The Tor Browser: accessible/src/windows/sdn/sdnTextAccessible.cpp@97036ab72558

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

     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

     5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

     7 #include "sdnTextAccessible.h"

     9 #include "ISimpleDOMText_i.c"

    11 #include "nsCoreUtils.h"

    12 #include "DocAccessible.h"

    14 #include "nsIFrame.h"

    15 #include "nsFontMetrics.h"

    16 #include "nsPresContext.h"

    17 #include "nsLayoutUtils.h"

    18 #include "gfxFont.h"

    19 #include "nsIAccessibleTypes.h"

    20 #include "mozilla/gfx/2D.h"

    22 using namespace mozilla::a11y;

    24 ////////////////////////////////////////////////////////////////////////////////

    25 // sdnTextAccessible

    26 ////////////////////////////////////////////////////////////////////////////////

    28 IMPL_IUNKNOWN_QUERY_HEAD(sdnTextAccessible)

    29   IMPL_IUNKNOWN_QUERY_IFACE(ISimpleDOMText)

    30 IMPL_IUNKNOWN_QUERY_TAIL_AGGREGATED(mAccessible)

    32 STDMETHODIMP

    33 sdnTextAccessible::get_domText(BSTR __RPC_FAR* aText)

    34 {

    35   A11Y_TRYBLOCK_BEGIN

    37   if (!aText)

    38     return E_INVALIDARG;

    39   *aText = nullptr;

    41   if (mAccessible->IsDefunct())

    42     return CO_E_OBJNOTCONNECTED;

    44   nsAutoString nodeValue;

    46   nsCOMPtr<nsIDOMNode> DOMNode(do_QueryInterface(mAccessible->GetContent()));

    47   DOMNode->GetNodeValue(nodeValue);

    48   if (nodeValue.IsEmpty())

    49     return S_FALSE;

    51   *aText = ::SysAllocStringLen(nodeValue.get(), nodeValue.Length());

    52   return *aText ? S_OK : E_OUTOFMEMORY;

    54   A11Y_TRYBLOCK_END

    55 }

    57 STDMETHODIMP

    58 sdnTextAccessible::get_clippedSubstringBounds(unsigned int aStartIndex,

    59                                               unsigned int aEndIndex,

    60                                               int __RPC_FAR* aX,

    61                                               int __RPC_FAR* aY,

    62                                               int __RPC_FAR* aWidth,

    63                                               int __RPC_FAR* aHeight)

    64 {

    65   A11Y_TRYBLOCK_BEGIN

    67   nscoord x = 0, y = 0, width = 0, height = 0;

    68   HRESULT rv = get_unclippedSubstringBounds(aStartIndex, aEndIndex,

    69                                             &x, &y, &width, &height);

    70   if (FAILED(rv))

    71     return rv;

    73   DocAccessible* document = mAccessible->Document();

    74   NS_ASSERTION(document,

    75                "There must always be a doc accessible, but there isn't. Crash!");

    77   nscoord docX = 0, docY = 0, docWidth = 0, docHeight = 0;

    78   document->GetBounds(&docX, &docY, &docWidth, &docHeight);

    80   nsIntRect unclippedRect(x, y, width, height);

    81   nsIntRect docRect(docX, docY, docWidth, docHeight);

    83   nsIntRect clippedRect;

    84   clippedRect.IntersectRect(unclippedRect, docRect);

    86   *aX = clippedRect.x;

    87   *aY = clippedRect.y;

    88   *aWidth = clippedRect.width;

    89   *aHeight = clippedRect.height;

    90   return S_OK;

    92   A11Y_TRYBLOCK_END

    93 }

    95 STDMETHODIMP

    96 sdnTextAccessible::get_unclippedSubstringBounds(unsigned int aStartIndex,

    97                                                 unsigned int aEndIndex,

    98                                                 int __RPC_FAR* aX,

    99                                                 int __RPC_FAR* aY,

   100                                                 int __RPC_FAR* aWidth,

   101                                                 int __RPC_FAR* aHeight)

   102 {

   103   A11Y_TRYBLOCK_BEGIN

   105   if (!aX || !aY || !aWidth || !aHeight)

   106     return E_INVALIDARG;

   107   *aX = *aY = *aWidth = *aHeight = 0;

   109   if (mAccessible->IsDefunct())

   110     return CO_E_OBJNOTCONNECTED;

   112   nsIFrame *frame = mAccessible->GetFrame();

   113   NS_ENSURE_TRUE(frame, E_FAIL);

   115   nsPoint startPoint, endPoint;

   116   nsIFrame* startFrame = GetPointFromOffset(frame, aStartIndex, true, startPoint);

   117   nsIFrame* endFrame = GetPointFromOffset(frame, aEndIndex, false, endPoint);

   118   if (!startFrame || !endFrame)

   119     return E_FAIL;

   121   nsRect sum;

   122   nsIFrame* iter = startFrame;

   123   nsIFrame* stopLoopFrame = endFrame->GetNextContinuation();

   124   for (; iter != stopLoopFrame; iter = iter->GetNextContinuation()) {

   125     nsRect rect = iter->GetScreenRectInAppUnits();

   126     nscoord start = (iter == startFrame) ? startPoint.x : 0;

   127     nscoord end = (iter == endFrame) ? endPoint.x : rect.width;

   128     rect.x += start;

   129     rect.width = end - start;

   130     sum.UnionRect(sum, rect);

   131   }

   133   nsPresContext* presContext = mAccessible->Document()->PresContext();

   134   *aX = presContext->AppUnitsToDevPixels(sum.x);

   135   *aY = presContext->AppUnitsToDevPixels(sum.y);

   136   *aWidth = presContext->AppUnitsToDevPixels(sum.width);

   137   *aHeight = presContext->AppUnitsToDevPixels(sum.height);

   139   return S_OK;

   141   A11Y_TRYBLOCK_END

   142 }

   144 STDMETHODIMP

   145 sdnTextAccessible::scrollToSubstring(unsigned int aStartIndex,

   146                                      unsigned int aEndIndex)

   147 {

   148   A11Y_TRYBLOCK_BEGIN

   150   if (mAccessible->IsDefunct())

   151     return CO_E_OBJNOTCONNECTED;

   153   nsRefPtr<nsRange> range = new nsRange(mAccessible->GetContent());

   154   if (NS_FAILED(range->SetStart(mAccessible->GetContent(), aStartIndex)))

   155     return E_FAIL;

   157   if (NS_FAILED(range->SetEnd(mAccessible->GetContent(), aEndIndex)))

   158     return E_FAIL;

   160   nsresult rv =

   161     nsCoreUtils::ScrollSubstringTo(mAccessible->GetFrame(), range,

   162                                    nsIAccessibleScrollType::SCROLL_TYPE_ANYWHERE);

   163   return GetHRESULT(rv);

   165   A11Y_TRYBLOCK_END

   166 }

   168 STDMETHODIMP

   169 sdnTextAccessible::get_fontFamily(BSTR __RPC_FAR* aFontFamily)

   170 {

   171   A11Y_TRYBLOCK_BEGIN

   173   if (!aFontFamily)

   174     return E_INVALIDARG;

   175   *aFontFamily = nullptr;

   177   if (mAccessible->IsDefunct())

   178     return CO_E_OBJNOTCONNECTED;

   180   nsIFrame* frame = mAccessible->GetFrame();

   181   if (!frame)

   182     return E_FAIL;

   184   nsRefPtr<nsFontMetrics> fm;

   185   nsLayoutUtils::GetFontMetricsForFrame(frame, getter_AddRefs(fm));

   187   const nsString& name = fm->GetThebesFontGroup()->GetFontAt(0)->GetName();

   188   if (name.IsEmpty())

   189     return S_FALSE;

   191   *aFontFamily = ::SysAllocStringLen(name.get(), name.Length());

   192   return *aFontFamily ? S_OK : E_OUTOFMEMORY;

   194   A11Y_TRYBLOCK_END

   195 }

   197 nsIFrame*

   198 sdnTextAccessible::GetPointFromOffset(nsIFrame* aContainingFrame,

   199                                       int32_t aOffset,

   200                                       bool aPreferNext,

   201                                       nsPoint& aOutPoint)

   202 {

   203   nsIFrame* textFrame = nullptr;

   204   int32_t outOffset;

   205   aContainingFrame->GetChildFrameContainingOffset(aOffset, aPreferNext,

   206                                                   &outOffset, &textFrame);

   207   if (textFrame)

   208     textFrame->GetPointFromOffset(aOffset, &aOutPoint);

   210   return textFrame;

   211 }

The Tor Browser / file revision

accessible/src/windows/sdn/sdnTextAccessible.cpp@97036ab72558

accessible/src/windows/sdn/sdnTextAccessible.cpp