Files
openlayers/src/ol/style/IconImageCache.js
2017-12-12 06:53:17 -07:00

107 lines
2.4 KiB
JavaScript

goog.provide('ol.style.IconImageCache');
goog.require('ol.color');
/**
* Singleton class. Available through {@link ol.style.iconImageCache}.
* @constructor
*/
ol.style.IconImageCache = function() {
/**
* @type {Object.<string, ol.style.IconImage>}
* @private
*/
this.cache_ = {};
/**
* @type {number}
* @private
*/
this.cacheSize_ = 0;
/**
* @type {number}
* @private
*/
this.maxCacheSize_ = 32;
};
/**
* @param {string} src Src.
* @param {?string} crossOrigin Cross origin.
* @param {ol.Color} color Color.
* @return {string} Cache key.
*/
ol.style.IconImageCache.getKey = function(src, crossOrigin, color) {
var colorString = color ? ol.color.asString(color) : 'null';
return crossOrigin + ':' + src + ':' + colorString;
};
/**
* FIXME empty description for jsdoc
*/
ol.style.IconImageCache.prototype.clear = function() {
this.cache_ = {};
this.cacheSize_ = 0;
};
/**
* FIXME empty description for jsdoc
*/
ol.style.IconImageCache.prototype.expire = function() {
if (this.cacheSize_ > this.maxCacheSize_) {
var i = 0;
var key, iconImage;
for (key in this.cache_) {
iconImage = this.cache_[key];
if ((i++ & 3) === 0 && !iconImage.hasListener()) {
delete this.cache_[key];
--this.cacheSize_;
}
}
}
};
/**
* @param {string} src Src.
* @param {?string} crossOrigin Cross origin.
* @param {ol.Color} color Color.
* @return {ol.style.IconImage} Icon image.
*/
ol.style.IconImageCache.prototype.get = function(src, crossOrigin, color) {
var key = ol.style.IconImageCache.getKey(src, crossOrigin, color);
return key in this.cache_ ? this.cache_[key] : null;
};
/**
* @param {string} src Src.
* @param {?string} crossOrigin Cross origin.
* @param {ol.Color} color Color.
* @param {ol.style.IconImage} iconImage Icon image.
*/
ol.style.IconImageCache.prototype.set = function(src, crossOrigin, color, iconImage) {
var key = ol.style.IconImageCache.getKey(src, crossOrigin, color);
this.cache_[key] = iconImage;
++this.cacheSize_;
};
/**
* Set the cache size of the icon cache. Default is `32`. Change this value when
* your map uses more than 32 different icon images and you are not caching icon
* styles on the application level.
* @param {number} maxCacheSize Cache max size.
* @api
*/
ol.style.IconImageCache.prototype.setSize = function(maxCacheSize) {
this.maxCacheSize_ = maxCacheSize;
this.expire();
};