Issue 119 - Switch to injecting CSS for element hiding

src/plugin/PluginTabBase.cpp

Index: src/plugin/PluginTabBase.cpp
diff --git a/src/plugin/PluginTabBase.cpp b/src/plugin/PluginTabBase.cpp
index fd95b5a7621848f8afc61ba5d0b9f0afd2faec0e..511846100f112febe46c0d32bbc47e28d2b33287 100644
--- a/src/plugin/PluginTabBase.cpp
+++ b/src/plugin/PluginTabBase.cpp
@@ -24,6 +24,7 @@
 #include "IeVersion.h"
 #include "../shared/Utils.h"
 #include <Mshtmhst.h>
+#include "../shared/Utils.h"
 
 CPluginTabBase::CPluginTabBase(CPluginClass* plugin)
   : m_plugin(plugin)
@@ -165,6 +166,7 @@ void CPluginTabBase::InjectABP(IWebBrowser2* browser)
     DEBUG_ERROR_LOG(0, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT, PLUGIN_ERROR_CREATE_SETTINGS_JAVASCRIPT_INVOKE, "CPluginTabBase::InjectABP - Failed to QI document");
     return;
   }
+
   CComPtr<IHTMLWindow2> pWnd2;
   pDoc2->get_parentWindow(&pWnd2);
   if (!pWnd2)
@@ -204,6 +206,119 @@ void CPluginTabBase::InjectABP(IWebBrowser2* browser)
   }
 }
 
+bool CPluginTabBase::IsTraverserEnabled()
+{
+  return !IsCSSInjectionEnabled();
+}
+
+bool CPluginTabBase::IsCSSInjectionEnabled()
+{
+  return IsWindowsVistaOrLater() && AdblockPlus::IE::InstalledMajorVersion() >= 10;
+}

[Eric, 2015/12/02 17:00:15]

I'd like to see a user setting for these predicates that can override what's
already here. The use cases are for developers running and debugging traverser
code. Without something we can override, it's going to be quite a bother
degrading the IE version just to run the traverser code.

I suggest two mechanisms.

(1) An in-memory static variable that can be explicitly toggled inside the VS
debugger. This can be evaluated the first time and left alone after that, which
means a second "is initialized" value somewhere.

(2) An external configuration option, either in a file or in the registry, that
configures operation when not running under the debugger.

[sergei, 2016/02/25 17:48:28]

I have created those methods exactly for that reason.
Currently developers can insert `return false;` here or add some code to read it
from some file (3 lines of code) or use something else. Not so difficult, I
guess.

I agree that we need some external flag, see #3631.

+
+namespace
+{
+  void InjectABPCSS(IHTMLDocument2& htmlDocument2, const std::vector<std::wstring>& hideFilters)
+  {
+    // pseudocode: styleHtmlElement = htmlDocument2.createElement("style");
+    ATL::CComQIPtr<IHTMLStyleElement> styleHtmlElement;
+    {
+      ATL::CComPtr<IHTMLElement> stylePureHtmlElement;
+      if (FAILED(htmlDocument2.createElement(ATL::CComBSTR(L"style"), &stylePureHtmlElement)))
+      {
+        DEBUG_GENERAL(L"Cannot create style element");
+        return;
+      }
+      if (!(styleHtmlElement = stylePureHtmlElement))
+      {
+        DEBUG_GENERAL(L"Cannot obtain IHTMLStyleElement from IHTMLElement");
+        return;
+      }
+    }
+    // pseudocode: styleHtmlElement.type = "text/css";
+    if (FAILED(styleHtmlElement->put_type(ATL::CComBSTR("text/css"))))
+    {
+      DEBUG_GENERAL(L"Cannot set type text/css");
+      return;
+    }
+    // pseudocode: styleSheet4 = styleHtmlElement.sheet;
+    ATL::CComQIPtr<IHTMLStyleSheet4> styleSheet4;
+    {
+      // IHTMLStyleElement2 is availabe starting from IE9, Vista
+      ATL::CComQIPtr<IHTMLStyleElement2> styleHtmlElement2 = styleHtmlElement;
+      if (!styleHtmlElement2)
+      {
+        DEBUG_GENERAL(L"Cannot obtain IHTMLStyleElement2 from IHTMLStyleElement");
+        return;
+      }
+      ATL::CComQIPtr<IHTMLStyleSheet> styleSheet;
+      if (FAILED(styleHtmlElement2->get_sheet(&styleSheet)) || !styleSheet)
+      {
+        DEBUG_GENERAL(L"Cannot obtain IHTMLStyleSheet");
+        return;
+      }
+      // IHTMLStyleSheet4 is availabe starting from IE9, Vista
+      styleSheet4 = styleSheet;
+      if (!styleSheet4)
+      {
+        DEBUG_GENERAL(L"Cannot obtain IHTMLStyleSheet4");
+        return;
+      }
+    }
+    // pseudocode: for (auto i = 0; i < hideFilters.length; ++i) {
+    // pseudocode:   i = styleSheet4.insertRule(hideFilters + cssValue, i);
+    // pseudocode: }
+    long newIndex = 0;
+    std::wstring cssValue = L"{ display: none !important; }";
+    for (const auto& selector : hideFilters)
+    {
+      auto cssRule = selector + cssValue;
+      ATL::CComBSTR selector(cssRule.size(), cssRule.c_str());
+      if (SUCCEEDED(styleSheet4->insertRule(selector, newIndex, &newIndex)))
+      {
+        ++newIndex;
+      }
+      else
+      {
+        DEBUG_GENERAL(L"Cannot add rule for selector " + cssRule);
+      }
+    }
+
+    // pseudocode: htmlDocument2.head.appendChild(styleHtmlElement);
+    {
+      // IHTMLDocument7 is availabe starting from IE9, Vista
+      ATL::CComQIPtr<IHTMLDocument7> htmlDocument7 = &htmlDocument2;
+      if (!htmlDocument7)
+      {
+        DEBUG_GENERAL(L"Cannot obtain IHTMLDocument7 from htmlDocument2");
+        return;
+      }
+      ATL::CComPtr<IHTMLElement> headHtmlElement;
+      if (FAILED(htmlDocument7->get_head(&headHtmlElement)))
+      {
+        DEBUG_GENERAL(L"Cannot obtain head from pDoc7");
+        return;
+      }
+      ATL::CComQIPtr<IHTMLDOMNode> headNode = headHtmlElement;
+      if (!headNode)
+      {
+        DEBUG_GENERAL(L"Cannot obtain headNode from headHtmlElement");
+        return;
+      }
+      ATL::CComQIPtr<IHTMLDOMNode> styleNode = styleHtmlElement;
+      if (!styleNode)
+      {
+        DEBUG_GENERAL(L"Cannot obtain IHTMLDOMNode from stylePureHtmlElement");
+        return;
+      }
+      if (FAILED(headNode->appendChild(styleNode, nullptr)))
+      {
+        DEBUG_GENERAL(L"Cannot append blocking style");
+      }
+    }
+  }
+}
+
 namespace
 {
   ATL::CComPtr<IWebBrowser2> GetParent(IWebBrowser2& browser)
@@ -252,11 +367,14 @@ namespace
 
 void CPluginTabBase::OnDownloadComplete(IWebBrowser2* browser)
 {
-  CPluginClient* client = CPluginClient::GetInstance();
-  std::wstring url = GetDocumentUrl();
-  if (!client->IsWhitelistedUrl(url) && !client->IsElemhideWhitelistedOnDomain(url))
+  if (IsTraverserEnabled())
   {
-    m_traverser->TraverseDocument(browser, GetDocumentDomain(), GetDocumentUrl());
+    CPluginClient* client = CPluginClient::GetInstance();
+    std::wstring url = GetDocumentUrl();
+    if (!client->IsWhitelistedUrl(url) && !client->IsElemhideWhitelistedOnDomain(url))
+    {
+      m_traverser->TraverseDocument(browser, GetDocumentDomain(), GetDocumentUrl());
+    }
   }
   InjectABP(browser);
 }
@@ -274,38 +392,45 @@ void CPluginTabBase::OnDocumentComplete(IWebBrowser2* browser, const std::wstrin
     InjectABP(browser);
   }
   CString urlLegacy = ToCString(url);
-  if (urlLegacy.Left(6) != "res://")
+  if (urlLegacy.Left(6) == "res://")
   {
-    // Get document
-    CComPtr<IDispatch> pDocDispatch;
-    HRESULT hr = browser->get_Document(&pDocDispatch);
-    if (FAILED(hr) || !pDocDispatch)
-    {
-      return;
-    }
+    return;
+  }

[Eric, 2015/12/02 17:00:15]

This optimization, for early return on a "res://" URL, could be committed
separately and immediately. It will make the changes below easier to review. At
present it all looks different because the indentation changes, when in fact
most of it's the same.

[sergei, 2016/02/25 17:48:28]

Done. It's already not relevant.

+  // Get document
+  CComPtr<IDispatch> pDocDispatch;
+  HRESULT hr = browser->get_Document(&pDocDispatch);
+  if (FAILED(hr) || !pDocDispatch)
+  {
+    return;
+  }
 
-    CComQIPtr<IHTMLDocument2> pDoc(pDocDispatch);
-    if (!pDoc)
-    {
-      return;
-    }
+  CComQIPtr<IHTMLDocument2> pDoc(pDocDispatch);
+  if (!pDoc)
+  {
+    return;
+  }
 
-    CComPtr<IOleObject> pOleObj;
-    pDocDispatch->QueryInterface(&pOleObj);
-    if (!pOleObj)
+  if (IsCSSInjectionEnabled() && CPluginSettings::GetInstance()->GetPluginEnabled())
+  {
+    if (!IsFrameWhiteListed(browser))
     {
-      return;
+      DEBUG_GENERAL(L"Inject CSS into " + url);
+      InjectABPCSS(*pDoc, m_filter->GetHideFilters());
     }
-    CComPtr<IOleClientSite> pClientSite;
-    pOleObj->GetClientSite(&pClientSite);
-    if (pClientSite != NULL)
+  }
+
+  ATL::CComQIPtr<IOleObject> pOleObj(pDocDispatch);
+  if (!pOleObj)
+    return;
+
+  ATL::CComQIPtr<IOleClientSite> pClientSite;
+  pOleObj->GetClientSite(&pClientSite);
+  if (pClientSite != NULL)
+  {
+    ATL::CComQIPtr<IDocHostUIHandler> docHostUIHandler(pClientSite);
+    if (docHostUIHandler != NULL)
     {
-      CComPtr<IDocHostUIHandler> docHostUIHandler;
-      pClientSite->QueryInterface(&docHostUIHandler);
-      if (docHostUIHandler != NULL)
-      {
-        docHostUIHandler->UpdateUI();
-      }
+      docHostUIHandler->UpdateUI();
     }
   }
 }