package.src.plots.mapbox.convert_text_opts.js Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of plotly.js Show documentation

The open source javascript graphing library that powers plotly

The newest version!

'use strict';

var Lib = require('../../lib');

/**
 * Convert plotly.js 'textposition' to mapbox-gl 'anchor' and 'offset'
 * (with the help of the icon size).
 *
 * @param {string} textpostion : plotly.js textposition value
 * @param {number} iconSize : plotly.js icon size (e.g. marker.size for traces)
 *
 * @return {object}
 *      - anchor
 *      - offset
 */
module.exports = function convertTextOpts(textposition, iconSize) {
    var parts = textposition.split(' ');
    var vPos = parts[0];
    var hPos = parts[1];

    // ballpack values
    var factor = Lib.isArrayOrTypedArray(iconSize) ? Lib.mean(iconSize) : iconSize;
    var xInc = 0.5 + (factor / 100);
    var yInc = 1.5 + (factor / 100);

    var anchorVals = ['', ''];
    var offset = [0, 0];

    switch(vPos) {
        case 'top':
            anchorVals[0] = 'top';
            offset[1] = -yInc;
            break;
        case 'bottom':
            anchorVals[0] = 'bottom';
            offset[1] = yInc;
            break;
    }

    switch(hPos) {
        case 'left':
            anchorVals[1] = 'right';
            offset[0] = -xInc;
            break;
        case 'right':
            anchorVals[1] = 'left';
            offset[0] = xInc;
            break;
    }

    // Mapbox text-anchor must be one of:
    //  center, left, right, top, bottom,
    //  top-left, top-right, bottom-left, bottom-right

    var anchor;
    if(anchorVals[0] && anchorVals[1]) anchor = anchorVals.join('-');
    else if(anchorVals[0]) anchor = anchorVals[0];
    else if(anchorVals[1]) anchor = anchorVals[1];
    else anchor = 'center';

    return { anchor: anchor, offset: offset };
};