1 files changed, 288 insertions, 0 deletions
diff --git a/devtools/client/webaudioeditor/models.js b/devtools/client/webaudioeditor/models.js
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+++ b/devtools/client/webaudioeditor/models.js
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+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+// Import as different name `coreEmit`, so we don't conflict
+// with the global `window` listener itself.
+const { emit: coreEmit } = require("sdk/event/core");
+
+/**
+ * Representational wrapper around AudioNodeActors. Adding and destroying
+ * AudioNodes should be performed through the AudioNodes collection.
+ *
+ * Events:
+ * - `connect`: node, destinationNode, parameter
+ * - `disconnect`: node
+ */
+const AudioNodeModel = Class({
+  extends: EventTarget,
+
+  // Will be added via AudioNodes `add`
+  collection: null,
+
+  initialize: function (actor) {
+    this.actor = actor;
+    this.id = actor.actorID;
+    this.type = actor.type;
+    this.bypassable = actor.bypassable;
+    this._bypassed = false;
+    this.connections = [];
+  },
+
+  /**
+   * Stores connection data inside this instance of this audio node connecting
+   * to another node (destination). If connecting to another node's AudioParam,
+   * the second argument (param) must be populated with a string.
+   *
+   * Connecting nodes is idempotent. Upon new connection, emits "connect" event.
+   *
+   * @param AudioNodeModel destination
+   * @param String param
+   */
+  connect: function (destination, param) {
+    let edge = findWhere(this.connections, { destination: destination.id, param: param });
+
+    if (!edge) {
+      this.connections.push({ source: this.id, destination: destination.id, param: param });
+      coreEmit(this, "connect", this, destination, param);
+    }
+  },
+
+  /**
+   * Clears out all internal connection data. Emits "disconnect" event.
+   */
+  disconnect: function () {
+    this.connections.length = 0;
+    coreEmit(this, "disconnect", this);
+  },
+
+  /**
+   * Gets the bypass status of the audio node.
+   *
+   * @return Boolean
+   */
+  isBypassed: function () {
+    return this._bypassed;
+  },
+
+  /**
+   * Sets the bypass value of an AudioNode.
+   *
+   * @param Boolean enable
+   * @return Promise
+   */
+  bypass: function (enable) {
+    this._bypassed = enable;
+    return this.actor.bypass(enable).then(() => coreEmit(this, "bypass", this, enable));
+  },
+
+  /**
+   * Returns a promise that resolves to an array of objects containing
+   * both a `param` name property and a `value` property.
+   *
+   * @return Promise->Object
+   */
+  getParams: function () {
+    return this.actor.getParams();
+  },
+
+  /**
+   * Returns a promise that resolves to an object containing an
+   * array of event information and an array of automation data.
+   *
+   * @param String paramName
+   * @return Promise->Array
+   */
+  getAutomationData: function (paramName) {
+    return this.actor.getAutomationData(paramName);
+  },
+
+  /**
+   * Takes a `dagreD3.Digraph` object and adds this node to
+   * the graph to be rendered.
+   *
+   * @param dagreD3.Digraph
+   */
+  addToGraph: function (graph) {
+    graph.addNode(this.id, {
+      type: this.type,
+      label: this.type.replace(/Node$/, ""),
+      id: this.id,
+      bypassed: this._bypassed
+    });
+  },
+
+  /**
+   * Takes a `dagreD3.Digraph` object and adds edges to
+   * the graph to be rendered. Separate from `addToGraph`,
+   * as while we depend on D3/Dagre's constraints, we cannot
+   * add edges for nodes that have not yet been added to the graph.
+   *
+   * @param dagreD3.Digraph
+   */
+  addEdgesToGraph: function (graph) {
+    for (let edge of this.connections) {
+      let options = {
+        source: this.id,
+        target: edge.destination
+      };
+
+      // Only add `label` if `param` specified, as this is an AudioParam
+      // connection then. `label` adds the magic to render with dagre-d3,
+      // and `param` is just more explicitly the param, ignoring
+      // implementation details.
+      if (edge.param) {
+        options.label = options.param = edge.param;
+      }
+
+      graph.addEdge(null, this.id, edge.destination, options);
+    }
+  },
+
+  toString: () => "[object AudioNodeModel]",
+});
+
+
+/**
+ * Constructor for a Collection of `AudioNodeModel` models.
+ *
+ * Events:
+ * - `add`: node
+ * - `remove`: node
+ * - `connect`: node, destinationNode, parameter
+ * - `disconnect`: node
+ */
+const AudioNodesCollection = Class({
+  extends: EventTarget,
+
+  model: AudioNodeModel,
+
+  initialize: function () {
+    this.models = new Set();
+    this._onModelEvent = this._onModelEvent.bind(this);
+  },
+
+  /**
+   * Iterates over all models within the collection, calling `fn` with the
+   * model as the first argument.
+   *
+   * @param Function fn
+   */
+  forEach: function (fn) {
+    this.models.forEach(fn);
+  },
+
+  /**
+   * Creates a new AudioNodeModel, passing through arguments into the AudioNodeModel
+   * constructor, and adds the model to the internal collection store of this
+   * instance.
+   *
+   * Emits "add" event on instance when completed.
+   *
+   * @param Object obj
+   * @return AudioNodeModel
+   */
+  add: function (obj) {
+    let node = new this.model(obj);
+    node.collection = this;
+
+    this.models.add(node);
+
+    node.on("*", this._onModelEvent);
+    coreEmit(this, "add", node);
+    return node;
+  },
+
+  /**
+   * Removes an AudioNodeModel from the internal collection. Calls `delete` method
+   * on the model, and emits "remove" on this instance.
+   *
+   * @param AudioNodeModel node
+   */
+  remove: function (node) {
+    this.models.delete(node);
+    coreEmit(this, "remove", node);
+  },
+
+  /**
+   * Empties out the internal collection of all AudioNodeModels.
+   */
+  reset: function () {
+    this.models.clear();
+  },
+
+  /**
+   * Takes an `id` from an AudioNodeModel and returns the corresponding
+   * AudioNodeModel within the collection that matches that id. Returns `null`
+   * if not found.
+   *
+   * @param Number id
+   * @return AudioNodeModel|null
+   */
+  get: function (id) {
+    return findWhere(this.models, { id: id });
+  },
+
+  /**
+   * Returns the count for how many models are a part of this collection.
+   *
+   * @return Number
+   */
+  get length() {
+    return this.models.size;
+  },
+
+  /**
+   * Returns detailed information about the collection. used during tests
+   * to query state. Returns an object with information on node count,
+   * how many edges are within the data graph, as well as how many of those edges
+   * are for AudioParams.
+   *
+   * @return Object
+   */
+  getInfo: function () {
+    let info = {
+      nodes: this.length,
+      edges: 0,
+      paramEdges: 0
+    };
+
+    this.models.forEach(node => {
+      let paramEdgeCount = node.connections.filter(edge => edge.param).length;
+      info.edges += node.connections.length - paramEdgeCount;
+      info.paramEdges += paramEdgeCount;
+    });
+    return info;
+  },
+
+  /**
+   * Adds all nodes within the collection to the passed in graph,
+   * as well as their corresponding edges.
+   *
+   * @param dagreD3.Digraph
+   */
+  populateGraph: function (graph) {
+    this.models.forEach(node => node.addToGraph(graph));
+    this.models.forEach(node => node.addEdgesToGraph(graph));
+  },
+
+  /**
+   * Called when a stored model emits any event. Used to manage
+   * event propagation, or listening to model events to react, like
+   * removing a model from the collection when it's destroyed.
+   */
+  _onModelEvent: function (eventName, node, ...args) {
+    if (eventName === "remove") {
+      // If a `remove` event from the model, remove it
+      // from the collection, and let the method handle the emitting on
+      // the collection
+      this.remove(node);
+    } else {
+      // Pipe the event to the collection
+      coreEmit(this, eventName, node, ...args);
+    }
+  },
+
+  toString: () => "[object AudioNodeCollection]",
+});