ueblueprint/js/selection/FastSelectionModel.js

import OrderedIndexArray from "./OrderedIndexArray.js"

/**
 * @typedef {typeof import("../Blueprint.js").default.nodeBoundariesSupplier} BoundariesFunction
 * @typedef {typeof import("../Blueprint.js").default.nodeSelectToggleFunction} SelectionFunction
 * @typedef {{
 *     primaryBoundary: Number,
 *     secondaryBoundary: Number,
 *     insertionPosition?: Number,
 *     rectangle: Number
 *     onSecondaryAxis: Boolean
 * }} Metadata
 */
export default class FastSelectionModel {

    /**
     * @param {Coordinates} initialPosition
     * @param {NodeElement[]} rectangles
     * @param {BoundariesFunction} boundariesFunc
     * @param {SelectionFunction} selectFunc
     */
    constructor(initialPosition, rectangles, boundariesFunc, selectFunc) {
        this.initialPosition = initialPosition
        this.finalPosition = initialPosition
        /** @type {Metadata[]} */
        this.metadata = new Array(rectangles.length)
        this.primaryOrder = new OrderedIndexArray((element) => this.metadata[element].primaryBoundary)
        this.secondaryOrder = new OrderedIndexArray((element) => this.metadata[element].secondaryBoundary)
        this.selectFunc = selectFunc
        this.rectangles = rectangles
        this.primaryOrder.reserve(this.rectangles.length)
        this.secondaryOrder.reserve(this.rectangles.length)

        rectangles.forEach((rect, index) => {
            /** @type {Metadata} */
            let rectangleMetadata = {
                primaryBoundary: this.initialPosition[0],
                secondaryBoundary: this.initialPosition[1],
                rectangle: index,
                onSecondaryAxis: false,
            }
            this.metadata[index] = rectangleMetadata
            selectFunc(rect, false) // Initially deselected (Eventually)
            const rectangleBoundaries = boundariesFunc(rect)

            // Secondary axis first because it may be inserted in this.secondaryOrder during the primary axis check
            if (this.initialPosition[1] < rectangleBoundaries.secondaryInf) { // Initial position is before the rectangle
                rectangleMetadata.secondaryBoundary = rectangleBoundaries.secondaryInf
            } else if (rectangleBoundaries.secondarySup < this.initialPosition[1]) { // Initial position is after the rectangle
                rectangleMetadata.secondaryBoundary = rectangleBoundaries.secondarySup
            } else {
                rectangleMetadata.onSecondaryAxis = true
            }

            if (this.initialPosition[0] < rectangleBoundaries.primaryInf) { // Initial position is before the rectangle
                rectangleMetadata.primaryBoundary = rectangleBoundaries.primaryInf
                this.primaryOrder.insert(index)
            } else if (rectangleBoundaries.primarySup < this.initialPosition[0]) { // Initial position is after the rectangle
                rectangleMetadata.primaryBoundary = rectangleBoundaries.primarySup
                this.primaryOrder.insert(index)
            } else { // Initial lays inside the rectangle (considering just this axis)
                // Secondary order depends on primary order, if primary boundaries are not satisfied, the element is not watched for secondary ones
                if (rectangleBoundaries.secondarySup < this.initialPosition[1] || this.initialPosition[1] < rectangleBoundaries.secondaryInf) {
                    this.secondaryOrder.insert(index)
                } else {
                    selectFunc(rect, true)
                }
            }
        })
        this.primaryOrder.currentPosition = this.primaryOrder.getPosition(this.initialPosition[0])
        this.secondaryOrder.currentPosition = this.secondaryOrder.getPosition(this.initialPosition[1])
        this.computeBoundaries()
    }

    computeBoundaries() {
        this.boundaries = {
            // Primary axis negative expanding
            primaryN: {
                v: this.primaryOrder.getPrevValue(),
                i: this.primaryOrder.getPrev()
            },
            primaryP: {
                v: this.primaryOrder.getNextValue(),
                i: this.primaryOrder.getNext()
            },
            // Secondary axis negative expanding
            secondaryN: {
                v: this.secondaryOrder.getPrevValue(),
                i: this.secondaryOrder.getPrev()
            },
            // Secondary axis positive expanding
            secondaryP: {
                v: this.secondaryOrder.getNextValue(),
                i: this.secondaryOrder.getNext()
            }
        }
    }

    selectTo(finalPosition) {
        const direction = [
            Math.sign(finalPosition[0] - this.initialPosition[0]),
            Math.sign(finalPosition[1] - this.initialPosition[1])
        ]
        const primaryBoundaryCrossed = (index, added) => {
            if (this.metadata[index].onSecondaryAxis) {
                this.selectFunc(this.rectangles[index], added)
            } else {
                if (added) {
                    this.secondaryOrder.insert(index, finalPosition[1])
                    const secondaryBoundary = this.metadata[index].secondaryBoundary
                    if (
                        // If inserted before the current position
                        Math.sign(finalPosition[1] - secondaryBoundary) == direction[1]
                        // And after initial position
                        && Math.sign(secondaryBoundary - this.initialPosition[1]) == direction[1]
                    ) {
                        // Secondary axis is already satisfied then
                        this.selectFunc(this.rectangles[index], true)
                    }
                } else {
                    this.selectFunc(this.rectangles[index], false)
                    this.secondaryOrder.remove(index)
                }
            }
            this.computeBoundaries()
            this.selectTo(finalPosition)
        }

        if (finalPosition[0] < this.boundaries.primaryN.v) {
            --this.primaryOrder.currentPosition
            primaryBoundaryCrossed(
                this.boundaries.primaryN.i,
                this.initialPosition[0] > this.boundaries.primaryN.v && finalPosition[0] < this.initialPosition[0])
        } else if (finalPosition[0] > this.boundaries.primaryP.v) {
            ++this.primaryOrder.currentPosition
            primaryBoundaryCrossed(
                this.boundaries.primaryP.i,
                this.initialPosition[0] < this.boundaries.primaryP.v && this.initialPosition[0] < finalPosition[0])
        }

        const secondaryBoundaryCrossed = (index, added) => {
            this.selectFunc(this.rectangles[index], added)
            this.computeBoundaries()
            this.selectTo(finalPosition)
        }

        if (finalPosition[1] < this.boundaries.secondaryN.v) {
            --this.secondaryOrder.currentPosition
            secondaryBoundaryCrossed(
                this.boundaries.secondaryN.i,
                this.initialPosition[1] > this.boundaries.secondaryN.v && finalPosition[1] < this.initialPosition[1])
        } else if (finalPosition[1] > this.boundaries.secondaryP.v) {
            ++this.secondaryOrder.currentPosition
            secondaryBoundaryCrossed(
                this.boundaries.secondaryP.i,
                this.initialPosition[1] < this.boundaries.secondaryP.v && this.initialPosition[1] < finalPosition[1])
        }
        this.finalPosition = finalPosition
    }
}