Module: ol/interaction/Draw

ol/interaction/Draw


Classes

DrawEvent
Draw

Functions

import {createBox} from 'ol/interaction/Draw';

Create a geometryFunction that will create a box-shaped polygon (aligned with the coordinate system axes). Use this with the draw interaction and type: 'Circle' to return a box instead of a circle geometry.

Returns:
Function that draws a box-shaped polygon.

createRegularPolygon(sides, angle){GeometryFunction}

import {createRegularPolygon} from 'ol/interaction/Draw';

Create a geometryFunction for type: 'Circle' that will create a regular polygon with a user specified number of sides and start angle instead of a Circle geometry.

Name Type Description
sides number | undefined

Number of sides of the regular polygon. Default is 32.

angle number | undefined

Angle of the first point in counter-clockwise radians. 0 means East. Default is the angle defined by the heading from the center of the regular polygon to the current pointer position.

Returns:
Function that draws a polygon.

Type Definitions

GeometryFunction()

Function that takes an array of coordinates and an optional existing geometry and a projection as arguments, and returns a geometry. The optional existing geometry is the geometry that is returned when the function is called without a second argument.

LineCoordType{Array<Coordinate>}

Coordinate type when drawing lines.

Mode{'Point'} {'LineString'} {'Polygon'} {'Circle'}

Draw mode. This collapses multi-part geometry types with their single-part cousins.

Options{Object}

Properties:
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. The draw interaction can have up to three sketch features, depending on the mode. It will always contain a feature with a Point geometry that corresponds to the current cursor position. If the mode is LineString or Polygon, and there is at least one drawn point, it will also contain a feature with a LineString geometry that corresponds to the line between the already drawn points and the current cursor position. If the mode is Polygon, and there is at least one drawn point, it will also contain a feature with a Polygon geometry that corresponds to the polygon between the already drawn points and the current cursor position (note that this polygon has only two points if only one point is drawn). If the mode is Circle, and there is one point drawn, it will also contain a feature with a Circle geometry whose center is the drawn point and the radius is determined by the distance between the drawn point and the cursor.

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.

PointCoordType{Coordinate}

Coordinate type when drawing points.

PointSegmentRelationship{Object}

Properties:
Name Type Description
along number

The closest point expressed as a fraction along the segment length.

squaredDistance number

The squared distance of the point to the segment.

PolyCoordType{Array<Array<Coordinate>>}

Coordinate type when drawing polygons.

Types used for drawing coordinates.

TraceState{Object}

Properties:
Name Type Description
active boolean

Tracing active.

startPx Pixel | undefined

The initially clicked pixel location.

targets Array<TraceTarget> | undefined

Targets available for tracing.

targetIndex number | undefined

The index of the currently traced target. A value of -1 indicates that no trace target is active.

TraceTarget{Object}

Properties:
Name Type Description
coordinates Array<Coordinate>

Target coordinates.

ring boolean

The target coordinates are a linear ring.

startIndex number

The index of first traced coordinate. A fractional index represents an edge intersection. Index values for rings will wrap (may be negative or larger than coordinates length).

endIndex number

The index of last traced coordinate. Details from startIndex also apply here.

TraceTargetUpdateInfo{Object}

Properties:
Name Type Description
index number

The new target index.

endIndex number

The new segment end index.