/* 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. */
/**
* Class: OpenLayers.Icon
*
* The icon represents a graphical icon on the screen. Typically used in
* conjunction with a <OpenLayers.Marker> to represent markers on a screen.
*
* An icon has a url, size and position. It also contains an offset which
* allows the center point to be represented correctly. This can be
* provided either as a fixed offset or a function provided to calculate
* the desired offset.
*
*/
OpenLayers.Icon = OpenLayers.Class({
/**
* Property: url
* {String} image url
*/
url: null,
/**
* Property: size
* {<OpenLayers.Size>}
*/
size: null,
/**
* Property: offset
* {<OpenLayers.Pixel>} distance in pixels to offset the image when being rendered
*/
offset: null,
/**
* Property: calculateOffset
* {<OpenLayers.Pixel>} Function to calculate the offset (based on the size)
*/
calculateOffset: null,
/**
* Property: imageDiv
* {DOMElement}
*/
imageDiv: null,
/**
* Property: px
* {<OpenLayers.Pixel>}
*/
px: null,
/**
* Constructor: OpenLayers.Icon
* Creates an icon, which is an image tag in a div.
*
* url - {String}
* size - {<OpenLayers.Size>}
* offset - {<OpenLayers.Pixel>}
* calculateOffset - {Function}
*/
initialize: function(url, size, offset, calculateOffset) {
this.url = url;
this.size = (size) ? size : new OpenLayers.Size(20,20);
this.offset = offset ? offset : new OpenLayers.Pixel(-(this.size.w/2), -(this.size.h/2));
this.calculateOffset = calculateOffset;
var id = OpenLayers.Util.createUniqueID("OL_Icon_");
this.imageDiv = OpenLayers.Util.createAlphaImageDiv(id);
},
/**
* Method: destroy
* Nullify references and remove event listeners to prevent circular
* references and memory leaks
*/
destroy: function() {
// erase any drawn elements
this.erase();
OpenLayers.Event.stopObservingElement(this.imageDiv.firstChild);
this.imageDiv.innerHTML = "";
this.imageDiv = null;
},
/**
* Method: clone
*
* Returns:
* {<OpenLayers.Icon>} A fresh copy of the icon.
*/
clone: function() {
return new OpenLayers.Icon(this.url,
this.size,
this.offset,
this.calculateOffset);
},
/**
* Method: setSize
*
* Parameters:
* size - {<OpenLayers.Size>}
*/
setSize: function(size) {
if (size != null) {
this.size = size;
}
this.draw();
},
/**
* Method: setUrl
*
* Parameters:
* url - {String}
*/
setUrl: function(url) {
if (url != null) {
this.url = url;
}
this.draw();
},
/**
* Method: draw
* Move the div to the given pixel.
*
* Parameters:
* px - {<OpenLayers.Pixel>}
*
* Returns:
* {DOMElement} A new DOM Image of this icon set at the location passed-in
*/
draw: function(px) {
OpenLayers.Util.modifyAlphaImageDiv(this.imageDiv,
null,
null,
this.size,
this.url,
"absolute");
this.moveTo(px);
return this.imageDiv;
},
/**
* Method: erase
* Erase the underlying image element.
*
*/
erase: function() {
if (this.imageDiv != null && this.imageDiv.parentNode != null) {
OpenLayers.Element.remove(this.imageDiv);
}
},
/**
* Method: setOpacity
* Change the icon's opacity
*
* Parameters:
* opacity - {float}
*/
setOpacity: function(opacity) {
OpenLayers.Util.modifyAlphaImageDiv(this.imageDiv, null, null, null,
null, null, null, null, opacity);
},
/**
* Method: moveTo
* move icon to passed in px.
*
* Parameters:
* px - {<OpenLayers.Pixel>}
*/
moveTo: function (px) {
//if no px passed in, use stored location
if (px != null) {
this.px = px;
}
if (this.imageDiv != null) {
if (this.px == null) {
this.display(false);
} else {
if (this.calculateOffset) {
this.offset = this.calculateOffset(this.size);
}
var offsetPx = this.px.offset(this.offset);
OpenLayers.Util.modifyAlphaImageDiv(this.imageDiv, null, offsetPx);
}
}
},
/**
* Method: display
* Hide or show the icon
*
* Parameters:
* display - {Boolean}
*/
display: function(display) {
this.imageDiv.style.display = (display) ? "" : "none";
},
/**
* APIMethod: isDrawn
*
* Returns:
* {Boolean} Whether or not the icon is drawn.
*/
isDrawn: function() {
// nodeType 11 for ie, whose nodes *always* have a parentNode
// (of type document fragment)
var isDrawn = (this.imageDiv && this.imageDiv.parentNode &&
(this.imageDiv.parentNode.nodeType != 11));
return isDrawn;
},
CLASS_NAME: "OpenLayers.Icon"
});