Bug 1592517 - Migrate devtools DOMHelpers.jsm from JSM to plain JS module r=ochameau

Depends on D51054

Summary of the changes here:
- move DOMHelpers.jsm to dom-helpers.js
- remove all unused methods
- converted to a static helper to avoid instanciating DOMHelpers objects for no reason
- updated call sites accordingly

Differential Revision: https://phabricator.services.mozilla.com/D51065

--HG--
rename : devtools/shared/DOMHelpers.jsm => devtools/shared/dom-helpers.js
extra : moz-landing-system : lando

devtools/client/framework/toolbox-hosts.js

@@ -7,7 +7,7 @@
 const EventEmitter = require("devtools/shared/event-emitter");
 const promise = require("promise");
 const Services = require("Services");
-const { DOMHelpers } = require("resource://devtools/shared/DOMHelpers.jsm");
+const { DOMHelpers } = require("devtools/shared/dom-helpers");
 
 loader.lazyRequireGetter(
   this,
@@ -78,12 +78,11 @@ BottomHost.prototype = {
     this.frame.setAttribute("src", "about:blank");
 
     const frame = await new Promise(resolve => {
-      const domHelper = new DOMHelpers(this.frame.contentWindow);
       const frameLoad = () => {
         this.emit("ready", this.frame);
         resolve(this.frame);
       };
-      domHelper.onceDOMReady(frameLoad);
+      DOMHelpers.onceDOMReady(this.frame.contentWindow, frameLoad);
       focusTab(this.hostTab);
     });
 
@@ -174,12 +173,11 @@ class SidebarHost {
     this.frame.setAttribute("src", "about:blank");
 
     const frame = await new Promise(resolve => {
-      const domHelper = new DOMHelpers(this.frame.contentWindow);
       const frameLoad = () => {
         this.emit("ready", this.frame);
         resolve(this.frame);
       };
-      domHelper.onceDOMReady(frameLoad);
+      DOMHelpers.onceDOMReady(this.frame.contentWindow, frameLoad);
       focusTab(this.hostTab);
     });
 

devtools/client/framework/toolbox.js

@@ -27,7 +27,7 @@ var EventEmitter = require("devtools/shared/event-emitter");
 const Selection = require("devtools/client/framework/selection");
 var Telemetry = require("devtools/client/shared/telemetry");
 const { getUnicodeUrl } = require("devtools/client/shared/unicode-url");
-var { DOMHelpers } = require("resource://devtools/shared/DOMHelpers.jsm");
+var { DOMHelpers } = require("devtools/shared/dom-helpers");
 const { KeyCodes } = require("devtools/client/shared/keycodes");
 var Startup = Cc["@mozilla.org/devtools/startup-clh;1"].getService(
   Ci.nsISupports
@@ -727,11 +727,14 @@ Toolbox.prototype = {
         this._debugTargetData = this._getDebugTargetData();
       }
 
-      const domHelper = new DOMHelpers(this.win);
       const domReady = new Promise(resolve => {
-        domHelper.onceDOMReady(() => {
-          resolve();
-        }, this._URL);
+        DOMHelpers.onceDOMReady(
+          this.win,
+          () => {
+            resolve();
+          },
+          this._URL
+        );
       });
 
       // Optimization: fire up a few other things before waiting on
@@ -2479,8 +2482,7 @@ Toolbox.prototype = {
       // on the DOM node every time because this won't work
       // if the (xul chrome) iframe is loaded in a content docshell.
       if (iframe.contentWindow) {
-        const domHelper = new DOMHelpers(iframe.contentWindow);
-        domHelper.onceDOMReady(onLoad);
+        DOMHelpers.onceDOMReady(iframe.contentWindow, onLoad);
       } else {
         const callback = () => {
           iframe.removeEventListener("DOMContentLoaded", callback);

devtools/client/shared/test/browser_html_tooltip-02.js

@@ -200,11 +200,10 @@ async function testClickInInnerIframe(doc) {
 
   iframe.srcdoc = "<div id=test style='height:50px'></div>";
   await new Promise(r => {
-    const domHelper = new DOMHelpers(iframe.contentWindow);
     const frameLoad = () => {
       r();
     };
-    domHelper.onceDOMReady(frameLoad);
+    DOMHelpers.onceDOMReady(iframe.contentWindow, frameLoad);
   });
 
   await waitUntil(() => iframe.contentWindow.document.getElementById("test"));

devtools/client/shared/test/head.js

@@ -13,9 +13,7 @@ Services.scriptloader.loadSubScript(
   this
 );
 
-const { DOMHelpers } = ChromeUtils.import(
-  "resource://devtools/shared/DOMHelpers.jsm"
-);
+const { DOMHelpers } = require("devtools/shared/dom-helpers");
 const { Hosts } = require("devtools/client/framework/toolbox-hosts");
 
 const TEST_URI_ROOT = "http://example.com/browser/devtools/client/shared/test/";
@@ -119,9 +117,8 @@ const createHost = async function(
   const iframe = await host.create();
 
   await new Promise(resolve => {
-    const domHelper = new DOMHelpers(iframe.contentWindow);
     iframe.setAttribute("src", src);
-    domHelper.onceDOMReady(resolve);
+    DOMHelpers.onceDOMReady(iframe.contentWindow, resolve);
   });
 
   return [host, iframe.contentWindow, iframe.contentDocument];

devtools/client/shared/widgets/Graphs.js

@@ -8,7 +8,7 @@ const {
 } = require("devtools/client/shared/widgets/view-helpers");
 const { getCurrentZoom } = require("devtools/shared/layout/utils");
 const DevToolsUtils = require("devtools/shared/DevToolsUtils");
-const { DOMHelpers } = require("resource://devtools/shared/DOMHelpers.jsm");
+const { DOMHelpers } = require("devtools/shared/dom-helpers");
 
 loader.lazyRequireGetter(this, "EventEmitter", "devtools/shared/event-emitter");
 
@@ -1293,8 +1293,7 @@ AbstractCanvasGraph.createIframe = function(url, parent, callback) {
 
   // Use DOMHelpers to wait for the frame load. DOMHelpers relies on chromeEventHandler
   // so this will still work if DevTools are loaded in a content frame.
-  const domHelper = new DOMHelpers(iframe.contentWindow);
-  domHelper.onceDOMReady(function() {
+  DOMHelpers.onceDOMReady(iframe.contentWindow, function() {
     callback(iframe);
   });
 

devtools/server/actors/inspector/node.js

@@ -146,7 +146,7 @@ loader.lazyRequireGetter(
 loader.lazyRequireGetter(
   this,
   "DOMHelpers",
-  "resource://devtools/shared/DOMHelpers.jsm",
+  "devtools/shared/dom-helpers",
   true
 );
 
@@ -742,8 +742,7 @@ const NodeActor = protocol.ActorClassWithSpec(nodeSpec, {
     const { contentDocument, contentWindow } = this.rawNode;
     if (contentDocument && contentDocument.readyState !== "complete") {
       await new Promise(resolve => {
-        const domHelper = new DOMHelpers(contentWindow);
-        domHelper.onceDOMReady(resolve);
+        DOMHelpers.onceDOMReady(contentWindow, resolve);
       });
     }
   },

devtools/shared/DOMHelpers.jsm

@@ -1,174 +0,0 @@
-/* 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 { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
-const { require } = ChromeUtils.import("resource://devtools/shared/Loader.jsm");
-const nodeFilterConstants = require("devtools/shared/dom-node-filter-constants");
-
-this.EXPORTED_SYMBOLS = ["DOMHelpers"];
-
-/**
- * DOMHelpers
- * Makes DOM traversal easier. Goes through iframes.
- *
- * @constructor
- * @param nsIDOMWindow win
- *        The content window, owning the document to traverse.
- */
-this.DOMHelpers = function DOMHelpers(win) {
-  if (!win) {
-    throw new Error("window can't be null or undefined");
-  }
-  this.window = win;
-};
-
-DOMHelpers.prototype = {
-  getParentObject: function(node) {
-    const parentNode = node ? node.parentNode : null;
-
-    if (!parentNode) {
-      // Documents have no parentNode; Attr, Document, DocumentFragment, Entity,
-      // and Notation. top level windows have no parentNode
-      if (node && node == this.window.Node.DOCUMENT_NODE) {
-        // document type
-        if (node.defaultView) {
-          const embeddingFrame = node.defaultView.frameElement;
-          if (embeddingFrame) {
-            return embeddingFrame.parentNode;
-          }
-        }
-      }
-      // a Document object without a parentNode or window
-      return null; // top level has no parent
-    }
-
-    if (parentNode.nodeType == this.window.Node.DOCUMENT_NODE) {
-      if (parentNode.defaultView) {
-        return parentNode.defaultView.frameElement;
-      }
-      // parent is document element, but no window at defaultView.
-      return null;
-    }
-
-    if (!parentNode.localName) {
-      return null;
-    }
-
-    return parentNode;
-  },
-
-  getChildObject: function(
-    node,
-    index,
-    previousSibling,
-    showTextNodesWithWhitespace
-  ) {
-    if (!node) {
-      return null;
-    }
-
-    if (node.contentDocument) {
-      // then the node is a frame
-      if (index == 0) {
-        return node.contentDocument.documentElement; // the node's HTMLElement
-      }
-      return null;
-    }
-
-    if (node.getSVGDocument) {
-      const svgDocument = node.getSVGDocument();
-      if (svgDocument) {
-        // then the node is a frame
-        if (index == 0) {
-          return svgDocument.documentElement; // the node's SVGElement
-        }
-        return null;
-      }
-    }
-
-    let child = null;
-    if (previousSibling) {
-      // then we are walking
-      child = this.getNextSibling(previousSibling);
-    } else {
-      child = this.getFirstChild(node);
-    }
-
-    if (showTextNodesWithWhitespace) {
-      return child;
-    }
-
-    for (; child; child = this.getNextSibling(child)) {
-      if (!this.isWhitespaceText(child)) {
-        return child;
-      }
-    }
-
-    return null; // we have no children worth showing.
-  },
-
-  getFirstChild: function(node) {
-    const SHOW_ALL = nodeFilterConstants.SHOW_ALL;
-    this.treeWalker = node.ownerDocument.createTreeWalker(node, SHOW_ALL, null);
-    return this.treeWalker.firstChild();
-  },
-
-  getNextSibling: function(node) {
-    const next = this.treeWalker.nextSibling();
-
-    if (!next) {
-      delete this.treeWalker;
-    }
-
-    return next;
-  },
-
-  isWhitespaceText: function(node) {
-    return (
-      node.nodeType == this.window.Node.TEXT_NODE &&
-      !/[^\s]/.exec(node.nodeValue)
-    );
-  },
-
-  destroy: function() {
-    delete this.window;
-    delete this.treeWalker;
-  },
-
-  /**
-   * A simple way to be notified (once) when a window becomes
-   * interactive (DOMContentLoaded).
-   *
-   * It is based on the chromeEventHandler. This is useful when
-   * chrome iframes are loaded in content docshells (in Firefox
-   * tabs for example).
-   */
-  onceDOMReady: function(callback, targetURL) {
-    const window = this.window;
-    const docShell = window.docShell;
-    const onReady = function(event) {
-      if (event.target == window.document) {
-        docShell.chromeEventHandler.removeEventListener(
-          "DOMContentLoaded",
-          onReady
-        );
-        // If in `callback` the URL of the window is changed and a listener to DOMContentLoaded
-        // is attached, the event we just received will be also be caught by the new listener.
-        // We want to avoid that so we execute the callback in the next queue.
-        Services.tm.dispatchToMainThread(callback);
-      }
-    };
-    if (
-      (window.document.readyState == "complete" ||
-        window.document.readyState == "interactive") &&
-      window.location.href == targetURL
-    ) {
-      Services.tm.dispatchToMainThread(callback);
-    } else {
-      docShell.chromeEventHandler.addEventListener("DOMContentLoaded", onReady);
-    }
-  },
-};

devtools/shared/dom-helpers.js

@@ -0,0 +1,53 @@
+/* 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 Services = require("Services");
+
+exports.DOMHelpers = {
+  /**
+   * A simple way to be notified (once) when a window becomes
+   * interactive (DOMContentLoaded).
+   *
+   * It is based on the chromeEventHandler. This is useful when
+   * chrome iframes are loaded in content docshells (in Firefox
+   * tabs for example).
+   *
+   * @param nsIDOMWindow win
+   *        The content window, owning the document to traverse.
+   * @param Function callback
+   *        The method to call when the frame is loaded.
+   * @param String targetURL
+   *        (optional) Check that the frame URL corresponds to the provided URL
+   *        before calling the callback.
+   */
+  onceDOMReady: function(win, callback, targetURL) {
+    if (!win) {
+      throw new Error("window can't be null or undefined");
+    }
+    const docShell = win.docShell;
+    const onReady = function(event) {
+      if (event.target == win.document) {
+        docShell.chromeEventHandler.removeEventListener(
+          "DOMContentLoaded",
+          onReady
+        );
+        // If in `callback` the URL of the window is changed and a listener to DOMContentLoaded
+        // is attached, the event we just received will be also be caught by the new listener.
+        // We want to avoid that so we execute the callback in the next queue.
+        Services.tm.dispatchToMainThread(callback);
+      }
+    };
+    if (
+      (win.document.readyState == "complete" ||
+        win.document.readyState == "interactive") &&
+      win.location.href == targetURL
+    ) {
+      Services.tm.dispatchToMainThread(callback);
+    } else {
+      docShell.chromeEventHandler.addEventListener("DOMContentLoaded", onReady);
+    }
+  },
+};

devtools/shared/moz.build

@@ -53,9 +53,9 @@ DevToolsModules(
     'debounce.js',
     'defer.js',
     'DevToolsUtils.js',
+    'dom-helpers.js',
     'dom-node-constants.js',
     'dom-node-filter-constants.js',
-    'DOMHelpers.jsm',
     'event-emitter.js',
     'execution-point-utils.js',
     'extend.js',