path: root/accessible/ipc/win/handler/AccessibleHandler.h

/* -*- 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 __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) || defined(__WIDL__)

import "Accessible2_3.idl";

#else

#  include "HandlerData.h"

#  include <windows.h>

namespace mozilla {
namespace a11y {

static const GUID kUnsupportedServices[] = {
    // clang-format off
  // Unknown, queried by Windows on devices with touch screens or similar devices
  // connected.
  {0x33f139ee, 0xe509, 0x47f7, {0xbf, 0x39, 0x83, 0x76, 0x44, 0xf7, 0x45, 0x76}},
  // Unknown, queried by Windows
  {0xFDA075CF, 0x7C8B, 0x498C, { 0xB5, 0x14, 0xA9, 0xCB, 0x52, 0x1B, 0xBF, 0xB4 }},
  // Unknown, queried by Windows
  {0x8EDAA462, 0x21F4, 0x4C87, { 0xA0, 0x12, 0xB3, 0xCD, 0xA3, 0xAB, 0x01, 0xFC }},
  // Unknown, queried by Windows
  {0xacd46652, 0x829d, 0x41cb, { 0xa5, 0xfc, 0x17, 0xac, 0xf4, 0x36, 0x61, 0xac }},
  // SID_IsUIAutomationObject (undocumented), queried by Windows
  {0xb96fdb85, 0x7204, 0x4724, { 0x84, 0x2b, 0xc7, 0x05, 0x9d, 0xed, 0xb9, 0xd0 }},
  // IIS_IsOleaccProxy (undocumented), queried by Windows
  {0x902697FA, 0x80E4, 0x4560, {0x80, 0x2A, 0xA1, 0x3F, 0x22, 0xA6, 0x47, 0x09}},
  // IID_IHTMLElement, queried by JAWS
  {0x3050F1FF, 0x98B5, 0x11CF, {0xBB, 0x82, 0x00, 0xAA, 0x00, 0xBD, 0xCE, 0x0B}}
    // clang-format on
};

}
}  // namespace mozilla

#  if !defined(MOZILLA_INTERNAL_API)

#    include "Accessible2_3.h"
#    include "AccessibleHyperlink.h"
#    include "AccessibleHypertext2.h"
#    include "AccessibleTableCell.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 IAccessibleHyperlink,
                                public IAccessibleTableCell,
                                public IAccessibleHypertext2 {
 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 GetMarshalInterface(REFIID aMarshalAsIid, NotNull<IUnknown*> aProxy,
                              NotNull<IID*> aOutIid,
                              NotNull<IUnknown**> aOutUnk) 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;

  // IAccessibleAction
  STDMETHODIMP nActions(long* nActions) override;
  STDMETHODIMP doAction(long actionIndex) override;
  STDMETHODIMP get_description(long actionIndex, BSTR* description) override;
  STDMETHODIMP get_keyBinding(long actionIndex, long nMaxBindings,
                              BSTR** keyBindings, long* nBindings) override;
  STDMETHODIMP get_name(long actionIndex, BSTR* name) override;
  STDMETHODIMP get_localizedName(long actionIndex,
                                 BSTR* localizedName) override;

  // IAccessibleHyperlink
  STDMETHODIMP get_anchor(long index, VARIANT* anchor) override;
  STDMETHODIMP get_anchorTarget(long index, VARIANT* anchorTarget) override;
  STDMETHODIMP get_startIndex(long* index) override;
  STDMETHODIMP get_endIndex(long* index) override;
  STDMETHODIMP get_valid(boolean* valid) override;

  // IAccessibleTableCell
  STDMETHODIMP get_columnExtent(long* nColumnsSpanned) override;
  STDMETHODIMP get_columnHeaderCells(IUnknown*** cellAccessibles,
                                     long* nColumnHeaderCells) override;
  STDMETHODIMP get_columnIndex(long* columnIndex) override;
  STDMETHODIMP get_rowExtent(long* nRowsSpanned) override;
  STDMETHODIMP get_rowHeaderCells(IUnknown*** cellAccessibles,
                                  long* nRowHeaderCells) override;
  STDMETHODIMP get_rowIndex(long* rowIndex) override;
  STDMETHODIMP get_isSelected(boolean* isSelected) override;
  STDMETHODIMP get_rowColumnExtents(long* row, long* column, long* rowExtents,
                                    long* columnExtents,
                                    boolean* isSelected) override;
  STDMETHODIMP get_table(IUnknown** table) override;

  // IAccessibleText
  STDMETHODIMP addSelection(long startOffset, long endOffset) override;
  STDMETHODIMP get_attributes(long offset, long* startOffset, long* endOffset,
                              BSTR* textAttributes) override;
  STDMETHODIMP get_caretOffset(long* offset) override;
  STDMETHODIMP get_characterExtents(long offset,
                                    enum IA2CoordinateType coordType, long* x,
                                    long* y, long* width,
                                    long* height) override;
  STDMETHODIMP get_nSelections(long* nSelections) override;
  STDMETHODIMP get_offsetAtPoint(long x, long y,
                                 enum IA2CoordinateType coordType,
                                 long* offset) override;
  STDMETHODIMP get_selection(long selectionIndex, long* startOffset,
                             long* endOffset) override;
  STDMETHODIMP get_text(long startOffset, long endOffset, BSTR* text) override;
  STDMETHODIMP get_textBeforeOffset(long offset,
                                    enum IA2TextBoundaryType boundaryType,
                                    long* startOffset, long* endOffset,
                                    BSTR* text) override;
  STDMETHODIMP get_textAfterOffset(long offset,
                                   enum IA2TextBoundaryType boundaryType,
                                   long* startOffset, long* endOffset,
                                   BSTR* text) override;
  STDMETHODIMP get_textAtOffset(long offset,
                                enum IA2TextBoundaryType boundaryType,
                                long* startOffset, long* endOffset,
                                BSTR* text) override;
  STDMETHODIMP removeSelection(long selectionIndex) override;
  STDMETHODIMP setCaretOffset(long offset) override;
  STDMETHODIMP setSelection(long selectionIndex, long startOffset,
                            long endOffset) override;
  STDMETHODIMP get_nCharacters(long* nCharacters) override;
  STDMETHODIMP scrollSubstringTo(long startIndex, long endIndex,
                                 enum IA2ScrollType scrollType) override;
  STDMETHODIMP scrollSubstringToPoint(long startIndex, long endIndex,
                                      enum IA2CoordinateType coordinateType,
                                      long x, long y) override;
  STDMETHODIMP get_newText(IA2TextSegment* newText) override;
  STDMETHODIMP get_oldText(IA2TextSegment* oldText) override;

  // IAccessibleHypertext
  STDMETHODIMP get_nHyperlinks(long* hyperlinkCount) override;
  STDMETHODIMP get_hyperlink(long index,
                             IAccessibleHyperlink** hyperlink) override;
  STDMETHODIMP get_hyperlinkIndex(long charIndex,
                                  long* hyperlinkIndex) override;

  // IAccessibleHypertext2
  STDMETHODIMP get_hyperlinks(IAccessibleHyperlink*** hyperlinks,
                              long* nHyperlinks) override;

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

  HRESULT ResolveIA2();
  HRESULT ResolveIDispatch();
  HRESULT ResolveIAHyperlink();
  HRESULT ResolveIAHypertext();
  HRESULT ResolveIATableCell();
  HRESULT MaybeUpdateCachedData();
  HRESULT GetAllTextInfo(BSTR* aText);
  void ClearTextCache();
  HRESULT GetRelationsInfo();
  void ClearRelationCache();

  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
  IAccessibleHyperlink* mIAHyperlinkPassThru;   // weak
  IAccessibleTableCell* mIATableCellPassThru;   // weak
  IAccessibleHypertext2* mIAHypertextPassThru;  // weak
  IA2Payload mCachedData;
  bool mCachedDynamicDataMarshaledByCom;
  UniquePtr<mscom::StructToStream> mSerializer;
  uint32_t mCacheGen;
  IAccessibleHyperlink** mCachedHyperlinks;
  long mCachedNHyperlinks;
  IA2TextSegment* mCachedTextAttribRuns;
  long mCachedNTextAttribRuns;
  IARelationData* mCachedRelations;
  long mCachedNRelations;
  bool mIsEmulatedWindow;
};

inline static BSTR CopyBSTR(BSTR aSrc) {
  if (!aSrc) {
    return nullptr;
  }

  return ::SysAllocStringLen(aSrc, ::SysStringLen(aSrc));
}

}  // namespace a11y
}  // namespace mozilla

#  endif  // !defined(MOZILLA_INTERNAL_API)

#endif  // defined(__midl)

#endif  // mozilla_a11y_AccessibleHandler_h