accessible/base/AccEvent.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 "AccEvent.h"
   8
   9 #include "nsAccUtils.h"
  10 #include "xpcAccEvents.h"
  11 #include "States.h"
  12 #include "TextRange.h"
  13 #include "xpcAccessibleDocument.h"
  14 #include "xpcAccessibleTextRange.h"
  15
  16 #include "mozilla/dom/Selection.h"
  17 #include "mozilla/dom/UserActivation.h"
  18
  19 #include "nsComponentManagerUtils.h"
  20 #include "nsIMutableArray.h"
  21
  22 using namespace mozilla;
  23 using namespace mozilla::a11y;
  24
  25 static_assert(static_cast<bool>(eNoUserInput) == false &&
  26                   static_cast<bool>(eFromUserInput) == true,
  27               "EIsFromUserInput cannot be casted to bool");
  28
  29 ////////////////////////////////////////////////////////////////////////////////
  30 // AccEvent
  31 ////////////////////////////////////////////////////////////////////////////////
  32
  33 ////////////////////////////////////////////////////////////////////////////////
  34 // AccEvent constructors
  35
  36 AccEvent::AccEvent(uint32_t aEventType, LocalAccessible* aAccessible,
  37                    EIsFromUserInput aIsFromUserInput, EEventRule aEventRule)
  38     : mEventType(aEventType), mEventRule(aEventRule), mAccessible(aAccessible) {
  39   if (aIsFromUserInput == eAutoDetect) {
  40     mIsFromUserInput = dom::UserActivation::IsHandlingUserInput();
  41   } else {
  42     mIsFromUserInput = aIsFromUserInput == eFromUserInput ? true : false;
  43   }
  44 }
  45
  46 ////////////////////////////////////////////////////////////////////////////////
  47 // AccEvent cycle collection
  48
  49 NS_IMPL_CYCLE_COLLECTION_CLASS(AccEvent)
  50
  51 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(AccEvent)
  52   NS_IMPL_CYCLE_COLLECTION_UNLINK(mAccessible)
  53   if (AccTreeMutationEvent* tmEvent = downcast_accEvent(tmp)) {
  54     tmEvent->SetNextEvent(nullptr);
  55     tmEvent->SetPrevEvent(nullptr);
  56   }
  57 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
  58
  59 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(AccEvent)
  60   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mAccessible)
  61   if (AccTreeMutationEvent* tmEvent = downcast_accEvent(tmp)) {
  62     CycleCollectionNoteChild(cb, tmEvent->NextEvent(), "mNext");
  63     CycleCollectionNoteChild(cb, tmEvent->PrevEvent(), "mPrevEvent");
  64   }
  65 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
  66
  67 ////////////////////////////////////////////////////////////////////////////////
  68 ////////////////////////////////////////////////////////////////////////////////
  69 // AccTextChangeEvent
  70 ////////////////////////////////////////////////////////////////////////////////
  71
  72 // Note: we pass in eAllowDupes to the base class because we don't support text
  73 // events coalescence. We fire delayed text change events in DocAccessible but
  74 // we continue to base the event off the accessible object rather than just the
  75 // node. This means we won't try to create an accessible based on the node when
  76 // we are ready to fire the event and so we will no longer assert at that point
  77 // if the node was removed from the document. Either way, the AT won't work with
  78 // a defunct accessible so the behaviour should be equivalent.
  79 AccTextChangeEvent::AccTextChangeEvent(LocalAccessible* aAccessible,
  80                                        int32_t aStart,
  81                                        const nsAString& aModifiedText,
  82                                        bool aIsInserted,
  83                                        EIsFromUserInput aIsFromUserInput)
  84     : AccEvent(
  85           aIsInserted
  86               ? static_cast<uint32_t>(nsIAccessibleEvent::EVENT_TEXT_INSERTED)
  87               : static_cast<uint32_t>(nsIAccessibleEvent::EVENT_TEXT_REMOVED),
  88           aAccessible, aIsFromUserInput, eAllowDupes),
  89       mStart(aStart),
  90       mIsInserted(aIsInserted),
  91       mModifiedText(aModifiedText) {
  92   // XXX We should use IsFromUserInput here, but that isn't always correct
  93   // when the text change isn't related to content insertion or removal.
  94   mIsFromUserInput =
  95       mAccessible->State() & (states::FOCUSED | states::EDITABLE);
  96 }
  97
  98 ////////////////////////////////////////////////////////////////////////////////
  99 // AccHideEvent
 100 ////////////////////////////////////////////////////////////////////////////////
 101
 102 AccHideEvent::AccHideEvent(LocalAccessible* aTarget, bool aNeedsShutdown)
 103     : AccMutationEvent(::nsIAccessibleEvent::EVENT_HIDE, aTarget),
 104       mNeedsShutdown(aNeedsShutdown) {
 105   mNextSibling = mAccessible->LocalNextSibling();
 106   mPrevSibling = mAccessible->LocalPrevSibling();
 107 }
 108
 109 ////////////////////////////////////////////////////////////////////////////////
 110 // AccShowEvent
 111 ////////////////////////////////////////////////////////////////////////////////
 112
 113 ////////////////////////////////////////////////////////////////////////////////
 114 // AccTextSelChangeEvent
 115 ////////////////////////////////////////////////////////////////////////////////
 116
 117 AccTextSelChangeEvent::AccTextSelChangeEvent(HyperTextAccessible* aTarget,
 118                                              dom::Selection* aSelection,
 119                                              int32_t aReason,
 120                                              int32_t aGranularity)
 121     : AccEvent(nsIAccessibleEvent::EVENT_TEXT_SELECTION_CHANGED, aTarget,
 122                eAutoDetect, eCoalesceTextSelChange),
 123       mSel(aSelection),
 124       mReason(aReason),
 125       mGranularity(aGranularity) {}
 126
 127 AccTextSelChangeEvent::~AccTextSelChangeEvent() {}
 128
 129 bool AccTextSelChangeEvent::IsCaretMoveOnly() const {
 130   return mSel->RangeCount() == 1 && mSel->IsCollapsed() &&
 131          ((mReason & (nsISelectionListener::COLLAPSETOSTART_REASON |
 132                       nsISelectionListener::COLLAPSETOEND_REASON)) == 0);
 133 }
 134
 135 void AccTextSelChangeEvent::SelectionRanges(
 136     nsTArray<TextRange>* aRanges) const {
 137   TextRange::TextRangesFromSelection(mSel, aRanges);
 138 }
 139
 140 ////////////////////////////////////////////////////////////////////////////////
 141 // AccSelChangeEvent
 142 ////////////////////////////////////////////////////////////////////////////////
 143
 144 AccSelChangeEvent::AccSelChangeEvent(LocalAccessible* aWidget,
 145                                      LocalAccessible* aItem,
 146                                      SelChangeType aSelChangeType)
 147     : AccEvent(0, aItem, eAutoDetect, eCoalesceSelectionChange),
 148       mWidget(aWidget),
 149       mItem(aItem),
 150       mSelChangeType(aSelChangeType),
 151       mPreceedingCount(0),
 152       mPackedEvent(nullptr) {
 153   if (aSelChangeType == eSelectionAdd) {
 154     if (mWidget->GetSelectedItem(1)) {
 155       mEventType = nsIAccessibleEvent::EVENT_SELECTION_ADD;
 156     } else {
 157       mEventType = nsIAccessibleEvent::EVENT_SELECTION;
 158     }
 159   } else {
 160     mEventType = nsIAccessibleEvent::EVENT_SELECTION_REMOVE;
 161   }
 162 }
 163
 164 already_AddRefed<nsIAccessibleEvent> a11y::MakeXPCEvent(AccEvent* aEvent) {
 165   DocAccessible* doc = aEvent->Document();
 166   LocalAccessible* acc = aEvent->GetAccessible();
 167   nsINode* node = acc->GetNode();
 168   bool fromUser = aEvent->IsFromUserInput();
 169   uint32_t type = aEvent->GetEventType();
 170   uint32_t eventGroup = aEvent->GetEventGroups();
 171   nsCOMPtr<nsIAccessibleEvent> xpEvent;
 172
 173   if (eventGroup & (1 << AccEvent::eStateChangeEvent)) {
 174     AccStateChangeEvent* sc = downcast_accEvent(aEvent);
 175     bool extra = false;
 176     uint32_t state = nsAccUtils::To32States(sc->GetState(), &extra);
 177     xpEvent = new xpcAccStateChangeEvent(type, ToXPC(acc), ToXPCDocument(doc),
 178                                          node, fromUser, state, extra,
 179                                          sc->IsStateEnabled());
 180     return xpEvent.forget();
 181   }
 182
 183   if (eventGroup & (1 << AccEvent::eTextChangeEvent)) {
 184     AccTextChangeEvent* tc = downcast_accEvent(aEvent);
 185     nsString text;
 186     tc->GetModifiedText(text);
 187     xpEvent = new xpcAccTextChangeEvent(
 188         type, ToXPC(acc), ToXPCDocument(doc), node, fromUser,
 189         tc->GetStartOffset(), tc->GetLength(), tc->IsTextInserted(), text);
 190     return xpEvent.forget();
 191   }
 192
 193   if (eventGroup & (1 << AccEvent::eHideEvent)) {
 194     AccHideEvent* hideEvent = downcast_accEvent(aEvent);
 195     xpEvent = new xpcAccHideEvent(type, ToXPC(acc), ToXPCDocument(doc), node,
 196                                   fromUser, ToXPC(hideEvent->TargetParent()),
 197                                   ToXPC(hideEvent->TargetNextSibling()),
 198                                   ToXPC(hideEvent->TargetPrevSibling()));
 199     return xpEvent.forget();
 200   }
 201
 202   if (eventGroup & (1 << AccEvent::eCaretMoveEvent)) {
 203     AccCaretMoveEvent* cm = downcast_accEvent(aEvent);
 204     xpEvent = new xpcAccCaretMoveEvent(
 205         type, ToXPC(acc), ToXPCDocument(doc), node, fromUser,
 206         cm->GetCaretOffset(), cm->IsSelectionCollapsed(), cm->IsAtEndOfLine(),
 207         cm->GetGranularity());
 208     return xpEvent.forget();
 209   }
 210
 211   if (eventGroup & (1 << AccEvent::eTextSelChangeEvent)) {
 212     AccTextSelChangeEvent* tsc = downcast_accEvent(aEvent);
 213     AutoTArray<TextRange, 1> ranges;
 214     tsc->SelectionRanges(&ranges);
 215
 216     nsCOMPtr<nsIMutableArray> xpcRanges =
 217         do_CreateInstance(NS_ARRAY_CONTRACTID);
 218     uint32_t len = ranges.Length();
 219     for (uint32_t idx = 0; idx < len; idx++) {
 220       xpcRanges->AppendElement(new xpcAccessibleTextRange(ranges[idx]));
 221     }
 222
 223     xpEvent = new xpcAccTextSelectionChangeEvent(
 224         type, ToXPC(acc), ToXPCDocument(doc), node, fromUser, xpcRanges);
 225     return xpEvent.forget();
 226   }
 227
 228   if (eventGroup & (1 << AccEvent::eObjectAttrChangedEvent)) {
 229     AccObjectAttrChangedEvent* oac = downcast_accEvent(aEvent);
 230     nsString attribute;
 231     oac->GetAttribute()->ToString(attribute);
 232     xpEvent = new xpcAccObjectAttributeChangedEvent(
 233         type, ToXPC(acc), ToXPCDocument(doc), node, fromUser, attribute);
 234     return xpEvent.forget();
 235   }
 236
 237   if (eventGroup & (1 << AccEvent::eScrollingEvent)) {
 238     AccScrollingEvent* sa = downcast_accEvent(aEvent);
 239     xpEvent = new xpcAccScrollingEvent(
 240         type, ToXPC(acc), ToXPCDocument(doc), node, fromUser, sa->ScrollX(),
 241         sa->ScrollY(), sa->MaxScrollX(), sa->MaxScrollY());
 242     return xpEvent.forget();
 243   }
 244
 245   if (eventGroup & (1 << AccEvent::eAnnouncementEvent)) {
 246     AccAnnouncementEvent* aa = downcast_accEvent(aEvent);
 247     xpEvent = new xpcAccAnnouncementEvent(type, ToXPC(acc), ToXPCDocument(doc),
 248                                           node, fromUser, aa->Announcement(),
 249                                           aa->Priority());
 250     return xpEvent.forget();
 251   }
 252
 253   xpEvent =
 254       new xpcAccEvent(type, ToXPC(acc), ToXPCDocument(doc), node, fromUser);
 255   return xpEvent.forget();
 256 }