DistanceTool

DistanceTool is the distance measurement tool. It extends DrawTool. After the user clicks to draw a polyline on the map, the tool calculates and displays the length of each segment and the total length. It supports metric/imperial unit switching, configurable label formatting, and measuring multiple polylines.

import { DistanceTool } from "maptalks";

const distanceTool = new DistanceTool({
  metric: true,
  imperial: false
}).addTo(map);

Constructor

new DistanceTool(options)

Parameters:

• options — DistanceTool options. Some properties match the DistanceTool.options table below; the rest are inherited from DrawTool.

options

Name	Type	Description	Default
language	String	The language of measurement hints	'zh-CN'
metric	Boolean	Whether metric units are enabled	true
imperial	Boolean	Whether imperial units are enabled	false
vertexSymbol	Object	The symbol for vertex labels	null
labelOptions	Object	Options for measurement labels	null
decimalPlaces	Number	The number of decimal places in the result	2
formatLabelContent	Function	A custom formatter for the label content	null
clearButtonSymbol	Object	The symbol of the clear button	null

Member Methods

• clear() — Clears all current measurement results.
• getMeasureLayers(): Layer[] — Gets the layers used to render measurement results.
• getLastMeasure(): number — Gets the last measurement result.
• undo() — Undoes the last step.
• redo() — Redoes the last step.