accessible/html/HTMLLinkAccessible.cpp

   1 /* -*- Mode: C++; tab-width: 2; 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 "HTMLLinkAccessible.h"
   7
   8 #include "CacheConstants.h"
   9 #include "nsCoreUtils.h"
  10 #include "DocAccessible.h"
  11 #include "Role.h"
  12 #include "States.h"
  13
  14 #include "nsContentUtils.h"
  15 #include "mozilla/EventStates.h"
  16 #include "mozilla/dom/Element.h"
  17 #include "mozilla/dom/MutationEventBinding.h"
  18
  19 using namespace mozilla;
  20 using namespace mozilla::a11y;
  21
  22 ////////////////////////////////////////////////////////////////////////////////
  23 // HTMLLinkAccessible
  24 ////////////////////////////////////////////////////////////////////////////////
  25
  26 HTMLLinkAccessible::HTMLLinkAccessible(nsIContent* aContent,
  27                                        DocAccessible* aDoc)
  28     : HyperTextAccessibleWrap(aContent, aDoc) {
  29   mType = eHTMLLinkType;
  30 }
  31
  32 ////////////////////////////////////////////////////////////////////////////////
  33 // nsIAccessible
  34
  35 role HTMLLinkAccessible::NativeRole() const { return roles::LINK; }
  36
  37 uint64_t HTMLLinkAccessible::NativeState() const {
  38   return HyperTextAccessibleWrap::NativeState() & ~states::READONLY;
  39 }
  40
  41 uint64_t HTMLLinkAccessible::NativeLinkState() const {
  42   EventStates eventState = mContent->AsElement()->State();
  43   if (eventState.HasState(NS_EVENT_STATE_UNVISITED)) return states::LINKED;
  44
  45   if (eventState.HasState(NS_EVENT_STATE_VISITED)) {
  46     return states::LINKED | states::TRAVERSED;
  47   }
  48
  49   // This is a either named anchor (a link with also a name attribute) or
  50   // it doesn't have any attributes. Check if 'click' event handler is
  51   // registered, otherwise bail out.
  52   return nsCoreUtils::HasClickListener(mContent) ? states::LINKED : 0;
  53 }
  54
  55 uint64_t HTMLLinkAccessible::NativeInteractiveState() const {
  56   uint64_t state = HyperTextAccessibleWrap::NativeInteractiveState();
  57
  58   // This is how we indicate it is a named anchor. In other words, this anchor
  59   // can be selected as a location :) There is no other better state to use to
  60   // indicate this.
  61   if (mContent->AsElement()->HasAttr(kNameSpaceID_None, nsGkAtoms::name)) {
  62     state |= states::SELECTABLE;
  63   }
  64
  65   return state;
  66 }
  67
  68 void HTMLLinkAccessible::Value(nsString& aValue) const {
  69   aValue.Truncate();
  70
  71   HyperTextAccessible::Value(aValue);
  72   if (aValue.IsEmpty()) {
  73     nsContentUtils::GetLinkLocation(mContent->AsElement(), aValue);
  74   }
  75 }
  76
  77 uint8_t HTMLLinkAccessible::ActionCount() const {
  78   return IsLinked() ? 1 : HyperTextAccessible::ActionCount();
  79 }
  80
  81 void HTMLLinkAccessible::ActionNameAt(uint8_t aIndex, nsAString& aName) {
  82   aName.Truncate();
  83
  84   if (!IsLinked()) {
  85     HyperTextAccessible::ActionNameAt(aIndex, aName);
  86     return;
  87   }
  88
  89   // Action 0 (default action): Jump to link
  90   if (aIndex == eAction_Jump) aName.AssignLiteral("jump");
  91 }
  92
  93 bool HTMLLinkAccessible::DoAction(uint8_t aIndex) const {
  94   if (!IsLinked()) return HyperTextAccessible::DoAction(aIndex);
  95
  96   // Action 0 (default action): Jump to link
  97   if (aIndex != eAction_Jump) return false;
  98
  99   DoCommand();
 100   return true;
 101 }
 102
 103 bool HTMLLinkAccessible::AttributeChangesState(nsAtom* aAttribute) {
 104   return aAttribute == nsGkAtoms::href ||
 105          HyperTextAccessibleWrap::AttributeChangesState(aAttribute);
 106 }
 107
 108 void HTMLLinkAccessible::DOMAttributeChanged(int32_t aNameSpaceID,
 109                                              nsAtom* aAttribute,
 110                                              int32_t aModType,
 111                                              const nsAttrValue* aOldValue,
 112                                              uint64_t aOldState) {
 113   HyperTextAccessibleWrap::DOMAttributeChanged(aNameSpaceID, aAttribute,
 114                                                aModType, aOldValue, aOldState);
 115
 116   if (aAttribute == nsGkAtoms::href &&
 117       (aModType == dom::MutationEvent_Binding::ADDITION ||
 118        aModType == dom::MutationEvent_Binding::REMOVAL)) {
 119     SendCache(CacheDomain::Actions, CacheUpdateType::Update);
 120   }
 121 }
 122
 123 ////////////////////////////////////////////////////////////////////////////////
 124 // HyperLinkAccessible
 125
 126 bool HTMLLinkAccessible::IsLink() const {
 127   // Expose HyperLinkAccessible unconditionally.
 128   return true;
 129 }
 130
 131 already_AddRefed<nsIURI> HTMLLinkAccessible::AnchorURIAt(
 132     uint32_t aAnchorIndex) const {
 133   return aAnchorIndex == 0 ? mContent->GetHrefURI() : nullptr;
 134 }
 135
 136 ////////////////////////////////////////////////////////////////////////////////
 137 // HTMLLinkAccessible
 138
 139 bool HTMLLinkAccessible::IsLinked() const {
 140   EventStates state = mContent->AsElement()->State();
 141   return state.HasAtLeastOneOfStates(NS_EVENT_STATE_VISITED |
 142                                      NS_EVENT_STATE_UNVISITED);
 143 }