@joint/core/src/connectionStrategies/index.mjs

JavaScript diagramming library

import * as util from '../util/index.mjs';

function abs2rel(absolute, max) {

    if (max === 0) return '0%';
    // round to 3 decimal places
    const dp = 1000;
    const relative = Math.round(absolute / max * 100 * dp) / dp;
    return `${relative}%`;
}

function pin(relative) {

    return function(end, view, magnet, coords) {
        var fn = (view.isNodeConnection(magnet)) ? pinnedLinkEnd : pinnedElementEnd;
        return fn(relative, end, view, magnet, coords);
    };
}

function pinnedElementEnd(relative, end, view, magnet, coords) {

    var angle = view.model.angle();
    var bbox = view.getNodeUnrotatedBBox(magnet);
    var origin = view.model.getBBox().center();
    coords.rotate(origin, angle);
    var dx = coords.x - bbox.x;
    var dy = coords.y - bbox.y;

    if (relative) {
        dx = abs2rel(dx, bbox.width);
        dy = abs2rel(dy, bbox.height);
    }

    end.anchor = {
        name: 'topLeft',
        args: {
            dx: dx,
            dy: dy,
            rotate: true
        }
    };

    return end;
}

function pinnedLinkEnd(relative, end, view, _magnet, coords) {

    var connection = view.getConnection();
    if (!connection) return end;
    var length = connection.closestPointLength(coords);
    if (relative) {
        var totalLength = connection.length();
        end.anchor = {
            name: 'connectionRatio',
            args: {
                ratio: length / totalLength
            }
        };
    } else {
        end.anchor = {
            name: 'connectionLength',
            args: {
                length: length
            }
        };
    }
    return end;
}

export const useDefaults = util.noop;
export const pinAbsolute = pin(false);
export const pinRelative = pin(true);