accessible/windows/msaa/EnumVariant.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=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 file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "EnumVariant.h"
   8
   9 using namespace mozilla;
  10 using namespace mozilla::a11y;
  11
  12 ////////////////////////////////////////////////////////////////////////////////
  13 // ChildrenEnumVariant
  14 ////////////////////////////////////////////////////////////////////////////////
  15
  16 IMPL_IUNKNOWN_QUERY_HEAD(ChildrenEnumVariant)
  17 IMPL_IUNKNOWN_QUERY_IFACE(IEnumVARIANT)
  18 IMPL_IUNKNOWN_QUERY_TAIL_AGGREGATED(mAnchorMsaa)
  19
  20 STDMETHODIMP
  21 ChildrenEnumVariant::Next(ULONG aCount, VARIANT FAR* aItems,
  22                           ULONG FAR* aCountFetched) {
  23   if (!aItems || !aCountFetched) return E_INVALIDARG;
  24
  25   *aCountFetched = 0;
  26
  27   Accessible* anchor = mAnchorMsaa->Acc();
  28   if (!anchor || anchor->ChildAt(mCurIndex) != mCurAcc) {
  29     return CO_E_OBJNOTCONNECTED;
  30   }
  31
  32   ULONG countFetched = 0;
  33   while (mCurAcc && countFetched < aCount) {
  34     VariantInit(aItems + countFetched);
  35
  36     IDispatch* accNative = MsaaAccessible::NativeAccessible(mCurAcc);
  37
  38     ++mCurIndex;
  39     mCurAcc = anchor->ChildAt(mCurIndex);
  40
  41     // Don't output the accessible and count it as having been fetched unless
  42     // it is non-null
  43     MOZ_ASSERT(accNative);
  44     if (!accNative) {
  45       continue;
  46     }
  47
  48     aItems[countFetched].pdispVal = accNative;
  49     aItems[countFetched].vt = VT_DISPATCH;
  50     ++countFetched;
  51   }
  52
  53   (*aCountFetched) = countFetched;
  54
  55   return countFetched < aCount ? S_FALSE : S_OK;
  56 }
  57
  58 STDMETHODIMP
  59 ChildrenEnumVariant::Skip(ULONG aCount) {
  60   Accessible* anchor = mAnchorMsaa->Acc();
  61   if (!anchor || anchor->ChildAt(mCurIndex) != mCurAcc) {
  62     return CO_E_OBJNOTCONNECTED;
  63   }
  64
  65   mCurIndex += aCount;
  66   mCurAcc = anchor->ChildAt(mCurIndex);
  67
  68   return mCurAcc ? S_OK : S_FALSE;
  69 }
  70
  71 STDMETHODIMP
  72 ChildrenEnumVariant::Reset() {
  73   Accessible* anchor = mAnchorMsaa->Acc();
  74   if (!anchor) return CO_E_OBJNOTCONNECTED;
  75
  76   mCurIndex = 0;
  77   mCurAcc = anchor->ChildAt(0);
  78
  79   return S_OK;
  80 }
  81
  82 STDMETHODIMP
  83 ChildrenEnumVariant::Clone(IEnumVARIANT** aEnumVariant) {
  84   if (!aEnumVariant) return E_INVALIDARG;
  85
  86   *aEnumVariant = new ChildrenEnumVariant(*this);
  87   (*aEnumVariant)->AddRef();
  88
  89   return S_OK;
  90 }