Issue 154 - Added devtools panel showing blocked and blockable items

lib/devtools.js

Index: lib/devtools.js
===================================================================
new file mode 100644
--- /dev/null
+++ b/lib/devtools.js
@@ -0,0 +1,267 @@
+/*
+ * 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/>.
+ */
+
+let info = require("info");
+if (info.platform == "chromium")
+{
+  let {WhitelistFilter, ElemHideFilter} = require("filterClasses");
+  let {SpecialSubscription} = require("subscriptionClasses");
+  let {FilterStorage} = require("filterStorage");
+  let {defaultMatcher} = require("matcher");
+  let {FilterNotifier} = require("filterNotifier");
+  let {stringifyURL, isThirdParty} = require("url");
+
+  // Mapping of inspected tabs to their devpanel page
+  // and recorded items. We can't use a PageMap here,
+  // because data must persist after navigation/reload.
+  let panels = Object.create(null);
+
+  function getRequestInfo(request)
+  {
+    return {
+      url: request.url && stringifyURL(request.url),
+      type: request.type,
+      docDomain: request.docDomain
+    };
+  }
+
+  function getFilterInfo(filter)
+  {
+    if (!filter)
+      return null;
+
+    let userDefined = false;
+    let subscriptionTitle = null;
+
+    for (let subscription of filter.subscriptions)
+    {
+      if (!subscription.disabled)
+      {
+        if (subscription instanceof SpecialSubscription)
+          userDefined = true;
+        else
+          subscriptionTitle = subscription.title;
+      }
+    }
+
+    return {
+      text: filter.text,
+      whitelisted: filter instanceof WhitelistFilter,
+      userDefined: userDefined,
+      subscription: subscriptionTitle
+    };
+  }
+
+  function addRecord(panel, request, filter)
+  {
+    panel.page.sendMessage({
+      type: "add-record",
+      request: getRequestInfo(request),
+      filter: getFilterInfo(filter)
+    });
+
+    panel.records.push({
+      request: request,
+      filter: filter
+    });
+  }
+
+  function matchRequest(request)
+  {
+    return defaultMatcher.matchesAny(
+      stringifyURL(request.url),
+      request.type,
+      request.docDomain,
+      isThirdParty(request.url, request.docDomain),
+      request.sitekey
+    );
+  }
+
+  /**
+   * Logs a request in the devtools panel.
+   *
+   * @param {Page}   page       The page the request occured on
+   * @param {URL]    url        The URL of the request
+   * @param {string} type       The request type
+   * @param {string} docDomain  The IDN-decoded hostname of the document
+   * @param {string} [sitekey]  The active sitekey if there is any
+   * @param {filter} [filter]   The matched filter or null if there is no match
+   */
+  function logRequest(page, url, type, docDomain, sitekey, filter)
+  {
+    let panel = panels[page._id];
+    if (panel)
+    {
+      let request = {
+        url: url,
+        type: type,
+        docDomain: docDomain,
+        sitekey: sitekey
+      };
+
+      addRecord(panel, request, filter);
+    }
+  }
+  exports.logRequest = logRequest;
+
+  /**
+   * Logs active element hiding filters in the devtools panel.
+   *
+   * @param {Page}     page       The page the elements were hidden on
+   * @param {string[]} selectors  The CSS selectors of active elemhide filters
+   * @param {string}   docDomain  The IDN-decoded hostname of the document
+   */
+  function logHiddenElements(page, selectors, docDomain)
+  {
+    let panel = panels[page._id];
+    if (panel)
+    {
+      for (let subscription of FilterStorage.subscriptions)
+      {
+        if (subscription.disabled)
+          continue;
+
+        for (let filter of subscription.filters)
+        {
+          if (!(filter instanceof ElemHideFilter))
+            continue;
+          if (selectors.indexOf(filter.selector) == -1)
+            continue;
+          if (!filter.isActiveOnDomain(docDomain))
+            continue;
+          if (panel.records.some(record => record.request.type == "ELEMHIDE" &&
+                                           record.request.docDomain == docDomain &&
+                                           record.filter.selector == filter.selector))
+            continue;
+
+          addRecord(panel, {type: "ELEMHIDE", docDomain: docDomain}, filter);
+        }
+      }
+    }
+  };
+  exports.logHiddenElements = logHiddenElements;
+
+  /**
+   * Starts to record items and shows them in the devtools panel.
+   *
+   * @param {Page}   panelPage      The page of the the devtools panel
+   * @param {number} inpectedTabId  The ID of the tab to record item from
+   */
+  function initDevToolsPanel(panelPage, inpectedTabId)
+  {
+    panels[inpectedTabId] = {page: panelPage, records: []};
+
+    // Forget about this devtools panel and the items recorded there
+    // so far, when the panel (not the tab it is inspecting) is closed.
+    function onRemoved(tabId)
+    {
+      if (tabId == panelPage._id)
+      {
+        delete panels[inpectedTabId];
+        chrome.tabs.onRemoved.removeListener(onRemoved);
+      }
+    }
+    chrome.tabs.onRemoved.addListener(onRemoved);
+  }
+  exports.initDevToolsPanel = initDevToolsPanel;
+
+  /**
+   * Checks whether a page is inspected by the devtools panel.
+   *
+   * @param {Page} page
+   * @return {Boolean}
+   */
+  function hasDevToolsPanel(page)
+  {
+    return page._id in panels;
+  }
+  exports.hasDevToolsPanel = hasDevToolsPanel;
+
+  chrome.webNavigation.onBeforeNavigate.addListener(function(details)
+  {
+    let panel = panels[details.tabId];
+    if (panel && details.frameId == 0)
+    {
+      // We have to flush the in-memory cache on page load.
+      // Otherwise requests answered from the in-memory cache
+      // will not be shown in the devtools panel.
+      chrome.webRequest.handlerBehaviorChanged();
+
+      panel.records = [];
+      panel.page.sendMessage({type: "reset"});
+    }
+  });
+
+  FilterNotifier.addListener(function(action, filter)
+  {
+    if (action != "filter.added" && action != "filter.removed")
+      return;
+
+    for (let tabId in panels)
+    {
+      let panel = panels[tabId];
+
+      for (let i = 0; i < panel.records.length; i++)
+      {
+        let record = panel.records[i];
+
+        if (action == "filter.added")
+        {
+          if (record.request.type == "ELEMHIDE")
+            continue;
+
+          if (matchRequest(record.request) != filter)
+            continue;
+
+          record.filter = filter;
+        }
+
+        if (action == "filter.removed")
+        {
+          if (record.filter != filter)
+            continue;
+
+          if (record.request.type == "ELEMHIDE")
+          {
+            panel.page.sendMessage({
+              type: "remove-record",
+              index: i
+            });
+            panel.records.splice(i--, 1);
+            continue;
+          }
+
+          record.filter = matchRequest(record.request);
+        }
+
+        panel.page.sendMessage({
+          type: "update-record",
+          index: i,
+          request: getRequestInfo(record.request),
+          filter: getFilterInfo(record.filter)
+        });
+      }
+    }
+  });
+}
+else
+{
+  exports.logRequest        = () => {};
+  exports.logHiddenElements = () => {};
+  exports.initDevToolsPanel = () => {};
+  exports.hasDevToolsPanel  = () => false;
+}