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