accessible/base/SelectionManager.cpp

   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
  17 #include "mozilla/PresShell.h"
  18 #include "mozilla/dom/Document.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   // Remove 'this' registered as selection listener for the spellcheck
  52   // selection.
  53   if (mCurrCtrlSpellSel) {
  54     mCurrCtrlSpellSel->RemoveSelectionListener(this);
  55     mCurrCtrlSpellSel = nullptr;
  56   }
  57 }
  58
  59 void SelectionManager::SetControlSelectionListener(dom::Element* aFocusedElm) {
  60   // When focus moves such that the caret is part of a new frame selection
  61   // this removes the old selection listener and attaches a new one for
  62   // the current focus.
  63   ClearControlSelectionListener();
  64
  65   nsIFrame* controlFrame = aFocusedElm->GetPrimaryFrame();
  66   if (!controlFrame) return;
  67
  68   const nsFrameSelection* frameSel = controlFrame->GetConstFrameSelection();
  69   NS_ASSERTION(frameSel, "No frame selection for focused element!");
  70   if (!frameSel) return;
  71
  72   // Register 'this' as selection listener for the normal selection.
  73   Selection* normalSel = frameSel->GetSelection(SelectionType::eNormal);
  74   normalSel->AddSelectionListener(this);
  75   mCurrCtrlNormalSel = normalSel;
  76
  77   // Register 'this' as selection listener for the spell check selection.
  78   Selection* spellSel = frameSel->GetSelection(SelectionType::eSpellCheck);
  79   spellSel->AddSelectionListener(this);
  80   mCurrCtrlSpellSel = spellSel;
  81 }
  82
  83 void SelectionManager::AddDocSelectionListener(PresShell* aPresShell) {
  84   const nsFrameSelection* frameSel = aPresShell->ConstFrameSelection();
  85
  86   // Register 'this' as selection listener for the normal selection.
  87   Selection* normalSel = frameSel->GetSelection(SelectionType::eNormal);
  88   normalSel->AddSelectionListener(this);
  89
  90   // Register 'this' as selection listener for the spell check selection.
  91   Selection* spellSel = frameSel->GetSelection(SelectionType::eSpellCheck);
  92   spellSel->AddSelectionListener(this);
  93 }
  94
  95 void SelectionManager::RemoveDocSelectionListener(PresShell* aPresShell) {
  96   const nsFrameSelection* frameSel = aPresShell->ConstFrameSelection();
  97
  98   // Remove 'this' registered as selection listener for the normal selection.
  99   Selection* normalSel = frameSel->GetSelection(SelectionType::eNormal);
 100   normalSel->RemoveSelectionListener(this);
 101
 102   // Remove 'this' registered as selection listener for the spellcheck
 103   // selection.
 104   Selection* spellSel = frameSel->GetSelection(SelectionType::eSpellCheck);
 105   spellSel->RemoveSelectionListener(this);
 106
 107   if (mCurrCtrlNormalSel) {
 108     if (mCurrCtrlNormalSel->GetPresShell() == aPresShell) {
 109       // Remove 'this' registered as selection listener for the normal selection
 110       // if we are removing listeners for its PresShell.
 111       mCurrCtrlNormalSel->RemoveSelectionListener(this);
 112       mCurrCtrlNormalSel = nullptr;
 113     }
 114   }
 115
 116   if (mCurrCtrlSpellSel) {
 117     if (mCurrCtrlSpellSel->GetPresShell() == aPresShell) {
 118       // Remove 'this' registered as selection listener for the spellcheck
 119       // selection if we are removing listeners for its PresShell.
 120       mCurrCtrlSpellSel->RemoveSelectionListener(this);
 121       mCurrCtrlSpellSel = nullptr;
 122     }
 123   }
 124 }
 125
 126 void SelectionManager::ProcessTextSelChangeEvent(AccEvent* aEvent) {
 127   // Fire selection change event if it's not pure caret-move selection change,
 128   // i.e. the accessible has or had not collapsed selection.
 129   AccTextSelChangeEvent* event = downcast_accEvent(aEvent);
 130   if (!event->IsCaretMoveOnly()) nsEventShell::FireEvent(aEvent);
 131
 132   // Fire caret move event if there's a caret in the selection.
 133   nsINode* caretCntrNode = nsCoreUtils::GetDOMNodeFromDOMPoint(
 134       event->mSel->GetFocusNode(), event->mSel->FocusOffset());
 135   if (!caretCntrNode) return;
 136
 137   HyperTextAccessible* caretCntr = nsAccUtils::GetTextContainer(caretCntrNode);
 138   NS_ASSERTION(
 139       caretCntr,
 140       "No text container for focus while there's one for common ancestor?!");
 141   if (!caretCntr) return;
 142
 143   Selection* selection = caretCntr->DOMSelection();
 144
 145   // XXX Sometimes we can't get a selection for caretCntr, in that case assume
 146   // event->mSel is correct.
 147   if (!selection) selection = event->mSel;
 148
 149   mCaretOffset = caretCntr->DOMPointToOffset(selection->GetFocusNode(),
 150                                              selection->FocusOffset());
 151   mAccWithCaret = caretCntr;
 152   if (mCaretOffset != -1) {
 153     RefPtr<AccCaretMoveEvent> caretMoveEvent =
 154         new AccCaretMoveEvent(caretCntr, mCaretOffset, selection->IsCollapsed(),
 155                               caretCntr->IsCaretAtEndOfLine(),
 156                               event->GetGranularity(), aEvent->FromUserInput());
 157     nsEventShell::FireEvent(caretMoveEvent);
 158   }
 159 }
 160
 161 NS_IMETHODIMP
 162 SelectionManager::NotifySelectionChanged(dom::Document* aDocument,
 163                                          Selection* aSelection, int16_t aReason,
 164                                          int32_t aAmount) {
 165   if (NS_WARN_IF(!aDocument) || NS_WARN_IF(!aSelection)) {
 166     return NS_ERROR_INVALID_ARG;
 167   }
 168
 169   DocAccessible* document = GetAccService()->GetDocAccessible(aDocument);
 170
 171 #ifdef A11Y_LOG
 172   if (logging::IsEnabled(logging::eSelection)) {
 173     logging::SelChange(aSelection, document, aReason);
 174   }
 175 #endif
 176
 177   if (document) {
 178     // Selection manager has longer lifetime than any document accessible,
 179     // so that we are guaranteed that the notification is processed before
 180     // the selection manager is destroyed.
 181     RefPtr<SelData> selData = new SelData(aSelection, aReason, aAmount);
 182     document->HandleNotification<SelectionManager, SelData>(
 183         this, &SelectionManager::ProcessSelectionChanged, selData);
 184   }
 185
 186   return NS_OK;
 187 }
 188
 189 void SelectionManager::ProcessSelectionChanged(SelData* aSelData) {
 190   Selection* selection = aSelData->mSel;
 191   if (!selection->GetPresShell()) return;
 192
 193   const nsRange* range = selection->GetAnchorFocusRange();
 194   nsINode* cntrNode = nullptr;
 195   if (range) {
 196     cntrNode = range->GetClosestCommonInclusiveAncestor();
 197   }
 198
 199   if (!cntrNode) {
 200     cntrNode = selection->GetFrameSelection()->GetAncestorLimiter();
 201     if (!cntrNode) {
 202       cntrNode = selection->GetPresShell()->GetDocument();
 203       NS_ASSERTION(aSelData->mSel->GetPresShell()->ConstFrameSelection() ==
 204                        selection->GetFrameSelection(),
 205                    "Wrong selection container was used!");
 206     }
 207   }
 208
 209   HyperTextAccessible* text = nsAccUtils::GetTextContainer(cntrNode);
 210   if (!text) {
 211     // FIXME bug 1126649
 212     NS_ERROR("We must reach document accessible implementing text interface!");
 213     return;
 214   }
 215
 216   if (selection->GetType() == SelectionType::eNormal) {
 217     RefPtr<AccEvent> event = new AccTextSelChangeEvent(
 218         text, selection, aSelData->mReason, aSelData->mGranularity);
 219     text->Document()->FireDelayedEvent(event);
 220
 221   } else if (selection->GetType() == SelectionType::eSpellCheck) {
 222     // XXX: fire an event for container accessible of the focus/anchor range
 223     // of the spelcheck selection.
 224     text->Document()->FireDelayedEvent(
 225         nsIAccessibleEvent::EVENT_TEXT_ATTRIBUTE_CHANGED, text);
 226   }
 227 }
 228
 229 SelectionManager::~SelectionManager() = default;