OpenLayers

Class: Snap

ol.interaction.Snap

Handles snapping of vector features while modifying or drawing them. The features can come from a ol.source.Vector or ol.Collection Any interaction object that allows the user to interact with the features using the mouse can benefit from the snapping, as long as it is added before.

The snap interaction modifies map browser event coordinate and pixel properties to force the snap to occur to any interaction that them.

Example:

var snap = new ol.interaction.Snap({
  source: source
});

new ol.interaction.Snap(opt_options)

src/ol/interaction/snap.js, line 42
Name Type Description
options

Options.

Name Type Description
features ol.Collection.<ol.Feature> | undefined

Snap to these features. Either this option or source should be provided.
edge boolean | undefined

Snap to edges. Default is true.
vertex boolean | undefined

Snap to vertices. Default is true.
pixelTolerance number | undefined

Pixel tolerance for considering the pointer close enough to a segment or vertex for snapping. Default is 10 pixels.
source ol.source.Vector | undefined

Snap to features from this source. Either this option or features should be provided
Fires:

Extends

Observable Properties

Name Type Settable ol.Object.Event type Description
active boolean yes change:active

true if the interaction is active, false otherwise.

Methods

addFeature(feature, opt_listen)

src/ol/interaction/snap.js, line 161

Add a feature to the collection of features that we may snap to.

Name Type Description
feature ol.Feature

Feature.
listen boolean

Whether to listen to the feature change or not Defaults to true.

changed() inherited

src/ol/observable.js, line 58

Increases the revision counter and dispatches a 'change' event.

dispatchEvent(event) inherited

src/ol/observable.js, line 75

Dispatches an event and calls all listeners listening for events of this type. The event parameter can either be a string or an Object with a type property.

Name Type Description
event Object | ol.events.Event | string

Event object.

get(key){*} inherited

src/ol/object.js, line 101

Gets a value.

Name Type Description
key string

Key name.
Returns:
Value.

getActive(){boolean} inherited

src/ol/interaction/interaction.js, line 55

Return whether the interaction is currently active.

Returns:
true if the interaction is active, false otherwise.

getKeys(){Array.<string>} inherited

src/ol/object.js, line 115

Get a list of object property names.

Returns:
List of property names.

getMap(){ol.Map} inherited

src/ol/interaction/interaction.js, line 66

Get the map associated with this interaction.

Returns:
Map.

getProperties(){Object.<string, *>} inherited

src/ol/object.js, line 125

Get an object of all property names and values.

Returns:
Object.

getRevision(){number} inherited

src/ol/observable.js, line 84

Get the version number for this object. Each time the object is modified, its version number will be incremented.

Returns:
Revision.

on(type, listener, opt_this){ol.EventsKey|Array.<ol.EventsKey>} inherited

src/ol/observable.js, line 99

Listen for a certain type of event.

Name Type Description
type string | Array.<string>

The event type or array of event types.
listener function

The listener function.
this Object

The object to use as this in listener.
Returns:
Unique key for the listener. If called with an array of event types as the first argument, the return will be an array of keys.

once(type, listener, opt_this){ol.EventsKey|Array.<ol.EventsKey>} inherited

src/ol/observable.js, line 124

Listen once for a certain type of event.

Name Type Description
type string | Array.<string>

The event type or array of event types.
listener function

The listener function.
this Object

The object to use as this in listener.
Returns:
Unique key for the listener. If called with an array of event types as the first argument, the return will be an array of keys.

removeFeature(feature, opt_unlisten)

src/ol/interaction/snap.js, line 270

Remove a feature from the collection of features that we may snap to.

Name Type Description
feature ol.Feature

Feature
unlisten boolean

Whether to unlisten to the feature change or not. Defaults to true.

set(key, value, opt_silent) inherited

src/ol/object.js, line 150

Sets a value.

Name Type Description
key string

Key name.
value *

Value.
silent boolean

Update without triggering an event.

setActive(active) inherited

src/ol/interaction/interaction.js, line 77

Activate or deactivate the interaction.

Name Type Description
active boolean

Active.

setProperties(values, opt_silent) inherited

src/ol/object.js, line 170

Sets a collection of key-value pairs. Note that this changes any existing properties and adds new ones (it does not remove any existing properties).

Name Type Description
values Object.<string, *>

Values.
silent boolean

Update without triggering an event.

un(type, listener, opt_this) inherited

src/ol/observable.js, line 147

Unlisten for a certain type of event.

Name Type Description
type string | Array.<string>

The event type or array of event types.
listener function

The listener function.
this Object

The object which was used as this by the listener.

unset(key, opt_silent) inherited

src/ol/object.js, line 184

Unsets a property.

Name Type Description
key string

Key name.
silent boolean

Unset without triggering an event.