Minidrag NPM | npm.io

minidrag

A simple solution to make an HTML element draggable. There is no dependencies.

Usage

minidrag(element, options);

Where element is the HTMLElement that will be draggable, and options is an object containing the options.

Example

A simple example that just makes the handle draggable:

<div id="container">
  <div id="handle"></div>
</div>

var minidrag = require('minidrag');

var handle = document.querySelector('#handle');
var container = document.querySelector('#container');

minidrag(handle, { constraint: container });

A more complex example with two handles that won’t overlap themselves:

<div id="container">
  <div id="handle-1"></div>
  <div id="handle-2"></div>
</div>

var minidrag = require('minidrag');

var handle1 = container.querySelector('#handle-1');
var handle2 = container.querySelector('#handle-2');
var container = document.querySelector('#container');

// starting x values
var handle1X = 0;
var handle2X = 560;

var handleWidth = 40;
handle2.style.left = handle2X + 'px';

minidrag(handle1, {
  constraint: container,
  move: function(position) { handle1X = position.left },

  // constraintFn: this function can change the position values
  // before they are applied to the dragged element. It doesn’t replace
  // the `constraint` option: both are applied.
  constraintFn: function(position) {
    if (position.left + handleWidth > handle2X) {
      position.left = handle2X - handleWidth;
    }
    return position;
  }
});

minidrag(handle2, {
  constraint: container,
  move: function(position) { handle2X = position.left },
  constraintFn: function(position) {
    if (position.left < handle1X + handleWidth) {
      position.left = handle1X + handleWidth;
    }
    return position;
  }
});

Installation

$ npm install minidrag

Options

`constraint`

The constraint (limits) of the dragged Element. Possible values: null (no constraints), 'x', 'y' (horizontal / vertical axis), or an HTMLElement (stay in the limits of the Element).

`constraintFn`

In addition to the constraint parameter, this function can change the position of the dragged Element, adding another limitation if needed (see the second example above). It must return the new position.

This function takes one paramater, which is the current position ({ top: Number, left: Number }) of the handle, after the constraint has been applied to it.