accessible/windows/msaa/ServiceProvider.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "ServiceProvider.h"
   8
   9 #include "AccessibleApplication_i.c"
  10 #include "ApplicationAccessibleWrap.h"
  11 #include "DocAccessible.h"
  12 #include "nsAccUtils.h"
  13 #include "nsCoreUtils.h"
  14 #include "Relation.h"
  15 #include "RootAccessible.h"
  16 #include "uiaRawElmProvider.h"
  17
  18 #include "mozilla/a11y/DocAccessibleChild.h"
  19 #include "mozilla/Preferences.h"
  20
  21 #include "ISimpleDOM.h"
  22
  23 namespace mozilla {
  24 namespace a11y {
  25
  26 IMPL_IUNKNOWN_QUERY_HEAD(ServiceProvider)
  27 IMPL_IUNKNOWN_QUERY_IFACE(IServiceProvider)
  28 IMPL_IUNKNOWN_QUERY_TAIL_AGGREGATED(mMsaa)
  29
  30 ////////////////////////////////////////////////////////////////////////////////
  31 // IServiceProvider
  32
  33 STDMETHODIMP
  34 ServiceProvider::QueryService(REFGUID aGuidService, REFIID aIID,
  35                               void** aInstancePtr) {
  36   if (!aInstancePtr) return E_INVALIDARG;
  37
  38   *aInstancePtr = nullptr;
  39   Accessible* acc = mMsaa->Acc();
  40   if (!acc) {
  41     return CO_E_OBJNOTCONNECTED;
  42   }
  43   AccessibleWrap* localAcc = mMsaa->LocalAcc();
  44
  45   // UIA IAccessibleEx
  46   if (aGuidService == IID_IAccessibleEx &&
  47       Preferences::GetBool("accessibility.uia.enable") && localAcc) {
  48     uiaRawElmProvider* accEx = new uiaRawElmProvider(localAcc);
  49     HRESULT hr = accEx->QueryInterface(aIID, aInstancePtr);
  50     if (FAILED(hr)) delete accEx;
  51
  52     return hr;
  53   }
  54
  55   // Provide a special service ID for getting the accessible for the browser tab
  56   // document that contains this accessible object. If this accessible object
  57   // is not inside a browser tab then the service fails with E_NOINTERFACE.
  58   // A use case for this is for screen readers that need to switch context or
  59   // 'virtual buffer' when focus moves from one browser tab area to another.
  60   static const GUID SID_IAccessibleContentDocument = {
  61       0xa5d8e1f3,
  62       0x3571,
  63       0x4d8f,
  64       {0x95, 0x21, 0x07, 0xed, 0x28, 0xfb, 0x07, 0x2e}};
  65   if (aGuidService == SID_IAccessibleContentDocument && localAcc) {
  66     if (aIID != IID_IAccessible) return E_NOINTERFACE;
  67
  68     // If acc is within an OOP iframe document, the top level document
  69     // lives in a different process.
  70     if (XRE_IsContentProcess()) {
  71       RootAccessible* root = localAcc->RootAccessible();
  72       // root will be null if acc is the ApplicationAccessible.
  73       if (root) {
  74         DocAccessibleChild* ipcDoc = root->IPCDoc();
  75         if (ipcDoc) {
  76           RefPtr<IAccessible> topDoc = ipcDoc->GetTopLevelDocIAccessible();
  77           // topDoc will be null if this isn't an OOP iframe document.
  78           if (topDoc) {
  79             topDoc.forget(aInstancePtr);
  80             return S_OK;
  81           }
  82         }
  83       }
  84     }
  85
  86     Relation rel = localAcc->RelationByType(RelationType::CONTAINING_TAB_PANE);
  87     AccessibleWrap* tabDoc = static_cast<AccessibleWrap*>(rel.Next());
  88     if (!tabDoc) return E_NOINTERFACE;
  89
  90     RefPtr<IAccessible> result;
  91     tabDoc->GetNativeInterface(getter_AddRefs(result));
  92     result.forget(aInstancePtr);
  93     return S_OK;
  94   }
  95
  96   // Can get to IAccessibleApplication from any node via QS
  97   // Note: in case of JAWS we want to check if aIID is
  98   // IID_IAccessibleApplication.
  99   if (aGuidService == IID_IAccessibleApplication ||
 100       aIID == IID_IAccessibleApplication) {
 101     ApplicationAccessibleWrap* applicationAcc =
 102         static_cast<ApplicationAccessibleWrap*>(ApplicationAcc());
 103     if (!applicationAcc) return E_NOINTERFACE;
 104
 105     RefPtr<IAccessible> appIa;
 106     applicationAcc->GetNativeInterface(getter_AddRefs(appIa));
 107     return appIa->QueryInterface(aIID, aInstancePtr);
 108   }
 109
 110   static const GUID IID_SimpleDOMDeprecated = {
 111       0x0c539790,
 112       0x12e4,
 113       0x11cf,
 114       {0xb6, 0x61, 0x00, 0xaa, 0x00, 0x4c, 0xd6, 0xd8}};
 115   if (aGuidService == IID_ISimpleDOMNode ||
 116       aGuidService == IID_SimpleDOMDeprecated ||
 117       aGuidService == IID_IAccessible || aGuidService == IID_IAccessible2)
 118     return mMsaa->QueryInterface(aIID, aInstancePtr);
 119
 120   return E_INVALIDARG;
 121 }
 122
 123 }  // namespace a11y
 124 }  // namespace mozilla