@xeokit/xeokit-sdk
Version:
3D BIM IFC Viewer SDK for AEC engineering applications. Open Source JavaScript Toolkit based on pure WebGL for top performance, real-world coordinates and full double precision
233 lines (215 loc) • 7.1 kB
JavaScript
import {Map} from "./scene/utils/Map.js";
import {core} from "./scene/core.js";
/**
@desc Base class for {@link Viewer} plugin classes.
*/
class Plugin {
/**
* Creates this Plugin and installs it into the given {@link Viewer}.
*
* @param {string} id ID for this plugin, unique among all plugins in the viewer.
* @param {Viewer} viewer The viewer.
* @param {Object} [cfg] Options
*/
constructor(id, viewer, cfg) {
/**
* ID for this Plugin, unique within its {@link Viewer}.
*
* @type {string}
*/
this.id = (cfg && cfg.id) ? cfg.id : id;
/**
* The Viewer that contains this Plugin.
*
* @type {Viewer}
*/
this.viewer = viewer;
this._subIdMap = null; // Subscription subId pool
this._subIdEvents = null; // Subscription subIds mapped to event names
this._eventSubs = null; // Event names mapped to subscribers
this._eventSubsNum = null;
this._events = null; // Maps names to events
this._eventCallDepth = 0; // Helps us catch stack overflows from recursive events
viewer.addPlugin(this);
}
/**
* Schedule a task to perform on the next browser interval
* @param task
*/
scheduleTask(task) {
core.scheduleTask(task, null);
}
/**
* Fires an event on this Plugin.
*
* Notifies existing subscribers to the event, optionally retains the event to give to
* any subsequent notifications on the event as they are made.
*
* @param {String} event The event type name
* @param {Object} value The event parameters
* @param {Boolean} [forget=false] When true, does not retain for subsequent subscribers
*/
fire(event, value, forget) {
if (!this._events) {
this._events = {};
}
if (!this._eventSubs) {
this._eventSubs = {};
this._eventSubsNum = {};
}
if (forget !== true) {
this._events[event] = value || true; // Save notification
}
const subs = this._eventSubs[event];
let sub;
if (subs) { // Notify subscriptions
for (const subId in subs) {
if (subs.hasOwnProperty(subId)) {
sub = subs[subId];
this._eventCallDepth++;
if (this._eventCallDepth < 300) {
sub.callback.call(sub.scope, value);
} else {
this.error("fire: potential stack overflow from recursive event '" + event + "' - dropping this event");
}
this._eventCallDepth--;
}
}
}
}
/**
* Subscribes to an event on this Plugin.
*
* The callback is be called with this Plugin as scope.
*
* @param {String} event The event
* @param {Function} callback Called fired on the event
* @param {Object} [scope=this] Scope for the callback
* @return {String} Handle to the subscription, which may be used to unsubscribe with {@link #off}.
*/
on(event, callback, scope) {
if (!this._events) {
this._events = {};
}
if (!this._subIdMap) {
this._subIdMap = new Map(); // Subscription subId pool
}
if (!this._subIdEvents) {
this._subIdEvents = {};
}
if (!this._eventSubs) {
this._eventSubs = {};
}
if (!this._eventSubsNum) {
this._eventSubsNum = {};
}
let subs = this._eventSubs[event];
if (!subs) {
subs = {};
this._eventSubs[event] = subs;
this._eventSubsNum[event] = 1;
} else {
this._eventSubsNum[event]++;
}
const subId = this._subIdMap.addItem(); // Create unique subId
subs[subId] = {
callback: callback,
scope: scope || this
};
this._subIdEvents[subId] = event;
const value = this._events[event];
if (value !== undefined) { // A publication exists, notify callback immediately
callback.call(scope || this, value);
}
return subId;
}
/**
* Cancels an event subscription that was previously made with {@link Plugin#on} or {@link Plugin#once}.
*
* @param {String} subId Subscription ID
*/
off(subId) {
if (subId === undefined || subId === null) {
return;
}
if (!this._subIdEvents) {
return;
}
const event = this._subIdEvents[subId];
if (event) {
delete this._subIdEvents[subId];
const subs = this._eventSubs[event];
if (subs) {
delete subs[subId];
this._eventSubsNum[event]--;
}
this._subIdMap.removeItem(subId); // Release subId
}
}
/**
* Subscribes to the next occurrence of the given event, then un-subscribes as soon as the event is subIdd.
*
* This is equivalent to calling {@link Plugin#on}, and then calling {@link Plugin#off} inside the callback function.
*
* @param {String} event Data event to listen to
* @param {Function} callback Called when fresh data is available at the event
* @param {Object} [scope=this] Scope for the callback
*/
once(event, callback, scope) {
const self = this;
const subId = this.on(event,
function (value) {
self.off(subId);
callback.call(scope || this, value);
},
scope);
}
/**
* Returns true if there are any subscribers to the given event on this Plugin.
*
* @param {String} event The event
* @return {Boolean} True if there are any subscribers to the given event on this Plugin.
*/
hasSubs(event) {
return (this._eventSubsNum && (this._eventSubsNum[event] > 0));
}
/**
* Logs a message to the JavaScript developer console, prefixed with the ID of this Plugin.
*
* @param {String} msg The error message
*/
log(msg) {
console.log(`[xeokit plugin ${this.id}]: ${msg}`);
}
/**
* Logs a warning message to the JavaScript developer console, prefixed with the ID of this Plugin.
*
* @param {String} msg The error message
*/
warn(msg) {
console.warn(`[xeokit plugin ${this.id}]: ${msg}`);
}
/**
* Logs an error message to the JavaScript developer console, prefixed with the ID of this Plugin.
*
* @param {String} msg The error message
*/
error(msg) {
console.error(`[xeokit plugin ${this.id}]: ${msg}`);
}
/**
* Sends a message to this Plugin.
*
* @private
*/
send(name, value) {
//...
}
/**
* Destroys this Plugin and removes it from its {@link Viewer}.
*/
destroy() {
this.viewer.removePlugin(this);
}
}
export {Plugin}