sdnTextAccessible.cpp

Enable keyboard shortcuts

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=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/. */

#include "sdnTextAccessible.h"

#include "ISimpleDOM.h"

#include "nsCoreUtils.h"

#include "DocAccessible.h"

#include "nsIFrame.h"

#include "nsFontMetrics.h"

#include "nsPresContext.h"

#include "nsLayoutUtils.h"

#include "nsRange.h"

#include "gfxTextRun.h"

#include "nsIAccessibleTypes.h"

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

using namespace mozilla::a11y;

////////////////////////////////////////////////////////////////////////////////

// sdnTextAccessible

////////////////////////////////////////////////////////////////////////////////

IMPL_IUNKNOWN_QUERY_HEAD(sdnTextAccessible)

IMPL_IUNKNOWN_QUERY_IFACE(ISimpleDOMText)

IMPL_IUNKNOWN_QUERY_TAIL_AGGREGATED(mMsaa)

STDMETHODIMP

sdnTextAccessible::get_domText(BSTR __RPC_FAR* aText) {

  if (!aText) return E_INVALIDARG;

  *aText = nullptr;

  AccessibleWrap* acc = mMsaa->LocalAcc();

  if (!acc) return CO_E_OBJNOTCONNECTED;

  nsAutoString nodeValue;

  acc->GetContent()->GetNodeValue(nodeValue);

  if (nodeValue.IsEmpty()) return S_FALSE;

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

  return *aText ? S_OK : E_OUTOFMEMORY;

STDMETHODIMP

sdnTextAccessible::get_clippedSubstringBounds(

    unsigned int aStartIndex, unsigned int aEndIndex, int __RPC_FAR* aX,

    int __RPC_FAR* aY, int __RPC_FAR* aWidth, int __RPC_FAR* aHeight) {

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

  HRESULT rv = get_unclippedSubstringBounds(aStartIndex, aEndIndex, &x, &y,

                                            &width, &height);

  if (FAILED(rv)) return rv;

  DocAccessible* document = mMsaa->LocalAcc()->Document();

  NS_ASSERTION(

      document,

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

  LayoutDeviceIntRect docRect = document->Bounds();

  LayoutDeviceIntRect unclippedRect(x, y, width, height);

  LayoutDeviceIntRect clippedRect;

  clippedRect.IntersectRect(unclippedRect, docRect);

  *aX = clippedRect.X();

  *aY = clippedRect.Y();

  *aWidth = clippedRect.Width();

  *aHeight = clippedRect.Height();

  return S_OK;

STDMETHODIMP

sdnTextAccessible::get_unclippedSubstringBounds(

    unsigned int aStartIndex, unsigned int aEndIndex, int __RPC_FAR* aX,

    int __RPC_FAR* aY, int __RPC_FAR* aWidth, int __RPC_FAR* aHeight) {

  if (!aX || !aY || !aWidth || !aHeight) return E_INVALIDARG;

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

  AccessibleWrap* acc = mMsaa->LocalAcc();

  if (!acc) return CO_E_OBJNOTCONNECTED;

  nsIFrame* frame = acc->GetFrame();

  NS_ENSURE_TRUE(frame, E_FAIL);

  nsPoint startPoint, endPoint;

  nsIFrame* startFrame =

      GetPointFromOffset(frame, aStartIndex, true, startPoint);

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

  if (!startFrame || !endFrame) return E_FAIL;

  nsRect sum;

  nsIFrame* iter = startFrame;

  nsIFrame* stopLoopFrame = endFrame->GetNextContinuation();

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

    nsRect rect = iter->GetScreenRectInAppUnits();

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

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

    rect.MoveByX(start);

    rect.SetWidth(end - start);

    sum.UnionRect(sum, rect);

  nsPresContext* presContext = acc->Document()->PresContext();

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

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

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

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

  return S_OK;

STDMETHODIMP

sdnTextAccessible::scrollToSubstring(unsigned int aStartIndex,

                                     unsigned int aEndIndex) {

  AccessibleWrap* acc = mMsaa->LocalAcc();

  if (!acc) return CO_E_OBJNOTCONNECTED;

  RefPtr<nsRange> range = nsRange::Create(acc->GetContent());

  if (NS_FAILED(range->SetStart(acc->GetContent(), aStartIndex))) return E_FAIL;

  if (NS_FAILED(range->SetEnd(acc->GetContent(), aEndIndex))) return E_FAIL;

  nsresult rv = nsCoreUtils::ScrollSubstringTo(

      acc->GetFrame(), range, nsIAccessibleScrollType::SCROLL_TYPE_ANYWHERE);

  return GetHRESULT(rv);

STDMETHODIMP

sdnTextAccessible::get_fontFamily(BSTR __RPC_FAR* aFontFamily) {

  if (!aFontFamily) return E_INVALIDARG;

  *aFontFamily = nullptr;

  AccessibleWrap* acc = mMsaa->LocalAcc();

  if (!acc) return CO_E_OBJNOTCONNECTED;

  nsIFrame* frame = acc->GetFrame();

  if (!frame) return E_FAIL;

  RefPtr<nsFontMetrics> fm = nsLayoutUtils::GetFontMetricsForFrame(frame, 1.0f);

  RefPtr<gfxFont> font = fm->GetThebesFontGroup()->GetFirstValidFont();

  const nsCString& name = font->GetName();

  if (name.IsEmpty()) return S_FALSE;

  NS_ConvertUTF8toUTF16 str(name);

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

  return *aFontFamily ? S_OK : E_OUTOFMEMORY;

nsIFrame* sdnTextAccessible::GetPointFromOffset(nsIFrame* aContainingFrame,

                                                int32_t aOffset,

                                                bool aPreferNext,

                                                nsPoint& aOutPoint) {

  nsIFrame* textFrame = nullptr;

  int32_t outOffset;

  aContainingFrame->GetChildFrameContainingOffset(aOffset, aPreferNext,

                                                  &outOffset, &textFrame);

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

  return textFrame;