Convert the inspector framework to use ES6 classes.

sky/framework/inspector/dom-agent.sky

 <script>
-function DOMAgent(delegate) {
-  this.enabled = false;
-  this.delegate_ = delegate;
-  this.nextNodeId_ = 1;
-  this.nodeToId_ = new Map();
-  this.idToNode_ = new Map();
-}
-
-DOMAgent.prototype.getIdForNode_ = function(node) {
-  if (this.nodeToId_.has(node))
-    return this.nodeToId_.get(node);
-  var id = this.nextNodeId_++;
-  this.nodeToId_.set(node, id);
-  this.idToNode_.set(id, node);
-  return id;
-};
-
-DOMAgent.prototype.getNodeForId = function(nodeId) {
-  return this.idToNode_.get(nodeId);
-};
-
-DOMAgent.prototype.serializeChildren_ = function(node) {
-  var children = [];
-  for (var child = node.firstChild; child; child = child.nextSibling) {
-    var record = this.serializeNode_(child);
-    if (record)
-      children.push(record);
-  }
-  return children;
-};
-
-DOMAgent.prototype.serializeAttributes_ = function(element) {
-  var attributes = [];
-  var attrs = element.getAttributes();
-  for (var i = 0; i < attrs.length; ++i) {
-    var attr = attrs[i];
-    attributes.push(attr.name);
-    attributes.push(attr.value);
-  }
-  return attributes;
-};
-
-DOMAgent.prototype.serializeNode_ = function(node) {
-  var id = this.getIdForNode_(node);
-
-  var record = {
-    nodeId: id,
-  };
-
-  var isContainer = false;
-
-  if (node instanceof Element) {
-    isContainer = true;
-    record.nodeType = 1;
-    record.nodeName = node.tagName;
-    record.localName = node.tagName;
-    record.nodeValue = "";
-    record.attributes = this.serializeAttributes_(node);
-  } else if (node instanceof Text) {
-    record.nodeType = 3;
-    record.nodeName = "#text";
-    var nodeValue = node.data;
-    if (!nodeValue.trim())
-      return null;
-    record.nodeValue = nodeValue;
-  } else if (node instanceof Document) {
-    isContainer = true;
-    record.nodeType = 9;
-    record.nodeName = "#document";
-    record.localName = "";
-    record.nodeValue = "";
-    record.documentURL = node.URL;
-    record.baseURL = node.baseURI;
-  } else if (node instanceof DocumentFragment) {
-    isContainer = true;
-    record.nodeType = 11;
-    record.nodeName = "#document-fragment";
-    record.localName = "";
-    record.nodeValue = "";
-  } else {
-    console.log("Unknown node type");
-    return null;
+class DOMAgent {
+  constructor(delegate) {
+    this.enabled = false;
+    this.delegate_ = delegate;
+    this.nextNodeId_ = 1;
+    this.nodeToId_ = new Map();
+    this.idToNode_ = new Map();
+    Object.preventExtensions(this);
   }
 
-  if (isContainer) {
-    var children = this.serializeChildren_(node);
-    if (children.length) {
-      record.childNodeCount = children.length;
-      record.children = children;
+  getIdForNode_(node) {
+    if (this.nodeToId_.has(node))
+      return this.nodeToId_.get(node);
+    var id = this.nextNodeId_++;
+    this.nodeToId_.set(node, id);
+    this.idToNode_.set(id, node);
+    return id;
+  }
+
+  getNodeForId(nodeId) {
+    return this.idToNode_.get(nodeId);
+  }
+
+  serializeChildren_(node) {
+    var children = [];
+    for (var child = node.firstChild; child; child = child.nextSibling) {
+      var record = this.serializeNode_(child);
+      if (record)
+        children.push(record);
+    }
+    return children;
+  }
+
+  serializeAttributes_(element) {
+    var attributes = [];
+    var attrs = element.getAttributes();
+    for (var i = 0; i < attrs.length; ++i) {
+      var attr = attrs[i];
+      attributes.push(attr.name);
+      attributes.push(attr.value);
+    }
+    return attributes;
+  }
+
+  serializeNode_(node) {
+    var id = this.getIdForNode_(node);
+
+    var record = {
+      nodeId: id,
+    };
+
+    var isContainer = false;
+
+    if (node instanceof Element) {
+      isContainer = true;
+      record.nodeType = 1;
+      record.nodeName = node.tagName;
+      record.localName = node.tagName;
+      record.nodeValue = "";
+      record.attributes = this.serializeAttributes_(node);
+    } else if (node instanceof Text) {
+      record.nodeType = 3;
+      record.nodeName = "#text";
+      var nodeValue = node.data;
+      if (!nodeValue.trim())
+        return null;
+      record.nodeValue = nodeValue;
+    } else if (node instanceof Document) {
+      isContainer = true;
+      record.nodeType = 9;
+      record.nodeName = "#document";
+      record.localName = "";
+      record.nodeValue = "";
+      record.documentURL = node.URL;
+      record.baseURL = node.baseURI;
+    } else if (node instanceof DocumentFragment) {
+      isContainer = true;
+      record.nodeType = 11;
+      record.nodeName = "#document-fragment";
+      record.localName = "";
+      record.nodeValue = "";
+    } else {
+      console.log("Unknown node type");
+      return null;
+    }
+
+    if (isContainer) {
+      var children = this.serializeChildren_(node);
+      if (children.length) {
+        record.childNodeCount = children.length;
+        record.children = children;
+      }
+    }
+
+    return record;
+  }
+
+  enable() {
+    this.enabled = true;
+    this.observer_ = new MutationObserver(this.mutationCallback_.bind(this));
+    this.observer_.observe(document, {
+      childList: true,
+      attributes: true,
+      characterData: true,
+      subtree : true,
+    });
+  }
+
+  getDocument() {
+    return {
+      root: this.serializeNode_(document),
+    };
+  }
+
+  hideHighlight() {
+  }
+
+  highlightNode() {
+  }
+
+  mutationCallback_(mutationRecords) {
+    for (var i = 0; i < mutationRecords.length; ++i) {
+      var record = mutationRecords[i];
+      var type = record.type;
+      var target = record.target;
+      var nodeId = this.getIdForNode_(target);
+      if (type == "attributes") {
+        var attributeName = record.attributeName;
+        if (target.hasAttribute(attributeName)) {
+          this.delegate_.sendMessage("DOM.attributeModified", {
+            nodeId: nodeId,
+            name: attributeName,
+            value: target.getAttribute(attributeName),
+          });
+        } else {
+          this.delegate_.sendMessage("DOM.attributeRemoved", {
+            nodeId: nodeId,
+            name: attributeName,
+          });
+        }
+      } else if (type == "characterData") {
+        this.delegate_.sendMessage("DOM.characterDataModified", {
+          nodeId: nodeId,
+          characterData: target.data,
+        });
+      } else if (type == "childList") {
+        // FIXME: If this subtree isn't expanded, we only need to send across the
+        // {"method":"DOM.childNodeCountUpdated","params":"nodeId":648,"childNodeCount":2}
+
+        Array.prototype.forEach.call(record.removedNodes, function(node) {
+          this.delegate_.sendMessage("DOM.childNodeRemoved", {
+            parentNodeId: nodeId,
+            nodeId: this.getIdForNode_(node),
+          });
+        }.bind(this));
+
+        Array.prototype.forEach.call(record.addedNodes, function(node) {
+          var previousNodeId = node.previousSibling ? this.getIdForNode_(node.previousSibling) : 0;
+          this.delegate_.sendMessage("DOM.childNodeInserted", {
+            parentNodeId: nodeId,
+            previousNodeId: previousNodeId,
+            node: this.serializeNode_(node),
+          });
+        }.bind(this));
+      }
     }
   }
-
-  return record;
-};
-
-DOMAgent.prototype.enable = function() {
-  this.enabled = true;
-  this.observer_ = new MutationObserver(this.mutationCallback_.bind(this));
-  this.observer_.observe(document, {
-    childList: true,
-    attributes: true,
-    characterData: true,
-    subtree : true,
-  });
-};
-
-DOMAgent.prototype.getDocument = function() {
-  return {
-    root: this.serializeNode_(document),
-  };
-};
-
-DOMAgent.prototype.hideHighlight = function() {
-};
-
-DOMAgent.prototype.highlightNode = function() {
-};
-
-DOMAgent.prototype.mutationCallback_ = function(mutationRecords) {
-  for (var i = 0; i < mutationRecords.length; ++i) {
-    var record = mutationRecords[i];
-    var type = record.type;
-    var target = record.target;
-    var nodeId = this.getIdForNode_(target);
-    if (type == "attributes") {
-      var attributeName = record.attributeName;
-      if (target.hasAttribute(attributeName)) {
-        this.delegate_.sendMessage("DOM.attributeModified", {
-          nodeId: nodeId,
-          name: attributeName,
-          value: target.getAttribute(attributeName),
-        });
-      } else {
-        this.delegate_.sendMessage("DOM.attributeRemoved", {
-          nodeId: nodeId,
-          name: attributeName,
-        });
-      }
-    } else if (type == "characterData") {
-      this.delegate_.sendMessage("DOM.characterDataModified", {
-        nodeId: nodeId,
-        characterData: target.data,
-      });
-    } else if (type == "childList") {
-      // FIXME: If this subtree isn't expanded, we only need to send across the
-      // {"method":"DOM.childNodeCountUpdated","params":"nodeId":648,"childNodeCount":2}
-
-      Array.prototype.forEach.call(record.removedNodes, function(node) {
-        this.delegate_.sendMessage("DOM.childNodeRemoved", {
-          parentNodeId: nodeId,
-          nodeId: this.getIdForNode_(node),
-        });
-      }.bind(this));
-
-      Array.prototype.forEach.call(record.addedNodes, function(node) {
-        var previousNodeId = node.previousSibling ? this.getIdForNode_(node.previousSibling) : 0;
-        this.delegate_.sendMessage("DOM.childNodeInserted", {
-          parentNodeId: nodeId,
-          previousNodeId: previousNodeId,
-          node: this.serializeNode_(node),
-        });
-      }.bind(this));
-    }
-  }
-};
+}
 
 module.exports = DOMAgent;
 </script>