tor-browser

The Tor Browser
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SelectionManager.cpp (8598B)

      1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
      2 /* This Source Code Form is subject to the terms of the Mozilla Public
      3 * License, v. 2.0. If a copy of the MPL was not distributed with this
      4 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
      5 
      6 #include "mozilla/a11y/SelectionManager.h"
      7 
      8 #include "DocAccessible-inl.h"
      9 #include "HyperTextAccessible.h"
     10 #include "HyperTextAccessible-inl.h"
     11 #include "nsAccessibilityService.h"
     12 #include "nsAccUtils.h"
     13 #include "nsCoreUtils.h"
     14 #include "nsEventShell.h"
     15 #include "nsFrameSelection.h"
     16 #include "TextLeafRange.h"
     17 
     18 #include "mozilla/PresShell.h"
     19 #include "mozilla/dom/Selection.h"
     20 #include "mozilla/dom/Element.h"
     21 
     22 using namespace mozilla;
     23 using namespace mozilla::a11y;
     24 using mozilla::dom::Selection;
     25 
     26 struct mozilla::a11y::SelData final {
     27  SelData(Selection* aSel, int32_t aReason, int32_t aGranularity)
     28      : mSel(aSel), mReason(aReason), mGranularity(aGranularity) {}
     29 
     30  RefPtr<Selection> mSel;
     31  int16_t mReason;
     32  int32_t mGranularity;
     33 
     34  NS_INLINE_DECL_REFCOUNTING(SelData)
     35 
     36 private:
     37  // Private destructor, to discourage deletion outside of Release():
     38  ~SelData() {}
     39 };
     40 
     41 SelectionManager::SelectionManager()
     42    : mCaretOffset(-1), mAccWithCaret(nullptr) {}
     43 
     44 void SelectionManager::ClearControlSelectionListener() {
     45  // Remove 'this' registered as selection listener for the normal selection.
     46  if (mCurrCtrlNormalSel) {
     47    mCurrCtrlNormalSel->RemoveSelectionListener(this);
     48    mCurrCtrlNormalSel = nullptr;
     49  }
     50 }
     51 
     52 void SelectionManager::SetControlSelectionListener(dom::Element* aFocusedElm) {
     53  // When focus moves such that the caret is part of a new frame selection
     54  // this removes the old selection listener and attaches a new one for
     55  // the current focus.
     56  ClearControlSelectionListener();
     57 
     58  nsIFrame* controlFrame = aFocusedElm->GetPrimaryFrame();
     59  if (!controlFrame) return;
     60 
     61  const nsFrameSelection* frameSel = controlFrame->GetConstFrameSelection();
     62  NS_ASSERTION(frameSel, "No frame selection for focused element!");
     63  if (!frameSel) return;
     64 
     65  // Register 'this' as selection listener for the normal selection.
     66  Selection& normalSel = frameSel->NormalSelection();
     67  normalSel.AddSelectionListener(this);
     68  mCurrCtrlNormalSel = &normalSel;
     69 }
     70 
     71 void SelectionManager::AddDocSelectionListener(PresShell* aPresShell) {
     72  const nsFrameSelection* frameSel = aPresShell->ConstFrameSelection();
     73 
     74  // Register 'this' as selection listener for the normal selection.
     75  Selection& normalSel = frameSel->NormalSelection();
     76  normalSel.AddSelectionListener(this);
     77 }
     78 
     79 void SelectionManager::RemoveDocSelectionListener(PresShell* aPresShell) {
     80  const nsFrameSelection* frameSel = aPresShell->ConstFrameSelection();
     81 
     82  // Remove 'this' registered as selection listener for the normal selection.
     83  Selection& normalSel = frameSel->NormalSelection();
     84  normalSel.RemoveSelectionListener(this);
     85 
     86  if (mCurrCtrlNormalSel) {
     87    if (mCurrCtrlNormalSel->GetPresShell() == aPresShell) {
     88      // Remove 'this' registered as selection listener for the normal selection
     89      // if we are removing listeners for its PresShell.
     90      mCurrCtrlNormalSel->RemoveSelectionListener(this);
     91      mCurrCtrlNormalSel = nullptr;
     92    }
     93  }
     94 }
     95 
     96 void SelectionManager::ProcessTextSelChangeEvent(AccEvent* aEvent) {
     97  // Fire selection change event if it's not pure caret-move selection change,
     98  // i.e. the accessible has or had not collapsed selection. Also, it must not
     99  // be a collapsed selection on the container of a focused text field, since
    100  // the text field has an independent selection and will thus fire its own
    101  // selection events.
    102  AccTextSelChangeEvent* event = downcast_accEvent(aEvent);
    103  if (!event->IsCaretMoveOnly() &&
    104      !(event->mSel->IsCollapsed() && event->mSel != mCurrCtrlNormalSel &&
    105        FocusMgr() && FocusMgr()->FocusedLocalAccessible() &&
    106        FocusMgr()->FocusedLocalAccessible()->IsTextField())) {
    107    nsEventShell::FireEvent(aEvent);
    108  }
    109 
    110  // Fire caret move event if there's a caret in the selection.
    111  nsINode* caretCntrNode = nsCoreUtils::GetDOMNodeFromDOMPoint(
    112      event->mSel->GetFocusNode(), event->mSel->FocusOffset());
    113  if (!caretCntrNode) return;
    114 
    115  HyperTextAccessible* caretCntr = nsAccUtils::GetTextContainer(caretCntrNode);
    116  NS_ASSERTION(
    117      caretCntr,
    118      "No text container for focus while there's one for common ancestor?!");
    119  if (!caretCntr) return;
    120 
    121  Selection* selection = caretCntr->DOMSelection();
    122 
    123  // XXX Sometimes we can't get a selection for caretCntr, in that case assume
    124  // event->mSel is correct.
    125  if (!selection) selection = event->mSel;
    126 
    127  mCaretOffset = caretCntr->DOMPointToOffset(selection->GetFocusNode(),
    128                                             selection->FocusOffset());
    129  mAccWithCaret = caretCntr;
    130  if (mCaretOffset != -1) {
    131    TextLeafPoint caret = TextLeafPoint::GetCaret(caretCntr);
    132    RefPtr<AccCaretMoveEvent> caretMoveEvent =
    133        new AccCaretMoveEvent(caretCntr, mCaretOffset, selection->IsCollapsed(),
    134                              caret.mIsEndOfLineInsertionPoint,
    135                              event->GetGranularity(), aEvent->FromUserInput());
    136    nsEventShell::FireEvent(caretMoveEvent);
    137  }
    138 }
    139 
    140 NS_IMETHODIMP
    141 SelectionManager::NotifySelectionChanged(dom::Document* aDocument,
    142                                         Selection* aSelection, int16_t aReason,
    143                                         int32_t aAmount) {
    144  if (NS_WARN_IF(!aDocument) || NS_WARN_IF(!aSelection)) {
    145    return NS_ERROR_INVALID_ARG;
    146  }
    147 
    148  DocAccessible* document = GetAccService()->GetDocAccessible(aDocument);
    149 
    150 #ifdef A11Y_LOG
    151  if (logging::IsEnabled(logging::eSelection)) {
    152    logging::SelChange(aSelection, document, aReason);
    153  }
    154 #endif
    155 
    156  if (document) {
    157    // Selection manager has longer lifetime than any document accessible,
    158    // so that we are guaranteed that the notification is processed before
    159    // the selection manager is destroyed.
    160    RefPtr<SelData> selData = new SelData(aSelection, aReason, aAmount);
    161    document->HandleNotification<SelectionManager, SelData>(
    162        this, &SelectionManager::ProcessSelectionChanged, selData);
    163  }
    164 
    165  return NS_OK;
    166 }
    167 
    168 void SelectionManager::ProcessSelectionChanged(SelData* aSelData) {
    169  Selection* selection = aSelData->mSel;
    170  if (!selection->GetPresShell()) return;
    171 
    172  const nsRange* range = selection->GetAnchorFocusRange();
    173  nsINode* cntrNode = nullptr;
    174  if (range) {
    175    cntrNode = range->GetClosestCommonInclusiveAncestor();
    176  }
    177 
    178  if (!cntrNode) {
    179    cntrNode = selection->GetFrameSelection()->GetAncestorLimiter();
    180    if (!cntrNode) {
    181      cntrNode = selection->GetPresShell()->GetDocument();
    182      NS_ASSERTION(aSelData->mSel->GetPresShell()->ConstFrameSelection() ==
    183                       selection->GetFrameSelection(),
    184                   "Wrong selection container was used!");
    185    }
    186  }
    187 
    188  HyperTextAccessible* text = nsAccUtils::GetTextContainer(cntrNode);
    189  if (!text) {
    190    // FIXME bug 1126649
    191    NS_ERROR("We must reach document accessible implementing text interface!");
    192    return;
    193  }
    194 
    195  if (selection->GetType() == SelectionType::eNormal) {
    196    RefPtr<AccEvent> event = new AccTextSelChangeEvent(
    197        text, selection, aSelData->mReason, aSelData->mGranularity);
    198    text->Document()->FireDelayedEvent(event);
    199  }
    200 }
    201 
    202 /* static */
    203 bool SelectionManager::SelectionRangeChanged(SelectionType aType,
    204                                             const dom::AbstractRange& aRange) {
    205  if (aType != SelectionType::eSpellCheck &&
    206      aType != SelectionType::eTargetText &&
    207      aType != SelectionType::eHighlight) {
    208    // We don't need to handle range changes for this selection type.
    209    return false;
    210  }
    211  if (!GetAccService()) {
    212    return false;
    213  }
    214  nsINode* start = aRange.GetStartContainer();
    215  if (!start) {
    216    // This can happen when the document is being cleaned up.
    217    return false;
    218  }
    219  dom::Document* doc = start->OwnerDoc();
    220  MOZ_ASSERT(doc);
    221  nsINode* node = aRange.GetClosestCommonInclusiveAncestor();
    222  if (!node) {
    223    // Bug 1954751: This can happen when a Selection is being garbage collected,
    224    // but it's unclear exactly what other circumstances are involved.
    225    return false;
    226  }
    227  HyperTextAccessible* acc = nsAccUtils::GetTextContainer(node);
    228  if (!acc) {
    229    return true;
    230  }
    231  MOZ_ASSERT(acc->Document());
    232  acc->Document()->FireDelayedEvent(
    233      nsIAccessibleEvent::EVENT_TEXT_ATTRIBUTE_CHANGED, acc);
    234  if (IPCAccessibilityActive()) {
    235    TextLeafPoint::UpdateCachedTextOffsetAttributes(doc, aRange);
    236  }
    237  return true;
    238 }
    239 
    240 SelectionManager::~SelectionManager() = default;