1 files changed, 247 insertions, 0 deletions
diff --git a/devtools/client/framework/selection.js b/devtools/client/framework/selection.js
new file mode 100644
index 000000000..8125f8508
--- /dev/null
+++ b/devtools/client/framework/selection.js
@@ -0,0 +1,247 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* 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";
+
+const nodeConstants = require("devtools/shared/dom-node-constants");
+var EventEmitter = require("devtools/shared/event-emitter");
+
+/**
+ * API
+ *
+ *   new Selection(walker=null)
+ *   destroy()
+ *   node (readonly)
+ *   setNode(node, origin="unknown")
+ *
+ * Helpers:
+ *
+ *   window
+ *   document
+ *   isRoot()
+ *   isNode()
+ *   isHTMLNode()
+ *
+ * Check the nature of the node:
+ *
+ *   isElementNode()
+ *   isAttributeNode()
+ *   isTextNode()
+ *   isCDATANode()
+ *   isEntityRefNode()
+ *   isEntityNode()
+ *   isProcessingInstructionNode()
+ *   isCommentNode()
+ *   isDocumentNode()
+ *   isDocumentTypeNode()
+ *   isDocumentFragmentNode()
+ *   isNotationNode()
+ *
+ * Events:
+ *   "new-node-front" when the inner node changed
+ *   "attribute-changed" when an attribute is changed
+ *   "detached-front" when the node (or one of its parents) is removed from
+ *   the document
+ *   "reparented" when the node (or one of its parents) is moved under
+ *   a different node
+ */
+
+/**
+ * A Selection object. Hold a reference to a node.
+ * Includes some helpers, fire some helpful events.
+ */
+function Selection(walker) {
+  EventEmitter.decorate(this);
+
+  this._onMutations = this._onMutations.bind(this);
+  this.setWalker(walker);
+}
+
+exports.Selection = Selection;
+
+Selection.prototype = {
+  _walker: null,
+
+  _onMutations: function (mutations) {
+    let attributeChange = false;
+    let pseudoChange = false;
+    let detached = false;
+    let parentNode = null;
+
+    for (let m of mutations) {
+      if (!attributeChange && m.type == "attributes") {
+        attributeChange = true;
+      }
+      if (m.type == "childList") {
+        if (!detached && !this.isConnected()) {
+          if (this.isNode()) {
+            parentNode = m.target;
+          }
+          detached = true;
+        }
+      }
+      if (m.type == "pseudoClassLock") {
+        pseudoChange = true;
+      }
+    }
+
+    // Fire our events depending on what changed in the mutations array
+    if (attributeChange) {
+      this.emit("attribute-changed");
+    }
+    if (pseudoChange) {
+      this.emit("pseudoclass");
+    }
+    if (detached) {
+      this.emit("detached-front", parentNode);
+    }
+  },
+
+  destroy: function () {
+    this.setWalker(null);
+  },
+
+  setWalker: function (walker) {
+    if (this._walker) {
+      this._walker.off("mutations", this._onMutations);
+    }
+    this._walker = walker;
+    if (this._walker) {
+      this._walker.on("mutations", this._onMutations);
+    }
+  },
+
+  setNodeFront: function (value, reason = "unknown") {
+    this.reason = reason;
+
+    // If an inlineTextChild text node is being set, then set it's parent instead.
+    let parentNode = value && value.parentNode();
+    if (value && parentNode && parentNode.inlineTextChild === value) {
+      value = parentNode;
+    }
+
+    this._nodeFront = value;
+    this.emit("new-node-front", value, this.reason);
+  },
+
+  get documentFront() {
+    return this._walker.document(this._nodeFront);
+  },
+
+  get nodeFront() {
+    return this._nodeFront;
+  },
+
+  isRoot: function () {
+    return this.isNode() &&
+           this.isConnected() &&
+           this._nodeFront.isDocumentElement;
+  },
+
+  isNode: function () {
+    return !!this._nodeFront;
+  },
+
+  isConnected: function () {
+    let node = this._nodeFront;
+    if (!node || !node.actorID) {
+      return false;
+    }
+
+    while (node) {
+      if (node === this._walker.rootNode) {
+        return true;
+      }
+      node = node.parentNode();
+    }
+    return false;
+  },
+
+  isHTMLNode: function () {
+    let xhtmlNs = "http://www.w3.org/1999/xhtml";
+    return this.isNode() && this.nodeFront.namespaceURI == xhtmlNs;
+  },
+
+  // Node type
+
+  isElementNode: function () {
+    return this.isNode() && this.nodeFront.nodeType == nodeConstants.ELEMENT_NODE;
+  },
+
+  isPseudoElementNode: function () {
+    return this.isNode() && this.nodeFront.isPseudoElement;
+  },
+
+  isAnonymousNode: function () {
+    return this.isNode() && this.nodeFront.isAnonymous;
+  },
+
+  isAttributeNode: function () {
+    return this.isNode() && this.nodeFront.nodeType == nodeConstants.ATTRIBUTE_NODE;
+  },
+
+  isTextNode: function () {
+    return this.isNode() && this.nodeFront.nodeType == nodeConstants.TEXT_NODE;
+  },
+
+  isCDATANode: function () {
+    return this.isNode() && this.nodeFront.nodeType == nodeConstants.CDATA_SECTION_NODE;
+  },
+
+  isEntityRefNode: function () {
+    return this.isNode() &&
+      this.nodeFront.nodeType == nodeConstants.ENTITY_REFERENCE_NODE;
+  },
+
+  isEntityNode: function () {
+    return this.isNode() && this.nodeFront.nodeType == nodeConstants.ENTITY_NODE;
+  },
+
+  isProcessingInstructionNode: function () {
+    return this.isNode() &&
+      this.nodeFront.nodeType == nodeConstants.PROCESSING_INSTRUCTION_NODE;
+  },
+
+  isCommentNode: function () {
+    return this.isNode() &&
+      this.nodeFront.nodeType == nodeConstants.PROCESSING_INSTRUCTION_NODE;
+  },
+
+  isDocumentNode: function () {
+    return this.isNode() && this.nodeFront.nodeType == nodeConstants.DOCUMENT_NODE;
+  },
+
+  /**
+   * @returns true if the selection is the <body> HTML element.
+   */
+  isBodyNode: function () {
+    return this.isHTMLNode() &&
+           this.isConnected() &&
+           this.nodeFront.nodeName === "BODY";
+  },
+
+  /**
+   * @returns true if the selection is the <head> HTML element.
+   */
+  isHeadNode: function () {
+    return this.isHTMLNode() &&
+           this.isConnected() &&
+           this.nodeFront.nodeName === "HEAD";
+  },
+
+  isDocumentTypeNode: function () {
+    return this.isNode() && this.nodeFront.nodeType == nodeConstants.DOCUMENT_TYPE_NODE;
+  },
+
+  isDocumentFragmentNode: function () {
+    return this.isNode() &&
+      this.nodeFront.nodeType == nodeConstants.DOCUMENT_FRAGMENT_NODE;
+  },
+
+  isNotationNode: function () {
+    return this.isNode() && this.nodeFront.nodeType == nodeConstants.NOTATION_NODE;
+  },
+};