launchpad-mini/examples/print-selected-buttons.js

JavaScript library for interacting with the Novation’s midi board LAUNCHPAD MINI.

#!/usr/bin/env node

const Launchpad = require( '../launchpad-mini' );

const sortByX = ( a, b ) => {
    if ( a[ 0 ] < b[ 0 ] ) return -1;
    if ( a[ 0 ] > b[ 0 ] ) return 1;
    return a[ 1 ] - b[ 1 ];
};

const tReset = 2000;

const pad = new Launchpad();
pad.connect().then( () => {
    pad.reset();
    console.log( `Hold any button for more than ${tReset / 1000} s to reset the pad.` );

    let keys = new Map();
    let lastKeydown = 0;

    pad.on( 'key', ( k ) => {
        if ( k.pressed ) {

            lastKeydown = Date.now();

            if ( keys.has( k.id ) ) {
                keys.delete( k.id );
                pad.col( Launchpad.Colors.off, k );
            } else {
                keys.set( k.id, k );
                pad.col( Launchpad.Colors.green, k );
            }

            const sortedKeys = Array.from( keys.values() )
                .map( el => ([ el.x, el.y ]) )
                .sort( sortByX );
            console.log( JSON.stringify( sortedKeys ) );

        } else {
            if ( Date.now() - lastKeydown > tReset ) {
                keys.clear();
                pad.reset();
            }
        }
    } );

} );