gecko-dev/accessible/windows/msaa/ServiceProvider.cpp

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3.9 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=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 "ServiceProvider.h"
#include "ApplicationAccessibleWrap.h"
#include "DocAccessible.h"
#include "nsAccUtils.h"
#include "nsCoreUtils.h"
#include "Relation.h"
#include "RootAccessible.h"
#include "uiaRawElmProvider.h"
#include "mozilla/a11y/DocAccessibleChild.h"
#include "mozilla/Preferences.h"
#include "ISimpleDOM.h"
namespace mozilla {
namespace a11y {
IMPL_IUNKNOWN_QUERY_HEAD(ServiceProvider)
IMPL_IUNKNOWN_QUERY_IFACE(IServiceProvider)
IMPL_IUNKNOWN_QUERY_TAIL_AGGREGATED(mAccessible)
////////////////////////////////////////////////////////////////////////////////
// IServiceProvider
STDMETHODIMP
ServiceProvider::QueryService(REFGUID aGuidService, REFIID aIID,
void** aInstancePtr) {
if (!aInstancePtr) return E_INVALIDARG;
*aInstancePtr = nullptr;
// UIA IAccessibleEx
if (aGuidService == IID_IAccessibleEx &&
Preferences::GetBool("accessibility.uia.enable")) {
uiaRawElmProvider* accEx = new uiaRawElmProvider(mAccessible);
HRESULT hr = accEx->QueryInterface(aIID, aInstancePtr);
if (FAILED(hr)) delete accEx;
return hr;
}
// Provide a special service ID for getting the accessible for the browser tab
// document that contains this accessible object. If this accessible object
// is not inside a browser tab then the service fails with E_NOINTERFACE.
// A use case for this is for screen readers that need to switch context or
// 'virtual buffer' when focus moves from one browser tab area to another.
static const GUID SID_IAccessibleContentDocument = {
0xa5d8e1f3,
0x3571,
0x4d8f,
{0x95, 0x21, 0x07, 0xed, 0x28, 0xfb, 0x07, 0x2e}};
if (aGuidService == SID_IAccessibleContentDocument) {
if (aIID != IID_IAccessible) return E_NOINTERFACE;
// If mAccessible is within an OOP iframe document, the top level document
// lives in a different process.
if (XRE_IsContentProcess()) {
RootAccessible* root = mAccessible->RootAccessible();
// root will be null if mAccessible is the ApplicationAccessible.
if (root) {
DocAccessibleChild* ipcDoc = root->IPCDoc();
if (ipcDoc) {
RefPtr<IAccessible> topDoc = ipcDoc->GetTopLevelDocIAccessible();
// topDoc will be null if this isn't an OOP iframe document.
if (topDoc) {
topDoc.forget(aInstancePtr);
return S_OK;
}
}
}
}
Relation rel =
mAccessible->RelationByType(RelationType::CONTAINING_TAB_PANE);
AccessibleWrap* tabDoc = static_cast<AccessibleWrap*>(rel.Next());
if (!tabDoc) return E_NOINTERFACE;
*aInstancePtr = static_cast<IAccessible*>(tabDoc);
(reinterpret_cast<IUnknown*>(*aInstancePtr))->AddRef();
return S_OK;
}
// Can get to IAccessibleApplication from any node via QS
// Note: in case of JAWS we want to check if aIID is
// IID_IAccessibleApplication.
if (aGuidService == IID_IAccessibleApplication ||
aIID == IID_IAccessibleApplication) {
ApplicationAccessibleWrap* applicationAcc =
static_cast<ApplicationAccessibleWrap*>(ApplicationAcc());
if (!applicationAcc) return E_NOINTERFACE;
return applicationAcc->QueryInterface(aIID, aInstancePtr);
}
static const GUID IID_SimpleDOMDeprecated = {
0x0c539790,
0x12e4,
0x11cf,
{0xb6, 0x61, 0x00, 0xaa, 0x00, 0x4c, 0xd6, 0xd8}};
if (aGuidService == IID_ISimpleDOMNode ||
aGuidService == IID_SimpleDOMDeprecated ||
aGuidService == IID_IAccessible || aGuidService == IID_IAccessible2)
return mAccessible->QueryInterface(aIID, aInstancePtr);
return E_INVALIDARG;
}
} // namespace a11y
} // namespace mozilla