labelslayer.js ➔ ... ➔ L.TileLayer.extend.prepareLabels - Code Metrics - Inspection of "[TASK] Update to leaflet v1" - ffrgb/meshviewer - Measure and Improve Code Quality continuously with Scrutinizer

Completed

Pull Request — develop (#85)

by Xaver

created 2017-03-10 22:44 UTC

labelslayer.js ➔ ... ➔ L.TileLayer.extend.prepareLabels B

↳ Parent: Project

Complexity

Conditions	3
Paths	4

Size

Total Lines

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
cc	3
c	0
b	0
f	0
nc	4
dl	0
loc	94
rs	8.4378
nop	0

3 Functions

Rating	Name	Size	Complexity
A	labelslayer.js ➔ ... ➔ nodeToRect	6	1
A	labelslayer.js ➔ ... ➔ labels.filter	3	1
B	labelslayer.js ➔ ... ➔ labels.map	37	3

How to fix Long Method

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

    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.nodeinfo.location.latitude, d.nodeinfo.location.longitude),
          label: d.nodeinfo.hostname,
          offset: offset,
          fillStyle: fillStyle,
          height: fontSize * 1.2,
          font: font,
          stroke: stroke,
          width: measureText(font, d.nodeinfo.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
      };

      var x = p.x + offset[0] + dx[anchor[0]];
      var y = p.y + offset[1] + dy[anchor[1]];

      return { minX: x, minY: y, maxX: x + width, maxY: y + height };
    }

    return L.TileLayer.extend({
      onAdd: function (map) {
        L.TileLayer.prototype.onAdd.call(this, map);
        if (this.data) {
          this.prepareLabels();
        }
      },
      setData: function (d) {
        this.data = d;
        this.updateLayer();
      },
      updateLayer: function () {
        if (this._map) {
          this.prepareLabels();
        }
      },
      prepareLabels: function () {
        var d = this.data;

        // label:
        // - position (WGS84 coords)
        // - offset (2D vector in pixels)
        // - anchor (tuple, textAlignment, textBaseline)
        // - minZoom (inclusive)
        // - label (string)
        // - color (string)

        var labelsOnline = d.online.map(prepareLabel(null, 11, 8, true));
        var labelsOffline = d.offline.map(prepareLabel('rgba(212, 62, 42, 0.9)', 9, 5, false));
        var labelsNew = d.new.map(prepareLabel('rgba(48, 99, 20, 0.9)', 11, 8, true));
        var labelsLost = d.lost.map(prepareLabel('rgba(212, 62, 42, 0.9)', 11, 8, true));

        var labels = []
          .concat(labelsNew)
          .concat(labelsLost)
          .concat(labelsOnline)
          .concat(labelsOffline);

        var minZoom = this.options.minZoom;
        var maxZoom = this.options.maxZoom;

        var trees = [];

        var map = this._map;

        function nodeToRect(z) {
          return function (n) {
            var p = map.project(n.position, z);
            return { minX: p.x - nodeRadius, minY: p.y - nodeRadius, maxX: p.x + nodeRadius, maxY: p.y + nodeRadius };
          };
        }

        for (var z = minZoom; z <= maxZoom; z++) {
          trees[z] = rbush(9);
          trees[z].load(labels.map(nodeToRect(z)));
        }

        labels = labels.map(function (n) {
          var best = labelLocations.map(function (loc) {
            var offset = calcOffset(n.offset, loc);
            var i;

            for (i = maxZoom; i >= minZoom; i--) {
              var p = map.project(n.position, i);
              var rect = labelRect(p, offset, loc, n, minZoom, maxZoom, i);
              var candidates = trees[i].search(rect);

              if (candidates.length > 0) {
                break;
              }
            }

            return { loc: loc, z: i + 1 };
          }).filter(function (k) {
            return k.z <= maxZoom;
          }).sort(function (a, b) {
            return a.z - b.z;
          })[0];

          if (best !== undefined) {
            n.offset = calcOffset(n.offset, best.loc);
            n.minZoom = best.z;
            n.anchor = best.loc;

            for (var i = maxZoom; i >= best.z; i--) {
              var p = map.project(n.position, i);
              var rect = labelRect(p, n.offset, best.loc, n, minZoom, maxZoom, i);
              trees[i].insert(rect);
            }

            return n;
          }
          return undefined;
        }).filter(function (n) {
          return n !== undefined;
        });

        this.margin = 16;

        if (labels.length > 0) {
          this.margin += labels.map(function (n) {
            return n.width;
          }).sort().reverse()[0];
        }

        this.labels = rbush(9);
        this.labels.load(labels.map(mapRTree));

        this.redraw();
      },
      drawTile: function (canvas, tilePoint, zoom) {
        if (!this.labels && zoom >= this.options.minZoom) {
          return;
        }

        var tileSize = this.options.tileSize;
        var s = tilePoint.multiplyBy(tileSize);
        var map = this._map;
        bodyStyle = window.getComputedStyle(document.querySelector('body'));
        labelShadow = bodyStyle.backgroundColor.replace(/rgb/i, 'rgba').replace(/\)/i, ',0.7)');

        function projectNodes(d) {
          var p = map.project(d.label.position);

          p.x -= s.x;
          p.y -= s.y;

          return { p: p, label: d.label };
        }

        var bbox = helper.getTileBBox(s, map, tileSize, this.margin);
        var labels = this.labels.search(bbox).map(projectNodes);
        var ctx = canvas.getContext('2d');

        ctx.lineWidth = 5;
        ctx.strokeStyle = labelShadow;
        ctx.miterLimit = 2;

        function drawLabel(d) {
          ctx.font = d.label.font;
          ctx.textAlign = d.label.anchor[0];
          ctx.textBaseline = d.label.anchor[1];
          ctx.fillStyle = d.label.fillStyle === null ? bodyStyle.color : d.label.fillStyle;

          if (d.label.stroke) {
            ctx.strokeText(d.label.label, d.p.x + d.label.offset[0], d.p.y + d.label.offset[1]);
          }

          ctx.fillText(d.label.label, d.p.x + d.label.offset[0], d.p.y + d.label.offset[1]);
        }

        labels.filter(function (d) {
          return zoom >= d.label.minZoom;
        }).forEach(drawLabel);
      }
    });
  });


1			define(['leaflet', 'rbush', 'helper'],
2			function (L, rbush, helper) {
3			'use strict';
4
5			var labelLocations = [['left', 'middle', 0 / 8],
6			['center', 'top', 6 / 8],
7			['right', 'middle', 4 / 8],
8			['left', 'top', 7 / 8],
9			['left', 'ideographic', 1 / 8],
10			['right', 'top', 5 / 8],
11			['center', 'ideographic', 2 / 8],
12			['right', 'ideographic', 3 / 8]];
13			var labelShadow;
14			var bodyStyle = { fontFamily: 'sans-serif' };
15			var nodeRadius = 4;
16
17			var cFont = document.createElement('canvas').getContext('2d');
18
19			function measureText(font, text) {
20			cFont.font = font;
21			return cFont.measureText(text);
22			}
23
24			function mapRTree(d) {
25			return { minX: d.position.lat, minY: d.position.lng, maxX: d.position.lat, maxY: d.position.lng, label: d };
26			}
27
28			function prepareLabel(fillStyle, fontSize, offset, stroke) {
29			return function (d) {
30			var font = fontSize + 'px ' + bodyStyle.fontFamily;
31			return {
32			position: L.latLng(d.nodeinfo.location.latitude, d.nodeinfo.location.longitude),
33			label: d.nodeinfo.hostname,
34			offset: offset,
35			fillStyle: fillStyle,
36			height: fontSize * 1.2,
37			font: font,
38			stroke: stroke,
39			width: measureText(font, d.nodeinfo.hostname).width
40			};
41			};
42			}
43
44			function calcOffset(offset, loc) {
45			return [offset * Math.cos(loc[2] * 2 * Math.PI),
46			-offset * Math.sin(loc[2] * 2 * Math.PI)];
47			}
48
49			function labelRect(p, offset, anchor, label, minZoom, maxZoom, z) {
50			var margin = 1 + 1.41 * (1 - (z - minZoom) / (maxZoom - minZoom));
51
52			var width = label.width * margin;
53			var height = label.height * margin;
54
55			var dx = {
56			left: 0,
57			right: -width,
58			center: -width / 2
59			};
60
61			var dy = {
62			top: 0,
63			ideographic: -height,
64			middle: -height / 2
65			};
66
67			var x = p.x + offset[0] + dx[anchor[0]];
68			var y = p.y + offset[1] + dy[anchor[1]];
69
70			return { minX: x, minY: y, maxX: x + width, maxY: y + height };
71			}
72
73			return L.TileLayer.extend({
74			onAdd: function (map) {
75			L.TileLayer.prototype.onAdd.call(this, map);
76			if (this.data) {
77			this.prepareLabels();
78			}
79			},
80			setData: function (d) {
81			this.data = d;
82			this.updateLayer();
83			},
84			updateLayer: function () {
85			if (this._map) {
86			this.prepareLabels();
87			}
88			},
89			prepareLabels: function () {
90			var d = this.data;
91
92			// label:
93			// - position (WGS84 coords)
94			// - offset (2D vector in pixels)
95			// - anchor (tuple, textAlignment, textBaseline)
96			// - minZoom (inclusive)
97			// - label (string)
98			// - color (string)
99
100			var labelsOnline = d.online.map(prepareLabel(null, 11, 8, true));
101			var labelsOffline = d.offline.map(prepareLabel('rgba(212, 62, 42, 0.9)', 9, 5, false));
102			var labelsNew = d.new.map(prepareLabel('rgba(48, 99, 20, 0.9)', 11, 8, true));
103			var labelsLost = d.lost.map(prepareLabel('rgba(212, 62, 42, 0.9)', 11, 8, true));
104
105			var labels = []
106			.concat(labelsNew)
107			.concat(labelsLost)
108			.concat(labelsOnline)
109			.concat(labelsOffline);
110
111			var minZoom = this.options.minZoom;
112			var maxZoom = this.options.maxZoom;
113
114			var trees = [];
115
116			var map = this._map;
117
118			function nodeToRect(z) {
119			return function (n) {
120			var p = map.project(n.position, z);
121			return { minX: p.x - nodeRadius, minY: p.y - nodeRadius, maxX: p.x + nodeRadius, maxY: p.y + nodeRadius };
122			};
123			}
124
125			for (var z = minZoom; z <= maxZoom; z++) {
126			trees[z] = rbush(9);
127			trees[z].load(labels.map(nodeToRect(z)));
128			}
129
130			labels = labels.map(function (n) {
131			var best = labelLocations.map(function (loc) {
132			var offset = calcOffset(n.offset, loc);
133			var i;
134
135			for (i = maxZoom; i >= minZoom; i--) {
136			var p = map.project(n.position, i);
137			var rect = labelRect(p, offset, loc, n, minZoom, maxZoom, i);
138			var candidates = trees[i].search(rect);
139
140			if (candidates.length > 0) {
141			break;
142			}
143			}
144
145			return { loc: loc, z: i + 1 };
146			}).filter(function (k) {
147			return k.z <= maxZoom;
148			}).sort(function (a, b) {
149			return a.z - b.z;
150			})[0];
151
152			if (best !== undefined) {
153			n.offset = calcOffset(n.offset, best.loc);
154			n.minZoom = best.z;
155			n.anchor = best.loc;
156
157			for (var i = maxZoom; i >= best.z; i--) {
158			var p = map.project(n.position, i);
159			var rect = labelRect(p, n.offset, best.loc, n, minZoom, maxZoom, i);
160			trees[i].insert(rect);
161			}
162
163			return n;
164			}
165			return undefined;
166			}).filter(function (n) {
167			return n !== undefined;
168			});
169
170			this.margin = 16;
171
172			if (labels.length > 0) {
173			this.margin += labels.map(function (n) {
174			return n.width;
175			}).sort().reverse()[0];
176			}
177
178			this.labels = rbush(9);
179			this.labels.load(labels.map(mapRTree));
180
181			this.redraw();
182			},
183			drawTile: function (canvas, tilePoint, zoom) {
184			if (!this.labels && zoom >= this.options.minZoom) {
185			return;
186			}
187
188			var tileSize = this.options.tileSize;
189			var s = tilePoint.multiplyBy(tileSize);
190			var map = this._map;
191			bodyStyle = window.getComputedStyle(document.querySelector('body'));
192			labelShadow = bodyStyle.backgroundColor.replace(/rgb/i, 'rgba').replace(/\)/i, ',0.7)');
193
194			function projectNodes(d) {
195			var p = map.project(d.label.position);
196
197			p.x -= s.x;
198			p.y -= s.y;
199
200			return { p: p, label: d.label };
201			}
202
203			var bbox = helper.getTileBBox(s, map, tileSize, this.margin);
204			var labels = this.labels.search(bbox).map(projectNodes);
205			var ctx = canvas.getContext('2d');
206
207			ctx.lineWidth = 5;
208			ctx.strokeStyle = labelShadow;
209			ctx.miterLimit = 2;
210
211			function drawLabel(d) {
212			ctx.font = d.label.font;
213			ctx.textAlign = d.label.anchor[0];
214			ctx.textBaseline = d.label.anchor[1];
215			ctx.fillStyle = d.label.fillStyle === null ? bodyStyle.color : d.label.fillStyle;
216
217			if (d.label.stroke) {
218			ctx.strokeText(d.label.label, d.p.x + d.label.offset[0], d.p.y + d.label.offset[1]);
219			}
220
221			ctx.fillText(d.label.label, d.p.x + d.label.offset[0], d.p.y + d.label.offset[1]);
222			}
223
224			labels.filter(function (d) {
225			return zoom >= d.label.minZoom;
226			}).forEach(drawLabel);
227			}
228			});
229			});
230

ffrgb / meshviewer

Pull Request — develop (#85)

labelslayer.js ➔ ... ➔ L.TileLayer.extend.prepareLabels B

Complexity

Size

Duplication

Importance

3 Functions

How to fix Long Method

Long Method

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