accessible/ipc/win/handler/AccessibleHandler.h
author Sylvestre Ledru <sledru@mozilla.com>
Thu, 17 Aug 2017 11:13:01 +0200
changeset 648192 c236dfe7dc98c387219d7cb45d0693560db708fd
parent 556398 f99777cc035922c20b7019354ef61f8b109974f1
permissions -rw-r--r--
indent all (with js specific coding style) MozReview-Commit-ID: LU1md2wyB8

/* -*- 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/. */

#ifndef mozilla_a11y_AccessibleHandler_h
#define mozilla_a11y_AccessibleHandler_h

#define NEWEST_IA2_BASENAME Accessible2_3

#define __QUOTE(idl) #idl
#define __GENIDL(base) __QUOTE(base##.idl)
#define IDLFOR(base) __GENIDL(base)
#define NEWEST_IA2_IDL IDLFOR(NEWEST_IA2_BASENAME)

#define __GENIFACE(base) I##base
#define INTERFACEFOR(base) __GENIFACE(base)
#define NEWEST_IA2_INTERFACE INTERFACEFOR(NEWEST_IA2_BASENAME)

#define __GENIID(iface) IID_##iface
#define IIDFOR(iface) __GENIID(iface)
#define NEWEST_IA2_IID IIDFOR(NEWEST_IA2_INTERFACE)

#if defined(__midl)

import NEWEST_IA2_IDL;

#else

#include "HandlerData.h"

#include <windows.h>

#if !defined(MOZILLA_INTERNAL_API)

#include "Accessible2_3.h"
#include "Handler.h"
#include "mozilla/mscom/StructStream.h"
#include "mozilla/UniquePtr.h"

#include <ocidl.h>
#include <servprov.h>

namespace mozilla {
namespace a11y {

class AccessibleHandler final
  : public mscom::Handler
  , public NEWEST_IA2_INTERFACE
  , public IServiceProvider
  , public IProvideClassInfo
{
public:
  static HRESULT Create(IUnknown* aOuter, REFIID aIid, void** aOutInterface);

  // mscom::Handler
  HRESULT QueryHandlerInterface(IUnknown* aProxyUnknown,
                                REFIID aIid,
                                void** aOutInterface) override;
  HRESULT ReadHandlerPayload(IStream* aStream, REFIID aIid) override;

  REFIID MarshalAs(REFIID aRequestedIid) override;
  HRESULT GetHandlerPayloadSize(REFIID aIid, DWORD* aOutPayloadSize) override;
  HRESULT WriteHandlerPayload(IStream* aStream, REFIID aIId) override;

  // IUnknown
  STDMETHODIMP QueryInterface(REFIID riid, void** ppv) override;
  STDMETHODIMP_(ULONG) AddRef() override;
  STDMETHODIMP_(ULONG) Release() override;

  // IDispatch
  STDMETHODIMP GetTypeInfoCount(UINT* pctinfo) override;
  STDMETHODIMP GetTypeInfo(UINT iTInfo,
                           LCID lcid,
                           ITypeInfo** ppTInfo) override;
  STDMETHODIMP GetIDsOfNames(REFIID riid,
                             LPOLESTR* rgszNames,
                             UINT cNames,
                             LCID lcid,
                             DISPID* rgDispId) override;
  STDMETHODIMP Invoke(DISPID dispIdMember,
                      REFIID riid,
                      LCID lcid,
                      WORD wFlags,
                      DISPPARAMS* pDispParams,
                      VARIANT* pVarResult,
                      EXCEPINFO* pExcepInfo,
                      UINT* puArgErr) override;

  // IAccessible
  STDMETHODIMP get_accParent(IDispatch** ppdispParent) override;
  STDMETHODIMP get_accChildCount(long* pcountChildren) override;
  STDMETHODIMP get_accChild(VARIANT varChild, IDispatch** ppdispChild) override;
  STDMETHODIMP get_accName(VARIANT varChild, BSTR* pszName) override;
  STDMETHODIMP get_accValue(VARIANT varChild, BSTR* pszValue) override;
  STDMETHODIMP get_accDescription(VARIANT varChild,
                                  BSTR* pszDescription) override;
  STDMETHODIMP get_accRole(VARIANT varChild, VARIANT* pvarRole) override;
  STDMETHODIMP get_accState(VARIANT varChild, VARIANT* pvarState) override;
  STDMETHODIMP get_accHelp(VARIANT varChild, BSTR* pszHelp) override;
  STDMETHODIMP get_accHelpTopic(BSTR* pszHelpFile,
                                VARIANT varChild,
                                long* pidTopic) override;
  STDMETHODIMP get_accKeyboardShortcut(VARIANT varChild,
                                       BSTR* pszKeyboardShortcut) override;
  STDMETHODIMP get_accFocus(VARIANT* pvarChild) override;
  STDMETHODIMP get_accSelection(VARIANT* pvarChildren) override;
  STDMETHODIMP get_accDefaultAction(VARIANT varChild,
                                    BSTR* pszDefaultAction) override;
  STDMETHODIMP accSelect(long flagsSelect, VARIANT varChild) override;
  STDMETHODIMP accLocation(long* pxLeft,
                           long* pyTop,
                           long* pcxWidth,
                           long* pcyHeight,
                           VARIANT varChild) override;
  STDMETHODIMP accNavigate(long navDir,
                           VARIANT varStart,
                           VARIANT* pvarEndUpAt) override;
  STDMETHODIMP accHitTest(long xLeft, long yTop, VARIANT* pvarChild) override;
  STDMETHODIMP accDoDefaultAction(VARIANT varChild) override;
  STDMETHODIMP put_accName(VARIANT varChild, BSTR szName) override;
  STDMETHODIMP put_accValue(VARIANT varChild, BSTR szValue) override;

  // IAccessible2
  STDMETHODIMP get_nRelations(long* nRelations) override;
  STDMETHODIMP get_relation(long relationIndex,
                            IAccessibleRelation** relation) override;
  STDMETHODIMP get_relations(long maxRelations,
                             IAccessibleRelation** relations,
                             long* nRelations) override;
  STDMETHODIMP role(long* role) override;
  STDMETHODIMP scrollTo(IA2ScrollType scrollType) override;
  STDMETHODIMP scrollToPoint(IA2CoordinateType coordinateType,
                             long x,
                             long y) override;
  STDMETHODIMP get_groupPosition(long* groupLevel,
                                 long* similarItemsInGroup,
                                 long* positionInGroup) override;
  STDMETHODIMP get_states(AccessibleStates* states) override;
  STDMETHODIMP get_extendedRole(BSTR* extendedRole) override;
  STDMETHODIMP get_localizedExtendedRole(BSTR* localizedExtendedRole) override;
  STDMETHODIMP get_nExtendedStates(long* nExtendedStates) override;
  STDMETHODIMP get_extendedStates(long maxExtendedStates,
                                  BSTR** extendedStates,
                                  long* nExtendedStates) override;
  STDMETHODIMP get_localizedExtendedStates(
    long maxLocalizedExtendedStates,
    BSTR** localizedExtendedStates,
    long* nLocalizedExtendedStates) override;
  STDMETHODIMP get_uniqueID(long* uniqueID) override;
  STDMETHODIMP get_windowHandle(HWND* windowHandle) override;
  STDMETHODIMP get_indexInParent(long* indexInParent) override;
  STDMETHODIMP get_locale(IA2Locale* locale) override;
  STDMETHODIMP get_attributes(BSTR* attributes) override;

  // IAccessible2_2
  STDMETHODIMP get_attribute(BSTR name, VARIANT* attribute) override;
  STDMETHODIMP get_accessibleWithCaret(IUnknown** accessible,
                                       long* caretOffset) override;
  STDMETHODIMP get_relationTargetsOfType(BSTR type,
                                         long maxTargets,
                                         IUnknown*** targets,
                                         long* nTargets) override;

  // IAccessible2_3
  STDMETHODIMP get_selectionRanges(IA2Range** ranges, long* nRanges) override;

  // IServiceProvider
  STDMETHODIMP QueryService(REFGUID aServiceId,
                            REFIID aIid,
                            void** aOutInterface) override;

  // IProvideClassInfo
  STDMETHODIMP GetClassInfo(ITypeInfo** aOutTypeInfo) override;

private:
  AccessibleHandler(IUnknown* aOuter, HRESULT* aResult);
  virtual ~AccessibleHandler();

  HRESULT ResolveIA2();
  HRESULT ResolveIDispatch();
  HRESULT MaybeUpdateCachedData();

  RefPtr<IUnknown> mDispatchUnk;
  /**
   * Handlers aggregate their proxies. This means that their proxies delegate
   * their IUnknown implementation to us.
   *
   * mDispatchUnk and the result of Handler::GetProxy() are both strong
   * references to the aggregated objects. OTOH, any interfaces that are QI'd
   * from those aggregated objects have delegated unknowns.
   *
   * AddRef'ing an interface with a delegated unknown ends up incrementing the
   * refcount of the *aggregator*. Since we are the aggregator of mDispatchUnk
   * and of the wrapped proxy, holding a strong reference to any interfaces
   * QI'd off of those objects would create a reference cycle.
   *
   * We may hold onto pointers to those references, but when we query them we
   * must immediately Release() them to prevent these cycles.
   *
   * It is safe for us to use these raw pointers because the aggregated
   * objects's lifetimes are proper subsets of our own lifetime.
   */
  IDispatch* mDispatch;                // weak
  NEWEST_IA2_INTERFACE* mIA2PassThru;  // weak
  IServiceProvider* mServProvPassThru; // weak
  IA2Payload mCachedData;
  UniquePtr<mscom::StructToStream> mSerializer;
  uint32_t mCacheGen;
};

} // namespace a11y
} // namespace mozilla

#endif // !defined(MOZILLA_INTERNAL_API)

#endif // defined(__midl)

#endif // mozilla_a11y_AccessibleHandler_h