Class: Snap

ol/interaction/Snap~Snap 


import Snap from 'ol/interaction/Snap.js';

Handles snapping of vector features while modifying or drawing them. The features can come from a VectorSource or 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 uses them.

Example:

import Snap from 'ol/interaction/Snap.js';

const snap = new Snap({
  source: source
});

map.addInteraction(snap);

new Snap(options)

interaction/Snap.js, line 110
Name Type Description
features Collection<Feature> | undefined

Snap to these features. Either this option or source should be provided.
edge boolean (defaults to true)

Snap to edges.
vertex boolean (defaults to true)

Snap to vertices.
pixelTolerance number (defaults to 10)

Pixel tolerance for considering the pointer close enough to a segment or vertex for snapping.
source VectorSource | undefined

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

Extends

Observable Properties

Name Type Settable ObjectEvent type Description
active boolean yes change:active

true if the interaction is active, false otherwise.

Methods

addFeature(feature, register)

interaction/Snap.js, line 238

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

Name Type Description
feature Feature

Feature.
register boolean | undefined

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

changed() inherited

Observable.js, line 68

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

dispatchEvent(event){boolean | undefined} inherited

events/Target.js, line 85

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 BaseEvent | string

Event object.
Returns:
false if anyone called preventDefault on the event object or if any of the listeners returned false.

get(key){*} inherited

Object.js, line 135

Gets a value.

Name Type Description
key string

Key name.
Returns:
Value.

getActive(){boolean} inherited

interaction/Interaction.js, line 82

Return whether the interaction is currently active.

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

getKeys(){Array.<string>} inherited

Object.js, line 148

Get a list of object property names.

Returns:
List of property names.

getMap(){Map | null} inherited

interaction/Interaction.js, line 91

Get the map associated with this interaction.

Returns:
Map.

getPointerCount(){number} inherited

interaction/Pointer.js, line 95

Returns the current number of pointers involved in the interaction, e.g. 2 when two fingers are used.

Returns:
The number of pointers.

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

Object.js, line 157

Get an object of all property names and values.

Returns:
Object.

getRevision(){number} inherited

Observable.js, line 79

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

Returns:
Revision.

handleEvent(evt){boolean}

interaction/Snap.js, line 297
Name Type Description
evt MapBrowserEvent

Map browser event.
Returns:
false to stop event propagation.

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

Observable.js, line 152

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.
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){EventsKey | Array<EventsKey>} inherited

Observable.js, line 164

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.
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, unlisten)

interaction/Snap.js, line 374

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

Name Type Description
feature Feature

Feature
unlisten boolean | undefined

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

set(key, value, silent) inherited

Object.js, line 215

Sets a value.

Name Type Description
key string

Key name.
value *

Value.
silent boolean | undefined

Update without triggering an event.

setActive(active) inherited

interaction/Interaction.js, line 111

Activate or deactivate the interaction.

Name Type Description
active boolean

Active.

setProperties(values, silent) inherited

Object.js, line 235

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 | undefined

Update without triggering an event.

un(type, listener) inherited

Observable.js, line 173

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.

unset(key, silent) inherited

Object.js, line 259

Unsets a property.

Name Type Description
key string

Key name.
silent boolean | undefined

Unset without triggering an event.