Class: Draw

ol/interaction/Draw~Draw


import Draw from 'ol/interaction/Draw';

Interaction for drawing feature geometries.

new Draw(options)

Name Type Description
type Type

Geometry type of the geometries being drawn with this instance.

clickTolerance number (defaults to 6)

The maximum distance in pixels between "down" and "up" for a "up" event to be considered a "click" event and actually add a point/vertex to the geometry being drawn. The default of 6 was chosen for the draw interaction to behave correctly on mouse as well as on touch devices.

features Collection<Feature> | undefined

Destination collection for the drawn features.

source VectorSource | undefined

Destination source for the drawn features.

dragVertexDelay number (defaults to 500)

Delay in milliseconds after pointerdown before the current vertex can be dragged to its exact position.

snapTolerance number (defaults to 12)

Pixel distance for snapping to the drawing finish. Must be greater than 0.

stopClick boolean (defaults to false)

Stop click, singleclick, and doubleclick events from firing during drawing.

maxPoints number | undefined

The number of points that can be drawn before a polygon ring or line string is finished. By default there is no restriction.

minPoints number | undefined

The number of points that must be drawn before a polygon ring or line string can be finished. Default is 3 for polygon rings and 2 for line strings.

finishCondition Condition | undefined

A function that takes an MapBrowserEvent and returns a boolean to indicate whether the drawing can be finished. Not used when drawing POINT or MULTI_POINT geometries.

style StyleLike | FlatStyleLike | undefined

Style for sketch features.

geometryFunction GeometryFunction | undefined

Function that is called when a geometry's coordinates are updated.

geometryName string | undefined

Geometry name to use for features created by the draw interaction.

condition Condition | undefined

A function that takes an MapBrowserEvent and returns a boolean to indicate whether that event should be handled. By default noModifierKeys, i.e. a click, adds a vertex or deactivates freehand drawing.

freehand boolean (defaults to false)

Operate in freehand mode for lines, polygons, and circles. This makes the interaction always operate in freehand mode and takes precedence over any freehandCondition option.

freehandCondition Condition | undefined

Condition that activates freehand drawing for lines and polygons. This function takes an MapBrowserEvent and returns a boolean to indicate whether that event should be handled. The default is shiftKeyOnly, meaning that the Shift key activates freehand drawing.

trace boolean | Condition (defaults to false)

Trace a portion of another geometry. Ignored when in freehand mode.

traceSource VectorSource | undefined

Source for features to trace. If tracing is active and a traceSource is not provided, the interaction's source will be used. Tracing requires that the interaction is configured with either a traceSource or a source.

wrapX boolean (defaults to false)

Wrap the world horizontally on the sketch overlay.

geometryLayout GeometryLayout (defaults to 'XY')

Layout of the feature geometries created by the draw interaction.

Fires:

Extends

Observable Properties

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

true if the interaction is active, false otherwise.

Methods

abortDrawing()

Stop drawing without adding the sketch feature to the target layer.

appendCoordinates(coordinates)

Append coordinates to the end of the geometry that is currently being drawn. This can be used when drawing LineStrings or Polygons. Coordinates will either be appended to the current LineString or the outer ring of the current Polygon. If no geometry is being drawn, a new one will be created.

Name Type Description
coordinates LineCoordType

Linear coordinates to be appended to the coordinate array.

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

dispatchEvent(event){boolean | undefined} inherited

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.

extend(feature)

Initiate draw mode by starting from an existing geometry which will receive new additional points. This only works on features with LineString geometries, where the interaction will extend lines by adding points to the end of the coordinates array. This will change the original feature, instead of drawing a copy.

The function will dispatch a drawstart event.

Name Type Description
feature Feature<LineString>

Feature to be extended.

finishDrawing()

Stop drawing and add the sketch feature to the target layer. The DRAWEND event is dispatched before inserting the feature.

Gets a value.

Name Type Description
key string

Key name.

Returns:
Value.

Return whether the interaction is currently active.

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

getKeys(){Array.<string>} inherited

Get a list of object property names.

Returns:
List of property names.

Get the map associated with this interaction.

Returns:
Map.

Get the overlay layer that this interaction renders sketch features to.

Returns:
Overlay layer.

getPointerCount(){number} inherited

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

Get an object of all property names and values.

Returns:
Object.

getRevision(){number} inherited

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

Returns:
Revision.

handleEvent(event){boolean}

Handles the map browser event and may actually draw or finish the drawing.

Name Type Description
event MapBrowserEvent

Map browser event.

Returns:
false to stop event propagation.

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

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

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.

removeLastPoint()

Remove last point of the feature currently being drawn. Does not do anything when drawing POINT or MULTI_POINT geometries.

set(key, value, silent) inherited

Sets a value.

Name Type Description
key string

Key name.

value *

Value.

silent boolean | undefined

Update without triggering an event.

Activate or deactivate the interaction.

Name Type Description
active boolean

Active.

setProperties(values, silent) inherited

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

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

Unsets a property.

Name Type Description
key string

Key name.

silent boolean | undefined

Unset without triggering an event.