Issue 3223 - Make context menu e10s compatible in Firefox

lib/child/contextMenu.js

Index: lib/child/contextMenu.js
===================================================================
new file mode 100644
--- /dev/null
+++ b/lib/child/contextMenu.js
@@ -0,0 +1,141 @@
+/*
+ * This file is part of Adblock Plus <https://adblockplus.org/>,
+ * Copyright (C) 2006-2015 Eyeo GmbH
+ *
+ * Adblock Plus is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Adblock Plus is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+"use strict";
+
+let {Services} = Cu.import("resource://gre/modules/Services.jsm", {});
+let {XPCOMUtils} = Cu.import("resource://gre/modules/XPCOMUtils.jsm", {});
+
+let {Utils} = require("utils");
+let {RequestNotifier} = require("child/requestNotifier");
+let {storeNodes} = require("child/contentPolicy");
+
+let getContextInfo =
+/**
+ * Determines the context menu entries to be shown for a contextmenu event.
+ * @param {Event} event
+ * @return {Array}
+ */
+exports.getContextInfo = function(event)
+{
+  let items = [];
+  let target = event.target;
+  if (target.localName == "menupopup" && target.triggerNode)
+  {
+    // SeaMonkey gives us the context menu's popupshowing event
+    target = target.triggerNode;
+  }
+  if (target instanceof Ci.nsIDOMHTMLMapElement || target instanceof Ci.nsIDOMHTMLAreaElement)
+  {
+    // HTML image maps will usually receive events when the mouse pointer is
+    // over a different element, get the real event target.
+    let rect = target.getClientRects()[0];
+    target = target.ownerDocument.elementFromPoint(Math.max(rect.left, 0), Math.max(rect.top, 0));
+  }
+
+  if (!target)
+    return items;
+
+  let addMenuItem = function([node, nodeData])
+  {
+    let nodeID = null;
+    if (node && node.nodeType == Ci.nsIDOMNode.ELEMENT_NODE)
+      nodeID = storeNodes([node]);
+    items.push([nodeID, nodeData]);
+  }.bind(this);
+
+  // Look up data that we have for the node
+  let data = RequestNotifier.getDataForNode(target);
+  let hadImage = false;
+  if (data && !data[1].filter)
+  {
+    addMenuItem(data);
+    hadImage = (data[1].type == "IMAGE");
+  }
+
+  // Look for frame data
+  let wnd = Utils.getWindow(target);
+  if (wnd.frameElement)
+  {
+    let data = RequestNotifier.getDataForNode(wnd.frameElement, true);
+    if (data && !data[1].filter)
+      addMenuItem(data);
+  }
+
+  // Look for a background image
+  if (!hadImage)
+  {
+    let extractImageURL = function(computedStyle, property)
+    {
+      let value = computedStyle.getPropertyCSSValue(property);
+      // CSSValueList
+      if ("length" in value && value.length >= 1)
+        value = value[0];
+      // CSSValuePrimitiveType
+      if ("primitiveType" in value && value.primitiveType == value.CSS_URI)
+        return Utils.unwrapURL(value.getStringValue()).spec;
+
+      return null;
+    };
+
+    let node = target;
+    while (node)
+    {
+      if (node.nodeType == Ci.nsIDOMNode.ELEMENT_NODE)
+      {
+        let style = wnd.getComputedStyle(node, "");
+        let bgImage = extractImageURL(style, "background-image") || extractImageURL(style, "list-style-image");
+        if (bgImage)
+        {
+          let data = RequestNotifier.getDataForNode(wnd.document, true, "IMAGE", bgImage);
+          if (data && !data[1].filter)
+          {
+            addMenuItem(data);
+            break;
+          }
+        }
+      }
+
+      node = node.parentNode;
+    }
+  }
+
+  return items;
+};
+
+let ContextMenuObserver =
+{
+  observe: function(subject, topic, data)
+  {
+    if (topic == "content-contextmenu")
+    {
+      if (subject.wrappedJSObject)
+        subject = subject.wrappedJSObject;
+
+      if (subject.addonInfo)
+        subject.addonInfo.adblockplus = getContextInfo(subject.event);
+    }
+  },
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsISupportsWeakReference, Ci.nsIObserver])
+};
+
+let addObserver = Utils.getPropertyWithoutCompatShims(Services.obs, "addObserver");
+addObserver.call(Services.obs, ContextMenuObserver, "content-contextmenu", true);
+onShutdown.add(() => {
+  let removeObserver = Utils.getPropertyWithoutCompatShims(Services.obs, "removeObserver");
+  removeObserver.call(Services.obs, ContextMenuObserver, "content-contextmenu");
+});