openlayers
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Build tools and sources for developing OpenLayers based mapping applications
315 lines (276 loc) • 8.82 kB
JavaScript
goog.provide('ol.Feature');
goog.require('ol.asserts');
goog.require('ol.events');
goog.require('ol.events.EventType');
goog.require('ol');
goog.require('ol.Object');
goog.require('ol.geom.Geometry');
goog.require('ol.style.Style');
/**
* @classdesc
* A vector object for geographic features with a geometry and other
* attribute properties, similar to the features in vector file formats like
* GeoJSON.
*
* Features can be styled individually with `setStyle`; otherwise they use the
* style of their vector layer.
*
* Note that attribute properties are set as {@link ol.Object} properties on
* the feature object, so they are observable, and have get/set accessors.
*
* Typically, a feature has a single geometry property. You can set the
* geometry using the `setGeometry` method and get it with `getGeometry`.
* It is possible to store more than one geometry on a feature using attribute
* properties. By default, the geometry used for rendering is identified by
* the property name `geometry`. If you want to use another geometry property
* for rendering, use the `setGeometryName` method to change the attribute
* property associated with the geometry for the feature. For example:
*
* ```js
* var feature = new ol.Feature({
* geometry: new ol.geom.Polygon(polyCoords),
* labelPoint: new ol.geom.Point(labelCoords),
* name: 'My Polygon'
* });
*
* // get the polygon geometry
* var poly = feature.getGeometry();
*
* // Render the feature as a point using the coordinates from labelPoint
* feature.setGeometryName('labelPoint');
*
* // get the point geometry
* var point = feature.getGeometry();
* ```
*
* @constructor
* @extends {ol.Object}
* @param {ol.geom.Geometry|Object.<string, *>=} opt_geometryOrProperties
* You may pass a Geometry object directly, or an object literal
* containing properties. If you pass an object literal, you may
* include a Geometry associated with a `geometry` key.
* @api stable
*/
ol.Feature = function(opt_geometryOrProperties) {
ol.Object.call(this);
/**
* @private
* @type {number|string|undefined}
*/
this.id_ = undefined;
/**
* @type {string}
* @private
*/
this.geometryName_ = 'geometry';
/**
* User provided style.
* @private
* @type {ol.style.Style|Array.<ol.style.Style>|
* ol.FeatureStyleFunction}
*/
this.style_ = null;
/**
* @private
* @type {ol.FeatureStyleFunction|undefined}
*/
this.styleFunction_ = undefined;
/**
* @private
* @type {?ol.EventsKey}
*/
this.geometryChangeKey_ = null;
ol.events.listen(
this, ol.Object.getChangeEventType(this.geometryName_),
this.handleGeometryChanged_, this);
if (opt_geometryOrProperties !== undefined) {
if (opt_geometryOrProperties instanceof ol.geom.Geometry ||
!opt_geometryOrProperties) {
var geometry = opt_geometryOrProperties;
this.setGeometry(geometry);
} else {
/** @type {Object.<string, *>} */
var properties = opt_geometryOrProperties;
this.setProperties(properties);
}
}
};
ol.inherits(ol.Feature, ol.Object);
/**
* Clone this feature. If the original feature has a geometry it
* is also cloned. The feature id is not set in the clone.
* @return {ol.Feature} The clone.
* @api stable
*/
ol.Feature.prototype.clone = function() {
var clone = new ol.Feature(this.getProperties());
clone.setGeometryName(this.getGeometryName());
var geometry = this.getGeometry();
if (geometry) {
clone.setGeometry(geometry.clone());
}
var style = this.getStyle();
if (style) {
clone.setStyle(style);
}
return clone;
};
/**
* Get the feature's default geometry. A feature may have any number of named
* geometries. The "default" geometry (the one that is rendered by default) is
* set when calling {@link ol.Feature#setGeometry}.
* @return {ol.geom.Geometry|undefined} The default geometry for the feature.
* @api stable
* @observable
*/
ol.Feature.prototype.getGeometry = function() {
return /** @type {ol.geom.Geometry|undefined} */ (
this.get(this.geometryName_));
};
/**
* Get the feature identifier. This is a stable identifier for the feature and
* is either set when reading data from a remote source or set explicitly by
* calling {@link ol.Feature#setId}.
* @return {number|string|undefined} Id.
* @api stable
* @observable
*/
ol.Feature.prototype.getId = function() {
return this.id_;
};
/**
* Get the name of the feature's default geometry. By default, the default
* geometry is named `geometry`.
* @return {string} Get the property name associated with the default geometry
* for this feature.
* @api stable
*/
ol.Feature.prototype.getGeometryName = function() {
return this.geometryName_;
};
/**
* Get the feature's style. Will return what was provided to the
* {@link ol.Feature#setStyle} method.
* @return {ol.style.Style|Array.<ol.style.Style>|
* ol.FeatureStyleFunction} The feature style.
* @api stable
* @observable
*/
ol.Feature.prototype.getStyle = function() {
return this.style_;
};
/**
* Get the feature's style function.
* @return {ol.FeatureStyleFunction|undefined} Return a function
* representing the current style of this feature.
* @api stable
*/
ol.Feature.prototype.getStyleFunction = function() {
return this.styleFunction_;
};
/**
* @private
*/
ol.Feature.prototype.handleGeometryChange_ = function() {
this.changed();
};
/**
* @private
*/
ol.Feature.prototype.handleGeometryChanged_ = function() {
if (this.geometryChangeKey_) {
ol.events.unlistenByKey(this.geometryChangeKey_);
this.geometryChangeKey_ = null;
}
var geometry = this.getGeometry();
if (geometry) {
this.geometryChangeKey_ = ol.events.listen(geometry,
ol.events.EventType.CHANGE, this.handleGeometryChange_, this);
}
this.changed();
};
/**
* Set the default geometry for the feature. This will update the property
* with the name returned by {@link ol.Feature#getGeometryName}.
* @param {ol.geom.Geometry|undefined} geometry The new geometry.
* @api stable
* @observable
*/
ol.Feature.prototype.setGeometry = function(geometry) {
this.set(this.geometryName_, geometry);
};
/**
* Set the style for the feature. This can be a single style object, an array
* of styles, or a function that takes a resolution and returns an array of
* styles. If it is `null` the feature has no style (a `null` style).
* @param {ol.style.Style|Array.<ol.style.Style>|
* ol.FeatureStyleFunction} style Style for this feature.
* @api stable
* @observable
*/
ol.Feature.prototype.setStyle = function(style) {
this.style_ = style;
this.styleFunction_ = !style ?
undefined : ol.Feature.createStyleFunction(style);
this.changed();
};
/**
* Set the feature id. The feature id is considered stable and may be used when
* requesting features or comparing identifiers returned from a remote source.
* The feature id can be used with the {@link ol.source.Vector#getFeatureById}
* method.
* @param {number|string|undefined} id The feature id.
* @api stable
* @observable
*/
ol.Feature.prototype.setId = function(id) {
this.id_ = id;
this.changed();
};
/**
* Set the property name to be used when getting the feature's default geometry.
* When calling {@link ol.Feature#getGeometry}, the value of the property with
* this name will be returned.
* @param {string} name The property name of the default geometry.
* @api stable
*/
ol.Feature.prototype.setGeometryName = function(name) {
ol.events.unlisten(
this, ol.Object.getChangeEventType(this.geometryName_),
this.handleGeometryChanged_, this);
this.geometryName_ = name;
ol.events.listen(
this, ol.Object.getChangeEventType(this.geometryName_),
this.handleGeometryChanged_, this);
this.handleGeometryChanged_();
};
/**
* Convert the provided object into a feature style function. Functions passed
* through unchanged. Arrays of ol.style.Style or single style objects wrapped
* in a new feature style function.
* @param {ol.FeatureStyleFunction|!Array.<ol.style.Style>|!ol.style.Style} obj
* A feature style function, a single style, or an array of styles.
* @return {ol.FeatureStyleFunction} A style function.
*/
ol.Feature.createStyleFunction = function(obj) {
var styleFunction;
if (typeof obj === 'function') {
styleFunction = obj;
} else {
/**
* @type {Array.<ol.style.Style>}
*/
var styles;
if (Array.isArray(obj)) {
styles = obj;
} else {
ol.asserts.assert(obj instanceof ol.style.Style,
41); // Expected an `ol.style.Style` or an array of `ol.style.Style`
styles = [obj];
}
styleFunction = function() {
return styles;
};
}
return styleFunction;
};