dust/js/controls.js

import Rx, { Observable } from 'rxjs';
import { CONTROLS } from './enums';

function Controls(container, { animating, count, maxCount, speed }, customNodes) {
    this.nodes = {
        animating: createAnimatingControl(animating),
        count: createCountControl(count, maxCount),
        speed: createSpeedControl(speed),
    }

    container.appendChild(this.nodes.count);
    container.appendChild(this.nodes.speed);

    if (customNodes !== undefined) {
        customNodes.forEach(node => { container.appendChild(node); });
    }

    container.appendChild(this.nodes.animating);

    this.updateOptions({ key: CONTROLS.ANIMATING, value: animating });
    this.updateOptions({ key: CONTROLS.COUNT, value: count });
    this.updateOptions({ key: CONTROLS.SPEED, value: speed });
}

Controls.prototype.updateOptions = function({ key, value}) {
    if (key === CONTROLS.COUNT) {
        this.nodes.count.querySelector('span').innerHTML =
            (value == 1) ? '1 particle' : `${value} particles`;
    }

    if (key === CONTROLS.SPEED) {
        this.nodes.speed.querySelector('span').innerHTML =
            `Speed: ${value}`;
    }

    if (key === CONTROLS.ANIMATING) {
        this.nodes.animating.querySelector('span').innerHTML =
            (value ? '◼ Stop' : '▶ Start');
    }
}

Controls.prototype.mount = function(customNodes) {
    const animating$ = Rx.Observable.fromEvent(this.nodes.animating, 'change')
        .map(evt => ({ key: CONTROLS.ANIMATING, value: evt.target.checked }));

    const count$ = Rx.Observable.fromEvent(this.nodes.count, 'input')
        .map(evt => ({ key: CONTROLS.COUNT, value: evt.target.value * 1 }));

    const speed$ = Rx.Observable.fromEvent(this.nodes.speed, 'input')
        .map(evt => ({ key: CONTROLS.SPEED, value: evt.target.value * 1 }));

    const eventStack$ = Rx.Observable.merge(
        animating$,
        count$,
        speed$
    );

    eventStack$.subscribe(this.updateOptions.bind(this));

    return eventStack$;
}

function createAnimatingControl(value) {
    const label = document.createElement('label');
    label.className = 'controls-label';
    label.className = 'controls-animating';

    const text = document.createElement('span');
    text.innerHTML = '...';

    const checkbox = document.createElement('input');
    checkbox.type = 'checkbox';
    checkbox.checked = value;

    label.appendChild(checkbox);
    label.appendChild(text);

    return label;
}

function createCountControl(value, max) {
    const label = document.createElement('label');
    label.className = 'controls-range';

    const text = document.createElement('span');
    text.innerHTML = '...';
    text.className = 'controls-range-text';

    const slider = document.createElement('input');
    slider.type = 'range';
    slider.min = 1;
    slider.max = max;
    slider.value = value;
    slider.className = 'controls-range-input';

    label.appendChild(text);
    label.appendChild(slider);

    return label;
}

function createSpeedControl(value) {
    const label = document.createElement('label');
    label.className = 'controls-range';

    const text = document.createElement('span');
    text.className = 'controls-range-text';

    const slider = document.createElement('input');
    slider.type = 'range';
    slider.min = 1;
    slider.max = 15;
    slider.value = value;
    slider.className = 'controls-range-input';

    label.appendChild(text);
    label.appendChild(slider);

    return label;
}

export default Controls;