interactjs/src/Interactable.js

Drag and drop, resizing and multi-touch gestures with inertia and snapping for modern browsers (and also IE9+)

const clone     = require('./utils/clone');
const is        = require('./utils/is');
const events    = require('./utils/events');
const extend    = require('./utils/extend');
const actions   = require('./actions/base');
const scope     = require('./scope');
const Eventable = require('./Eventable');
const defaults  = require('./defaultOptions');
const signals   = require('./utils/Signals').new();

const {
  getElementRect,
  nodeContains,
  trySelector,
  matchesSelector,
}                    = require('./utils/domUtils');
const { getWindow }  = require('./utils/window');
const { contains }   = require('./utils/arr');
const { wheelEvent } = require('./utils/browser');

// all set interactables
scope.interactables = [];

class Interactable {
  /** */
  constructor (target, options) {
    options = options || {};

    this.target   = target;
    this.events   = new Eventable();
    this._context = options.context || scope.document;
    this._win     = getWindow(trySelector(target)? this._context : target);
    this._doc     = this._win.document;

    signals.fire('new', {
      target,
      options,
      interactable: this,
      win: this._win,
    });

    scope.addDocument( this._doc, this._win );

    scope.interactables.push(this);

    this.set(options);
  }

  setOnEvents (action, phases) {
    const onAction = 'on' + action;

    if (is.function(phases.onstart)       ) { this.events[onAction + 'start'        ] = phases.onstart         ; }
    if (is.function(phases.onmove)        ) { this.events[onAction + 'move'         ] = phases.onmove          ; }
    if (is.function(phases.onend)         ) { this.events[onAction + 'end'          ] = phases.onend           ; }
    if (is.function(phases.oninertiastart)) { this.events[onAction + 'inertiastart' ] = phases.oninertiastart  ; }

    return this;
  }

  setPerAction (action, options) {
    // for all the default per-action options
    for (const option in options) {
      // if this option exists for this action
      if (option in defaults[action]) {
        // if the option in the options arg is an object value
        if (is.object(options[option])) {
          // duplicate the object and merge
          this.options[action][option] = clone(this.options[action][option] || {});
          extend(this.options[action][option], options[option]);

          if (is.object(defaults.perAction[option]) && 'enabled' in defaults.perAction[option]) {
            this.options[action][option].enabled = options[option].enabled === false? false : true;
          }
        }
        else if (is.bool(options[option]) && is.object(defaults.perAction[option])) {
          this.options[action][option].enabled = options[option];
        }
        else if (options[option] !== undefined) {
          // or if it's not undefined, do a plain assignment
          this.options[action][option] = options[option];
        }
      }
    }
  }

  /**
   * The default function to get an Interactables bounding rect. Can be
   * overridden using {@link Interactable.rectChecker}.
   *
   * @param {Element} [element] The element to measure.
   * @return {object} The object's bounding rectangle.
   */
  getRect (element) {
    element = element || this.target;

    if (is.string(this.target) && !(is.element(element))) {
      element = this._context.querySelector(this.target);
    }

    return getElementRect(element);
  }

  /**
   * Returns or sets the function used to calculate the interactable's
   * element's rectangle
   *
   * @param {function} [checker] A function which returns this Interactable's
   * bounding rectangle. See {@link Interactable.getRect}
   * @return {function | object} The checker function or this Interactable
   */
  rectChecker (checker) {
    if (is.function(checker)) {
      this.getRect = checker;

      return this;
    }

    if (checker === null) {
      delete this.options.getRect;

      return this;
    }

    return this.getRect;
  }

  _backCompatOption (optionName, newValue) {
    if (trySelector(newValue) || is.object(newValue)) {
      this.options[optionName] = newValue;

      for (const action of actions.names) {
        this.options[action][optionName] = newValue;
      }

      return this;
    }

    return this.options[optionName];
  }

  /**
   * Gets or sets the origin of the Interactable's element.  The x and y
   * of the origin will be subtracted from action event coordinates.
   *
   * @param {Element | object | string} [origin] An HTML or SVG Element whose
   * rect will be used, an object eg. { x: 0, y: 0 } or string 'parent', 'self'
   * or any CSS selector
   *
   * @return {object} The current origin or this Interactable
   */
  origin (newValue) {
    return this._backCompatOption('origin', newValue);
  }

  /**
   * Returns or sets the mouse coordinate types used to calculate the
   * movement of the pointer.
   *
   * @param {string} [newValue] Use 'client' if you will be scrolling while
   * interacting; Use 'page' if you want autoScroll to work
   * @return {string | object} The current deltaSource or this Interactable
   */
  deltaSource (newValue) {
    if (newValue === 'page' || newValue === 'client') {
      this.options.deltaSource = newValue;

      return this;
    }

    return this.options.deltaSource;
  }

  /**
   * Gets the selector context Node of the Interactable. The default is
   * `window.document`.
   *
   * @return {Node} The context Node of this Interactable
   */
  context () {
    return this._context;
  }

  inContext (element) {
    return (this._context === element.ownerDocument
            || nodeContains(this._context, element));
  }

  /**
   * Calls listeners for the given InteractEvent type bound globally
   * and directly to this Interactable
   *
   * @param {InteractEvent} iEvent The InteractEvent object to be fired on this
   * Interactable
   * @return {Interactable} this Interactable
   */
  fire (iEvent) {
    this.events.fire(iEvent);

    return this;
  }

  _onOffMultiple (method, eventType, listener, options) {
    if (is.string(eventType) && eventType.search(' ') !== -1) {
      eventType = eventType.trim().split(/ +/);
    }

    if (is.array(eventType)) {
      for (const type of eventType) {
        this[method](type, listener, options);
      }

      return true;
    }

    if (is.object(eventType)) {
      for (const prop in eventType) {
        this[method](prop, eventType[prop], listener);
      }

      return true;
    }
  }

  /**
   * Binds a listener for an InteractEvent, pointerEvent or DOM event.
   *
   * @param {string | array | object} eventType  The types of events to listen
   * for
   * @param {function} listener   The function event (s)
   * @param {object | boolean} [options]    options object or useCapture flag
   * for addEventListener
   * @return {object} This Interactable
   */
  on (eventType, listener, options) {
    if (this._onOffMultiple('on', eventType, listener, options)) {
      return this;
    }

    if (eventType === 'wheel') { eventType = wheelEvent; }

    if (contains(Interactable.eventTypes, eventType)) {
      this.events.on(eventType, listener);
    }
    // delegated event for selector
    else if (is.string(this.target)) {
      events.addDelegate(this.target, this._context, eventType, listener, options);
    }
    else {
      events.add(this.target, eventType, listener, options);
    }

    return this;
  }

  /**
   * Removes an InteractEvent, pointerEvent or DOM event listener
   *
   * @param {string | array | object} eventType The types of events that were
   * listened for
   * @param {function} listener The listener function to be removed
   * @param {object | boolean} [options] options object or useCapture flag for
   * removeEventListener
   * @return {object} This Interactable
   */
  off (eventType, listener, options) {
    if (this._onOffMultiple('off', eventType, listener, options)) {
      return this;
    }

    if (eventType === 'wheel') { eventType = wheelEvent; }

    // if it is an action event type
    if (contains(Interactable.eventTypes, eventType)) {
      this.events.off(eventType, listener);
    }
    // delegated event
    else if (is.string(this.target)) {
      events.removeDelegate(this.target, this._context, eventType, listener, options);
    }
    // remove listener from this Interatable's element
    else {
      events.remove(this.target, eventType, listener, options);
    }

    return this;
  }

  /**
   * Reset the options of this Interactable
   *
   * @param {object} options The new settings to apply
   * @return {object} This Interactable
   */
  set (options) {
    if (!is.object(options)) {
      options = {};
    }

    this.options = clone(defaults.base);

    const perActions = clone(defaults.perAction);

    for (const actionName in actions.methodDict) {
      const methodName = actions.methodDict[actionName];

      this.options[actionName] = clone(defaults[actionName]);

      this.setPerAction(actionName, perActions);

      this[methodName](options[actionName]);
    }

    for (const setting of Interactable.settingsMethods) {
      this.options[setting] = defaults.base[setting];

      if (setting in options) {
        this[setting](options[setting]);
      }
    }

    signals.fire('set', {
      options,
      interactable: this,
    });

    return this;
  }

  /**
   * Remove this interactable from the list of interactables and remove it's
   * action capabilities and event listeners
   *
   * @return {interact}
   */
  unset () {
    events.remove(this.target, 'all');

    if (is.string(this.target)) {
      // remove delegated events
      for (const type in events.delegatedEvents) {
        const delegated = events.delegatedEvents[type];

        if (delegated.selectors[0] === this.target
            && delegated.contexts[0] === this._context) {

          delegated.selectors.splice(0, 1);
          delegated.contexts .splice(0, 1);
          delegated.listeners.splice(0, 1);

          // remove the arrays if they are empty
          if (!delegated.selectors.length) {
            delegated[type] = null;
          }
        }

        events.remove(this._context, type, events.delegateListener);
        events.remove(this._context, type, events.delegateUseCapture, true);
      }
    }
    else {
      events.remove(this, 'all');
    }

    signals.fire('unset', { interactable: this });

    scope.interactables.splice(scope.interactables.indexOf(this), 1);

    // Stop related interactions when an Interactable is unset
    for (const interaction of scope.interactions || []) {
      if (interaction.target === this && interaction.interacting() && !interaction._ending) {
        interaction.stop();
      }
    }

    return scope.interact;
  }
}

scope.interactables.indexOfElement = function indexOfElement (target, context) {
  context = context || scope.document;

  for (let i = 0; i < this.length; i++) {
    const interactable = this[i];

    if (interactable.target === target && interactable._context === context) {
      return i;
    }
  }
  return -1;
};

scope.interactables.get = function interactableGet (element, options, dontCheckInContext) {
  const ret = this[this.indexOfElement(element, options && options.context)];

  return ret && (is.string(element) || dontCheckInContext || ret.inContext(element))? ret : null;
};

scope.interactables.forEachMatch = function (element, callback) {
  for (const interactable of this) {
    let ret;

    if ((is.string(interactable.target)
        // target is a selector and the element matches
        ? (is.element(element) && matchesSelector(element, interactable.target))
        // target is the element
        : element === interactable.target)
        // the element is in context
      && (interactable.inContext(element))) {
      ret = callback(interactable);
    }

    if (ret !== undefined) {
      return ret;
    }
  }
};

// all interact.js eventTypes
Interactable.eventTypes = scope.eventTypes = [];

Interactable.signals = signals;

Interactable.settingsMethods = [ 'deltaSource', 'origin', 'preventDefault', 'rectChecker' ];

module.exports = Interactable;