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 +1,222 @@
+let info = require("info");
+if (info.platform == "chromium")
+{
+  let {WhitelistFilter} = require("filterClasses");
+  let {SpecialSubscription} = require("subscriptionClasses");
+  let {Filter, ElemHideFilter} = require("filterClasses");
+  let {FilterStorage} = require("filterStorage");
+  let {defaultMatcher} = require("matcher");
+  let {FilterNotifier} = require("filterNotifier");
+
+  let panels = Object.create(null);
+
+  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.port.postMessage({
+      type: "add-record",
+      request: request,
+      filter: getFilterInfo(filter)
+    });
+
+    panel.records.push({
+      request: request,
+      filter: filter
+    });
+  }
+
+  function matchRequest(request)
+  {
+    return defaultMatcher.matchesAny(
+      request.url,
+      request.type,
+      request.docDomain,
+      isThirdParty(
+        extractHostFromURL(request.url),
+        request.docDomain
+      ),
+      request.sitekey
+    );
+  }
+
+  function logRequest(tabId, url, type, docDomain, sitekey, filter)
+  {
+    let panel = panels[tabId];
+    if (panel)
+    {
+      let request = {
+        url: url,
+        type: type,
+        docDomain: docDomain,
+        sitekey: sitekey
+      };
+
+      addRecord(panel, request, filter);
+    }
+  }
+  exports.logRequest = logRequest;
+
+  function logHiddenElements(tabId, selectors, docDomain)
+  {
+    let panel = panels[tabId];
+    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;
+
+  function hasPanel(page)
+  {
+    return page._id in panels;
+  }
+  exports.hasPanel = hasPanel;
+
+  function onMessage(msg)
+  {
+    let filter = Filter.fromText(msg.filter);
+
+    switch (msg.action)
+    {
+      case "add":
+        FilterStorage.addFilter(filter);
+        break;
+
+      case "remove":
+        FilterStorage.removeFilter(filter);
+        break;
+    }
+  }
+
+  chrome.runtime.onConnect.addListener(function(port)
+  {
+    let match = port.name.match(/^devtools-(\d+)$/);
+    if (match)
+    {
+      let tabId = match[1];
+      panels[tabId] = {port: port, records: []};
+
+      port.onMessage.addListener(onMessage);
+      port.onDisconnect.addListener(() => delete panels[tabId]);
+    }
+  });
+
+  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.port.postMessage({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.port.postMessage({
+              type: "remove-record",
+              index: i
+            });
+            panel.records.splice(i--, 1);
+            continue;
+          }
+
+          record.filter = matchRequest(record.request);
+        }
+
+        panel.port.postMessage({
+          type: "update-record",
+          index: i,
+          request: record.request,
+          filter: getFilterInfo(record.filter)
+        });
+      }
+    }
+  });
+}
+else
+{
+  exports.logRequest        = () => {};
+  exports.logHiddenElements = () => {};
+  exports.hasPanel          = () => false;
+}