canvas) {
        let resolution = window.devicePixelRatio
        let current = this.delegate.interaction.current
        let context = canvas.getContext('2d')
        let radius = 20 * resolution
        context.clearRect(0, 0, canvas.width, canvas.height)
        context.fillStyle = 'rgba(0, 0, 0, 0.3)'
        context.lineWidth = 2
        context.strokeStyle = '#003300'
        for (let [key, point] of current.entries()) {
            let local = point
            context.beginPath()
            context.arc(local.x * resolution, local.y * resolution, radius, 0, 2 * Math.PI, false)
            context.fill()
            context.stroke()
        }
        requestAnimationFrame(dt => {
            this.showTouches(dt, canvas)
        })
    }

    preventPinch(event) {
        event = event.originalEvent || event
        if (event.scale !== 1) {
            event.preventDefault()
        }
    }

    /**
     * Removes an element from the scatter.
     *
     * @param {Scatter} scatter - Element to remove.
     * @memberof DOMScatterContainer
     */
    remove(scatter) {
        this.scatter.delete(scatter.element)
    }

    /**
     * Adds an element to the ScatterContainer.
     *
     * @param {Scatter} scatter - Element to add to the ScatterContainer.
     * @memberof DOMScatterContainer
     */
    add(scatter) {
        this.scatter.set(scatter.element, scatter)
    }

    capture(event) {
        if (this.onCapture) {
            return this.onCapture(event)
        }
        if (event.target == this.element && this.stopEvents) {
            Events.stop(event)
        }
        return true
    }

    mapPositionToPoint(point) {
        return Points.fromPageToNode(this.element, point)
    }

    isDescendant(parent, child, clickable = false) {
        if (parent == child) return true
        let node = child.parentNode
        while (node != null) {
            if (!clickable && node.onclick) {
                return false
            }
            if (node == parent) {
                return true
            }
            node = node.parentNode
        }
        return false
    }

    findTarget(event, local, global) {
        /*** Note that elementFromPoint works with clientX, clientY, not pageX, pageY
        The important point is that event should not be used, since the TouchEvent
        points are hidden in sub objects.
        ***/
        let found = document.elementFromPoint(global.x, global.y)
        for (let target of this.scatter.values()) {
            if (target.interactive && this.isDescendant(target.element, found)) {
                if (this.stopEvents) Events.stop(event)
                if (this.claimEvents) event.claimedByScatter = target
                return target
            }
        }
        return null
    }

    get center() {
        let r = this.bounds
        let w2 = r.width / 2
        let h2 = r.height / 2
        return { x: w2, y: h2 }
    }

    get bounds() {
        return this.element.getBoundingClientRect()
    }

    get polygon() {
        let r = this.bounds
        let w2 = r.width / 2
        let h2 = r.height / 2
        let center = { x: w2, y: h2 }
        let polygon = new Polygon(center)
        polygon.addPoint({ x: -w2, y: -h2 })
        polygon.addPoint({ x: w2, y: -h2 })
        polygon.addPoint({ x: w2, y: h2 })
        polygon.addPoint({ x: -w2, y: h2 })
        return polygon
    }
}

export class DOMScatter extends AbstractScatter {
    constructor(
        element,
        container,
        {
            startScale = 1.0,
            minScale = 0.1,
            maxScale = 1.0,
            overdoScaling = 1.5,
            autoBringToFront = true,
            translatable = true,
            scalable = true,
            rotatable = true,
            movableX = true,
            movableY = true,
            rotationDegrees = null,
            rotation = null,
            onTransform = null,
            transformOrigin = 'center center',
            // extras which are in part needed
            x = 0,
            y = 0,
            width = null, // required
            height = null, // required
            resizable = false,
            tapDelegate = null,
            triggerSVGClicks = false,
            allowClickDistance = 44,
            verbose = true,
            onResize = null,
            touchAction = 'none',
            throwVisibility = 44,
            throwDamping = 0.95,
            autoThrow = true,
            scaleAutoClose = false,
            onClose = null,
            scaleCloseThreshold = 0.1,
            scaleCloseBuffer = 0.05,
            useLowPassFilter = false,
            maxRotation = Angle.degree2radian(15),
            minInteractionDistance = 200
        } = {}
    ) {
        super({
            minScale,
            maxScale,
            startScale,
            overdoScaling,
            autoBringToFront,
            translatable,
            scalable,
            rotatable,
            movableX,
            movableY,
            resizable,
            rotationDegrees,
            rotation,
            onTransform,
            throwVisibility,
            throwDamping,
            autoThrow,
            scaleAutoClose,
            scaleCloseThreshold,
            scaleCloseBuffer,
            onClose,
            useLowPassFilter,
            maxRotation,
            minInteractionDistance
        })
        if (container == null || width == null || height == null) {
            throw new Error('Invalid value: null')
        }
        element.scatter = this
        this.element = element
        this.x = x
        this.y = y
        this.oldX = 0
        this.oldY = 0
        this.meanX = x
        this.meanY = y
        this.width = width
        this.height = height
        this.throwVisibility = Math.min(width, height, throwVisibility)
        this.container = container
        this.tapDelegate = tapDelegate
        this.scale = startScale
        this.rotationDegrees = this.startRotationDegrees
        this.transformOrigin = transformOrigin
        this.initialValues = {
            x: x,
            y: y,
            width: width,
            height: height,
            scale: startScale,
            rotation: this.startRotationDegrees,
            transformOrigin: transformOrigin
        }
        this.tapNodes = new Map()

        // For tweenlite we need initial values in _gsTransform
        TweenLite.set(element, this.initialValues)
        this.onResize = onResize
        this.verbose = verbose
        if (touchAction !== null) {
            Elements.setStyle(element, { touchAction })
        }
        this.resizeButton = null
        if (resizable) {
            let button = document.createElement('div')
            button.style.position = 'absolute'
            button.style.right = '0px'
            button.style.bottom = '0px'
            button.style.width = '50px'
            button.style.height = '50px'
            button.className = 'interactiveElement'
            this.element.appendChild(button)

            button.addEventListener('pointerdown', e => {
                this.startResize(e)
            })

            button.addEventListener('pointermove', e => {
                this.resize(e)
            })

            button.addEventListener('pointerup', e => {
                this.stopResize(e)
            })
            this.resizeButton = button
        }
        if (tapDelegate) {
            tapDelegate.handleClicks()
        }
        container.add(this)
    }

    /** Returns geometry data as object. **/
    getState() {
        return {
            scale: this.scale,
            x: this.x,
            y: this.y,
            rotation: this.rotation
        }
    }

    close() {
        super.close()
        let parent = this.element.parentNode
        if (parent) parent.removeChild(this.element)
    }

    get rotationOrigin() {
        return this.center
    }

    get x() {
        return this._x
    }

    get y() {
        return this._y
    }

    set x(value) {
        this._x = value
        TweenLite.set(this.element, { x: value })
    }

    set y(value) {
        this._y = value
        TweenLite.set(this.element, { y: value })
    }

    get position() {
        let transform = this.element._gsTransform
        let x = transform.x
        let y = transform.y
        return { x, y }
    }

    get origin() {
        let p = this.fromNodeToPage(0, 0)
        return Points.fromPageToNode(this.container.element, p)
    }

    get bounds() {
        let stage = this.container.element.getBoundingClientRect()
        let rect = this.element.getBoundingClientRect()
        return {
            top: rect.top - stage.top,
            left: rect.left - stage.left,
            width: rect.width,
            height: rect.height
        }
    }

    get center() {
        let r = this.bounds
        let w2 = r.width / 2
        let h2 = r.height / 2
        //   if (this.resizable) {
        //             w2 *= this.scale
        //             h2 *= this.scale
        //         }
        var x = r.left + w2
        var y = r.top + h2
        return { x, y }
    }

    set rotation(radians) {
        let rad = radians // Angle.normalize(radians)
        let degrees = Angle.radian2degree(rad)
        TweenLite.set(this.element, { rotation: degrees })
        this._rotation = rad
    }

    set rotationDegrees(degrees) {
        let deg = degrees // Angle.normalizeDegree(degrees)
        TweenLite.set(this.element, { rotation: deg })
        this._rotation = Angle.degree2radian(deg)
    }

    get rotation() {
        return this._rotation
    }

    get rotationDegrees() {
        return this._rotation
    }

    set scale(scale) {
        TweenLite.set(this.element, {
            scale: scale,
            transformOrigin: this.transformOrigin
        })
        this._scale = scale
    }

    get scale() {
        return this._scale
    }

    get containerBounds() {
        return this.container.bounds
    }

    get containerPolygon() {
        return this.container.polygon
    }

    mapPositionToContainerPoint(point) {
        return this.container.mapPositionToPoint(point)
    }

    capture(event) {
        return true
    }

    reset() {
        TweenLite.set(this.element, this.initialValues)
    }

    hide() {
        TweenLite.to(this.element, 0.1, {
            display: 'none',
            onComplete: e => {
                this.element.parentNode.removeChild(this.element)
            }
        })
    }

    show() {
        TweenLite.set(this.element, { display: 'block' })
    }

    showAt(p, rotationDegrees) {
        TweenLite.set(this.element, {
            display: 'block',
            x: p.x,
            y: p.y,
            rotation: rotationDegrees,
            transformOrigin: this.transformOrigin
        })
    }

    bringToFront() {
        // this.element.parentNode.appendChild(this.element)
        // uo: On Chome and Electon appendChild leads to flicker
        TweenLite.set(this.element, { zIndex: DOMScatter.zIndex++ })
    }

    isDescendant(parent, child) {
        let node = child.parentNode
        while (node != null) {
            if (node == parent) {
                return true
            }
            node = node.parentNode
        }
        return false
    }

    fromPageToNode(x, y) {
        return Points.fromPageToNode(this.element, { x, y })
    }

    fromNodeToPage(x, y) {
        return Points.fromNodeToPage(this.element, { x, y })
    }

    _move(delta) {
        // UO: We need to keep TweenLite's _gsTransform and the private
        // _x and _y attributes aligned
        let x = this.element._gsTransform.x
        let y = this.element._gsTransform.y
        if (this.movableX) {
            x += delta.x
        }
        if (this.movableY) {
            y += delta.y
        }
        this._x = x
        this._y = y
        TweenLite.set(this.element, { x: x, y: y })
    }

    resizeAfterTransform(zoom) {
        if (this.onResize) {
            let w = this.width * this.scale
            let h = this.height * this.scale
            let event = new ResizeEvent(this, { width: w, height: h })
            this.onResize(event)
        }
    }

    startResize(e) {
        e.preventDefault()
        let event = new CustomEvent('resizeStarted')

        let oldPostition = {
            x: this.element.getBoundingClientRect().left,
            y: this.element.getBoundingClientRect().top
        }
        this.bringToFront()

        this.element.style.transformOrigin = '0% 0%'

        let newPostition = {
            x: this.element.getBoundingClientRect().left,
            y: this.element.getBoundingClientRect().top
        }

        let offset = Points.subtract(oldPostition, newPostition)

        this.oldX = e.clientX
        this.oldY = e.clientY

        e.target.setAttribute('resizing', 'true')
        e.target.setPointerCapture(e.pointerId)

        TweenLite.to(this.element, 0, { css: { left: '+=' + offset.x + 'px' } })
        TweenLite.to(this.element, 0, { css: { top: '+=' + offset.y + 'px' } })

        this.element.dispatchEvent(event)
    }

    resize(e) {
        e.preventDefault()

        let rotation = Angle.radian2degree(this.rotation)
        rotation = (rotation + 360) % 360
        let event = new CustomEvent('resized')
        if (e.target.getAttribute('resizing') == 'true') {
            let deltaX = e.clientX - this.oldX
            let deltaY = e.clientY - this.oldY

            let r = Math.sqrt(Math.pow(deltaX, 2) + Math.pow(deltaY, 2))
            let phi = Angle.radian2degree(Math.atan2(deltaX, deltaY))

            phi = (phi + 630) % 360
            let rot = (rotation + 90 + 630) % 360

            let diffAngle = (0 + rot + 360) % 360
            let phiCorrected = (phi + diffAngle + 360) % 360

            let resizeW = r * Math.cos(Angle.degree2radian(phiCorrected))
            let resizeH = -r * Math.sin(Angle.degree2radian(phiCorrected))

            if (
                (this.element.offsetWidth + resizeW) / this.scale > (this.width * 0.5) / this.scale &&
                (this.element.offsetHeight + resizeH) / this.scale > (this.height * 0.3) / this.scale
            )
                TweenLite.to(this.element, 0, {
                    width: this.element.offsetWidth + resizeW / this.scale,
                    height: this.element.offsetHeight + resizeH / this.scale
                })

            this.oldX = e.clientX
            this.oldY = e.clientY
            this.onResizing()

            this.element.dispatchEvent(event)
        }
    }

    stopResize(e) {
        e.preventDefault()

        let event = new CustomEvent('resizeEnded')
        let oldPostition = {
            x: this.element.getBoundingClientRect().left,
            y: this.element.getBoundingClientRect().top
        }
        this.element.style.transformOrigin = '50% 50%'
        let newPostition = {
            x: this.element.getBoundingClientRect().left,
            y: this.element.getBoundingClientRect().top
        }
        let offset = Points.subtract(oldPostition, newPostition)

        TweenLite.to(this.element, 0, { css: { left: '+=' + offset.x + 'px' } })
        TweenLite.to(this.element, 0, { css: { top: '+=' + offset.y + 'px' } })

        e.target.setAttribute('resizing', 'false')

        this.element.dispatchEvent(event)
    }
}

DOMScatter.zIndex = 1000