Visual dom-selection library

This README is always up-to-date with the lastest version. Check out releases if you want to check out the documentation for your version.

Features

• Tiny (only ~4kb)
• Simple usage
• Highly optimized
• Zero dependencies
• Mobile / touch support
• Vertical and horizontal scroll support

Install

Via npm:

$ npm install @simonwep/selection-js

Via yarn:

$ yarn add @simonwep/selection-js

Include via jsdelivr.net:

<script src="https://cdn.jsdelivr.net/npm/@simonwep/selection-js/lib/selection.min.js"></script>

Or using ES6 modules:

import SelectionArea from "https://cdn.jsdelivr.net/npm/@simonwep/selection-js/lib/selection.min.mjs"

Last but not least you'll need to add some basic styles to make your selection-area visible:

.selection-area {
    background: rgba(46, 115, 252, 0.11);
    border: 2px solid rgba(98, 155, 255, 0.81);
    border-radius: 0.1em;
}

Usage

const selection = new SelectionArea({

    // document object - if you want to use it within an embed document (or iframe).
    document: window.document,

    // Class for the selection-area element.
    class: 'selection-area',

    // Query selector or dom-node to set up container for the selection-area element.
    container: 'body',

    // Query selectors for elements which can be selected.
    selectables: [],

    // Query selectors for elements from where a selection can be started from.
    startareas: ['html'],

    // Query selectors for elements which will be used as boundaries for the selection.
    boundaries: ['html'],

    // px, how many pixels the point should move before starting the selection (combined distance).
    // Or specifiy the threshold for each axis by passing an object like {x: <number>, y: <number>}.
    startThreshold: 10,

    // Enable / disable touch support
    allowTouch: true,

    // On which point an element should be selected.
    // Available modes are cover (cover the entire element), center (touch the center) or
    // the default mode is touch (just touching it).
    intersect: 'touch',

    // Configuration in case a selectable gets just clicked.
    singleTap: {

        // Enable single-click selection (Also disables range-selection via shift + ctrl).
        allow: true,

        // 'native' (element was mouse-event target) or 'touch' (element visually touched).
        intersect: 'native'
    },

    // Scroll configuration.
    scrolling: {

        // On scrollable areas the number on px per frame is devided by this amount.
        // Default is 10 to provide a enjoyable scroll experience.
        speedDivider: 10,

        // Browsers handle mouse-wheel events differently, this number will be used as 
        // numerator to calculate the mount of px while scrolling manually: manualScrollSpeed / scrollSpeedDivider.
        manualSpeed: 750
    }
});

Events

Use the on(event, cb) and off(event, cb) functions to bind / unbind event-listener.

You may want to checkout the source used in the demo-page, it's easier than reading through the manual.

Event	Description
beforestart	The user tapped one of the areas within the specified boundaries. Return false to cancel selection immediatly.
start	Selection started, here you can decide if you want to keep your previously selected elements.
move	Selection is active, user is moving the pointer around.
stop	Selection has stopped.

Check out types.ts to see what kind of data is passed to each event.

Example:

selection.on('beforestart', evt => {
    
    // Use this event to decide whether a selection should take place or not.
    // For example if the user should be able to normally interact with input-elements you 
    // may want to prevent a selection if the user clicks such a element:
    // selection.on('beforestart', ({event}) => {
    //   return event.target.tagName !== 'INPUT'; // Returning false prevents a selection
    // });
    
    console.log('beforestart', evt);
}).on('start', evt => {

    // A selection got initiated, you could now clear the previous selection or
    // keep it if in case of multi-selection.
    console.log('start', evt);
}).on('move', evt => {

    // Here you can update elements based on their state.
    console.log('move', evt);
}).on('stop', evt => {

    // The last event can be used to call functions like keepSelection() in case the user wants
    // to select multiple elements.
    console.log('stop', evt);
});

You can find event-related examples here.

Methods

Method	Description
on(event:String, cb:Function)	Adds an event listener to the given corresponding event-name (see section Events), returns the current instance, so it can be chained.
off(event:String, cb:Function)	Removes an event listener from the given corresponding event-name (see section Events), returns the current instance, so it can be chained.
disable()	Disable the functionality to make selections.
enable()	Enable the functionality to make selections.
destroy()	Unbinds all events and removes the area-element.
cancel()	Cancels the current selection process.
trigger(evt:MouseEvent | TouchEvent, silent: boolean = true)	Manually triggers the start of a selection. If silent is set to true, no beforestart event will be fired.
keepSelection()	Will save the current selected elements and will append those to the next selection. Can be used to allow multiple selections.
clearSelection(store:boolean = true)	Clear the previous selection (elements which were stored by calling keepSelection()). Pass false to only clear the currently selected elements.
getSelection()	Returns currently selected elements.
resolveSelectables()	Need to be called if during a selection elements have been added / removed.
select(query:(String | Element)[])	Manually appends elements to the selection, can be a / an array of queries / elements. Returns actual selected elements as array.
deselect(el:HTMLElement, silent: boolean = true)	Removes a particular element from the current selection. silent determines whether the move event should be fired.