Bug 1206711 - add support for HWND emulation for content top level docs on Windows. r=tbsaunde

MozReview-Commit-ID: GQ1LxCwtv3j

accessible/ipc/DocAccessibleParent.cpp

@@ -12,6 +12,13 @@
 #include "nsAccUtils.h"
 #include "nsCoreUtils.h"
 
+#if defined(XP_WIN)
+#include "AccessibleWrap.h"
+#include "Compatibility.h"
+#include "nsWinUtils.h"
+#include "RootAccessible.h"
+#endif
+
 namespace mozilla {
 namespace a11y {
 
@@ -525,7 +532,43 @@ DocAccessibleParent::SetCOMProxy(const RefPtr<IAccessible>& aCOMProxy)
 
   IAccessibleHolder::COMPtrType ptr(rawNative);
   IAccessibleHolder holder(Move(ptr));
-  Unused << SendParentCOMProxy(holder);
+
+  if (nsWinUtils::IsWindowEmulationStarted()) {
+    RootAccessible* rootDocument = outerDoc->RootAccessible();
+    MOZ_ASSERT(rootDocument);
+
+    bool isActive = true;
+    nsIntRect rect(CW_USEDEFAULT, CW_USEDEFAULT, 0, 0);
+    if (Compatibility::IsDolphin()) {
+      rect = Bounds();
+      nsIntRect rootRect = rootDocument->Bounds();
+      rect.x = rootRect.x - rect.x;
+      rect.y -= rootRect.y;
+      tab->GetDocShellIsActive(&isActive);
+    }
+
+    HWND parentWnd = reinterpret_cast<HWND>(rootDocument->GetNativeWindow());
+    HWND hWnd = nsWinUtils::CreateNativeWindow(kClassNameTabContent,
+                                               parentWnd, rect.x, rect.y,
+                                               rect.width, rect.height,
+                                               isActive);
+    if (hWnd) {
+      // Attach accessible document to the emulated native window
+      ::SetPropW(hWnd, kPropNameDocAccParent, (HANDLE)this);
+      SetEmulatedWindowHandle(hWnd);
+    }
+  }
+  Unused << SendParentCOMProxy(holder, reinterpret_cast<uintptr_t>(
+                               mEmulatedWindowHandle));
+}
+
+void
+DocAccessibleParent::SetEmulatedWindowHandle(HWND aWindowHandle)
+{
+  if (!aWindowHandle && mEmulatedWindowHandle && IsTopLevel()) {
+    ::DestroyWindow(mEmulatedWindowHandle);
+  }
+  mEmulatedWindowHandle = aWindowHandle;
 }
 
 mozilla::ipc::IPCResult

accessible/ipc/DocAccessibleParent.h

@@ -30,6 +30,9 @@ public:
   DocAccessibleParent() :
     ProxyAccessible(this), mParentDoc(nullptr),
     mTopLevel(false), mShutdown(false)
+#if defined(XP_WIN)
+                                      , mEmulatedWindowHandle(nullptr)
+#endif // defined(XP_WIN)
   { MOZ_COUNT_CTOR_INHERITED(DocAccessibleParent, ProxyAccessible); }
   ~DocAccessibleParent()
   {
@@ -151,6 +154,13 @@ public:
 
   virtual mozilla::ipc::IPCResult RecvGetWindowedPluginIAccessible(
       const WindowsHandle& aHwnd, IAccessibleHolder* aPluginCOMProxy) override;
+
+  /**
+   * Set emulated native window handle for a document.
+   * @param aWindowHandle emulated native window handle
+   */
+  void SetEmulatedWindowHandle(HWND aWindowHandle);
+  HWND GetEmulatedWindowHandle() const { return mEmulatedWindowHandle; }
 #endif
 
 private:
@@ -187,6 +197,11 @@ private:
   nsTArray<DocAccessibleParent*> mChildDocs;
   DocAccessibleParent* mParentDoc;
 
+#if defined(XP_WIN)
+  // The handle associated with the emulated window that contains this document
+  HWND mEmulatedWindowHandle;
+#endif
+
   /*
    * Conceptually this is a map from IDs to proxies, but we store the ID in the
    * proxy object so we can't use a real map.

accessible/ipc/win/DocAccessibleChild.cpp

@@ -18,6 +18,7 @@ static StaticAutoPtr<PlatformChild> sPlatformChild;
 
 DocAccessibleChild::DocAccessibleChild(DocAccessible* aDoc)
   : DocAccessibleChildBase(aDoc)
+  , mEmulatedWindowHandle(nullptr)
   , mIsRemoteConstructed(false)
 {
   MOZ_COUNT_CTOR_INHERITED(DocAccessibleChild, DocAccessibleChildBase);
@@ -45,11 +46,13 @@ DocAccessibleChild::Shutdown()
 }
 
 ipc::IPCResult
-DocAccessibleChild::RecvParentCOMProxy(const IAccessibleHolder& aParentCOMProxy)
+DocAccessibleChild::RecvParentCOMProxy(const IAccessibleHolder& aParentCOMProxy,
+                                       const WindowsHandle& aEmulatedWindowHandle)
 {
   MOZ_ASSERT(!mParentProxy && !aParentCOMProxy.IsNull());
   mParentProxy.reset(const_cast<IAccessibleHolder&>(aParentCOMProxy).Release());
   SetConstructedInParentProcess();
+  mEmulatedWindowHandle = reinterpret_cast<HWND>(aEmulatedWindowHandle);
 
   for (uint32_t i = 0, l = mDeferredEvents.Length(); i < l; ++i) {
     mDeferredEvents[i]->Dispatch();

accessible/ipc/win/DocAccessibleChild.h

@@ -28,7 +28,10 @@ public:
   virtual void Shutdown() override;
 
   virtual ipc::IPCResult
-  RecvParentCOMProxy(const IAccessibleHolder& aParentCOMProxy) override;
+  RecvParentCOMProxy(const IAccessibleHolder& aParentCOMProxy,
+                     const WindowsHandle& aEmulatedWindowHandle) override;
+
+  HWND GetEmulatedWindowHandle() const { return mEmulatedWindowHandle; }
 
   IAccessible* GetParentIAccessible() const { return mParentProxy.get(); }
 
@@ -310,6 +313,7 @@ private:
   bool mIsRemoteConstructed;
   mscom::ProxyUniquePtr<IAccessible> mParentProxy;
   nsTArray<UniquePtr<DeferredEvent>> mDeferredEvents;
+  HWND mEmulatedWindowHandle;
 };
 
 } // namespace a11y

accessible/ipc/win/PDocAccessible.ipdl

@@ -66,7 +66,8 @@ parent:
     returns (IAccessibleHolder aPluginCOMProxy);
 
 child:
-  async ParentCOMProxy(IAccessibleHolder aParentCOMProxy);
+  async ParentCOMProxy(IAccessibleHolder aParentCOMProxy,
+                       WindowsHandle aEmulatedWindowHandle);
 
   async __delete__();
 };

accessible/windows/msaa/DocAccessibleWrap.cpp

@@ -120,6 +120,11 @@ DocAccessibleWrap::GetNativeWindow() const
 {
   if (XRE_IsContentProcess()) {
     DocAccessibleChild* ipcDoc = IPCDoc();
+    HWND hWnd = ipcDoc->GetEmulatedWindowHandle();
+    if (hWnd) {
+      return hWnd;
+    }
+
     auto tab = static_cast<dom::TabChild*>(ipcDoc->Manager());
     MOZ_ASSERT(tab);
     return reinterpret_cast<HWND>(tab->GetNativeWindowHandle());

accessible/windows/msaa/Platform.cpp

@@ -85,6 +85,10 @@ a11y::ProxyDestroyed(ProxyAccessible* aProxy)
   if (!wrapper)
     return;
 
+  if (aProxy->IsDoc() && nsWinUtils::IsWindowEmulationStarted()) {
+    aProxy->AsDoc()->SetEmulatedWindowHandle(nullptr);
+  }
+
   wrapper->Shutdown();
   aProxy->SetWrapper(0);
   wrapper->Release();

accessible/windows/msaa/moz.build

@@ -14,6 +14,7 @@ EXPORTS.mozilla.a11y += [
     'HyperTextAccessibleWrap.h',
     'IDSet.h',
     'MsaaIdGenerator.h',
+    'nsWinUtils.h',
 ]
 
 UNIFIED_SOURCES += [

accessible/windows/msaa/nsWinUtils.cpp

@@ -12,6 +12,7 @@
 #include "nsAccessibilityService.h"
 #include "nsCoreUtils.h"
 
+#include "mozilla/a11y/DocAccessibleParent.h"
 #include "mozilla/Preferences.h"
 #include "nsArrayUtils.h"
 #include "nsIArray.h"
@@ -20,6 +21,7 @@
 #include "nsIDocShellTreeItem.h"
 #include "mozilla/dom/Element.h"
 #include "nsXULAppAPI.h"
+#include "ProxyWrappers.h"
 
 using namespace mozilla;
 using namespace mozilla::a11y;
@@ -153,18 +155,25 @@ WindowProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
       // for details).
       int32_t objId = static_cast<DWORD>(lParam);
       if (objId == OBJID_CLIENT) {
+        IAccessible* msaaAccessible = nullptr;
         DocAccessible* document =
           reinterpret_cast<DocAccessible*>(::GetPropW(hWnd, kPropNameDocAcc));
         if (document) {
-          IAccessible* msaaAccessible = nullptr;
           document->GetNativeInterface((void**)&msaaAccessible); // does an addref
-          if (msaaAccessible) {
-            LRESULT result = ::LresultFromObject(IID_IAccessible, wParam,
-                                                 msaaAccessible); // does an addref
-            msaaAccessible->Release(); // release extra addref
-            return result;
+        } else {
+          DocAccessibleParent* docParent = static_cast<DocAccessibleParent*>(
+            ::GetPropW(hWnd, kPropNameDocAccParent));
+          if (docParent) {
+            auto wrapper = WrapperFor(docParent);
+            wrapper->GetNativeInterface((void**)&msaaAccessible); // does an addref
           }
         }
+        if (msaaAccessible) {
+          LRESULT result = ::LresultFromObject(IID_IAccessible, wParam,
+                                               msaaAccessible); // does an addref
+          msaaAccessible->Release(); // release extra addref
+          return result;
+        }
       }
       return 0;
     }

accessible/windows/msaa/nsWinUtils.h

@@ -23,6 +23,7 @@ class DocAccessible;
 const LPCWSTR kClassNameRoot = L"MozillaUIWindowClass";
 const LPCWSTR kClassNameTabContent = L"MozillaContentWindowClass";
 const LPCWSTR kPropNameDocAcc = L"MozDocAccessible";
+const LPCWSTR kPropNameDocAccParent = L"MozDocAccessibleParent";
 
 class nsWinUtils
 {

dom/ipc/TabParent.cpp

@@ -102,6 +102,7 @@
 
 #if defined(XP_WIN) && defined(ACCESSIBILITY)
 #include "mozilla/a11y/AccessibleWrap.h"
+#include "mozilla/a11y/nsWinUtils.h"
 #endif
 
 using namespace mozilla::dom;
@@ -269,6 +270,16 @@ TabParent::SetOwnerElement(Element* aElement)
         reinterpret_cast<uintptr_t>(widget->GetNativeData(NS_NATIVE_WINDOW));
     }
     Unused << SendUpdateNativeWindowHandle(newWindowHandle);
+    a11y::DocAccessibleParent* doc = GetTopLevelDocAccessible();
+    if (doc) {
+      HWND hWnd = reinterpret_cast<HWND>(doc->GetEmulatedWindowHandle());
+      if (hWnd) {
+        HWND parentHwnd = reinterpret_cast<HWND>(newWindowHandle);
+        if (parentHwnd != ::GetParent(hWnd)) {
+          ::SetParent(hWnd, parentHwnd);
+        }
+      }
+    }
   }
 #endif
 
@@ -921,6 +932,9 @@ TabParent::RecvPDocAccessibleConstructor(PDocAccessibleParent* aDoc,
     MOZ_ASSERT(aDocCOMProxy.IsNull());
     if (added) {
       a11y::WrapperFor(doc)->SetID(aMsaaID);
+      if (a11y::nsWinUtils::IsWindowEmulationStarted()) {
+        doc->SetEmulatedWindowHandle(parentDoc->GetEmulatedWindowHandle());
+      }
     }
 #endif
     if (!added) {