Scale.js
2.79 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
/* Copyright (c) 2006-2011 by OpenLayers Contributors (see authors.txt for
* full list of contributors). Published under the Clear BSD license.
* See http://svn.openlayers.org/trunk/openlayers/license.txt for the
* full text of the license. */
/**
* @requires OpenLayers/Control.js
* @requires OpenLayers/Lang.js
*/
/**
* Class: OpenLayers.Control.Scale
* The Scale control displays the current map scale as a ratio (e.g. Scale =
* 1:1M). By default it is displayed in the lower right corner of the map.
*
* Inherits from:
* - <OpenLayers.Control>
*/
OpenLayers.Control.Scale = OpenLayers.Class(OpenLayers.Control, {
/**
* Parameter: element
* {DOMElement}
*/
element: null,
/**
* APIProperty: geodesic
* {Boolean} Use geodesic measurement. Default is false. The recommended
* setting for maps in EPSG:4326 is false, and true EPSG:900913. If set to
* true, the scale will be calculated based on the horizontal size of the
* pixel in the center of the map viewport.
*/
geodesic: false,
/**
* Constructor: OpenLayers.Control.Scale
*
* Parameters:
* element - {DOMElement}
* options - {Object}
*/
initialize: function(element, options) {
OpenLayers.Control.prototype.initialize.apply(this, [options]);
this.element = OpenLayers.Util.getElement(element);
},
/**
* Method: draw
*
* Returns:
* {DOMElement}
*/
draw: function() {
OpenLayers.Control.prototype.draw.apply(this, arguments);
if (!this.element) {
this.element = document.createElement("div");
this.div.appendChild(this.element);
}
this.map.events.register( 'moveend', this, this.updateScale);
this.updateScale();
return this.div;
},
/**
* Method: updateScale
*/
updateScale: function() {
var scale;
if(this.geodesic === true) {
var units = this.map.getUnits();
if(!units) {
return;
}
var inches = OpenLayers.INCHES_PER_UNIT;
scale = (this.map.getGeodesicPixelSize().w || 0.000001) *
inches["km"] * OpenLayers.DOTS_PER_INCH;
} else {
scale = this.map.getScale();
}
if (!scale) {
return;
}
if (scale >= 9500 && scale <= 950000) {
scale = Math.round(scale / 1000) + "K";
} else if (scale >= 950000) {
scale = Math.round(scale / 1000000) + "M";
} else {
scale = Math.round(scale);
}
this.element.innerHTML = OpenLayers.i18n("Scale = 1 : ${scaleDenom}", {'scaleDenom':scale});
},
CLASS_NAME: "OpenLayers.Control.Scale"
});