Bug 1694865 part 13: Move DocAccessibleWrap's MSAA overrides to a new MsaaDocAccessible class. r=morgan

For now, DocAccessibleWrap inherits from MsaaDocAccessible and MsaaDocAccessible inherits from DocAccessible.
DocAccessible calls are made via a DocAcc() method which in turn calls MsaaAccessible::LocalAcc().
Since MsaaAccessible::LocalAcc() returns null if defunct, defunct checks have been adjusted accordingly.

Differential Revision: https://phabricator.services.mozilla.com/D112945

accessible/windows/msaa/DocAccessibleWrap.cpp

@@ -8,18 +8,13 @@
 
 #include "Compatibility.h"
 #include "mozilla/PresShell.h"
-#include "mozilla/dom/BrowserChild.h"
 #include "mozilla/dom/Document.h"
 #include "DocAccessibleChild.h"
 #include "nsWinUtils.h"
-#include "Role.h"
 #include "RootAccessible.h"
 #include "sdnDocAccessible.h"
 #include "Statistics.h"
 
-#include "nsIDocShell.h"
-#include "nsIInterfaceRequestorUtils.h"
-
 using namespace mozilla;
 using namespace mozilla::a11y;
 
@@ -29,7 +24,7 @@ using namespace mozilla::a11y;
 
 DocAccessibleWrap::DocAccessibleWrap(dom::Document* aDocument,
                                      PresShell* aPresShell)
-    : DocAccessible(aDocument, aPresShell), mHWND(nullptr) {}
+    : MsaaDocAccessible(aDocument, aPresShell), mHWND(nullptr) {}
 
 DocAccessibleWrap::~DocAccessibleWrap() {}
 
@@ -42,97 +37,6 @@ if (aIID == IID_ISimpleDOMDocument) {
 }
 IMPL_IUNKNOWN_QUERY_TAIL_INHERITED(HyperTextAccessibleWrap)
 
-STDMETHODIMP
-DocAccessibleWrap::get_accParent(
-    /* [retval][out] */ IDispatch __RPC_FAR* __RPC_FAR* ppdispParent) {
-  if (IsDefunct()) {
-    return CO_E_OBJNOTCONNECTED;
-  }
-
-  // We might be a top-level document in a content process.
-  DocAccessibleChild* ipcDoc = IPCDoc();
-  if (ipcDoc && static_cast<dom::BrowserChild*>(ipcDoc->Manager())
-                        ->GetTopLevelDocAccessibleChild() == ipcDoc) {
-    // Emulated window proxy is only set for the top level content document when
-    // emulation is enabled.
-    RefPtr<IDispatch> dispParent = ipcDoc->GetEmulatedWindowIAccessible();
-    if (!dispParent) {
-      dispParent = ipcDoc->GetParentIAccessible();
-    }
-
-    if (!dispParent) {
-      return S_FALSE;
-    }
-
-    dispParent.forget(ppdispParent);
-    return S_OK;
-  }
-
-  // In the parent process, return window system accessible object for root
-  // document accessibles, as well as tab document accessibles if window
-  // emulation is enabled.
-  if (XRE_IsParentProcess() &&
-      (!ParentDocument() ||
-       (nsWinUtils::IsWindowEmulationStarted() &&
-        nsCoreUtils::IsTopLevelContentDocInProcess(DocumentNode())))) {
-    HWND hwnd = static_cast<HWND>(GetNativeWindow());
-    if (hwnd && !ParentDocument()) {
-      nsIFrame* frame = GetFrame();
-      if (frame) {
-        nsIWidget* widget = frame->GetNearestWidget();
-        if (widget->WindowType() == eWindowType_child && !widget->GetParent()) {
-          // Bug 1427304: Windows opened with popup=yes (such as the WebRTC
-          // sharing indicator) get two HWNDs. The root widget is associated
-          // with the inner HWND, but the outer HWND still answers to
-          // WM_GETOBJECT queries. This means that getting the parent of the
-          // oleacc window accessible for the inner HWND returns this
-          // root accessible. Thus, to avoid a loop, we must never return the
-          // oleacc window accessible for the inner HWND. Instead, we use the
-          // outer HWND here.
-          HWND parentHwnd = ::GetParent(hwnd);
-          if (parentHwnd) {
-            MOZ_ASSERT(::GetWindowLongW(parentHwnd, GWL_STYLE) & WS_POPUP,
-                       "Parent HWND should be a popup!");
-            hwnd = parentHwnd;
-          }
-        }
-      }
-    }
-    if (hwnd &&
-        SUCCEEDED(::AccessibleObjectFromWindow(
-            hwnd, OBJID_WINDOW, IID_IAccessible, (void**)ppdispParent))) {
-      return S_OK;
-    }
-  }
-
-  return DocAccessible::get_accParent(ppdispParent);
-}
-
-STDMETHODIMP
-DocAccessibleWrap::get_accValue(VARIANT aVarChild, BSTR __RPC_FAR* aValue) {
-  if (!aValue) return E_INVALIDARG;
-  *aValue = nullptr;
-
-  // For backwards-compat, we still support old MSAA hack to provide URL in
-  // accValue Check for real value first
-  HRESULT hr = AccessibleWrap::get_accValue(aVarChild, aValue);
-  if (FAILED(hr) || *aValue || aVarChild.lVal != CHILDID_SELF) return hr;
-
-  // If document is being used to create a widget, don't use the URL hack
-  roles::Role role = Role();
-  if (role != roles::DOCUMENT && role != roles::APPLICATION &&
-      role != roles::DIALOG && role != roles::ALERT &&
-      role != roles::NON_NATIVE_DOCUMENT)
-    return hr;
-
-  nsAutoString url;
-  URL(url);
-  if (url.IsEmpty()) return S_FALSE;
-
-  *aValue = ::SysAllocStringLen(url.get(), url.Length());
-  return *aValue ? S_OK : E_OUTOFMEMORY;
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // LocalAccessible
 

accessible/windows/msaa/DocAccessibleWrap.h

@@ -7,7 +7,7 @@
 #ifndef mozilla_a11y_DocAccessibleWrap_h__
 #define mozilla_a11y_DocAccessibleWrap_h__
 
-#include "DocAccessible.h"
+#include "MsaaDocAccessible.h"
 
 namespace mozilla {
 
@@ -15,53 +15,24 @@ class PresShell;
 
 namespace a11y {
 
-class DocAccessibleWrap : public DocAccessible {
+class DocAccessibleWrap : public MsaaDocAccessible {
  public:
   DocAccessibleWrap(dom::Document* aDocument, PresShell* aPresShell);
   virtual ~DocAccessibleWrap();
 
   DECL_IUNKNOWN_INHERITED
 
-  // IAccessible
-
-  // Override get_accParent for e10s
-  virtual /* [id][propget] */ HRESULT STDMETHODCALLTYPE get_accParent(
-      /* [retval][out] */ IDispatch __RPC_FAR* __RPC_FAR* ppdispParent)
-      override;
-
-  // Override get_accValue to provide URL when no other value is available
-  virtual /* [id][propget] */ HRESULT STDMETHODCALLTYPE get_accValue(
-      /* [optional][in] */ VARIANT varChild,
-      /* [retval][out] */ BSTR __RPC_FAR* pszValue) override;
-
   // LocalAccessible
   virtual void Shutdown();
 
   // DocAccessible
   virtual void* GetNativeWindow() const;
 
-  /**
-   * Manage the mapping from id to Accessible.
-   */
-  void AddID(uint32_t aID, AccessibleWrap* aAcc) {
-    mIDToAccessibleMap.InsertOrUpdate(aID, aAcc);
-  }
-  void RemoveID(uint32_t aID) { mIDToAccessibleMap.Remove(aID); }
-  AccessibleWrap* GetAccessibleByID(uint32_t aID) const {
-    return mIDToAccessibleMap.Get(aID);
-  }
-
- protected:
-  // DocAccessible
-  virtual void DoInitialUpdate();
-
  protected:
   void* mHWND;
 
-  /*
-   * This provides a mapping from 32 bit id to accessible objects.
-   */
-  nsTHashMap<nsUint32HashKey, AccessibleWrap*> mIDToAccessibleMap;
+  // DocAccessible
+  virtual void DoInitialUpdate();
 };
 
 }  // namespace a11y

accessible/windows/msaa/MsaaDocAccessible.cpp

@@ -0,0 +1,118 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "MsaaDocAccessible.h"
+
+#include "DocAccessibleChild.h"
+#include "nsWinUtils.h"
+#include "Role.h"
+
+using namespace mozilla;
+using namespace mozilla::a11y;
+
+DocAccessible* MsaaDocAccessible::DocAcc() {
+  // XXX This first static_cast is a necessary hack until we get rid of the
+  // inheritance of DocAccessibleWrap.
+  auto wrap = static_cast<DocAccessible*>(this);
+  AccessibleWrap* acc = static_cast<MsaaAccessible*>(wrap)->LocalAcc();
+  return static_cast<DocAccessible*>(acc);
+}
+
+STDMETHODIMP
+MsaaDocAccessible::get_accParent(
+    /* [retval][out] */ IDispatch __RPC_FAR* __RPC_FAR* ppdispParent) {
+  DocAccessible* docAcc = DocAcc();
+  if (!docAcc) {
+    return CO_E_OBJNOTCONNECTED;
+  }
+
+  // We might be a top-level document in a content process.
+  DocAccessibleChild* ipcDoc = docAcc->IPCDoc();
+  if (ipcDoc && static_cast<dom::BrowserChild*>(ipcDoc->Manager())
+                        ->GetTopLevelDocAccessibleChild() == ipcDoc) {
+    // Emulated window proxy is only set for the top level content document when
+    // emulation is enabled.
+    RefPtr<IDispatch> dispParent = ipcDoc->GetEmulatedWindowIAccessible();
+    if (!dispParent) {
+      dispParent = ipcDoc->GetParentIAccessible();
+    }
+
+    if (!dispParent) {
+      return S_FALSE;
+    }
+
+    dispParent.forget(ppdispParent);
+    return S_OK;
+  }
+
+  // In the parent process, return window system accessible object for root
+  // document accessibles, as well as tab document accessibles if window
+  // emulation is enabled.
+  if (XRE_IsParentProcess() &&
+      (!docAcc->ParentDocument() ||
+       (nsWinUtils::IsWindowEmulationStarted() &&
+        nsCoreUtils::IsTopLevelContentDocInProcess(docAcc->DocumentNode())))) {
+    HWND hwnd = static_cast<HWND>(docAcc->GetNativeWindow());
+    if (hwnd && !docAcc->ParentDocument()) {
+      nsIFrame* frame = docAcc->GetFrame();
+      if (frame) {
+        nsIWidget* widget = frame->GetNearestWidget();
+        if (widget->WindowType() == eWindowType_child && !widget->GetParent()) {
+          // Bug 1427304: Windows opened with popup=yes (such as the WebRTC
+          // sharing indicator) get two HWNDs. The root widget is associated
+          // with the inner HWND, but the outer HWND still answers to
+          // WM_GETOBJECT queries. This means that getting the parent of the
+          // oleacc window accessible for the inner HWND returns this
+          // root accessible. Thus, to avoid a loop, we must never return the
+          // oleacc window accessible for the inner HWND. Instead, we use the
+          // outer HWND here.
+          HWND parentHwnd = ::GetParent(hwnd);
+          if (parentHwnd) {
+            MOZ_ASSERT(::GetWindowLongW(parentHwnd, GWL_STYLE) & WS_POPUP,
+                       "Parent HWND should be a popup!");
+            hwnd = parentHwnd;
+          }
+        }
+      }
+    }
+    if (hwnd &&
+        SUCCEEDED(::AccessibleObjectFromWindow(
+            hwnd, OBJID_WINDOW, IID_IAccessible, (void**)ppdispParent))) {
+      return S_OK;
+    }
+  }
+
+  return MsaaAccessible::get_accParent(ppdispParent);
+}
+
+STDMETHODIMP
+MsaaDocAccessible::get_accValue(VARIANT aVarChild, BSTR __RPC_FAR* aValue) {
+  if (!aValue) return E_INVALIDARG;
+  *aValue = nullptr;
+
+  // For backwards-compat, we still support old MSAA hack to provide URL in
+  // accValue Check for real value first
+  HRESULT hr = MsaaAccessible::get_accValue(aVarChild, aValue);
+  if (FAILED(hr) || *aValue || aVarChild.lVal != CHILDID_SELF) return hr;
+
+  DocAccessible* docAcc = DocAcc();
+  // MsaaAccessible::get_accValue should have failed (and thus we should have
+  // returned early) if the Accessible is dead.
+  MOZ_ASSERT(docAcc);
+  // If document is being used to create a widget, don't use the URL hack
+  roles::Role role = docAcc->Role();
+  if (role != roles::DOCUMENT && role != roles::APPLICATION &&
+      role != roles::DIALOG && role != roles::ALERT &&
+      role != roles::NON_NATIVE_DOCUMENT)
+    return hr;
+
+  nsAutoString url;
+  docAcc->URL(url);
+  if (url.IsEmpty()) return S_FALSE;
+
+  *aValue = ::SysAllocStringLen(url.get(), url.Length());
+  return *aValue ? S_OK : E_OUTOFMEMORY;
+}

accessible/windows/msaa/MsaaDocAccessible.h

@@ -0,0 +1,63 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_a11y_MsaaDocAccessible_h__
+#define mozilla_a11y_MsaaDocAccessible_h__
+
+#include "DocAccessible.h"
+#include "MsaaAccessible.h"
+
+namespace mozilla {
+
+class PresShell;
+
+namespace a11y {
+class DocAccessible;
+
+// XXX This should inherit from MsaaAccessible. Inheriting from DocAccessible
+// is a necessary hack until we remove the inheritance of DocAccessibleWrap.
+class MsaaDocAccessible : public DocAccessible {
+ public:
+  MsaaDocAccessible(dom::Document* aDocument, PresShell* aPresShell)
+      : DocAccessible(aDocument, aPresShell) {}
+
+  // IAccessible
+
+  // Override get_accParent for e10s
+  virtual /* [id][propget] */ HRESULT STDMETHODCALLTYPE get_accParent(
+      /* [retval][out] */ IDispatch __RPC_FAR* __RPC_FAR* ppdispParent)
+      override;
+
+  // Override get_accValue to provide URL when no other value is available
+  virtual /* [id][propget] */ HRESULT STDMETHODCALLTYPE get_accValue(
+      /* [optional][in] */ VARIANT varChild,
+      /* [retval][out] */ BSTR __RPC_FAR* pszValue) override;
+
+  /**
+   * Manage the mapping from id to Accessible.
+   */
+  void AddID(uint32_t aID, AccessibleWrap* aAcc) {
+    mIDToAccessibleMap.InsertOrUpdate(aID, aAcc);
+  }
+  void RemoveID(uint32_t aID) { mIDToAccessibleMap.Remove(aID); }
+  AccessibleWrap* GetAccessibleByID(uint32_t aID) const {
+    return mIDToAccessibleMap.Get(aID);
+  }
+
+ protected:
+  /*
+   * This provides a mapping from 32 bit id to accessible objects.
+   */
+  nsTHashMap<nsUint32HashKey, AccessibleWrap*> mIDToAccessibleMap;
+
+ private:
+  DocAccessible* DocAcc();
+};
+
+}  // namespace a11y
+}  // namespace mozilla
+
+#endif

accessible/windows/msaa/moz.build

@@ -32,6 +32,7 @@ UNIFIED_SOURCES += [
     "ImageAccessibleWrap.cpp",
     "IUnknownImpl.cpp",
     "MsaaAccessible.cpp",
+    "MsaaDocAccessible.cpp",
     "MsaaIdGenerator.cpp",
     "nsWinUtils.cpp",
     "Platform.cpp",