Leaflet.FreeHandShapes

 

Initially forked from and inspired by L.FreeDraw

What Is This?

This is a Leaflet plugin for adding/manipulating polygons from a Leaflet map. It is a freehand drawer that supports mobile, canvas, and multiple instances. Each instance adds polygons to a Leaflet FeatureGroup, optionally merging with other polygons using TurfJS. Polygons can also be subtracted by other polygons using TurfJS.

See the demo

Installation

via npm:

npm install leaflet-freehandshapes --save

Usage

// initialize
require('leaflet-freehandshapes');
var drawer = new L.FreeHandShapes();

// enable drawing
drawer.setMode('add');

// stop drawing
drawer.setMode('view');

// enable substraction
drawer.setMode('subtract');

// enable click-to-delete
drawer.setMode('delete');

Options

L.FreeHandShapes takes the following options:

• polygon (object) : Same options as L.Polygon

Default:

{
    className: 'leaflet-free-hand-shapes',
    smoothFactor: 1,
    fillOpacity : 0.5,
    noClip : true,
}

• polyline (object) : Same options as L.Polyline

Default:

{
    color:'#5cb85c',
    opacity:1,
    smoothFactor: 0,
    noClip : true,
    clickable : false,
    weight:2
}

• simplify_tolerance (float) : how much to simplify the polygon (argument given to L.LineUtil.simplify).

Default: 0.005

• merge_polygons (boolean)

Default: `true

Controls

There is no default control available for this plugin, because it is made to be more flexible, allowing for multiple instances and two drawing methods (addition/subtraction). For an example on how to build your own, take a look at the example, where multiple instances are created for a sample land use development project and bound to some controls (built with Bootstrap CSS) :

• HTML
• JS (See Line 14 for iteration/creation of instances, and Line 246 for handlers bound to the control buttons)

Pull Requests

Please limit each PR to one clear improvement each (PR's offering several improvements are harder to read). Any number of bug fixes are welcome!

Goals

• A built-in control (L.Control) for UI (probably for each instance)