accessible/windows/sdn/sdnTextAccessible.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
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "sdnTextAccessible.h"
   8
   9 #include "ISimpleDOM.h"
  10
  11 #include "nsCoreUtils.h"
  12 #include "DocAccessible.h"
  13
  14 #include "nsIFrame.h"
  15 #include "nsFontMetrics.h"
  16 #include "nsPresContext.h"
  17 #include "nsLayoutUtils.h"
  18 #include "nsRange.h"
  19 #include "gfxTextRun.h"
  20 #include "nsIAccessibleTypes.h"
  21 #include "mozilla/gfx/2D.h"
  22
  23 using namespace mozilla::a11y;
  24
  25 ////////////////////////////////////////////////////////////////////////////////
  26 // sdnTextAccessible
  27 ////////////////////////////////////////////////////////////////////////////////
  28
  29 IMPL_IUNKNOWN_QUERY_HEAD(sdnTextAccessible)
  30 IMPL_IUNKNOWN_QUERY_IFACE(ISimpleDOMText)
  31 IMPL_IUNKNOWN_QUERY_TAIL_AGGREGATED(mMsaa)
  32
  33 STDMETHODIMP
  34 sdnTextAccessible::get_domText(BSTR __RPC_FAR* aText) {
  35   if (!aText) return E_INVALIDARG;
  36   *aText = nullptr;
  37
  38   AccessibleWrap* acc = mMsaa->LocalAcc();
  39   if (!acc) return CO_E_OBJNOTCONNECTED;
  40
  41   nsAutoString nodeValue;
  42
  43   acc->GetContent()->GetNodeValue(nodeValue);
  44   if (nodeValue.IsEmpty()) return S_FALSE;
  45
  46   *aText = ::SysAllocStringLen(nodeValue.get(), nodeValue.Length());
  47   return *aText ? S_OK : E_OUTOFMEMORY;
  48 }
  49
  50 STDMETHODIMP
  51 sdnTextAccessible::get_clippedSubstringBounds(
  52     unsigned int aStartIndex, unsigned int aEndIndex, int __RPC_FAR* aX,
  53     int __RPC_FAR* aY, int __RPC_FAR* aWidth, int __RPC_FAR* aHeight) {
  54   nscoord x = 0, y = 0, width = 0, height = 0;
  55   HRESULT rv = get_unclippedSubstringBounds(aStartIndex, aEndIndex, &x, &y,
  56                                             &width, &height);
  57   if (FAILED(rv)) return rv;
  58
  59   DocAccessible* document = mMsaa->LocalAcc()->Document();
  60   NS_ASSERTION(
  61       document,
  62       "There must always be a doc accessible, but there isn't. Crash!");
  63
  64   LayoutDeviceIntRect docRect = document->Bounds();
  65   LayoutDeviceIntRect unclippedRect(x, y, width, height);
  66
  67   LayoutDeviceIntRect clippedRect;
  68   clippedRect.IntersectRect(unclippedRect, docRect);
  69
  70   *aX = clippedRect.X();
  71   *aY = clippedRect.Y();
  72   *aWidth = clippedRect.Width();
  73   *aHeight = clippedRect.Height();
  74   return S_OK;
  75 }
  76
  77 STDMETHODIMP
  78 sdnTextAccessible::get_unclippedSubstringBounds(
  79     unsigned int aStartIndex, unsigned int aEndIndex, int __RPC_FAR* aX,
  80     int __RPC_FAR* aY, int __RPC_FAR* aWidth, int __RPC_FAR* aHeight) {
  81   if (!aX || !aY || !aWidth || !aHeight) return E_INVALIDARG;
  82   *aX = *aY = *aWidth = *aHeight = 0;
  83
  84   AccessibleWrap* acc = mMsaa->LocalAcc();
  85   if (!acc) return CO_E_OBJNOTCONNECTED;
  86
  87   nsIFrame* frame = acc->GetFrame();
  88   NS_ENSURE_TRUE(frame, E_FAIL);
  89
  90   nsPoint startPoint, endPoint;
  91   nsIFrame* startFrame =
  92       GetPointFromOffset(frame, aStartIndex, true, startPoint);
  93   nsIFrame* endFrame = GetPointFromOffset(frame, aEndIndex, false, endPoint);
  94   if (!startFrame || !endFrame) return E_FAIL;
  95
  96   nsRect sum;
  97   nsIFrame* iter = startFrame;
  98   nsIFrame* stopLoopFrame = endFrame->GetNextContinuation();
  99   for (; iter != stopLoopFrame; iter = iter->GetNextContinuation()) {
 100     nsRect rect = iter->GetScreenRectInAppUnits();
 101     nscoord start = (iter == startFrame) ? startPoint.x : 0;
 102     nscoord end = (iter == endFrame) ? endPoint.x : rect.Width();
 103     rect.MoveByX(start);
 104     rect.SetWidth(end - start);
 105     sum.UnionRect(sum, rect);
 106   }
 107
 108   nsPresContext* presContext = acc->Document()->PresContext();
 109   *aX = presContext->AppUnitsToDevPixels(sum.X());
 110   *aY = presContext->AppUnitsToDevPixels(sum.Y());
 111   *aWidth = presContext->AppUnitsToDevPixels(sum.Width());
 112   *aHeight = presContext->AppUnitsToDevPixels(sum.Height());
 113
 114   return S_OK;
 115 }
 116
 117 STDMETHODIMP
 118 sdnTextAccessible::scrollToSubstring(unsigned int aStartIndex,
 119                                      unsigned int aEndIndex) {
 120   AccessibleWrap* acc = mMsaa->LocalAcc();
 121   if (!acc) return CO_E_OBJNOTCONNECTED;
 122
 123   RefPtr<nsRange> range = nsRange::Create(acc->GetContent());
 124   if (NS_FAILED(range->SetStart(acc->GetContent(), aStartIndex))) return E_FAIL;
 125
 126   if (NS_FAILED(range->SetEnd(acc->GetContent(), aEndIndex))) return E_FAIL;
 127
 128   nsresult rv = nsCoreUtils::ScrollSubstringTo(
 129       acc->GetFrame(), range, nsIAccessibleScrollType::SCROLL_TYPE_ANYWHERE);
 130   return GetHRESULT(rv);
 131 }
 132
 133 STDMETHODIMP
 134 sdnTextAccessible::get_fontFamily(BSTR __RPC_FAR* aFontFamily) {
 135   if (!aFontFamily) return E_INVALIDARG;
 136   *aFontFamily = nullptr;
 137
 138   AccessibleWrap* acc = mMsaa->LocalAcc();
 139   if (!acc) return CO_E_OBJNOTCONNECTED;
 140
 141   nsIFrame* frame = acc->GetFrame();
 142   if (!frame) return E_FAIL;
 143
 144   RefPtr<nsFontMetrics> fm = nsLayoutUtils::GetFontMetricsForFrame(frame, 1.0f);
 145   RefPtr<gfxFont> font = fm->GetThebesFontGroup()->GetFirstValidFont();
 146
 147   const nsCString& name = font->GetName();
 148   if (name.IsEmpty()) return S_FALSE;
 149
 150   NS_ConvertUTF8toUTF16 str(name);
 151   *aFontFamily = ::SysAllocStringLen(str.get(), str.Length());
 152   return *aFontFamily ? S_OK : E_OUTOFMEMORY;
 153 }
 154
 155 nsIFrame* sdnTextAccessible::GetPointFromOffset(nsIFrame* aContainingFrame,
 156                                                 int32_t aOffset,
 157                                                 bool aPreferNext,
 158                                                 nsPoint& aOutPoint) {
 159   nsIFrame* textFrame = nullptr;
 160   int32_t outOffset;
 161   aContainingFrame->GetChildFrameContainingOffset(aOffset, aPreferNext,
 162                                                   &outOffset, &textFrame);
 163   if (textFrame) textFrame->GetPointFromOffset(aOffset, &aOutPoint);
 164
 165   return textFrame;
 166 }