GeometryCollection

GeometryCollection is a geometry-collection class that extends Geometry. It provides the ability to manage multiple geometry objects as a whole, including batch add/remove, traversal, filtering, translation, visibility, and editing. A typical use is to combine several geometries into one collection, add it to a layer, and control them together.

import { GeometryCollection } from "maptalks";

const collection = new GeometryCollection([
  new Marker([100, 0]),
  new LineString([[100, 0], [101, 1]]),
  new Polygon([[[100, 0], [101, 0], [101, 1], [100, 0]]])
]);

layer.addGeometry(collection);

Constructor

new GeometryCollection(geometries?, options?)

Parameters:

• geometries — (Optional) An array of geometry objects used as the initial child geometries.
• options — (Optional) Geometry options, see the options of Geometry.

options

GeometryCollection has no class-specific options; it inherits the options of Geometry.

Methods

• setGeometries(geos): this — Sets the array of geometry objects in the collection.
• getGeometries(): Geometry[] — Gets the array of geometry objects in the collection.
• forEach(fn, ctx): this — Iterates over each child geometry, calling fn(geometry, index); ctx is the callback context.
• filter(fn): Geometry[] — Filters child geometries, returning the geometries that satisfy the predicate.
• translate(offset): this — Translates all child geometries by the given coordinate offset.
• isEmpty(): boolean — Returns whether the collection is empty.
• remove(): this — Removes the collection and its child geometries from the layer.
• show(): this — Shows the collection.
• hide(): this — Hides the collection.
• getSymbol(): object — Gets the symbol of the collection.
• setSymbol(s): this — Sets the symbol of the collection.
• startEdit / endEdit / isEditing — Starts editing / ends editing / returns whether editing is in progress.
• undoEdit / redoEdit — Undoes / redoes the last edit.

Static Methods

• GeometryCollection.fromJSON(json): GeometryCollection — Creates a GeometryCollection instance from a JSON object.

Events

• shapechange — Fired when the geometry shape changes.
• removestart / remove / removeend — Fired when a removal starts, progresses, and ends.
• show / hide — Fired when the collection is shown / hidden.
• editstart / editend — Fired when editing starts / ends.