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
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
|
/* Copyright (c) 2006-2013 by OpenLayers Contributors (see authors.txt for
* full list of contributors). Published under the 2-clause BSD license.
* See license.txt in the OpenLayers distribution or repository for the
* full text of the license. */
/**
* @requires OpenLayers/Control.js
*/
/**
* Class: OpenLayers.Control.ScaleLine
* The ScaleLine displays a small line indicator representing the current
* map scale on the map. By default it is drawn in the lower left corner of
* the map.
*
* Inherits from:
* - <OpenLayers.Control>
*
* Is a very close copy of:
* - <OpenLayers.Control.Scale>
*/
OpenLayers.Control.ScaleLine = OpenLayers.Class(OpenLayers.Control, {
/**
* Property: maxWidth
* {Integer} Maximum width of the scale line in pixels. Default is 100.
*/
maxWidth: 100,
/**
* Property: topOutUnits
* {String} Units for zoomed out on top bar. Default is km.
*/
topOutUnits: "km",
/**
* Property: topInUnits
* {String} Units for zoomed in on top bar. Default is m.
*/
topInUnits: "m",
/**
* Property: bottomOutUnits
* {String} Units for zoomed out on bottom bar. Default is mi.
*/
bottomOutUnits: "mi",
/**
* Property: bottomInUnits
* {String} Units for zoomed in on bottom bar. Default is ft.
*/
bottomInUnits: "ft",
/**
* Property: eTop
* {DOMElement}
*/
eTop: null,
/**
* Property: eBottom
* {DOMElement}
*/
eBottom: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.ScaleLine
* Create a new scale line control.
*
* Parameters:
* options - {Object} An optional object whose properties will be used
* to extend the control.
*/
/**
* Method: draw
*
* Returns:
* {DOMElement}
*/
draw: function() {
OpenLayers.Control.prototype.draw.apply(this, arguments);
if (!this.eTop) {
// stick in the top bar
this.eTop = document.createElement("div");
this.eTop.className = this.displayClass + "Top";
var theLen = this.topInUnits.length;
this.div.appendChild(this.eTop);
if((this.topOutUnits == "") || (this.topInUnits == "")) {
this.eTop.style.visibility = "hidden";
} else {
this.eTop.style.visibility = "visible";
}
// and the bottom bar
this.eBottom = document.createElement("div");
this.eBottom.className = this.displayClass + "Bottom";
this.div.appendChild(this.eBottom);
if((this.bottomOutUnits == "") || (this.bottomInUnits == "")) {
this.eBottom.style.visibility = "hidden";
} else {
this.eBottom.style.visibility = "visible";
}
}
this.map.events.register('moveend', this, this.update);
this.update();
return this.div;
},
/**
* Method: getBarLen
* Given a number, round it down to the nearest 1,2,5 times a power of 10.
* That seems a fairly useful set of number groups to use.
*
* Parameters:
* maxLen - {float} the number we're rounding down from
*
* Returns:
* {Float} the rounded number (less than or equal to maxLen)
*/
getBarLen: function(maxLen) {
// nearest power of 10 lower than maxLen
var digits = parseInt(Math.log(maxLen) / Math.log(10));
var pow10 = Math.pow(10, digits);
// ok, find first character
var firstChar = parseInt(maxLen / pow10);
// right, put it into the correct bracket
var barLen;
if(firstChar > 5) {
barLen = 5;
} else if(firstChar > 2) {
barLen = 2;
} else {
barLen = 1;
}
// scale it up the correct power of 10
return barLen * pow10;
},
/**
* Method: update
* Update the size of the bars, and the labels they contain.
*/
update: function() {
var res = this.map.getResolution();
if (!res) {
return;
}
var curMapUnits = this.map.getUnits();
var inches = OpenLayers.INCHES_PER_UNIT;
// convert maxWidth to map units
var maxSizeData = this.maxWidth * res * inches[curMapUnits];
var geodesicRatio = 1;
if(this.geodesic === true) {
var maxSizeGeodesic = (this.map.getGeodesicPixelSize().w ||
0.000001) * this.maxWidth;
var maxSizeKilometers = maxSizeData / inches["km"];
geodesicRatio = maxSizeGeodesic / maxSizeKilometers;
maxSizeData *= geodesicRatio;
}
// decide whether to use large or small scale units
var topUnits;
var bottomUnits;
if(maxSizeData > 100000) {
topUnits = this.topOutUnits;
bottomUnits = this.bottomOutUnits;
} else {
topUnits = this.topInUnits;
bottomUnits = this.bottomInUnits;
}
// and to map units units
var topMax = maxSizeData / inches[topUnits];
var bottomMax = maxSizeData / inches[bottomUnits];
// now trim this down to useful block length
var topRounded = this.getBarLen(topMax);
var bottomRounded = this.getBarLen(bottomMax);
// and back to display units
topMax = topRounded / inches[curMapUnits] * inches[topUnits];
bottomMax = bottomRounded / inches[curMapUnits] * inches[bottomUnits];
// and to pixel units
var topPx = topMax / res / geodesicRatio;
var bottomPx = bottomMax / res / geodesicRatio;
// now set the pixel widths
// and the values inside them
if (this.eBottom.style.visibility == "visible"){
this.eBottom.style.width = Math.round(bottomPx) + "px";
this.eBottom.innerHTML = bottomRounded + " " + bottomUnits ;
}
if (this.eTop.style.visibility == "visible"){
this.eTop.style.width = Math.round(topPx) + "px";
this.eTop.innerHTML = topRounded + " " + topUnits;
}
},
CLASS_NAME: "OpenLayers.Control.ScaleLine"
});
|
