labellayer.js

define(['leaflet', 'rbush', 'helper', 'moment'],
  function (L, RBush, helper, moment) {
    'use strict';

    var groupOnline;
    var groupOffline;
    var groupNew;
    var groupLost;
    var groupLines;

    var labelLocations = [['left', 'middle', 0 / 8],
      ['center', 'top', 6 / 8],
      ['right', 'middle', 4 / 8],
      ['left', 'top', 7 / 8],
      ['left', 'ideographic', 1 / 8],
      ['right', 'top', 5 / 8],
      ['center', 'ideographic', 2 / 8],
      ['right', 'ideographic', 3 / 8]];
    var labelShadow;
    var bodyStyle = { fontFamily: 'sans-serif' };
    var nodeRadius = 4;

    var cFont = document.createElement('canvas').getContext('2d');

    function measureText(font, text) {
      cFont.font = font;
      return cFont.measureText(text);
    }

    function mapRTree(d) {
      return { minX: d.position.lat, minY: d.position.lng, maxX: d.position.lat, maxY: d.position.lng, label: d };
    }

    function prepareLabel(fillStyle, fontSize, offset, stroke) {
      return function (d) {
        var font = fontSize + 'px ' + bodyStyle.fontFamily;
        return {
          position: L.latLng(d.location.latitude, d.location.longitude),
          label: d.hostname,
          offset: offset,
          fillStyle: fillStyle,
          height: fontSize * 1.2,
          font: font,
          stroke: stroke,
          width: measureText(font, d.hostname).width
        };
      };
    }

    function calcOffset(offset, loc) {
      return [offset * Math.cos(loc[2] * 2 * Math.PI),
        offset * Math.sin(loc[2] * 2 * Math.PI)];
    }

    function labelRect(p, offset, anchor, label, minZoom, maxZoom, z) {
      var margin = 1 + 1.41 * (1 - (z - minZoom) / (maxZoom - minZoom));

      var width = label.width * margin;
      var height = label.height * margin;

      var dx = {
        left: 0,
        right: -width,
        center: -width / 2
      };

      var dy = {
        top: 0,
        ideographic: -height,
        middle: -height / 2