/* Copyright (c) 2006-2010 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/Control/ArgParser.js
*/
/**
* Class: OpenLayers.Control.Permalink
* The Permalink control is hyperlink that will return the user to the
* current map view. By default it is drawn in the lower right corner of the
* map. The href is updated as the map is zoomed, panned and whilst layers
* are switched.
* `
* Inherits from:
* - <OpenLayers.Control>
*/
OpenLayers.Control.Permalink = OpenLayers.Class(OpenLayers.Control, {
/**
* APIProperty: argParserClass
* {Class} The ArgParser control class (not instance) to use with this
* control.
*/
argParserClass: OpenLayers.Control.ArgParser,
/**
* Property: element
* {DOMElement}
*/
element: null,
/**
* APIProperty: base
* {String}
*/
base: '',
/**
* APIProperty: displayProjection
* {<OpenLayers.Projection>} Requires proj4js support. Projection used
* when creating the coordinates in the link. This will reproject the
* map coordinates into display coordinates. If you are using this
* functionality, the permalink which is last added to the map will
* determine the coordinate type which is read from the URL, which
* means you should not add permalinks with different
* displayProjections to the same map.
*/
displayProjection: null,
/**
* Constructor: OpenLayers.Control.Permalink
*
* Parameters:
* element - {DOMElement}
* base - {String}
* options - {Object} options to the control.
*/
initialize: function(element, base, options) {
OpenLayers.Control.prototype.initialize.apply(this, [options]);
this.element = OpenLayers.Util.getElement(element);
this.base = base || document.location.href;
},
/**
* APIMethod: destroy
*/
destroy: function() {
if (this.element.parentNode == this.div) {
this.div.removeChild(this.element);
}
this.element = null;
this.map.events.unregister('moveend', this, this.updateLink);
OpenLayers.Control.prototype.destroy.apply(this, arguments);
},
/**
* Method: setMap
* Set the map property for the control.
*
* Parameters:
* map - {<OpenLayers.Map>}
*/
setMap: function(map) {
OpenLayers.Control.prototype.setMap.apply(this, arguments);
//make sure we have an arg parser attached
for(var i=0, len=this.map.controls.length; i<len; i++) {
var control = this.map.controls[i];
if (control.CLASS_NAME == this.argParserClass.CLASS_NAME) {
// If a permalink is added to the map, and an ArgParser already
// exists, we override the displayProjection to be the one
// on the permalink.
if (control.displayProjection != this.displayProjection) {
this.displayProjection = control.displayProjection;
}
break;
}
}
if (i == this.map.controls.length) {
this.map.addControl(new this.argParserClass(
{ 'displayProjection': this.displayProjection }));
}
},
/**
* Method: draw
*
* Returns:
* {DOMElement}
*/
draw: function() {
OpenLayers.Control.prototype.draw.apply(this, arguments);
if (!this.element) {
this.div.className = this.displayClass;
this.element = document.createElement("a");
this.element.innerHTML = OpenLayers.i18n("permalink");
this.element.href="";
this.div.appendChild(this.element);
}
this.map.events.on({
'moveend': this.updateLink,
'changelayer': this.updateLink,
'changebaselayer': this.updateLink,
scope: this
});
// Make it so there is at least a link even though the map may not have
// moved yet.
this.updateLink();
return this.div;
},
/**
* Method: updateLink
*/
updateLink: function() {
var href = this.base;
if (href.indexOf('?') != -1) {
href = href.substring( 0, href.indexOf('?') );
}
href += '?' + OpenLayers.Util.getParameterString(this.createParams());
this.element.href = href;
},
/**
* APIMethod: createParams
* Creates the parameters that need to be encoded into the permalink url.
*
* Parameters:
* center - {<OpenLayers.LonLat>} center to encode in the permalink.
* Defaults to the current map center.
* zoom - {Integer} zoom level to encode in the permalink. Defaults to the
* current map zoom level.
* layers - {Array(<OpenLayers.Layer>)} layers to encode in the permalink.
* Defaults to the current map layers.
*
* Returns:
* {Object} Hash of parameters that will be url-encoded into the
* permalink.
*/
createParams: function(center, zoom, layers) {
center = center || this.map.getCenter();
var params = OpenLayers.Util.getParameters(this.base);
// If there's still no center, map is not initialized yet.
// Break out of this function, and simply return the params from the
// base link.
if (center) {
//zoom
params.zoom = zoom || this.map.getZoom();
//lon,lat
var lat = center.lat;
var lon = center.lon;
if (this.displayProjection) {
var mapPosition = OpenLayers.Projection.transform(
{ x: lon, y: lat },
this.map.getProjectionObject(),
this.displayProjection );
lon = mapPosition.x;
lat = mapPosition.y;
}
params.lat = Math.round(lat*100000)/100000;
params.lon = Math.round(lon*100000)/100000;
//layers
layers = layers || this.map.layers;
params.layers = '';
for (var i=0, len=layers.length; i<len; i++) {
var layer = layers[i];
if (layer.isBaseLayer) {
params.layers += (layer == this.map.baseLayer) ? "B" : "0";
} else {
params.layers += (layer.getVisibility()) ? "T" : "F";
}
}
}
return params;
},
CLASS_NAME: "OpenLayers.Control.Permalink"
});